Ecologist's Notebook

American crow (in Pennsylvania) Photo by D. Sillman

(Click on the folloiwng link to listen to an audio version of this blog …Seattle crows Part 1

Going for a walk on any of the narrow streets of the Olympic Hills section of Lake City, Washington, you almost always gather up a trailing entourage of noisy, curious, and focused critters: the neighborhood crows! Groups of crows numbering between 3 and 8 individuals bounce between overhead utility lines and surrounding tree and shrub branches as they shadow along waiting for you, the nimble human in front of them, to conjure up some food. These neighborhood crows seemed to be more “in-your-face” than the more aloof crows of Colorado and Pennsylvania. They seem interested in pulling off a quick shakedown and not in developing some long-term symbiosis.

Often the crows already have food in their beaks especially if it’s garbage day (Fridays in the Olympic Hills). One time one of the crows following me was carrying an entire English muffin! I don’t see how he could have expected to improve on that!

Crow with food. Photo by V. Musilenko, Wikimedia Commons

Many of the other crows carry sticky looking wrappers and, sometimes, greasy looking bones or unidentifiable old pieces of food. Joe and Marlee have seen crows drop chicken bones into their back yard. Are they trying to feed Joe and Marlee’s dog, Ozzie? Is this some sort of religious sacrifice to a large, black, god-like dog? Is it some sort of peace offering, or are they trying to kill him? Anything seems possible.

There has been a great deal of research examining the intelligence of crows. Some of these studies have also explored the ability of crows to communicate and to remember traumatic events. Other studies have looked the ability of crows to solve problems or use tools (usually to get food!).

Flock of crows. Public Domain

In Bothell, Washington just north and east of here, 16,000 crows regularly gather in a winter flock on the campus of the University of Washington-Bothell. This winter roosting started in 2009 possibly because the campus’ trees had grown sufficiently tall to provide protective night roosts for the crows and also because a restored wetland on campus helped to make the area safe and secure for the birds. The wetland also generated a potential habitat for food. Gatherings like this are thought to provide the crows with opportunities to share foraging and landscape information. It’s also a chance to meet a non-related, potential mate (see Signs of Winter 5, January 20, 2022)

John Marzluff at the University of Washington in Seattle clearly showed that crows not only remember trauma and disturbance, but also can communicate the details of these events to their flock-mates. Back in the 1990’s,  Marzluff and his banding team wearing “caveman” masks caught and banded (and then released) a cohort of crows. Subsequently, Marzluff and his team returned to the crow banding area and were ignored unless they wore their caveman masks. Not only did the crows that had been directly captured and handled by the “caveman” scientists remember and react to the masks, but also their fellow flock members quickly learned the caveman face and joined in on the mobbing and commotion. Over the past thirty years Marluff and his team have regularly returned to this crow territory and though the originally trapped crows are now undoubtedly all dead and gone, the flock still responds in what the article describing the study calls a “crow-pocalyspe” whenever the caveman-masked researchers return.

American crow on flence. Photo by H. Paul. Flickr

These studies (along with some remarkable brain activity analyses using PET scanners and radioactive isotopes) not only show individual crows to be extremely intelligent (Mazluff calls them “flying monkeys!”) but also highly connected within their flocks to a communication and information system that has to be defined as culture!

One afternoon, shortly after we all moved to Seattle, I was sitting in my son’s backyard. Crow after crow flew over to see if I had anything edible to offer. I noticed, though, that the calling of these crows was different from the calls of the crows iI had known back in Colorado or Pennsylvania. The calls seemed more raspy and lower pitched, like the birds were clearing their throats! The Colorado and Pennsylvania crows had sharp, slappingly-loud caws. This realization stimulated me to look at the crows more closely: the Seattle crows didn’t look exactly like my Colorado or Pennsylvania crows: they were smaller and more slender. As I mentioned before, they behaved differently, too. They seemed more aggressively curious and much less concerned with human actions or boundaries.  Were these crows American crows (Corvus brachyrhynchos) or were they something else?

Northwestern crow. Photo by G. Leggett. Wikimedia Commons

I turned to my standard reference (thank goodness it was unpacked from our moving boxes and ready to read!) to see if it had any information about these “Seattle” crows: I paged through my well-thumbed copy of Peterson Field Guide to Birds of Western North America (5^th Ed.)(2020), and on page 278 came across a description of the “Northwestern crow (Corvus caurinus).” Peterson describes the Northwestern crow as a slightly smaller version (16 inches long) of the American crow (17 to 21 inches long). It is found exclusively on the narrow coastal strip (beaches, marshlands, and sounds) of northwestern North America. It is listed as “rare.” Was I seeing this rare species here in our neighborhood of Lake City Washington?

The brief description in the field guide also suggested that the Northwestern crow might not really be a unique species. It may just be a coastal variant of the American crow.

So I went to the Internet and found lots of articles about crows in Seattle and lots of discussions about the Northwestern crow.  Consensus: no one could really ID a Northwestern crow in the field (identifications seemed to be made based on location of the observer more than anything else. If you were on the coast, the crow must be a Northwestern crow). The Northwestern crow interbreeds extensively with the American crow. Most coastal crows were well-mixed hybrids. Finally, in 2020, The American Ornithological Society announced that it was removing Corvus courinus from its species list. The Northwest crow was now, officially, a type of American crow.

Northwestern crow. Photo by D. Daniels. Wikimedia Commons

So I wasn’t seeing a rare, coastal crow species gathering spilled garbage in my new Seattle neighborhood. But these crows were different from the larger, louder more aloof crows I have observed over the years in Pennsylvania and Colorado. Why were they smaller? Why did they “caw” differently? Why were they so active and into everything?

Crows are in the taxonomic family Corvidae. The earliest fossils of corvid species have been found in Europe and have been dated back to 17 million years ago. It is thought that the corvids originated in Southeast Asia and then quickly spread out across the globe diversifying rapidly. Their ability to live a wide range of environmental conditions and to consume a wide range of foods and their remarkably high levels of intelligence enabled them to colonize and adapt to habitats in almost every non-polar climate zone on the Earth. Currently there are 139 species in Corvidae (which includes jays, ravens, rooks, magpies, nutcrackers, crows and more). Crows are in the genus Corvus, and Corvus has 50 of these 139 Corvidae species. Crows, then embody the diversity and potential of this important group of birds.

(Next blog: more about coastal and continental crows!)

Rufous hummingbird. PublicDomain.

(Click on the following link to listen to an audio version of this blog … Seattle Hummingbirds Part 2

The Rufous Hummingbird is more slender and shorter than the Anna’s. It is between 2.8 and 3.5 inches long with a wingspan of 4.3 inches. It weighs between 0.1 and 0.2 ounces. The male is a bright orange on its back and belly (it looks “like a glowing coal ember”) and has an iridescent red throat. The female has a green back with hints of rufous on its sides and spots of rufous on its tail. Females also have an orange spot on their throats.

Rufous Hummingbirds nest in open or shrubby habitats and are especially fond of forest edges or the periphery of forest clearings. They hang their cup-shaped nests in many different locations including on the terminal branches of coniferous trees and from the exposed root masses of wind-thrown trees. The nests are made up primarily of plant fibers and moss bound together with gathered spider silk and are often covered with camouflaging lichens, bark and leaf fragments

Rufous hummingbird. Photo by R. Leche. Flickr

Rufous hummingbirds frequently reuse and/or rebuild old nests. They seem to have a good sense of ‘place” for their nests and return to a specific location several years in a row. They also, according to the Texas Breeding Bird Atlas, nest in groups that are sometimes as large as 20 or more pairs.

The Calliope Hummingbird like the Rufous migrates north in the summer. They generally following the mountain ranges of the Cascades and then loop back south flying near the Rockies to return to Mexico for the winter. Calliope Hummingbirds are the smallest bird in the United States! The male has stunning magenta-colored rays on his throat.

Calipoe hummingbird (male). Photo by B. Pancamo. Wikimedia Commons

The Calliope has an extensive breeding range that extends all across the western United States and Canada. The Calliope nests mostly at high altitudes in the Rocky Mountains from southern British Columbia and Alberta down to Colorado. It also breeds and nests in southern California. Nests are built in a variety of habitats including willow and alder thickets, mountain meadows and open coniferous forests.

