Readers’ wildlife

March 12, 2020 • 7:45 am

Here’s a nice set of photos from several batches I still have from John Avise, an evolutionary biologist at UC Irvine. His notes and IDs are indented:

Here are about another dozen miscellaneous photos from my collection.  This batch could be entitled “odd pairings”.
Toy glider (note the upswept wingtips:

Snowy Egret, Egretta thula; (note the upswept wingtips):

Same toy glider (note the black wingtips):

White Ibis, Eudocimus albus (note the black wingtips):

Common Raven (Corvus corax) chasing American Crow (Corvus brachyrhynchus); note the different sizes and silhouettes of these two species:

Black-necked Stilt (Himantopus mexicanus) and American Avocet (Recurvirostra americana):

American Wigeon (Anas americana) and Eurasian Wigeon (Anas penelope)

Blue-winged Teal (Anas discors) and Green-winged Teal (Anas crecca):

Western Grebe (Aechmophorus occidentalis) and Red-necked Grebe (Podiceps grisegena):

Pectoral Sandpiper (Caladris melanotos, to the left) and Lesser Yellowlegs (Tringa flavipes), plus their reflections:

Marbled Godwit (Limosa fedoa, to the rear) and Whimbrel (Numenius ohaeopus); note the bill curvatures:

12 thoughts on “Readers’ wildlife”

  8. Very nice comparison series.

    In the glider/egret upswept wingtips case there is an obvious aeronautical explanation, wingtip vortices. Air pressure below an aerofoil is greater than that above. At the wingtips the higher pressure air below pushes upwrds to create a vortex, which increases drag. Upward curved wingtips (or winglets on airliners) help reduce this.

    But black wingtips in the glider/Ibis case? I can’t see any benefit, other than it looks cool!

    Here’s a dramatic example of the vortices left in a C-17 Globemaster III’s wake:

    https://en.wikipedia.org/wiki/Wingtip_vortices#/media/File:C17-Vortex.JPG

  9. Those glider/bird comparisons were novel and very cool.
    Teals are exceedingly beautiful.

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