Since Jerry’s not feeling compelled to write much today, I thought I’d bring to readers’ attentions a must-have book: Evolution Illustrated by Waterfowl, by David Lack.
Many WEIT readers, like Jerry, are devoted anatophiles, which means you’ll want to have this small classic by the great British ornithologist, David Lack. Lack, though later becoming director of the Edward Grey Institute at Oxford, did perhaps his most influential work while an amateur prior to World War II. Employed as a master at Dartington Hall school, he took leave to visit the Galapagos Islands and the California Academy of Sciences, his studies during this time ultimately resulting in his classic book, Darwin’s Finches. (He had already published The Birds of Cambridgeshire and The Life of the Robin.)
In Evolution Illustrated by Waterfowl, he uses examples from ducks, geese, and swans to illustrate a broad range of evolutionary and ecological phenomena, including adaptation, speciation, convergent evolution, adaptive radiation, and sexual selection, among a wealth of others. The table of contents lays out the breadth of coverage.
Being an inexpensive book from 45 years ago, it does not have color illustrations, but it is illustrated with many fine line drawings and maps by Robert Gillmor, such as the one below, showing the diversity of Australian waterfowl.
So, get your copy today!
Lack, D. 1974. Evolution Illustrated by Waterfowl. Blackwell, Oxford.
On my recent visit to San Diego, I got to see one of my favorite ducks, a merganser. Mergansers are fish-eating diving ducks. Here’s a Red-breasted Merganser(Mergus serrator), diving in San Diego Bay, viewed from the Coronado Aquatics Center, on the Coronado Strand.
Mergansers have bills adapted to catch their prey, which are quite different from those of other ducks or, indeed, birds in general. Instead of the broad, flattened bill typical of ducks (the origin of the term ‘duckbilled’), their bills are long and narrow. And, though all modern birdslack teeth, there are a series of tooth-like serrations on the bills of mergansers which help them grab fish, frogs, and the like.
There are some geese that have similar structures on their bills, but they are more like transverse grooves rather than serrations. Geese are typical Anseriformes (the order to which ducks, geese, and swans belong) in their feeding habits, and do not catch fish; it is interesting that the only birds I know of with these approximations to teeth are in that order.
(The merganser skull shown above is probably one of the two species found in Wisconsin, either the Hooded Merganser [Lophodytes cucullatus; resident breeder in SE Wisconsin] or the Common Merganser [Mergus merganser; breeds from northern Wisconsin up through the taiga belt of Canada and Alaska, but winters in SE Wisconsin].)
I also saw a Surf Scoter (Melanitta perspicillata), another diving duck, also at the Aquatics Center. The body of water here is Glorietta Bay, a part of San Diego Bay enclosed by Coronado “Island”, the Strand which connects Coronado “Island” to the mainland (the reason Coronado “Island” is not an island), and a landfill extending from the Strand on which a Navy base is located. The scoters have broad bills, but they’re higher in the back (unlike mallards), and they feed on mollusks.
The bird in the video above is a male, as you can tell from the white markings on its head and neck. I saw several more Surf Scoters while sailing in San Diego Bay off National City, flying just above the water in small groups, but unfortunately did not get any photos. Both of these species of duck breed mostly on fresh water in the taiga and high arctic, and winter along the sea coasts, so it was a rare opportunity for me to see them.
I have often noted an excess of males when observing Mallards (often two males with a single female), as in the photo above, but I don’t know why that’s the case; a pair walked about near the pond.
As Cornell’s All About Birds reminds us, not everything that floats is a duck, and on a later visit to Balboa Park, I photographed this American Coot (Fulica americana). There were also more Mallards about that day—I counted 22 at the Pond.
The coot later went ashore and fell asleep. In looking at photos of the Mallards from my first visit, I noticed a coot in the background on the pond (first photo above)– probably the same individual. (You can find out more about the birds of Balboa Park at the Birds of Balboa Park page.)
With Honey and her fellow mallard inhabitants of Botany Pond in Chicago having flown the coop, and Jerry having done so himself for a few days, I had to travel north to Milwaukee to get my ration of duck feeding. There, on a visit with my vertebrate zoology class to the Milwaukee County Zoo, I was able to see Laysan Teal (Anas laysanensis) feeding.
Laysan Teal are relatives of mallards, and were once widespread in the Hawaiian archipelago, but were restricted to the small northwestern island of Laysan by the time of their scientific description by Lord Rothschild in 1892. They are still considered endangered, but other populations have been established by translocation within the Hawaiian Islands, and their numbers are now increasing. They do breed in captivity, and five ducklings were hatched at the Milwaukee County Zoo earlier this year.
The Teal are in the Aviary at the Zoo, in the Wetlands Hall, a large room with a “stream” running through it, surrounded by trees and herbaceous vegetation. Birds of several species fly about the hall. The teal prefer the shallow part of the stream.