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Saturday, July 12, 2008

Ridgewood Reservoir

On Friday afternoon, at around 5pm, I did a little birding at the Ridgewood Reservoir. While scanning the lake in the central basin I spotted a pair of Pied-billed Grebes. I did not see any of chicks, but their presence during the breeding season could be a positive sign. The pair stayed close to each other much of the time. Several times, they appeared to be pointing their heads into the air or turning their heads from side to side. This could have just been their way of looking out for predators. I found the following information about their courtship displays:

"Like other grebes, P. podiceps is monogamous on a seasonal or multi-seasonal basis. However, unlike other grebes, it has no intricate courtship display. Courtship has five different stages: Advertising, the Pirouette Ceremony, Ripple Dive, Circle Display, and Triumph Ceremony.

Advertising marks the beginning of courtship, swimming around with sleek feathers and elongated neck allow the single bird to let birds of opposite sex take notice of his or her availability. In the pirouette ceremony, each bird approaches the other and then takes an upright posture and may give a greeting call followed by a series of head turning jerks. The Ripple Dance involves dives and races underwater to show the other bird his or her swimming prowess. The Circle Display is self explanatory and can be initiated by either sex; during the Circle Display the pair are several meters apart on the water surface. The Triumph Ceremony, which takes place after mates have been established, consists of each mate circling around the other in a stooped position." (Palmer, R. 1962. Handbook of North American birds. New Haven, CT: Yale University Press)

I did a search of NatureServe to find out more information on the Conservation Status of Pied-billed Grebes. According to their database, they have "declined locally due to degradation, disturbance, and loss of wetlands. The greatest threat to populations in the northeast is alteration and loss of wetland habitat through draining, dredging, filling, pollution, acid rain, agricultural practices, and siltation (Gibbs and Melvin 1992). Palustrine emergent wetlands, including inland freshwater and brackish marshlands frequented by grebes, are among the most threatened wildlife habitats in the U.S. Over 4.75 million acres (1.92 million ha) of such wetlands were destroyed in the U.S. between the mid-1950s and mid-1970s, and losses continue at 160,000 ac/year (64,777 ha) (Tiner 1984)."

There are some very good views of Jamaica Bay from the Ridgewood Reservoirs high vantage point. While scoping the Fountain Avenue Landfill I noticed something curious. There was a plume of something rising up out of the old landfill that distorted the image. The effect was similar to heat distortion. I digiscoped the following video. I am assuming that it is a plume of methane, because landfills need to vent off methane that is produced during decomposition of organic matter.

Ridgewood Reservoir, 07/11/2008
Wood Duck (14)
Pied-billed Grebe (2. Possibly breeding.)
Red-tailed Hawk (1)
Laughing Gull
Ring-billed Gull
Chimney Swift
Red-bellied Woodpecker
Northern Flicker
Willow Flycatcher
Warbling Vireo
Red-eyed Vireo
Tree Swallow
Bank Swallow (2)
Barn Swallow
Black-capped Chickadee
Tufted Titmouse
Carolina Wren
House Wren
Gray Catbird
Northern Mockingbird
Brown Thrasher
Cedar Waxwing
Yellow Warbler
American Redstart
Common Yellowthroat
Eastern Towhee
Chipping Sparrow
Song Sparrow
Common Grackle
Orchard Oriole (1)
Baltimore Oriole
American Goldfinch

Other common species seen (or heard)
Herring Gull, Rock Pigeon, Mourning Dove, Downy Woodpecker, Blue Jay, American Crow, American Robin, European Starling, Northern Cardinal, Red-winged Blackbird, House Sparrow
by Rob Jett for "The City Birder"

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