Purple Martins and wood finches may be small in size, but these small songbirds can fly like the wind. They cover more than 300 miles a day on their annual migrations. These birds were fitted with new geolocators weighing only a little more than a paper clip track their travel between North America and the tropics where they winter and breed as reported in the Journal Science.
The speed of their migratory flight surprised many scientists including Bridget Stutchbury a professor of biology at York University in Toronto, Canada. The birds left Brazil on April 12 and would arrive home by the end of the month.”I don’t think anybody had an idea that these little songbirds could travel that fast,” she said. They made better time going north in the spring than heading south in the fall.
Wood thrushes and purple martins were captured in western Pennsylvania and fitted with the geolocators. The 1.5 gram clear plastic trackers sense and record sunrise and sunset. Upon their return, the birds were recaptured so the data can be downloaded to a computer. Purple martins and wood thrushes weigh about 50 grams(about 2 ounces).
The timing of sunrise and sunset gives the location of the bird on each day of recording. The tracking devices were placed on 14 wood thrushes and 20 purple martins during 2007 to track the fall takeoff, migration south, and journey back.
In the summer of 2008, the geolocators from only five wood thrushes and two purple martins were recovered. No one knows where the rest of the study birds went (or if the devices came off-editor). If you see one of these little birds with a pack on dead or alive, please contact us at Nature’s Crusaders so we can pass the information along to the research team.
The purple martins travel to the Amazon basin in Brazil for the winter, The wood thrushes wintered in a narrow band of Nicaragua and Honduras. Some of the birds took pauses along the way, spending a few days in the southeastern United States or in Mexico’s Yucatan area.The spring migration is faster possibly because there are major advantages to arriving first on breeding grounds, including getting the best nesting spots, the chance to get high quality mates and to start breeding first.
Reasons for the study
“Thirty species of songbird in North America show significant long-term decline,” Stutchbury said. “We need to know whether it’s the winter grounds or the breeding grounds driving these populations down.(It may not be breeding grounds at all, but other factors like the dramatic increase in microwave energies or planetary shifts not yet addressed.-editor)
The purpose of the research is to understand how migration, and changes such as in climate and habitat, are affecting songbirds.The research was funded by the Natural Science and Engineering Research Council of Canada, the National Geographic Society and the Purple Martin Conservation Association.
How you can help.
You can help these and other song birds survive and thrive by providing proper nesting nesting, mixed seeds, fruits and suet and cover to hide to raise their young. Below is a list of needs for wood thrushes and Purple Martins. Each songbird famiy may have different needs so look up the life style for each bird you want to attract.
The Purple martin (Progne subis) is the only other Northern American swallow that is dark all over. Females, young, and first-year males are light bellied and could be confused with smaller swallows. Look for purple iridescence on head and top of wings. They have broad wings and are known for their soaring ability. Song and calls are a distinctive, low-pitched, liquid, rolling twitter.
“Purple Martins are picky about where they nest.. Choose a pole that telescopes, or is equipped with a winch or lanyard, and housing that has easy access to compartments. Paint houses and gourds white, or a light color. White housing attract martins best, and reflects sunlight, keeping hatchlings cooler.
Compartment floor dimensions should be 7″ x 12″ with a special entrance hole will minimize starling problems. Height of compartments can be 6″ or 7.”
Entrance holes 1″ above the floor with a hole of 2 x 1″x 8″ is preferred by the martins.
Ventilation and drainage in each compartment.
Insulation to the attic, remodel interiors to offer double-size compartments, and add porch dividers. Dividers help keep males from claiming extra compartments, and can double occupancy rates. They also keep nestlings from wandering to other compartments, where they can get lost and die, or steal food from younger nestlings, causing them to starve.
External guards to protect against owls, hawks, crows, rat snakes, squirrels, and raccoons. Install guards before the martins arrive.
Fire ants protection :Teflon spray or tape, or a ring of grease on the pole, will stop the ants. Grease won’t stop snakes or raccoons, so install a pole guard, too.
Open bird housing at the right time, and don’t close it too soon.
Breeding and migration: Adult martins return to their original breeding sites. Last year’s young will take up residence in new sites, and will join the parent stock about 4 weeks after the first adults. New housing should not be opened earlier than four weeks after the other adults arrive to decrease opportunities for House Sparrows and Starlings to adopt the site before the first year subadult martins arrive.
Migration is a drawn-out affair, with martins arriving for 8-12 weeks in the north, 16-20 weeks in the south. Martins can arrive and begin nesting up through the end of June, so keep your housing ready; don’t close it up, or let other birds use it.“(1)
The Wood Thrush
One of the most common woodland birds of the East is the Wood Thrush best known for its hauntingly beautiful song.(Listen to its song below.) Thrushes have a complicated syrinx (song box) that allows them to sing two notes at the same time and harmonize with their own voice.
Feeding preferences: About the size of a robin this brown and white spotted thrush lives on the edge to deep within the forest. It prefers to dine on soil invertebrates and larvae, but will also eat fruits. In the summer, it feeds on insects continuously in order to meet daily metabolic needs.
Social Structure: It is solitary, but sometimes form mixed-species flocks. The Wood Thrush defends a territory that ranges in size from 800 to 28000 square meters.
The Wood Thrush is monogamous, and its breeding season begins in the spring; about 50 percent of all mated pairs are able to raise two broods, ranging in size from 2 to 4 chicks.. When the first brood fledges, both parents feed all the young, but when the last brood fledges, they divide the work, each one caring for half the brood.
Migration pattern: Wood Thrush begins departing from its breeding grounds in late August and completes migration to its Central American wintering grounds by late October. The species migrates primarily at night, and can be identified and censused by its distinctive nocturnal flight call.
Declines in population numbers of the Wood Thrush have been linked to acid rain and forest fragmentation by studies conducted by the Cornell Lab of Ornithology’s Bird Population Studies, using data from the Birds in Forested Landscapes project
The Brown-headed Cowbird frequently parasitizes the nests of Wood Thrushes. In some parts of the Midwest all of the Wood Thrush nests contain at least one cowbird egg, and some may contain up to eight eggs.
Unique behavior: “Anting” occurs when a bird picks up a single ant or group of ants and rubs them on its feathers. The purpose of this behavior is not well understood. It is thought that birds may be able to acquire defensive secretions from the ants possibly used for some medicinal purpose. Also may be a supplement to the bird’s own preen oil. (2)
How can we help this bird survive:
Get involved with a local group and help provide nesting sites and food.(audubon.org/bird/iba
The Wood Thrush breeds across most of eastern North America, ranging from the panhandle of Florida northward to southern Canada. The species generally reaches its western limit at the eastern edge of the Great Plains, although it can be found breeding along the Missouri River through central South Dakota. Many Audubon Important Bird Areas (IBAs) throughout the eastern United States provide nesting habitat for Wood Thrush, including North Carolina’s Eno River Bottomlands IBA and Delaware’s Coastal Zone IBA. The Wood Thrush winters mostly in primary, broad-leaved forests at lower elevations from southern Mexico to western Panama
Decrease pollution and our carbon footprint.
Save any local deciduous forests from being destroyed.
Excerpts courtesy of Purple Martin.org
2. Excerpts courtesy of Wikipedia http://en.wikipedia.org/wiki/Wood_Thrush
2. Cornell Lab of Ornithology All About Birds
Get involved: http://www.audubon.org/bird/iba/
Image 1. courtesy of Paul Noll Oregon/Birds/arrivalMartinPurple
Song of the Wood Thrush courtesy of Learn Bird Songs: http://www.learnbirdsongs.com/birdsong