The Calliope Hummingbird is distinctly smaller than the other hummingbird species. It is between 3.1 and 3.5 inches long but barely reaches 0.1 ounces in weight. It has a wingspan of 4.1 to 4.3 inches. The Calliope when it perches assumes a “hunched” posture (which makes it look even smaller than it is). Both male and female Calliopes are green on their backs and white on their chests and bellies. The male has, as I mentioned before, magenta streaks of feathers on his throat.

Calliope hummingbird (female). Photo by V J Anderson. Wikimedia Commons

The Calliope migrates in the fall  to the Southwestern United States, Mexico and even down into Central America. It is the smallest long-distance migrating bird in the world covering distances of up to 5600 miles twice a year.

Adult male Calliopes return to their breeding ranges weeks before the females. From the middle of April to early May, the males claim and defend prime mating territories in anticipation of the arrival of the females. A male will breed with as many females as possible and then leave the females to make the nest, incubate the eggs and raise the nestlings. Often the males actually leave the breeding area by the time the nestlings hatch. This behavior reduces competition for local nectar and insects and may result in increased vigor and survival of the nestlings

Female Calliope hummingbirds feedingtwo nestlinga at her nest. Photo by W. Wander. Wikimedia Commons

The Calliope nest is an open cup typically hung under a protective tree or shrub branch. Sometimes the nest is attached to the base of a large pine cone and is modeled to look like a pine cone itself. Nests may be used for several years. Two eggs are laid from late May to early July, and they hatch after a 15 to 16 day incubation. The nestlings fledge after another 20 days.

Female and fledgling Calliope Hummingbirds leave their nesting grounds almost immediately. They disperse into regions rich in late summer wildflowers and scatter themselves across the western mountains.

Male Black-Chinned Humingbird. Photo by Mdf. Wikimedia Commons

The Black-Chinned Hummingbird actually has a dark purple band below its black throat, but the light has to hit it just right to see its true color. Under most conditions, this throat band also looks black and just adds to the common name of this bird. The Black-Chinned Hummingbird is 3.5 inches long with a 4.3 inch wingspan. They weigh between 0.1 and 0.2 ounces. Both males and females are a dull, metallic green on their backs with a dull gray-white coloration on their bellies. They also have some metallic green feathers on their sides. The males, as we have previously mentioned, exhibit the eponymous “black” throat and chin.

Like the Rufous and Calliope the Black-Chinned Hummingbird is a migratory species. It can be found in a broad range of habitats across southwestern Canada and the western United States (from Alberta and British Columbia east to Oklahoma and south to Mexico).  We used to see Black-Chinned Hummingbirds at our backyard nectar feeder in Greeley!  They seldom come through Seattle but instead tend to stay both to the south and east of the Washington coast.

Female Black-Chined Hummingbird. Photo by Mdf. Wikimedia Commons

Black-Chinned Hummingbirds can be found in mountains, woodlands, orchards, meadows, and chaparral habitats. They most often breed in open, semiarid areas, usually near water. They can breed all across their North American range even as far south as Mexico. They especially favor moist environments like orchards, shaded canyons, and riparian woods. Males and females select different habitats before and after breeding possibly, like the Calliope Hummingbirds, to reduce intra-specific competition and make food resources more available for nestlings.

Nests are built entirely by the females and are densely constructed, cup-shaped structures made of plant fibers, spider silk, feathers and lichens. Nests are located 6 to 12 feet from the ground often on relatively exposed, horizontal tree branches just below the dense cover of the tree canopy.  Interestingly, these nests are often located near an active nest of a hawk! It is thought that the Black-Chinned Hummingbird is too small to be potential prey for a hawk, but that the presence of one of these larger raptors is an effective deterrent against smaller, avian predators (like jays and crows) that might prey on the hummingbird’s eggs and nestlings (or the hummingbirds themselves)!

Black-Chinned Hummingbirds are known to hybridize with a variety of other hummingbird species. Ten different hummingbird species from six different genera (including Anna’s, Lucifer, Broad-Tailed and Costa’s Hummingbirds) are known to breed with Black-Chinned Hummingbirds when their respective breeding grounds overlap. The subtle mix of characteristics and features can make identification of these hybrids difficult!

(Next two blogs are about Seattle’s crows!)

Anna’s humingbird (male). Photo by Ella May 81. Wikimedia Commons

(Click on the folloing link to listen to an audio version of this blog …. Seattle Hummingbirds Part 1

Most birding guides list four hummingbird species that live in the Seattle area: Anna’s Hummingbird (Calypte anna), the Rufous Hummingbird (Selasphorus rufus)), the Calliope Hummingbird (Selasphorus calliope)and the Black-chinned Hummingbird (Archilochus alexandri). Of these four species, though, only Anna’s and the Rufous Hummingbirds are regular visitors. The Calliope and the Black-chinned Hummingbirds are more likely to be seen east of the cascades and out further into eastern Washington and only very rarely visit Seattle.

The true hummingbird star of Seattle parks and backyards is Anna’s Hummingbird. They are year-round residents of this very high latitude location and often stake out a specific territory (usually associated with a well maintained nectar feeder!) for all of the summer, fall, winter and spring months of the year.

Hummingbirds are all small, but Anna’s occupies that large end of this “small” continuum. They are up to 3.5 inches long with wingspans of 4.7 inches. They only weigh 0.1 to 0.2 ounces, but have a solid, stocky body that makes them appear more substantial. They have broad tails that extend past their wingtips when they perch, and both males and females are covered with gray and green feathers. The males also have a very distinctively colored head that is covered with iridescent reddish-pink feathers.

Anna’s humingbird (female). Photo by M. Field. Wikimedia Commons

Anna’s Hummingbird’s original territory, as I have talked about before, (Signs of Winter 10, February 7, 2019) was the relatively small area of extreme southern California and the northern-most parts of Baja California. In this compact range the birds consumed a wide variety of types of insects and arachnids and drank nectar from a diverse group of flowering plants. They also drank tree sap (especially from trees whose bark had been fractured by feeding woodpeckers or sapsuckers) and readily ate any insects that might have gotten caught in the sticky secretions. They were by necessity extreme generalists with regard to their dietary preferences because no one plant or insect was present in sufficient abundance to support their entire population, and, for

Eucalyptis tree. Public Domain.

similar reasons, they were not terribly picky about where they built their nests. The desert to the east and the dry chaparral to the north very effectively restricted their dispersion out from their original range. Humans, though, eventually changed the vegetational map of the west coast and southwest deserts and freed Anna’s Hummingbird from its ecological confinement.

As people moved into California they planted more and more nectar producing, often exotic, plant species in their yards, parks and gardens. They also planted large numbers of exotic trees which were sources not only of insects but also nectar and tree sap. One type of tree around which large numbers of Anna’s Hummingbird are regularly found is the eucalyptus, and eucalyptus trees were extensively planted in California starting in the mid-1800’s.  By the early 1900’s, Anna’s Hummingbird began to spread out from its restricted habitat range. Its ability to consume so many different types of plant nectars and saps and insects and its broad tolerance of nesting sites allowed it to establish itself in almost any human modified habitat that it encountered.

Anna’s humingbird (male). Photo by USFWS. Public Domain

Anna’s Hummingbird spread north up the coast of California and now is found in abundance all the way up to Vancouver, Canada (with occasional birds found even further north all the way up into Alaska!). To get an historical time perspective on the rate of this spread, Anna’s was first recorded in the Puget Sound area around Seattle in 1964. Anna’s eastward movement through the desert (from one human manufactured oasis to the next) now stretches across Arizona and New Mexico into the western-most reaches of Texas and up into southern Nevada and Utah. Because of their ability to utilize human constructed, exotic species dominated plant communities of yards and parks, there are many more Anna’s hummingbirds today than there were prior to European colonization of the west coast! Anna’s Hummingbird is truly the backyard hummingbird for the entire West Coast!

One interesting behavior exhibited by male Anna’s Hummingbird is called “looping.” The intent of this rapid and repetitive movement is probably to assert ownership of section of a garden or yard and also to impress a potential mate. When looping, the Anna’s Hummingbird hovers in place near the ground and then slowly rises up to about 50 feet of height. They then dive back down at top speed generating a loud “chirp.” The chirp comes from air vibrating the edges of the rigidly held  tail feather like a reed vibrating in a woodwind orchestra instrument. The males then return to their starting spots and repeat the action over and over.

Anna’s hummingbird (male). Photo by Norvig. Wikimedia Commons

Hummingbirds are able to over-winter in Seattle  and the surrounding Pacific Northwest in spite of its high latitude because the area is kept relatively warm all winter by the proximity of the Pacific Ocean. There are some days, though, and many nights when temperatures drop below freezing and when snow may actually fall on coastal locations. Anna’s hummingbird is able to tolerate these extreme conditions by utilizing two physiological adaptations: 1. It can quickly convert the sucrose that consumes during the day into fat (which then serves as both a body insulator and also an efficient metabolic fuel for the long, cold night), and 2. It can go into a low metabolic rate torpor at night to conserve energy.

Humans can reduce the metabolic stress on Anna’s hummingbird by planting winter blooming plants in their yards (plants like winter jasmine, winter blooming grapes or witch hazel), or by maintaining outside nectar feeders throughout the winter. Keeping the nectar bottle from freezing is vital and the Seattle Audubon Society recommends using either plumber’s heat tape, a hanging, shop “trouble” light, or even a coiled up mass of outdoor Christmas lights to keep the nectar above freezing. Duct taping a hand-warmer packet to the side of the feeders is also a good short-term heat fix against nectar freezing! Taking the feeders in each evening is also a possibility, but you have to remember that hummingbirds get up VERY early in the morning!  The Seattle Audubon also stresses that the nectar should only be made with cane sugar (sucrose) and only be mixed in a one part sugar to four parts water ratio. Higher sugar concentrations may actually make it hard for the hummingbird to suck the sugar water up across their tongues and may even do damage to the bird’s kidneys and liver.

Rufous hummingbird. PublicDomain.

The Rufous Hummingbird, the other frequently seen Seattle hummingbird, is almost always actively migrating. They overwinter in southern Mexico and breed in Alaska, British Columbia and to a lesser degree down the Pacific Northwest to northern California. Typically, they pass through the Seattle area from February to July pausing for a week or two to refuel for their last flight to their northern breeding regions. They seldom stay in one place very long.

We’ll talk more about Rufous Hummingbirds and the other two possible hummingbird visitors to Seattle, in our next blog.

Lake City Way. Photo by SounderBruce. Wikimedia Commons

(Click on the following link to listen to an audio version of this blog …. People in seattle

As Deborah and I walk around our new neighborhood in Seattle’s Lake City section, or as we wander through the lobby of our apartment building or ride its (mostly) functional elevator up to our fourth floor apartment, we have noticed certain things about the people we see:

Most of the people we run into are in their mid to late 30’s. Most of these people look physically fit and almost everyone is wearing t-shirts and some form of well-worn shorts, jeans, hiking or sweat pants. No one is dressed up (no nice dresses, no suits or ties or even anything rising to the level of business casual). Feet are shod in flip-flops, leather sandals, name-brand athletic shoes or some form of hiking shoe/boot.

Almost everyone seems to have a dog. Some of these dogs are confined to yards from which they bark wildly as you walk by, but most of the dogs are walked once or twice daily by their owners who clutch their rolls of plastic poop-bags. The streets, in spite of the large traffic of dogs looking for a private place to defecate, are very clean and feces-free. The dog owners, then, are quite attentive and responsible.

Photo by Unsplash.

Almost all of the dogs (and all of the people) that we have met have been extremely friendly. The dogs love to get pats and scratches (and take some long sniffs of two people covered with the scents of two cats!) and the people are almost always interested in why two old people (that’s Deborah and I!)  have moved to Seattle! It’s a great conversation starter!

There are eight apartments on our end of the hall here on the fourth floor of our apartment building. Half of these apartments face east and have the same view we do: a wall of trees (a mix of western hemlock (Tsuga heterophylla) and western red cedar (Thuja plicata)) that are tightly intergrown to make a visually impenetrable barrier and a, mostly, effective sound barrier between us and the heavily trafficked Lake City Way that’s just two short blocks away. The trees are several feet taller than our four-story apartment building, so I estimate that they are between 50 and 60 feet tall. I would guess that they are about 40 years old. There are a few deciduous trees poking through the upper canopy layer of the conifers. From a distance, the leaves look like oaks (Oregon white oak (Quercus garryana)?). I will be able to ID them more precisely when I find my binoculars (which are still packed away in some, as yet unopened, shipping box).

Western red cedar. Photo by AnsweToTheRock. Wikimedia Commons

There are four dogs in the seven other apartments on our wing of the building. All of the dogs are small, terrier or toy varieties. All are extremely friendly and glad to be notice and petted. My cat Pizo has developed a bad habit of dashing out the apartment door when either Deborah or I come home. At first she just stood out in the hall but lately she has taken to heading down the hall at a determined cat-trot looking for something. I think that meeting one of these dogs might cure her of this annoying habit.

Most of the people we see are white but there is a large Asian sub-group (signs in store windows and also in documents published by the county (like the recycling and compost instructions and sorting guides) are not only printed in English and Spanish, but also Traditional Chinese, Vietnamese, Korean, and Simplified Chinese and also in Amharic, Hindi, Japanese, Punjabi, Russian, Somali, Tagalog and Tigrinya.). There are people here from everywhere! Conversations on the street and in bars and restaurants are conducted in a glorious cacophony of many languages.

Demonstration in Seattle. Photo by SounderBruce. Wikimedia Commons

Statistically, the population of Seattle is 69.5% white, 13.8% Asian, 9% Hispanic and 7.9% Black or African American. More people live alone in Seattle than in any other city in the United States except San Francisco, and only 20% of households in Seattle have children (the lowest child/home percentage in the country). The average age of someone living in Seattle is 35.5, and 38.6% of the population is between 25 and 45 years of age while only 14.5% of the population is under 18 (and this is the lowest percentage of children in a population of any large U.S. city). People over 70 years of age make up only 6% of Seattle’s population.  There are 6000 to 8000 un-housed people living in Seattle (Lake City, the area of Seattle in which we are living, for example, supports the infrastructure (water and sanitation) for a densely packed tent community that is located on the edge of the commercial district right next door to the public library).

Greeley street gathering. Public Domain.

All of this people watching and listening in Seattle is quite different from our interactions with the people living in Greeley. Greeley is almost half white and half Hispanic. Signs and documents are almost always written in both English and Spanish. The voices on the street and in the stores and restaurants are a mix of Spanish and English. No exotic Asian dialogs!  The average age of a person living in Greeley is 32.5 years, but only 27% of the population is between 25 and 44 years of age. There are large numbers of children (although the number of children per household was not available because of incomplete Census data), and 24% of the population is under 18. People over 70 years of age make up 9% of Greeley’s population, and in January, 2024 an actual head count of un-housed people in Greeley was made: the total was 313 people.

Two more observations: 1. a large percentage of these Seattle folks are quite tall! I am (or was before gravity and time played their cruel jokes on me) six foot four. I am used to standing up and over and being able to look out over the head-tops of people in crowds. In a Seattle crowd, though, I feel average … just barely average in height. Grocery shelves are set quite high to accommodate long arms and stretchy reaches, kitchen cabinets are so elevated that the top shelf is almost useless! Deborah has talked seriously about getting a step-ladder to access the strato-cabinetry in our apartment! And, 2. The term “park” means something different in this part of the country. Marian noticed that “parks” back in Colorado or Pennsylvania almost always meant “grass and lawns.” Here, “park” refers to a densely forested spot often bisected with narrow hiking trails. Hiking in the shade is not something we have done in quite awhile!

I will keep gathering data about all of this!

Next blog: Part 1 about the hummingbirds of Seattle (thank goodness they are not unusually tall!)!

Seattle with Mt Rainier: Photo by Seattle Public Archives. Wikimedia Commons

(Click on the folowing link to listen to an audio version of this blog .. Tale of Two Cities

I’m back! I plan to write new blogs on a semi-regular schedule: every other week? Once or twice a month? The once-a-week format that I had maintained for the past 14 years had just become too much like a job, and all that sitting in front of my computer may have contributed to or even caused the deep vein blood clots in my legs. I am still working on getting over those!

So what has happened in the two months I was away?

