It was a slow morning at Hudson Gardens this past Saturday. Thirteen of us, while moving from one patch of shade to the next, managed to tally only 24 species. We struck out on a few species that can generally be counted on such as Cooper’s Hawk, Cliff Swallow, and Yellow Warbler, so we had to find our entertainment from those species that we were able to locate.
First of all, we know that Canada Geese are primarily grazers. Create a few hundred golf courses, and watch the local geese population go up another ten thousand birds or so. However, on Saturday the geese were “grazing” in the riffles of the now relatively shallow South Platte River. What I did not know on Saturday, but have since learned, is that geese will at times eat crustaceans and mollusks. So, maybe there was some vegetation growing amidst the rocky riffles, but another possibility is that maybe the geese had switched over to being carnivores. Veloci-geese! Yikes!
I talked about eclipse plumage last year, and I’m going to repeat myself here, so I hope that’s okay. All of our male Mallards on Saturday were in eclipse plumage. This is when male ducks at the end of breeding season molt from their brilliant breeding plumage to a dull, cryptic plumage. This all happens at the same time that the main flight feathers are moulting, and some ducks actually become flightless for a few weeks. It makes good sense, if you are temporarily flightless, that it might be to your advantage to be more cryptically colored. The duration of the eclipse plumage varies between species, lasting for some just a couple of weeks, and for others persisting into early winter. With the next molt the brilliant male colors return. One interesting thing to contemplate in all this eclipse plumage business is to think about the inherent advantages in remaining cryptically colored for a longer period of time versus regaining one’s brilliance more rapidly. To be camouflaged longer is to be less visible to predators; while to regain breeding plumage more rapidly is to have a “leg up” on impressing the females, but may be deleterious if you really can’t quite fly yet.
The main highlight of the morning was getting to see three Snowy Egrets apparently cooperatively foraging with five Common Mergansers; and a Belted Kingfisher taking advantage of the chaos to get its share of what was happening, as did a Double-crested Cormorant. Four species of piscivores (fish-eaters) having a pretty successful time of it in the shallows at the edge of the river. I always enjoy seeing the “golden slippers” of the Snowy Egrets, but did you know that at the very peak of breeding season the feet actually become redish-orange, as does the bare skin between the beak and the eye – something to look for next year.
So, we still have young fledglings begging for food from their parents, we have some birds preparing to migrate, and others, apparently, have already hit the road. An interesting time of year!
I hope to see you on another walk soon!
Best, Chuck Aid
Hudson Gardens, Aug 26, 2017
Canada Goose (Branta canadensis) 19
Mallard (Anas platyrhynchos) 23
Common Merganser (Mergus merganser) 5
Double-crested Cormorant (Phalacrocorax auritus) 3
Great Blue Heron (Ardea herodias) 3
Snowy Egret (Egretta thula) 3
Black-crowned Night-Heron (Nycticorax nycticorax) 2
Red-tailed Hawk (Buteo jamaicensis) 1
Ring-billed Gull (Larus delawarensis) 9
Rock Pigeon (Feral Pigeon) (Columba livia (Feral Pigeon)) 1
Mourning Dove (Zenaida macroura) 1
Belted Kingfisher (Megaceryle alcyon) 2
Northern Flicker (Colaptes auratus) 4
Downy Woodpecker 1
Western Kingbird (Tyrannus verticalis) 1
American Crow (Corvus brachyrhynchos) 2
Barn Swallow (Hirundo rustica) 8
Black-capped Chickadee (Poecile atricapillus) 11
White-breasted Nuthatch (Sitta carolinensis) 2
House Wren (Troglodytes aedon) 3
Red-winged Blackbird (Agelaius phoeniceus) 7
House Finch (Haemorhous mexicanus) 10
American Goldfinch (Spinus tristis) 4