Ducks Make Spring Migration With "Carry-On" Baggage

Acrobatic Flyers Eyed by Satellites
MEMPHIS, TN, March 14----Northern pintail ducks, elegant in form and acrobatic in flight, are being watched and monitored by satellites. Female pintails have been outfitted with back-pack satellite transmitters, which allow scientists to track their migratory movements from the Central Valley of California, the most important pintail wintering area in the world. The results of Discovery for Recovery," with an accompanying biologists journal and online forum, are accessible on the web at www.ducks.org. The study, funded by a private grant to Ducks Unlimited from the Tuscany Research Institute, was initiated by a team of biologists from Ducks Unlimited, the U.S. