*

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Cat and Duckling
pencil

©1998 Darryl Wheye

 

In 2013, feral cats and indoor cats allowed to roam outdoors killed from 1.4 billion to 3.7 billion birds in the continental U.S. These cats were also implicated in raptor declines in some areas by reducing rodent populations. Their effect on ground-nesting lake and pond bird populations should come as no surprise.

Stanford's volunteer-driven Cat Network had been monitoring (and altering) the campus feral cat population for years before establishing itself as a 501(c)(3) nonprofit in 1989.  By then, the homeless cat population on campus had reached an estimated 1,500 individuals. The donation-funded network is now known as the Feline Friends Network.

Organizations supporting spay/neuter, feeding, and adoption programs are located in many areas.  They need your support.

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All artwork is available

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Portraits are from the Birds of Stanford website

ink and colored charcoal

©2000 Darryl Wheye

Species include:

Mourning Dove, Northern Flicker, Marsh Hawk, Peregrine Falcon, Spotted Towhee, Hermit Thrush, Downy Woodpecker, Great Blue Heron, White-breasted Nuthatch, Wilson's Warbler, White-throated Swift

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Brown Pelican Dripping Oil
(Pelecanus occidentalis)                                 
pencil, modified in Photoshop
30'' X 24 inches
©2014/2018 Darryl Wheye
 

It’s been estimated that each year turbine blades kill hundreds of thousands of birds, oil-waste pits kill up to a million, and power lines kill up to 175 million birds. With the Administration’s 2018 regulations, birds accidentally colliding with blades, trapped in uncovered oil-waste pits or killed by unmarked transmission lines, etc., will no longer be the responsibility of the energy operators. It seems likely that the number of deaths will quickly increase.

The responsibility rollback is based on reinterpreting the 1918 Migratory Bird Treaty Act (MBTA). The MBTA, for example, had been used to apply fines after environmental disasters like the 2010 Deepwater Horizon spill, when BP paid $100 million for violations. Those funds went to restoring wildlife habitat.

See also: Washington Post coverage 12/26/17
                 LA Times coverage 2/14/18

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Brown-headed Cowbird and Red-winged Blackbird--Too Late

(inside frame after Audubon)
pencil, 29 x 23 inches

©2014 Darryl Wheye

 

Audubon knew this bird as the "Cow-pen Bird," so-named for its habit of attending cows to consume associated insects and worms. He was aware that it does not nest, but instead lays each egg in the nest of another, to be raised by foster parents. He also knew the cowbird female doesn't force her way into a nest, but surreptitiously lays her egg. Sneaking an egg into the right nest is critical. The potential foster parents may eject the egg, bury it under a layer of nesting material, abandon the nest, or parent poorly.
 

Cowbird females lay a lot of eggs--up to 36 annually. They lay them early in the day and quickly. Although Red-winged Blackbirds, especially males, protest aggressively when a cowbird approaches the nest, blackbird pairs will not eject a cowbird egg and will foster the resulting nestling. The odd egg out in this photo of a Red-winged Blackbird nest is that of a cowbird.

Why aren’t the aggressive males more effective at deterring cowbirds? Red-winged Blackbirds are polygynous (males have more than one mate) and may need to defend the nest of more than one female. They also defend against more than cowbird intruders: Up to 50 percent of Red-winged Blackbird nestings carry no genes of the territorial male.

I show a Redwinged Blackbird returning to its nest moments too late:  A female Brown-headed Cowbird has stepped in and is laying her egg. 

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Drawings are from the Art at Exits: Seeing Stanford Species website.

pencil

©2014 Darryl Wheye

Species include:
California Quail, Brown-headed Cowbird, Red-winged Blackbird, Peregrine Falcon, American Goldfinch, American Crow, and Dark-eyed Junco.  Birds inside the frames after John James Audubon.  Birds on top of the frames illustrate aspects of their behavior.

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California Quail, with a chick and normal and stunted Subterranean Clover “subclover” (Trifolium subterraneum) (inside frame after Audubon)
pencil, 29 x 23 inches

©2014 Darryl Wheye

 

In dry years, the leaves of desert annuals are stunted. Eating these leaves, which are rich in phytoestrogens, especially formononetin and genistein, during drought appears to inhibit California Quail reproduction. This free “birth control” coordinates reproduction with prospective available food resources and helps adults avoid producing young that will starve.

