Birds of the Brick Works / Red-winged Blackbird: Leigh Davidson

Red-winged Blackbird

I always enjoy receiving nature information. This comes from one of our nature walkers: Leigh Davidson.

Here is what she wrote:

“Hi, Miles. It was great to get out & about again on Thursday.

Spring antics of RWBBs always remind me of the attached 1-pager tht I compiled years ago for the weekend outreach table at Brick Works. I think my favourite “fact” (hopefully accurate?) was this one about polygamy and blended families: “Typically five or more (up to 15) females crowd their nests into any one male’s territory. They typically mate with the territory holder, though many also mate with nearby males. (One-quarter to one-half of nestlings have a different father than the territorial male.)”

By the way I italicized people for our volunteers because of one male whoe was silly/ambitious enough to stake out his perch in a White Pine immediately adjacent to one of the busiest paths. More than one visitor stopped by our desk to report its dive-bombing.

I forget what my sources were. I assume much came from Wikipedia or allaboutbirds.”

Red-winged Blackbird (female)

RED-WINGED BLACKBIRD

• Possibly the most abundant native bird in North America – nearly 200 million in a range extending from SE Alaska and Canada down to Central America.

• One of the earliest migrants to return to T.O. each year (early March?)

• Flies south between Aug & Oct. Winters in U.S. and Mexico. In fall and winter, Red-winged Blackbirds congregate with other blackbirds, grackles, cowbirds, and starlings, feeding on open ground (agricultural fields, feedlots, pastures, and grassland) and roosting in flocks of thousands or millions of birds.

• Females choose the nest site with some input from the male. Typically, she puts the nest near the ground (or water surface in a marsh), in dense, grass-like vegetation such as cattails, bulrushes, sedges, and Phragmites […] 3 in – 14ft above water

• Males fiercely defend their territories during breeding season [May-July], spending more than a quarter of daylight hours in territory defense. He chases other males out of the territory and attacks nest predators, sometimes going after much larger animals, including horses and people.

• The male doesn’t always display his red & yellow epaulets:

o “Song spread” display: The male erects his epaulets and hunches his shoulders forward and lowers and spreads his tail. This dramatic display serves two functions: to defend his territory from other males and to attract females. As a male grows older, the epaulets grow more brilliant and conspicuous, and the black plumage more shiny and solid, Older males secure the highest quality territories and the fittest mates. In experiments, males with blackened epaulets often lose their territories.

o Flight display: The male raises his body feathers, especially on the epaulets, and spreads and lowers his tail. He beats his wings slowly and deeply to fly at minimum speed. Males perform this flight display only when above their own territory, usually in response to another male flying over or to an arriving female.

o Resting on territory: Inside his territory, when a male perches on a cattail, reed, or twig, he usually shows the red and yellow epaulets even when not displaying. Blackbirds perching outside their territory tend to show much less of the epaulet.

• RBBs nest in loose groups partly because appropriate marshy habitat is scarce. Typically five or more (up to 15) females crowd their nests into any one male’s territory. They typically mate with the territory holder, though many also mate with nearby males. (One-quarter to one-half of nestlings have a different father than the territorial male.) • Clutch Size = 2–4 eggs. Broods = 1-2. Incubation Period = 11–13 days. Nestling Period = 11–14 days.

• Omniverous – In summer, eats mainly insects (also berries, snails, frogs, eggs, worms); in winter eats mostly seeds, including corn and wheat, in the winter. Ground forager.

• Eggs are predated by snakes, raccoons, foxes, mink, other birds. [Birds] preyed on by hawks

• The oldest recorded Red-winged Blackbird was 15 years 9 months old.

Red-winged Blackbird (male)

Leigh Davidson

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