Hudson Gardens with Chuck Aid, July 30

Thirteen of us spent Saturday morning in and around Hudson Gardens.  In this period of post-breeding, things were a bit slow, and we only recorded 27 species (see list below).  However, we still managed to see a variety of interesting birds.  First of all, a month ago on the last Hudson Gardens walk we recorded a female Wood Duck with five little ducklings.  This time, while we did not see mom, we did once again see the five ducklings, which are close to adult size now, and a couple of them were starting to show the beginnings of the male’s spectacular plumage.  We also noted at least one juvenile Canada Goose.

Looking at Mallards we had to once again talk about eclipse plumage.  A reminder that eclipse plumage is when male ducks at the end of breeding season molt from their brilliant breeding plumage to a dull, cryptic plumage.  As the Birder’s Handbook says, “Their brilliance is dimmed – they go into ‘eclipse.’”  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.

Here are an eclipse plumage male Mallard (http://www.photosbygregstrong.comand) and male Wood Duck ( Note the bill color in both – a give away that you’re looking at males.

MALL Eclipse

WODU Eclipse

Another highlight of the morning was that we got to see a pair of juvenile Cooper’s Hawks hanging out in the cottonwood grove just downstream from Hudson Gardens. I believe that Cooper’s Hawks have been successful breeding in that same grove now for the last four years.

On a personal note, this has been a great year for Hummingbirds at my house. Lots of zipping around and high drama!

The next Front Range Birding Company bird walk is going to the Denver Botanic Gardens at Chatfield this coming Saturday, Aug 6. Please call the store to register – 303-979-2473.

Good Birding!  Chuck


Hudson Gardens

Jul 30, 2016

27 species

Canada Goose (Branta canadensis)  35

Wood Duck (Aix sponsa)  5

Mallard (Anas platyrhynchos)  18

Double-crested Cormorant (Phalacrocorax auritus)  5

American White Pelican (Pelecanus erythrorhynchos)  10

Great Blue Heron (Ardea herodias)  1

Cooper’s Hawk (Accipiter cooperii)  2

Red-tailed Hawk (Buteo jamaicensis)  2

Killdeer (Charadrius vociferus)  1

Spotted Sandpiper (Actitis macularius)  4

Mourning Dove (Zenaida macroura)  2

Broad-tailed Hummingbird (Selasphorus platycercus)  3

Belted Kingfisher (Megaceryle alcyon)  1

Downy Woodpecker (Picoides pubescens)  1

Northern Flicker (Colaptes auratus)  5

Barn Swallow (Hirundo rustica)  1

Black-capped Chickadee (Poecile atricapillus)  4

White-breasted Nuthatch (Sitta carolinensis)  2

American Robin (Turdus migratorius)  7

European Starling (Sturnus vulgaris)  2

Yellow Warbler (Setophaga petechia)  1

Song Sparrow (Melospiza melodia)  1

Spotted Towhee (Pipilo maculatus)  1

Red-winged Blackbird (Agelaius phoeniceus)  1

Common Grackle (Quiscalus quiscula)  3

House Finch (Haemorhous mexicanus)  25

American Goldfinch (Spinus tristis)  12