We have moved to Seattle! And when I say “we” I mean me, Deborah, my daughter Marian, her husband Lee, and their children Ari and Zofia, our three collective cats (Mora, Pizo and Pezz) and our two collective dogs (Heidi and Gedi). We have migrated to this city in the great Northwest for many different reasons: family unification (my son Joe and his wife Marlee and their son Ellis live here), work and networking opportunities and a chance to live in a milder climate that has abundant water and green ecosystems (we come to miss both water and the color green in Northern Colorado!).

I think that I will start this new blog system by comparing Greeley and Seattle. They are very different places!

West Seattle Bridge. Photo by J. Mabel. Wikimedia Commons

One of the most obvious points of comparison is altitude. Seattle is very close to sea level (average altitude of the city with a remarkably wide range of variability) is 174 feet. All of that variability expresses itself in the hilly terrain that dominates the city (walking or biking here often involves a real workout!). Greeley, on the other hand has an altitude of 4675 feet with a remarkably low range of variability across the city. Pretty high up but pretty flat with very few hills.

Altitude affects oxygen levels in the air! The air we breathe in Seattle is 20.9% oxygen while the air in Greeley was only 17.3% oxygen. Now Greeley is not considered a high altitude location (that designation comes at altitudes over 9 or 10 thousand feet), but differences in oxygen content between mid-altitude Greeley and sea level Seattle does have an impact on their inhabitants. I’ll talk more about this in a subsequent blog!

Bitersweet Park, Greeley, Colorado. Photo by City of Greeley. Wikimedia Commons

Seattle is not only near sea level, it is near the sea! Air masses rolling in from the nearby Pacific Ocean are rich in water vapor and generate a humid environment. The yearly average humidity of Seattle is 70% (with relatively dry months in the summer (60% (May)) and very moist months in the winter (81% (December)).  The yearly average humidity of Greeley is 48% (with very dry summers (42% (June)) and moister winters (61% (February)).

The coastal location of Seattle also contributes to its significant (although surprisingly moderate) yearly rainfall (38 inches/year)), while the extreme continental location of Greeley causes that area’s rainfall to be quite low (its former historical average of 15” of annual rain has been recently downgraded to 13” of annual rain).  I think that it is important to note that in the five years we lived in Greeley only one year exceeded either of these historical rainfall averages (2023 (16.77 inches). All of the other years we lived there were significantly drier than average (2020 (6.24”), 2021 (8.03”), 2022 (9.06”), 2024 (11.11”). The persisting drought affecting Colorado and much of the Western United States was one of the reasons we decided to leave that part of the country!

(An interesting, if not ironic, aside is that a few nights ago (right after Marian and Lee closed on their house, in fact) Greeley was hit with waves of thunderstorms that caused extensive flooding! Too little water, too much water!)

Lake City Way, Lake City Seattle. Photo by Sounder Bruce. Wikimedia Commmons

Seattle is known for being cloudy and, especially in the winter, rainy and gloomy. It has, on average 152 sunny days a year and 155 rainy days a year (I am not sure how the other 58 days are classified, but Seattle is said to have 226 cloudy days a year, so some of its “sunny” days must a bit cloudy!). Greeley has 270 sunny days a year. It is very unusual in Greeley to not see/feel/be-baked-by the sun!

It hardly ever snows in Seattle (yearly average is 5” snow and apparently any snowstorm at all is a cause for chaos and hysteria). Greeley can very occasionally get walloped by snow storms (and the people there get a bit hysterical, too!) (yearly average is 40” snow).

Seattle is green and moist and full of a riot of tightly crowded trees. There are  trees everywhere: tall trees, short trees, fat trees, skinny trees! The city is like a forest into which buildings and houses have been squeezed. Greeley is brown and crispy with shockingly large areas of lush grass (sustained by almost constant watering with increasingly expensive and increasingly scarce water), well-tended park and streetside trees that have been carefully planted, watered and nurtured to keep them growing in the middle of the dry grasslands of Northern Colorado. There is no feel of a forest in Greeley, no feel of a wild ecosystem. Maybe we could call it a human-sustained savannah.

Downtown Greeley. Phot by J. Beale. Wikimedia Commons

The streets in Greeley and Seattle are also quite different. The residential streets in Greeley look wide enough to land airplanes on them! According to the city of Greeley, residential streets are 30’ wide with pavement and 54’ wide with total right-of-way (neighborhood connecting streets are even wider with 34’ of pavement!). In Seattle the two-lane residential streets are 22’ wide and the arterial streets (which often carry very high volumes of traffic) are 24’wide (and both often have bumper-to-bumper on-street parking sometimes on both sides of the street).  Some arterial streets in Seattle feel like neighborhood streets but are actually components of a complex urban driving network. Shockingly, there are large, green highway/freeway signage overhead on several streets that have the feel of simply a busy residential road.

Lake Ciy Way, Seattle. Photo by Sounder Bruce. Wikimedia Commons

Seattle is limited by physical space: houses are built jumbled up with and next to other houses. Many backyards and empty lots have been developed into rental houses or condos. Block after block of old neighborhood streets have been transformed with densely packed apartment buildings.  Large stores are layered up in vertical tiers and built around  parking garages. There are parked cars everywhere! Seattle occupies a total area of 142 square miles, but 58 of these square miles are water! The population density of Seattle is 9298 people per square mile. You feel all of these people when you are walking or driving through the city (and most of them are walking around and crossing the streets staring at their phones!).

Greeley occupies a total area of 49 square miles (and, almost none of its urban area is water). Its population density is 2223 people per square mile. The key feature of the Greeley “ecosystem” is open space. Lots of room for big stores and parking lots. Lots of room to build houses with large yards and apartments and condos that are widely separated from each other. Extensions at the city limits into formerly irrigated corn and soybean fields, pastures or relic fields of sagebrush populated mostly by prairie dogs have given Greeley lots of horizontal room for growth.

So, we have chosen to live in a lively, moist, green, crowded place! Why? All of that and family!

(Next blog: People in Seattle!)

Spring peeper. Photo by USGS. Wikimedia Commons

(Click on the following link to listen to an audio version of this blog …. Vernal Pools revisited

(This a re-publishing of a blog I wrote back on April 26, 2016. Enjoy! I am going to take some time away from the blog in order to deal with some medical issues and to get moved to Seattle. Hope to be back in a couple of months!)

Spring frogs are important harbingers of the season in Western Pennsylvania, and Deborah and I listen for them carefully. The Spring Peepers (Hyla crucifer) are usually the first frogs to make their presence known. They begin their soft, peeping group choruses in and around small ponds and wetlands as soon as there are some warm, spring evenings. This year, however, we didn’t hear any peepers out in the usual places around our home.  This past winter’s lack of snow fall (leading to a low level of spring snow melt) may have cut into available water habitats for these little frogs to use as mating sites.

Gray tree frog. Photo by Randidawn, Wikimedia Commons

Gray tree frogs (Hyla versicolor) typically start their resonating trills soon after the peepers. This year we did hear some tree frogs out around our house in spite of absence of peepers, but their numbers and volumes seemed greatly reduced from previous years.  In some years the tree frogs continue to trill well into the summer. We’ll see if they can re-group or gather new strength.

There is a third frog that we regularly look for in this winter-to-spring transition: the wood frog (Rana sylvatica). We have to drive a ways, though, in order to see and hear wood frogs because they don’t do well in areas that have too many people.  They need dense, quiet woodlands with lots of leaves to hide under and lots of low spots for their spring mating pools!

Photo by D. Sillman

So, Deborah and I drove down to Ohiopyle last weekend and met up with Rob and Michele for our annual, spring hike around Ferncliff Peninsula. We were looking for any new (or different) signs of spring, but in particular we wanted to see if we could find the wood frogs that were so abundant here three years ago (on a warm afternoon hike late March 2013). The timing of the emergence of the wood frogs from hibernation and their frenetic mating in the temporary, spring (or “vernal”) pools of water (accompanied not by trilling or peeping but by a call that sounds like the quacking of a duck!) are all influenced by temperatures and the abundance of surface water. Because of our very non-typical winter and spring, we were curious if there would be any amphibians at all! Also, incompletely filled pools might dry out before the aquatic larvae of the breeding amphibians have had sufficient time to develop legs and lungs. This disastrous outcome could wipe out an entire year’s crop of young amphibians.

