By Deborah Huth Price For the Reporter-Herald
Posted: 04/10/2013 07:19:50 PM MDT
The lark bunting (
s state bird) depends on grasslands for survival. Breeding males are black with
white wings. (José Hugo Martínez Guerrero) Colorado
Not all birds live in trees -- many bird species depend on open grasslands for food and shelter, and their habitat is disappearing. Some of these little birds carry miniature transmitters and geo-locators on their backs, helping scientists understand migratory patterns, wintering grounds and survival needs.
Greg Levandoski, director of operations for the international program of Rocky Mountain Bird Observatory (RMBO), along with his colleagues, has been studying and researching grassland birds as they migrate from
Colorado and states farther north to the
southern United States and . He
concentrates on the Mexico , where he says
there are 15-17 grassland priority conservation areas that biologists and
conservationists think are the most important grasslands remaining. Their
research area covers Chihuahuan
Desert Arizona, New Mexico, Texas and
six states in . Mexico
According to RMBO information, the Chihahuan desert provides primary wintering grounds for more than 90 percent of grassland birds in western
North America. These range from
raptors to songbirds, including the Baird's and grasshopper sparrows, mountain
plover, Ferruginous hawk, western meadowlark and 's state bird, the lark bunting.
RMBO has about 140 species of grassland birds in their database, and focus on
about 30 high-priority species that either benefit from or require grasslands. Colorado
Follow the Birds
Learn more about migratory birds by attending the International Migratory Bird Celebration May 11 in
: . The event includes bird
banding stations, activities, and a bike, bird and brew tour. Fort Collins
"It's hard to help them and conserve them if you don't understand their needs," says Levandoski. To do this, RMBO has acquired grants and established partnerships with organizations such as the city of Fort Collins, U.S. Fish and Wildlife Service, Neotropical Migratory Bird Conservation Act, the Universidad Autnoma de Nuevo Leon in Monterrey, Mexico, and other organizations and agencies.
In order to better understand the birds' migratory paths and preferred wintering grounds, Levandoski says researchers captured and placed tiny radio transmitters on Baird's and grasshopper sparrows. "We have people out in the field every day with an antenna and a headset and they listen for little beeps broadcast by the transmitters."
A newer technology allowed researchers to use geolocators on black swifts. These small light sensors are attached to birds' backs and record daylight length and intensity. "Using calculations similar to those mariners used to make, you can figure out latitude and longitude," Levandoski explains. The instruments do not transmit data, but store information, which is then collected by recapturing birds the next year. Geo-locators are now getting small enough that Levandoski hopes they may soon be used on sparrows.
Grassland birds vary in their migratory ranges. Baird's sparrows breed in
North Dakota, Montana and the Saskatchewan
areas, flying south to
in the winter. Grasshopper sparrows are much more widespread, shares
Levandoski. "We have them on city properties breeding in summertime."
These and many other seed-eating birds need a large network of grasslands to
exist and thrive. Levandoski says that "Of all the groups of birds on the
continent, probably worldwide, grassland birds have been the most affected and
have had the most widespread population decline." Mexico
"One of the important lessons we've learned," says Levandoski, "is that due to the random nature of where rain falls each year in the desert, it's really important that we conserve a whole network of grasslands. Many of these species seem to shift the bulk of their wintering populations year to year depending on where the rain fell and where grass is in good condition."