Hooded Merganser Crests

Here are a couple pictures of Hooded Mergansers, male and female. The males are black and white around the head and neck while the females have more "earth tone" coloring. In the 1st picture, the male has a large, almost circular white patch on the side of his head, and in the 2nd picture the male has more of a white line on the side of his head.

While sometimes there's simply variation in individual plumage that can account for different appearances, and other times there are subspecies where whole populations look quite different from each other, but neither of these is what's going on here. Male Hooded Mergansers can raise their crests to present a large white circle, or they can lower them to present a smaller white line. Generally speaking, male Hooded Mergansers can go from 1 look or the other in seconds, making them the quick-change artists of the waterfowl world.

The strikingly different appearance of a raised versus lowered crest of Hooded Mergansers sometimes leads beginning birders to think these are different species, at least until they see them "transform". 

January 27, 2023 at Duke Farms
Photo 263367804, (c) jpviolette, some rights reserved (CC BY-NC)


January 28, 2023 at Duke Farms
Photo 263480419, (c) jpviolette, some rights reserved (CC BY-NC)



Comments

Post a Comment

Popular posts from this blog

Northern Watersnake

Image
This April I went to Great Swamp National Wildlife Refuge with the hope (among other hopes) of seeing the Northern Watersnakes during mating season. There were 2 problems with this: I think it was slightly late in the season for this. The boardwalk trail where I had seen them in the past was partially closed due to repairs. So although I didn't see any of the 2+ intertwined snakes that I'd seen in the past, but there were still Northern Watersnakes warming themselves in the sun: April 13, 2023 at Great Swamp Photo 272117862, (c) jpviolette, some rights reserved (CC BY-NC) And here's another one coming out of the water. April 13, 2023 at Great Swamp Photo 272119139, (c) jpviolette, some rights reserved (CC BY-NC)
Read more

Female Brown-headed Cowbird

Image
Like quite a few birds, this bird is easier to identify when spotted with her significant other ; she's a Brown-headed Cowbird . Due to their tendency to be monogamous plus plain old birds-of-a-feather behavior, I usually see them with prominently brown-headed males around, greatly improving my confidence in IDing them. My understanding is that Brown-headed Cowbirds are the only obligate brood parasites in my area. Obligate brood parasites have essentially lost all their parenting skills, and thus if they were ever unable to fool other birds into raising their young, they would (almost certainly) go extinct [1]. There are, however, other brood parasites in New Jersey. These are called facultative brood parasites, and these birds will usually raise their own offspring, but will also engage in brood parasitism. (Exactly when birds perform facultative brood parasitism seems variable; one source said it occurred when resources were scarce while another said it occurred when resource
Read more

Rooftop Turkey Vultures

Image
I met these Turkey Vultures by just walking out of my apartment. (I theoretically could have gotten a picture without going outside, but that extra layer of glass can degrade picture quality a little.) Although they don't show up on these rooftops daily, they're not an uncommon visitor to my apartment complex. Similar to this spot of the woods , I wouldn't expect this to be a great place to find carcasses. I'm thinking they're here mostly because: They don't have to worry much about predators up there. They get a pretty good view of the area in case something should happen to succumb. (This apartment was near the top of a hill, providing a better view than most of the other apartments.) Since this picture was from February, it's probably a slightly warmer spot, especially near those furnace vent pipes. Although these are Turkey Vultures, it's also not unusual to see Black Vultures up there too. February 28, 2023 at Finderne Photo 264703396, (c) jpviole
Read more