We walked out onto the Ferncliff Peninsula at Ohiopyle. The day was getting warm, and it felt good when the sun finally came out from behind the clouds. The first part of the hike was over the far shore’s rocks and boulders along the Youghiogheny River right at the Ohiopyle Falls. There was quite a bit of new flood debris along the shore, but Rob commented that the water level seemed lower than usual and the river rocks seemed more exposed and extensive than in previous years. Possibly in response to our near-drought more water is being held back behind the Youghiogheny Dam.

Photo by D. Sillman

The isolated pools up and around the shoreline rocks, though, were full of life. Hundreds of tiny, black tadpoles were clustered together in the sunlit sections of the pool. Water striders were whirling and skimming across the still water actively bouncing into each other (establishing territories or mating?) and searching for food.  There were several types of eggs in the pool including the very distinctive cloudy and opaque eggs masses of the spotted salamander. Rob saw a small, brown salamander hiding in the brown leaves at the bottom of one of the pools. He poked it with the tip of his hiking stick and it swam to the back of the pool and buried itself in the leaves.

Photo by D. Sillman

The trail climbed up away from the rocks and headed out along one side of the peninsula. The red maples and yellow poplars were all just starting to leaf out. They were covered with light green halos of tiny leaves. The abundant hemlocks and the scattered white pines made dark, bordering lines of green around the spindly hardwoods, and thick bunches of rhododendron bushes added their waxy deep greens to the landscape. The greens stood out sharply against the overwhelming brown ground cover of scattered, dead leaves. We also saw some spring wildflowers: red trillium, sessile leafed bellwort, and star chickweed (all pictured above and below).

Every time we hike this trail something happens to separate Deborah and Michele (who inevitably walk out

Sessile leafed bellwort Photo by D. Sillman

ahead at a rapid pace) from Rob and I (who lumber along at our slow (but steady!) pace). When we made the big turn in the trail after inching along a narrow rock side trail that ran along a steep drop to the river, we got a glimpse of two people walking up and over a trail that ran up to the top of the peninsula. We thought that Michele and Deborah had taken the turn to go up, so we did too. Unfortunately we realized (after fifteen minutes or so of scrambling up the rocky trail) that the people we were following were not Michele and Deborah. We hope that they didn’t notice that we were stalking after them!

We cut back down to the lower Ferncliff Trail, but by then were hopelessly separated from Deborah and Michele. Rob’s cell phone died in mid-text “where are…?” and so we plodded on following a couple and their three little girls trying not to fall too far behind them!  Rob and I

Star chickweed Photo by D. Sillman

continued on the Ferncliff Trail and eventually re-made contact with Deborah and Michele near the trail’s end parking lot.

Up along the Great Allegheny Passage Trail were the series of vernal pools in which we had found wood frogs back in 2013. We checked them out very hopefully but were very disappointed by the water levels and quality. The pools were about half of their widths and depths of three years ago and were choked with algae and sediment and bits of litter and tossed debris. We saw neither frogs nor any egg masses nor any tadpoles. It is not going to be a good year for amphibians in Western Pennsylvania!

Vernal pools are an important part of the forest habitats throughout the Eastern United States. They are small, shallow bodies of water with fluctuating water levels. Typically, these pools attain their maximum depths and volumes in the spring and their minimum depths and volumes in the summer. Many of these pools completely dry up especially in drought years or years of meager snow fall (like 2016!). A vernal pool must, according to Elizabeth Colburn in her excellent book Vernal Pools: Natural History and Conservation (2014), stay flooded for two or three continuous months, so it is, indeed, something more than just a rain puddle.

Vernal pools have no continuous inflows or outflows. They exist as isolated basins in the midst of their woodland ecosystems. This disconnection to streams and the possibility (or, more appropriately, the probability) of drying out generates a critical ecological feature of these pools: they do not have fish. And, this distinctive absence generates an aquatic habitat especially conducive to the development of a wide variety of amphibians whose eggs and immature life stages are heavily preyed upon by many fish species.

Wood frog. Photo by B. Gratwicken. Wikimedia Commons

Vernal pools are greatly affected by the types and densities of the trees that surround them.  The chemical nature of the prevailing leaf species influences the acidity, turbidity and nutrient levels of the pool waters.  The history of a pool and the regularity and predictability of its occurrence and duration also has profound influences on the diversity and abundance of its breeding amphibians.

These pools in the Ohiopyle forests have been in place for many years and only rely on sufficient melt and spring rain to fill them sufficiently. Let’s hope that next winter is a bit more snowy and that the March and April rains are more abundant. I need to hear ALL of the spring frogs next year!

(P.S. This Spring (2025) I got an mail from a woman who went hiking down at Ohiopyle in early March and happened onto a mass emergence of wood frogs from their overwintering pools! She said that it was a riot of rocketing frogs and glorious “duck-like” croaking! Maybe the wood frogs are not abundant every year, but 2025 is another great frog year for Western Pennsylvania!)

Mourning cloak butterfly. Photo by P. Killiov. Wikimedia Commons

(Click on the following link to listen to an audio verison of this blog …. Mourning cloaks

A number of years ago (Signs of Spring 3, March 15, 2018) I wrote about the evolution of the Lepidoptera (butterflies and moths). Fossilized lepidopteran wing scales have been found that are over 200 million years old! This is very significant because flowering, nectar producing plants which make up most of our modern day lepidopteran food bases did not evolve until some 50 million years later! What could those earliest lepidoptera have been eating? The logical answer to this question is actually on display in the early spring when several species of butterflies including the mourning cloak emerge weeks before the flowering of nectar-producing wild plants.

Mourning cloak butterflies (Nympalis antiopa) over-winter as adults. They find cracks and crevices in tree bark and down in between rocks and fold themselves up into these narrow, protective spaces and spend the winter in hibernation. In the spring they emerge, often when there is still snow on the ground, and sustain themselves for several weeks during which they mate and lay eggs.

Mourning cloak butterfly (side view). Photo by Xulescu G. Wikimedia Commons

Mourning cloaks are abundant here on the Front Range and may even emerge as early as mid-March if the Spring weather is warm enough. The emerging mourning cloaks vigorously contract their thoracic muscles to generate body heat. They also conspicuously and very uncharacteristically bask in the sunshine with their dark, colorful, dorsal wing surfaces (purple to maroon edged by an inner line of iridescent, blue spots and an outer border of yellow or creamy white) exposed to incoming sunlight. The venter (underside) of their wings is a dark, striated blackish-brown with a pale, gray border. Normally, the mourning cloak at rest or in hibernation folds its wings together so that only the drab, camouflaging coloration of the ventral wings is visible to potential predators.

The early spring mourning cloaks, quite possibly like the first lepidoptera 200 million years ago, drink sugar-rich tree saps that run from wounds in the bark of trees. In present days, these wounds are often caused by woodpeckers drilling in trees for insects. I am not sure what animal might have made holes like this 200 million years ago, but, whatever their origins might have been, these sap-filled holes probably provided vital nutrients for our ancient butterflies and moths.

Mourning cloaks are especially fond of oak trees and oak sap. These sap holes are accessed by the butterflies as they walk down the tree, upside down. Adult mourning cloaks also eat rotting fruit and flower nectar during the summer. They feed on nectars from a variety of wildflowers and weeds and have been noted to be especially fond of the flowers of two invasive plants (knapweed and scabiosa (“pincushion flowers”)). Mourning cloaks, like many butterflies, also swarm muddy puddles and even animal feces from which they gather not only moisture but also vital salts and nutrients.

Mourning cloaks mate shortly after emergence from hibernation. Males typically select a sunny perch from which they watch their habitat zones for females. There is a brief courtship, and then the fertilized female lays from 30 to 50 eggs in encircling clusters on the small branches of some selected host tree or shrub species. These eggs hatch into small, black caterpillars that are marked with white speckles and a very dark, continuous dorsal line.

Mournng cloak caterpillar. Photo by S.Katavich. Bugwood.org

The caterpillars are voracious eaters and readily consume the leaves of the American elm, aspen, cottonwood, hackberry, paper birch, and several species of willow. The caterpillars grow rapidly and undergo four molts as they move through their larval instars toward the inactive pupal stage. The pupa is encased in a gray chrysalis which hangs from a thread attached to branches or some type of overhanging structure. The metamorphosis into adults takes about 15 days.

