Bird Watchers Urgently Needed to Track Rusty Blackbirds

A century ago, the Rusty Blackbird was an incredibly abundant bird. Accounts from the period detail spectacular spring migrations between the species' wintering grounds in the bottomland forests of the southeastern United States and its breeding grounds in the forested wetlands of North America's vast boreal forest. Ornithological reports from New England and southern Canada describe waves of tens to hundreds of thousands of Rusty Blackbirds blackening the earth and clouding the sky in the spring. In many communities, the migration of Rusty Blackbirds was likened to the year's first chorus of tree frog--a sign that spring had finally arrived in the thawing countryside.

Today these reports seem unbelievable since Rusty Blackbirds populations have suffered one of most staggering population declines of any bird in North America. An understanding of the Rusty Blackbird's habitat requirements is urgently needed to conserve its remaining populations. This is especially true during spring migration when Rusty Blackbirds congregate in large flocks which may be particularly vulnerable to habitat losses, blackbird control programs, or other disturbances. Unfortunately, very little is known about the natural history requirements of the Rusty Blackbird during its northward migration.

To address this information gap, eBird is calling on bird watchers for help. April 1-7, look for Rusty Blackbirds on their northward migration. The data collected will help identify important migration stopover locations and habitats for conservation and will help researchers examine whether long-term changes to key migration habitats are responsible for the species' decline. If you are interested in participating, please collect the following information, then submit your data to eBird, taking note of the following:

1. Date, time, location of the observations. Area, traveling and stationary counts are preferred. Be as precise as possible when mapping your location.

2. Rusty Blackbird flock size, including an estimate of number of males vs. females. Answer 'yes' to the question 'do you want to report age/sex or add species comments' at the top of the eBird checklist page.

3. General behavior: flying, feeding, loafing (day), roosting (dawn, dusk, night). Put these in the species comments field.

4. Habitat: agricultural field, scrub-shrub wetland, forested wetland, shores of rivers or creeks, shores of lakes or ponds. Put these in general checklist comments field.

5. Comments: Please include "Rusty Blackbird Survey" in the general checklist comments section so we can determine whether you were specifically looking for Rusty Blackbirds during your birding expedition.

6. If possible please submit a complete checklist of the birds you identified on your outing, and answer 'yes' to the 'are you reporting all the species you saw/heard' question on the eBird checklist page. This will give us an idea of what other birds were in the area, as well as whether or not Rusty Blackbirds were associating with other blackbirds species during migration.

Identification and Photo Gallery

Overview

Rusty Blackbirds are uncommon blackbirds typically found in wooded swamps and damp forests. Increasingly, however, as this habitat is lost to development, they can be found in flooded agricultural fields and even on suburban lawns--habitats more typically associated with the similarly plumaged Brewer's Blackbird. While habitat should be taken into consideration when making blackbird identifications, care is needed, so please use the field marks below to help confirm your ID.

Rusty Blackbirds are often heard before they are seen, and then have a distinctive song. It has been likened to a rusty door hinge. You can hear a sample of it at All About Birds.

During spring, male Rusty Blackbirds are mostly blackish with females having more rusty edges to the wings and body. Two other species are more abundant and sometimes mistaken for Rusty Blackbirds. The Common Grackle is larger with a relatively long, keeled tail and larger bill. Males are iridescent, showing complex colors of purple, green and gold. The female Red-winged Blackbird could also be mistaken for a Rusty, but has bold streaking on the underparts, whereas the underparts of both sexes of Rusty Blackbird are plain. Brewer's Blackbirds are much more similar to Rusty Blackbirds overall, but are typically found in open fields and agricultural areas, not in wet woods, and are rare across much of eastern of North America. Rusty Blackbird usually appears thinner-billed and shorter-tailed than Brewer's Blackbird, and they have shorter legs. Female Brewer's Blackbirds usually have dark eyes, while Rusty Blackbirds have "staring" pale eyes.

Spring Plumage

Two male (right) and one female (left) Rusty Blackbird ground foraging. Note the male's overall blacker coloration, and the female's brighter rusty plumage.
^©Ron Howard

Male Rusty Blackbirds acquire their black plumage through wear over the course of the winter and spring. Fall males are the brightest, fringed with rusty overall. By mid-winter and early spring most look like this, largely blackish with some rusty fringes remaining.
^©Nick Anich

By April most males will be nearly all black, with rusty fringes evident only at close range. Note the short tail and staring yellow eye. The lack of iridescence helps separate this species from all Grackles and Brewer's Blackbird.
^©Mary Kay Rubey

Spring females are more rusty than males, generally with unstreaked grayish underparts and a mix of dark and rusty above. Note the bright yellow eye, and often notable dark cheek patch.
^©Mary Kay Rubey

Confusing spring females can be told from all other blackbirds by their rusty fringed tertials--the feathers in this view of the inner-wing that overlay the lower back and rump. Brewer's generally lack this field mark, as do all Grackles and Cowbirds. Female Red-winged Blackbirds are boldly streaked below, and should cause little confusion.
^©Ron Howard

Summer Plumage

Singing male Rusty Blackbird on Alaskan breeding grounds. By summer males are entirely black, but typically lack the glossy iridescence of other similar species.
^©David Shaw--www.wildimagephoto.com

Adult female Rusty Blackbird on Alaskan breeding grounds. Note overall grayish coloration and staring yellow eye.
^©David Shaw--www.wildimagephoto.com

Fall Plumage

In fall freshly molted Rusty Blackbirds are at the height of their brightness. Young birds and females are most colorful, while the black summer plumage of males is veiled in the rusty tips of fresh fall feathers, giving them an overall rusty hue.
^©Ron Howard

Habits

Look for Rusty Blackbirds on migration flying overhead in flocks as well as stopping off at local wet woodlands. They sometimes join other blackbirds during migration, so be careful when distinguishing them from the more common species.
^©Mary Kay Rubey

During migration and winter Rusty Blackbirds can often be found feeding around the edge of water, typically bogs, ponds or wet woods.
^©Nick Anich

To learn more about the Rusty Blackbirds visit the following webs sites:

International Rusty Blackbird Technical Working Group at the Smithsonian Migratory Bird Center

Boreal Songbird Initiative at http://www.borealbirds.org/

Save Our Boreal Birds at http://www.saveourborealbirds.org/

Much of the narrative of this news item was contributed by Rusty Blackbird Working Group member Steve Matsuoka--thanks Steve!

Thanks also to David Shaw, Nick Anich, Mary Kay Rubey and Ron Howard for use of their excellent images in the photo gallery.

Now get out there and count some Rusty Blackbirds!

Team eBird