Most Passerines only hold juvenal plumage for a few weeks, quickly molting to a more adult-like plumage soon after they fledge and before fall migration. It’s a plumage that is seen almost entirely on the breeding grounds, but the breeding grounds (and fledging time) of many birds overlaps broadly with the fall migration of others, […]
Juvenal plumage of songbirds: Gray Catbird Read More »
These are the only regularly occurring herons that are truly difficult to identify, as immatures of these two species are variable in bare-parts color and distinguishing them can require very careful study. The best clue is foraging posture, which can be seen at any distance and is very reliable. Most individuals are fairly easily separated
Distinguishing immature (white) Little Blue Heron from Snowy Egret Read More »
First Glance A quick judgment of the ground color of the breast and eyebrow stripe will separate most waterthrushes: bright white on Louisiana, yellowish on Northern. A yellowish waterthrush is definitely a Northern, while a whitish bird could be either species. Next look at the shape of the eyebrow stripe, which broadens to the rear
Identification of Waterthrushes Read More »
Identifying the white herons and egrets can be a challenge. We must rely mainly on structure, behavior, and the color of bare parts like bill and legs, because plumage offers very little in the way of field marks. One aspect of plumage can be very helpful, however. By looking at the shape and condition of
Determining the age of white egrets and herons in late summer Read More »
This is a bird sound that I recorded in August in Massachusetts. Listen to the recording and see if you can guess what it is. Some hints are below, and when you’re ready just follow the link for the answer. click to Read the Answer Hints It is a small bird, but larger than a
A little-known bird sound Read More »
The flippant answer is “…because they look alike”, and they can be very alike. Most of what you read about yellowlegs will tell you to look at bill length to distinguish the species. The bill of Greater Yellowlegs is actually longer (50 mm or more, compared to Lesser’s 40 mm or less) but birders deal
Why are Yellowlegs hard to identify? Read More »
Not really. A recently-published study used high-speed video of hummingbirds hovering in simulated rain to investigate questions of how hard it is to stay airborne while simultaneously getting wet (and heavier) and getting pelted with water drops that must be a significant blow to their 4 gram bodies. The conclusion is that the birds have
Is it hard for hummingbirds to hover in the rain? Read More »
Thanks to reader Skip Pothier for sending in these photos. They show a Purple Finch with yellow color instead of red. My first thought was to call it a male that didn’t develop the full red pigment (a similar variant due to poor diet and/or poor health is fairly common in male House Finches) but
A Yellow Purple Finch in Ontario Read More »
With the annual publication of the supplement to the AOU checklist, here is a listing of the changes to names in the Sibley Guide to Birds. There were a lot of other changes announced to names of neotropical birds, which are not discussed here. There were also some big changes in the sequence of species
Name changes of birds in the 2012 AOU supplement Read More »
An interesting study published recently found that cowbirds in bright sunlight were slower to detect predators, and cowbirds in shade were quicker. The study concludes that the delay happens because the cowbirds are slightly disabled by the glare of the bright sun. Could this explain why small birds are hard to find in bright sunny
Birds slow to react to predators because… the sun gets in their eyes Read More »