The eggs laid in early spring will pupate and emerge as adults by early summer (June or July). These new adults also typically have warm-weather inactivity phases (“aestivation”). This period of inactivity helps the mourning cloaks tolerate the extreme heat and dryness of our Colorado summer.  After they re-emerge in the late summer or early fall, they feed very actively in order to build up fat reserves for the winter ahead. These Spring-born adults are the cohort that then hibernates in their bark and rock crevices for the winter.

An individual experiencing a life cycle pattern stretching from a late Spring birth to an early Spring post-mating senescence may live up to 10 months or more! This makes the mourning cloak one of the longest lived butterflies in nature!

June or July emerging adults, though, may also, depending on the climatological conditions or levels of habitat resources, skip the aestivation phase and proceed directly to mating and egg laying. This second brood of eggs, then, hatches into caterpillars which grow, pupate and metamorphose into adults by August or September. This second brood, then, begins to feed and prepare itself for the long winter hibernation. In the northern sections of the mourning cloak’s range one or two seasonal broods are common. In the southern sections of the range, however, up to three brood generations are typical.

Oak forest. Photo by E. Papadopoulas. Wikmedia Commons

Mourning cloaks are found in forested ecosystems, urban park areas and in suburban yard ecosystems. They require deciduous trees (like oaks, willow, elms, cottonwoods, aspens and birches) for their overwintering hibernacula, adult food sources (sap) and leaves for their developing caterpillars.  The North American and European distributions of the mourning cloak are both expanding into more and more northern regions. It is thought that these expansions are yet another observation of the biological consequences of human induced global warming.

The sight of a mourning cloak fluttering past, usually high up in the surrounding tree canopy, is a beautiful and very welcome Sign of Spring! Also, the mourning cloak, along with the other early butterflies of spring are, in many ways, a recapitulation of how butterflies lived in their first 50 million years! Slurping up tree sap and nutrients from mud and fecal sources. Waiting for the flowers to come!

Human ear. Photo by T. Gunnarsson. Wikimedia Commons

(Click on the following link to listen to an audio version of this blog …Ear wax, body odor and itching

This week I have decided to get into some of the real nitty-gritty of what it means to be human. We’re really going to talk about some really fundamental features of the human condition: ear wax, body odor and itching!

Ear wax (“cerumin”) is produced by specialized sweat glands in the epithelium of ear canal. The purpose of ear wax is to protect the ear drum from drying out or from being damage by dirt, dust, bacteria or even small insects or other creepy-crawlers. The synthesis of ear wax in most people is matched by its steady rate of loss at the external opening of ear canal, so the amount of ear wax in the ear canal assumes a dynamic constancy. In some people, though, either because of an overly rapid rate of synthesis or unusually slow rate of shedding, ear wax can build up and form dense plugs in the ear canal.

Upper Nile natives (1911). Photo by E. Fothergil. Wikimedia Commons

The only previous scientific study concerning ear wax that I can remember coming across was a very speculative article published several years ago that noted that the density of a person’s ear wax was correlated to the curliness of their hair. This study was looking at a population of native people in the Upper Nile region of Africa. Curly hair was an almost universal trait among these people and was thought to be selected for because of its effectiveness in shading an individual’s  head out in this very hot, very sunny climate. The thick ear wax was also assumed to be favored to help keep everyone’s ear drums from drying out. These two features, though, were shown to be correlated but not related causally. They were independent adaptations to life in a hot, dry climate.

In a recent issue of The Science Digest (February 2, 2025) the quality of ear wax in a person’s ear canal was shown to be causally related to the intensity of their body odor. People with sticky, honey-colored ear wax tended to have smelly arm pits (which are also called “axillae”), while people with white, flaky ear wax tended to have much less smelly axillae.

Cassette transporter model. Image by A.Lomize. Wikimedia Commons

Amazingly, there is a genetic and molecular explanation for these observations! A simple, Mendelian  gene controls an important membrane transport system in both the ceruminous glands that make ear wax and the apocrine glands that make the scent molecules in the axillae and groin. The gene is called “ATP-binding cassette subfamily C number 11” (or, “ABCC11”). The cassette protein (literally a type of protein that slides in and out of an encasement in the cell membrane) that this gene controls transports proteins and lipids across the cell membrane of the secretory cells and, ultimately, releases these molecules onto the skin surface. If the ABCC11 gene has a dominant allele (either in a homozygous or heterozygous genome combination), then the cassette protein will transport its proteins and lipids. But, if the ABCC11 gene only has the recessive alleles (homozygous recessive genome) it will not be able to transport any of these proteins and lipids!

It turns out that these proteins and lipids are the molecular components that make the ear wax sticky and honey-colored. If these proteins and lipids are missing, the ear wax becomes flaky and white!

Further, if apocrine gland does not release these proteins and lipids, then bacteria in the microbiome of the skin have very little molecular material to consume and metabolize! It is these bacteria (especially bacteria in genus Chrynebacterium) that generate particularly foul odors in their waste products (“sour, musty, even fecal-like smells”).  If these proteins and lipids are not present, then these odors are generated.

Every person has a particular scent (ask any working blood-hound!). These scents are the very subtle products of each person unique skin bacterial microbiome acting on a genetically determined array of chemicals produced by their apocrine glands’ secretory cells!

Cat itching. Photo by Vannie. Wikimedia Commons

I included itching in this blog because it is, like ear wax and body odor, a feature of a human being that most people find unpleasant. Itching may be a signal that someone has fleas, lice or mange or some other “sharable” skin malady that each of us, instinctively, wants to avoid. Apparently, humans are not alone in manifesting a negative reaction to the presence of some individual of their own species scratching at their skin. Mice will cluster around a wounded fellow mouse, or any mouse for that matter who is in pain, and will display all sorts of soothing, empathetic behaviors (nuzzling, grooming, licking etc.). For a mouse, though, that is chronically itchy the almost universal response of his fellow mice is avoidance and isolation.

Photomicrograph of Pacinian corpuscles. Photo by E. Uthman. Wikimedia Commons

Exploration of the sensory structures of the skin has been going on for almost 300 years. Back in the early 1700’s the German anatomist Abraham Voter described the Pacinian corpuscle although its “rediscovery” almost 100 years later by the Italian Filippo Pancini led to its official recognition and naming. The Pacinian corpuscle transduces the sensations of pressure and vibration into nerve impulses. Numerous other mechanoreceptors were described in the mid to late 1800’s, and the transducers of the sensations of touch, sustained pressure, skin deformation and so on were clearly defined. The first of an array of cutaneous pain receptors (“nociceptors”) were described by Charles Sherrington in 1906 and cutaneous thermoreceptors and chemoreceptors quickly followed.  Most of the sensations modulated through the skin, then, were well described and linked to specific cutaneous structures except for the sensation of itching.

Itching is an important sensory phenomenon in the skin. Itching is symptom of many dermatological disorders (including allergic dermatitis, eczema, hives and psoriasis) and also a number of systemic illnesses (including chronic kidney disease, liver failure and Hodgkin’s lymphoma). Chronic itching (itching persisting for six weeks or more) occurs in 16 to 20% of the general population and is a common presenting symptom to physicians.

Specific ”itch receptors,” though, were not discovered until 2009 primarily because these receptors were not specialized cells but, instead, specialized molecular systems! Receptor proteins (which included histamine receptors, Mas-related G-protein coupled receptors, and many other protein complexes) were described on the outer cell membranes of free nerve fibers in the skin. The specific coupling of a stimulatory molecule to the external facing receptor site caused profound changes inside of the nerve fiber that included depolarization and the generation of nerve impulses. These sensory nerve fibers, then, carried the information of the molecularly stimulated  “itch” into the spinal cord and delivered it to the ascending spinal tracts which carried them up to the brain.

Model of histamine. Image by Apalmer. Wikimedia Commons

What kinds of molecules can stimulate an itch sensation? Histamine is a very common itch stimulator as are a broad array of inflammatory cytokines produced by various white blood cells (“leukocytes”) in allergic and other immune reaction webs. A very large number of specific chemicals, then, can initiate an itch reaction!

Further, these sensory nerve fibers and spinal transfer synapses can also carry and transfer pain sensations. Often, scratching an itch spot can stop the itch sensation because the tactile and pain stimuli overwhelm the peripheral nerve fibers and spinal gate synapses that had been dealing with the itch sensation. In extreme itching, though, uncontrolled scratching of an itchy skin area can shred the surface layers of the skin and result in scaring and bleeding sometimes with no immediate relief of the itching sensation.

