Tuesday, December 13, 2011

Hooded Mergansers: Coolin Off

Group, above, flying off. The two photos directly below show a female (bottom photo) and male (1st photo below) potentially courting each other by flapping their wings stationary as they cool off in the morning high tide.
This photo below shows the difference between the male and female mergansrs, with the female hooded mergansers swimming on the right. Young males also appear brown as the females do.
"The information on territoriality and pair formation in this species is scarce. The timing and duration of pair formation is uncertain. Some birds return to the breeding ground together as mated pairs; others participate in courtship and mating rituals after arriving...Female Hooded Mergansers show strong philopatry, returning to the same breeding area, but not necessarily the same nest site, as in previous years. Nesting begins as early as February and early March in the lower latitudes and milder regions of the merganser’s range."
This is the largest flock of Mergansers I've been able to capture on the creek this season. Hooded Mergansers are the only type of Merganser that breeds and winters entirely in North America. Hooded Mergansers are most commonly from Great Lakes region and eastern Canada, but are also found in the Pacific Northwest. Mergansers migrate south, and seem to enjoy Futch Creek as a resting place during the colder winter months. They prefer calm, clear waters with a sand or pebbled bottom, surrounded by deciduous woods.
The three male Mergansers above lead the line of (male & female) Mergansers meandering through the marsh. It appears that this might be a courtship group of Mergansers, even though they don't breed until early Spring. "Courtship groups consist of one to two females and several males. Males perform courtship rituals and displays, including crest-raising, head-shaking, head-throws, and head-pumping. Although normally silent, males make several vocalizations during some courtship displays. The most common is a rolling, frog-like call that is given immediately after a male performs a head-throw display. Males also may make short display flights. If anything, females perform only head-pumping displays." A few pictures above show the female first making a possible courtship 'dsplay' flight and then the male.
These images are of breeding male mergansers.
A hooded Merganser above takes the dive!
Tight group of breeding male and female Mergansers enjoying the morning high tide.
These pictures were taken of a small flock during high tide rising. I try to remain hidden when I photograph them because they fly away as soon as they see me. Mergansers are a quiet duck that depend on their eyesight to survive. They have spectacular vision, as they hunt fish based on their sight, and then dive after them with their nictitating membrane (third eyelid) protecting their eyes as goggles when they dive.
Hooded Mergansers in flight.
Male Hooded Merganser on left, and female on right.

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