 

In contrast, during wet years, such plants grow heartily and the “birth inhibiting” substances in the leaves are virtually absent.  The well-nourished quail population flourishes and the subsequent seed crop will be ample enough for the large population to make it through the winter.

I showed a quail chick and dry-year and wet-year "subclover".

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American Goldfinch Parental Feeding

(inside frame after Audubon)
pencil, 29 x 23 inches

©2014 Darryl Wheye

Audubon shows these birds foraging upside-down on Bull Thistle (Cirsium vulgare),an invasive here that provides food as well as down used to line its nest (which is so water-tight nestlings can drown during storms). Goldfinches typically breed late in the season, timed to the availability of thistle seeds.

I show an adult American Goldfinch feeding regurgitated thistle seeds, a kind of “bird milk” to its young. This "thistle milk" may be somewhat similar to almond milk, the dairy substitute derived from ground almonds and water that has been consumed by people at least since the Middle Ages. It may also be somewhat similar to "pigeon milk," a regurgitant with added nutrients derived from the pigeon's well-developed crop that provides more protein and fat than do cow or human milk.

Peregrine Falcon with Pigeons

(inside frame after Audubon)
pencil, 29 x 23 inches

©2014 Darryl Wheye

Nearly 200 years ago Audubon showed peregrines taking ducks as prey. Over time, with North American city scapes replicating cliff habitats and with non-native urban pigeons thriving, some of these predators have adapted to city life.

High-speed peregrines have better success capturing certain pigeons, and it has something to do with the color of their rump feathers. White-rumped pigeons evade diving peregrines better than do dark-rumped pigeons. Alberto Palleroni’s 2005 Harvard study found that in nearly 1,800 diving attacks that reached speeds of 250 mph or more, only two percent of the captured pigeons were white-rumps. Apparently, as the targeted pigeon drops one wing to roll out of reach, the flash of white on the rump, confuses the speeding falcon causing a miss.

Why, then, aren’t white-rumped pigeons ubiquitous? Female choice seems to play a role: Even white-rumped females prefer dark-rumped males. Also, at slower speeds--and for slower predators--the white patch might serve as a target, placing the birds at higher risk.

See:

Palleroni, A., Miller, C. T., Hauser, M., and P. Marler. 2005. Predation: Prey plumage adaptation against falcon attack. Nature 434, 973-974.

I attempted to show three pigeons watching the peregrines with trepidation.

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American Crow with a Walnut

(inside frame after Audubon)
pencil, 29 x 23 inches

©2014 Darryl Wheye

Audubon was a staunch defender of this bird and that might help explain why he placed it in a walnut tree, looking almost docile.  He wrote:

 

“The Crow devours myriads of grubs

every day of the year that might lay

waste the farmer’s fields; it destroys quadrupeds innumerable, every one

of which is an enemy to his poultry

and his flocks.” 

 

It was probably a hard sell, even then when the crow’s habit of taking helpful birds and raiding songbird nests was less known.  It’s a much harder sell today, as the bird’s reputation for devouring valued birds is widespread and crows are moving into neighborhoods where the loss of birdsong is noticed.  In the Bay area, they appear to be expanding westward from the Sacramento Valley, along with the San Joaquin Valley where nearly all commercial English walnuts are produced.*

 

I show a crow holding a shucked walnut.  Shucking the thick green husk would not have been easy.  The tough husk is a stark contrast with the delicate, saliva-bound lichen nest of the hummingbird on the lower branch of Audubon's painting.

 

*The U.S. is the world's largest exporter of walnuts. The Sacramento and San Joaquin valleys of California produce 99 percent of the nation’s commercial English walnuts.

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Dark-eyed Junco and Ivy Hiding a Nest

(inside frame after Audubon)
pencil, 29 x 23 inches

©2014 Darryl Wheye

The Dark-eyed Junco is social, easy to observe, and behaves in ways people are curious about.  Nestlings, for example, often have different fathers.

 

In some areas in California, juncos appear to be adapting well to campus habitats. Since the 1980s they’ve been found on the campus of the University of California, San Diego, and since the 1990s they’ve been found here. 

 

It’s not clear why juncos are on the Stanford University campus, but ivy provides a good place to hide their nest, as I’ve shown here.   As much as they seem to prefer hiding their nest, they seem to prefer being apparent to each other: dominance status and mating success are linked to the amount of white on tail feathers—makers we readily notice, as well.