River Bird Blog

Copyright 2007 by Richie Swanson

A Canada warbler singing on June eighth? More than 80 miles south of the nearest nest record in Wisconsin? Chip-chupety-swee-ditchety! He advertised for a female all morning, ending his song with itchity like a common yellowthroat, flashing his black necklace above ferns, fallen logs, upturned tree roots and mossy rocks on swampy-forested banks a l suitable nest cover. An Eastern kingbird fluttered shallow wingbeats in midair, bumping bills with another, hovering slowly down to a dike, rasping, Kitterkitterkitter! She picked up a stick and tossed her head high, shaking her prize up, down, sideways. She dropped it, seized it again, repeated her routine, then flew followed by the other. She performed stick-behavior I did not find in science, and then a yellowthroat raised his black mask, singing phrases I haven’t heard during 30 years of listening. We-chew we-chew we-chew a-chew! Chew-chew-chweet-chweet!

Though common yellowthroats usually sing witchity-witchity-witchity, the species has exhibited vocal learning in captivity and has been observed singing a chestnut-sided warbler song in the wild. Males sing perch songs individually recognizable by human ear, attracting females, defending territories. This morning the yellowthroat sings continually from a 20-foot maple beside a marsh, suddenly warbling as richly-toned as a Swainson’s warbler. He rises out of buttonbush, and so does the kingbird, fluttering up with an 18-inch branch more than double her height.

I call her she because females build the species’ nests, and she places her branch high atop a power-transmission pole, letting all its sloppy side-twigs dangle down a porcelain insulator. She brings and places a 12-inch twig on a metal plate between crossbars, flutters above a male on a wire, calls, Kt’zee! Kt’zee! He does not stir.

She brings an eight-inch twig, and he flutter-hovers down to her twig-pile. The metal plate conceals their wings, but their white-banded tails pump together, and then she takes a twig to a tree outside the power company’s right-of-way, perhaps to a nest-site safer from wind, rain or stray voltage. He stays on the wire again, perching with a handsome-dark face and white breast identical to hers, and she flutter-hovers a circle above him, holding another stick, and then they fly across a marsh to the dike where the stick routine occurred Friday.

Female kingbirds may build several potential nests before a final choice. She must also overcome aggressive territorial chases by the male before mating, perhaps charming him with stick displays, and then she drives him away while she incubates, but she allows him to feed nestlings and carry off fecal sacs.

As fickle as human couples? I walk down Prothonotary Trail to the Canada warbler spot, failing to encounter the species for the second straight day. The Canada has declined by 40% since 1966, and I’m disappointed I can’t add it to Aghaming’s breeding list. Nonetheless avian reproduction here seems layered with infinite activities and intricacies, endless questions and adaptations, not contradictions.

Eastern kingbirds hawk insects from wires but follow the ripening of fruit through Central America on their way here, dump eggs like cowbirds in one another’s nests, also allow third adults to help at nests probably first-year bachelors.

Female yellow-headed blackbirds emerge from cattails, suggesting males singing kuk-koh-koh-koh-waaaaaa and displaying rowing wing-beats do not merely exist as floaters here, waiting for a harem next year. Two American eagles perch above a nest empty of eaglets, squealing at intruders as if guarding the site to try again next February.

The osprey of Osprey Marsh hunkers low in her power-pole nest box, still incubating or brooding new hatchlings. A green heron grunts skee-ow! It flushes, and the sun turns its wings a sky-blue as glaring and glossy as a desert firmament. It tiptoes with blazing-orange feet, leans forward with a bittern-like neck and drops bait, maybe a feather or worm or mayfly, atop a slough for a fish.

One prothonotary warbler sits on five eggs in an open-topped stump. Another has a cowbird’s tail sticking out a nest-hole in the side of a thin-dead branch wedged straight in mud. Another peers from a hole in a broken bridge-rail. Another drops from a 25-foot trunk and immediately slaps and slurps a worm in a knee-high bush. Another pops in and out a chest-high stump as if just starting to choose a cavity.

A red-bellied woodpecker forages low on a trunk, and a great crested flycatcher dives down. Churrs! Chucks! Rurrs! Whit-weeps! The two dart and flap through leaves, and the flycatcher flies high to its hole, leaning halfway into cavity-shadow, twisting its sun-yellow breast, glaring over its shoulder, raising its smoky-gray crest. Its look says it clearly intends to remain in possession next week too, and woodpeckers are not allowed to excavate or eat anything inside.

SOURCES

Conway, C.J. 1999. Canada Warbler (Wilsonia Canadensis). In The Birds of North America, No. 421 (A. Poole and F. Gill, eds.). Philadelphia, PA.

Davis, W.E., Jr., and J.A. Kushlan. 1994. Green Heron (Butorides virescens). In The Birds of North America, No. 129 (A. Poole and F. Gill, eds.) Philadelphia: The Academy of Natural Sciences. Washington D.C. The Amemerican Onithologists’ Union.

Guzy, M.J., and G. Ritchinson. 1999. Commont Yellowthroat (Geothylpis trichas). In The Birds of North America, No. 448 (A. Poole and F. Gill, eds.). Philadelphia PA.

http://www.birds.cornell.edu/bfl/speciesaccts/canwar.html.

Murphy, M.T. 1996. Eastern Kingbird (Tyrannus tyrannus). In The Birds of North America, No. 253 (A. Poole and F. Gill, eds.) The Academy of Natural Sciences. Philadelpha, PA. The American Ornithologists’ Union. Washington D.C.

Stokes, Donald W. 1979. A Guide to Bird Behavior, Volume 1. Little, Brown & Company. Boston. Toronto.