Understanding the molecular basis of itch sensations is leading to the development of increasingly effective itch relief treatments. Maybe someday, itching won’t be a factor driving some of us apart!  We’ll always have, of course, ear wax and body odor!

Pastrami sandwich. Photo by Z. Zhou. Wikimedia Commons

(Click on the following link to listen to an audio version of this blog …. Artificial meats

Two weeks ago, we developed a number of ideas ideas about humans and meat. Looking at evolution and human physiology, we determined that people eat meat not because of some dietary necessity but, instead, people eat meat because they like meat. Eating meat has all sorts of environmental consequences. A huge percentage of the Earth’s arable land goes to sustain and support meat production. Natural ecosystems and the biodiversity they sustain are being destroyed to make more land available for livestock and to grow the grains they require. Meat has a huge water cost (1800 gallons of water is required to make one pound of beef!).  A substantial amount of the yearly production of the Earth’s greenhouse gases come directly from livestock. Choosing to eat chicken or fish instead of red meat reduces these environmental costs but does not complexly eliminate them.

Another way to get a “meat-like” food experience involved food companies manufacturing fake meat products. One of the first of these companies to sell its products nationwide is Morningstar Farms. Morningstar Farms introduced soy products to Americans as significant meat substitutes starting in 1974. The frozen, often patty-shaped discs of soy protein and soy flour (to which varying combinations of carrots, onions, mushrooms, water chestnuts, green bell peppers, brown rice, whole grain oats, wheat gluten and a mix of vegetable oils were added) were often eaten on a bun like a hamburger with added raw vegetables and condiments.

Morningstar Farms vegetarian tacos. Photo by the Skinny fork

Griller Patties, Chicken Patties, Black Bean Burgers, Veggie Burgers all served as direct substitutes for ground meat in hamburger-like sandwiches. Later soy bacon, hot dogs, chorizo and sausage patties and even soy sausages with wrapping pancakes (on a stick!) were added to the Morningstar Farms line of products.

The distinctive thing about these Morningstar products (and I ate many of these during the 1980’s, 1990’s and the first two decades of the 2000’s) is that they really didn’t taste like meat, but they tasted OK. Their texture was dry and a bit cardboard-like, but with catsup, tomatoes and onions they made a very good lunch or dinner (I never ate any of their breakfast products).

By the end of the first decade of the 2000’s, though, two new companies began, at first, very limited distributions of some true meat substitutes. These “meat analogs” grew in popularity and were soon being sold around the United States and then around the world.

Beyond Meat burger. Photo by cbc.ca

In 2009, “Beyond Meat” began blending a mix of pea protein, mung bean protein, rice protein, canola oil, coconut oil, cocoa butter, potato starch, apple extract, methylcellulose, lycopene (a red coloring agent from tomatoes), salt, potassium chloride, vinegar, pomegranate extract, beet extract, lemon juice and some vitamins and minerals into a sticky substitute for red meat.

Them in 2011, “Impossible Foods” developed their own process by which wheat protein (later changed to soy protein in 2019), coconut oil, sunflower lecithin, potato protein, methylcellulose, yeast extract, hemes, B vitamins, some minerals, gums, natural flavors, food starch, salt and water were blended together into a mixture that, especially when cooked, resembled hamburger meat.

Both Beyond Burgers and Impossible Burgers have more protein and less total fat than red meat hamburger. These “fake meats” also had no cholesterol and fewer calories than the animal meats they resembled. They also had more salt, but as one Impossible Foods scientist put it, “most people add salt to the their hamburger meat anyway.”

I first came across Impossible Burgers in May, 2019. My family had rented a cabin just outside of Yosemite National Park and we were spending the incredibly beautiful (although surprisingly rainy!) days hiking and climbing in the park. One particularly rainy afternoon we took shelter in the Yosemite Snack Bar and enjoyed a fast-food lunch with several hundred “close” (and very damp) friends. My son-in-law, Lee, noticed Impossible Burgers on the menu and ordered one. Then he ordered another, and, finally a third. It must have been all of that juicy methylcellulose and those tasty blended gums! He thought they tasted great, and he has favored plant-based meats at our family cookouts ever since!

In August, 2019, Deborah and I were back in Western Pennsylvania and noted that Burger King was selling an “Impossible Whopper.” We decided to get one Impossible Whopper and one regular Whopper and do a side-by-side taste test.

We bought our burgers (ordered to include “everything” on them except cheese) at the Burger King in Natrona Heights and noted the higher price of the Impossible Whopper (about a dollar more). We drove to nearby Harrison Hills Park and sat at one of the many roadside picnic benches. We unwrapped our burgers and compared them.

Whopper. Photo by Lombroio. Wikimedia Commons

The regular Whopper was a mess. The lettuce and tomato and onions were falling out of the bun and the ketchup and mustard were unevenly applied and spilling out onto the encasing paper. The hamburger patty was half in/half out of the bun. A reconstruction was required before eating.

The Impossible Whopper, though, was perfect. It looked a burger on TV commercial. The perfectly round, fake meat patty was centered on the bun, the slices of tomato were thick and symmetrically placed on the surface of the patty. The ketchup and mustard were swirled around on top of the tomato which was, in  turn carefully covered with lettuce, thin dill pickle chips and ring-shaped onion slices. There were also significantly more veggie toppings on the Impossible Whopper than on the Regular Whooper.

I wish that we had taken a picture of the two Whoopers, but we were hungry and wanted to get on with this experiment.

Impossible Whopper. Photo byMx Granger. Wikimedia Commons

The textures of the two sandwiches were very similar, although the Impossible Whooper was a bit more crumbly and became a bit less meat-like as you chewed it. The tastes, though, were quite different. The regular Whooper had the charred (acrylamide!), meaty taste of a grilled burger, while the Impossible Whooper, which did taste like meat, was blander and more homogeneous in its mouth feel. It also had an oily over-taste and a bean-like after taste. Most of the flavors in each sandwich were delivered by the toppings and  the condiments, so the abundance of the extra toppings really added to the appeal of the Impossible Whooper.

So the “fake meat” Whooper was tasty, different from a regular meat Whooper, but not unpleasantly so. According to information from the corporate websites of Beyond Meats and Impossible Foods, these artificial, plant-based meats use 95% less land than the production of traditional meat and emit 87% fewer greenhouse gases.  Two extensive nutritional studies comparing a variety of health variables between patients eating regular, red meat burgers and combinations of several of the plant-based meat burgers were published in the American Journal of Clinical Nutrition (November 5, 2020 and June 6, 2024). The protocols for each study were slightly different (different “fake meat” products used etc.) but the overall structure and purpose of each study were the same.

TMAO production and impacts. Figure by M. T. Velaesquez et al.

The 2020 study found that individuals eating the plant-based meats had lower cholesterol levels (especially LDL’s) and lost several pounds of body weight during the experimental period. Also, individuals eating the plant-based meats had reduced blood levels of trimethylamine N-oxide (“TMAO”). TMAO is synthesized by microflora bacteria in the large intestine in response to the presence of several chemical constituents of dietary meats. When TMAO is absorbed into the blood stream it promotes inflammation and the formation of blood clots. These two responses can worsen atherosclerosis and make heart attacks and strokes more likely.

The 2024 study, however, noted no differences in the health parameters between the meat-eating and the plant-based meat-eating groups. These results are typical of medical studies comparing diets with regular meat with diets with plant-based meats: some show modest health improvement in the plant-based meat eating group, others show no difference between plant-meat and regular meat eating individuals. None of the studies I have seen, though, have indicated any health harm from eating plant-based meats.

The market for plant-based meats seemed wide open and on the verge of almost limitless expansion in 2020. The meat-like quality of the products (especially from Beyond Meats and Impossible Foods), their overwhelmingly positive environmental comparison to animal-based meats and a growing mass of medical studies favoring the lower calories, lower saturated fats, absence of cholesterol and presence of dietary fiber in the plant-based meats all seemed to be solid foundation for growth and expanded market shares.

The plant-based meat industry, though, was quickly attacked  by two very different groups. The first group was a collective of meat and livestock subsidiaries that hired the former big tobacco strategist and lobbyist, Richard Berman, to draft a series of ads describing plant-based meat as “chemically laden” and the product of dubious industrial processes. Further, the whole idea of plant-based meat was pushed out into the raging, socio-political culture war and labeled as “liberal” and “woke.” Real men, the campaign stated, ate real meat not ground up peas and soybeans.

Ultraprocessed food. Photo by T. Tuasen. Wikimeida Commons

The second direction of the attack on plant-based meats came from food purists. These fake meats, they said, were “ultra-processed foods,” and anything, they declared, that was ultra-processed was bad for your health.    A major literature review paper published in the British Medical Journal in 2024 stated that eating foods that are ultra-processed increases a person’s chance of death from almost any cause. Specifically, a diet rich in ultra-processed foods increases the incidence of heart disease, type 2 diabetes, obesity and dozens of other specific medical disorders.

So, what is an ultra-processed food? A very simple rule of thumb is to say it is any food product with more than  five listed ingredients or, maybe, food products with more than two lines of ingredients printed on its package. Further, these listed ingredients often have substance that are almost never used in a home kitchen to prepare food. High fructose corn syrup, hydrogenated oils, hydrolyzed proteins, artificial flavorings, flavor enhancers, food dyes, emulsifiers, thickening agents etc. are just a short list of some of the “ultra-processing” ingredients.  Look at the ingredient lists for Beyond burgers and Impossible burgers (printed above): they are definitely ultra-processed foods!

Why are ultra-processed food bad? Many of them are designed to get you to over-eat them. The perfect blends of salt and sugars make many of these foods irresistible! They also contain “cocktails” of additive chemicals whose synergistic effect on the person ingesting them may include increased inflammation in the body or, possibly, unexpected stimulations or inhibitions of a range of normal physiological activities. Ultra-processed foods are almost always extensively packaged in plastics, too. Leading to the distinct possibility of hazardous chemicals from the plastic materials diffusing into the food.

There is a debate about whether or not all ultra-processed foods are “bad,” and the plant-based meats are at the center of this debate. The overwhelming environmental and nutritional benefits of these “fake meats” over “real,” animal based meats are facts that cannot be ignored or denied, but food chemistry and engineering that goes into every pound of plant-based meats must also be clearly recognized.

Marion Nestle is an emeritus professor of nutrition, food studies and public health at New York University. She states that although plant-base meat products are ultra-processed they are still obviously better for the meat consumer that animal-based, red meats. “I’m sure it’s environmentally better than beef, everything is,” she said. “My prediction would be if you’re not eating beef and you’re eating this (plant-based meat) instead, you’re going to do better than people who are eating beef.”

Cheeseburger. Photo by R. Comet. Public Domain

(Click on the following link to listen to an audio version of this blog … Why do we eat meat?

The “meat” I am talking about here is “red meat.” Meat derived from cows or pigs or wild game like deer or elk or moose. The title question can be spun around in a number of ways: Do we need to eat meat? And, if the answer if “no,” then why do we ?

The answer to the first question is very straightforward: No. We don’t need to eat meat. There are many ways that a person’s diet can be structured to deliver all of the protein and essential vitamins that come in a serving of red meat. Meat is not an essential part of the human diet.

The answer to the second question is much more complicated, but, basically, most of us eat meat because we like it!  Most of us, in fact, eat all of the things we eat because we like them. This “liking” of a food involves habit and tradition, it is all wrapped up in what our families ate at our everyday tables and we ate at our special holiday tables and we ate at our respective snack tables, too. The actual taste and texture of a food is sometimes less significant than its history. How else can you explain the Scandinavian passion for lutefisk? Or the Scottish passion for haggis? Or the English passion for fruit cake?

Neanderthals paiting (by Knight 1920). Public Domain

There are two ideas that have assumed mythological status in the discussion of the relationship of meat and human beings. The first is a theory that “meat made us human.” This theory focuses on the period of rapid brain growth that began about 2.5 million years ago in the line of species of the genus Homo. Brains demand a considerable amount of dietary energy in order to be made and maintained. The “meat made us human” theory assumes that that extra energy came from our ancestors eating meat. Lots and lots and lots of meat! A number of recent major studies, though, have challenged this idea. There is no evidence that meat consumption increased when the first Homo species (Homo erectus) came into existence. There is also significant question that meat could have provided the magnitude of the necessary nutrients to fuel the observed changes in the Homo evolutionary line.

More likely these increased nutrients came available to the Homo species because of changes in technology. The use of fire to cook food greatly increases the availability of nutrients. Cooking “pre-digests” the food material and makes absorption and assimilation of the food’s nutrients and calories much easier.

Paleodiet food pyramid

The other mythological idea that connects humans with meat is the jumble of observations and flights of imagination that underlies the very popular “paleodiet.” The essential idea of the paleodiet is that humans should only eat the kind of foods that we first evolved to eat. These “first foods” are the foods we are maximally designed to digest and utilize. It is also critical to assume, in order for this idea to hold together at all, that humans have not evolved since Homo erectus lived in the Stone Age. Paleodiet proponents follow the “meat made us human” line of thought and describe our Stone Age ancestors as high powered carnivores getting 70% or even 80% of their daily calories from meat.

Again, a number of recent studies have shown not only how preposterous this is, but they have also shown that the numbers describing the distribution of foods are completely backwards. Ancient humans were Hunters and Gatherers. In warm ecosystems the percentage of hunting relative to gathering is quite small. Between 70% and 80% of the actual daily calories that sustained these ancient people probably came from gathering and gleaning. Meat was an always welcomed addition to the diet, but our Stone Age ancestors were more accurately Gatherers and Hunters!

Family Thanksgiving. Public Domain

So, why do we eat meat? Humans have always eaten meat, although not nearly to the degree some would have us believe. Meat is a great protein source, and is a good healthy food that tastes great! Eating meat is often part of a group or family celebration. The whole clan gathers at the table to enjoy food and each other.

So, what’s wrong with meat? Why are so many people giving up eating meat? Why are so many people advocating that everyone give up eating meat? What are the costs of eating meat?

The average American eats 7000 animals in a lifetime. Some of these animals are fish (4500 fish) or fowl (2400 chickens and 80 turkeys), but some are definitely “red meat” (30 sheep, 27 pigs and 11 cows) (such a large number of sheep! I didn’t think that lamb and mutton were such major parts of an American diet!) (data from Scientific American, October 23, 2023).

Cattle. Public Domain

Over three-fourths (77%) of the Earth’s arable surface is dedicated to the support and production of meat and milk, but meat and milk provide only 18% of the world’s food energy. Around the world, pristine ecosystems (tropical rainforests etc.) are being destroyed to make more fields and pastures to raise cattle and the grain needed to feed them. It is estimated that the crops used to sustain and grow the animals we raise for meat each year could feed 4 billion people. Meat and milk are very “land and energy expensive!”

Agriculture consumes 90% of the world’s yearly fresh water, and the percentage of this agriculturally dedicated water that is used to raise livestock is huge! The water-use footprint per calorie equivalent in meat is 20X the water-footprint per calorie equivalent in grain. One pound of beef requires 1800 gallons of water, one pound of pork requires 720 gallons of water and one pound of chicken requires 520 gallons of water. Meat is very “water expensive!”

Livestock generate 18% of the Earth’s global greenhouse gas emissions (37% of the total methane, 9% of the total carbon dioxide). Beef production generates up to 10 times more greenhouse emissions than the equivalent production in chickens. Meat production is a major contributor to climate change

The environmental costs of eating meat, then, are staggering!

Cattle feedlot in Colorado. Photo by B. Hawthorn

Here in Greeley, Colorado, we are surrounded by the meat production and processing industry. The city is surrounded by feedlots that are full of cattle and sheep. Most days, for at least part of the day, the air is ripe with the scent of cow manure (better than pig manure, at least). Greeley is quite famous for its smell! Over on the northeast edge of the city is a gigantic JBS meat processing plant that employs 5000 workers. This plant, if it runs two shifts a day, can process 6000 cattle per day.

What are the alternatives to meat? Chicken and fish have less of an impact on the environment and are, from a nutritional point of view better (“healthier”) dietary choices than red meat. There are also a number of commercially made “artificial meats” that have close to the taste and texture of real meat with a tiny fraction of the environmental costs. We’ll talk about some of these “fake meats” next week.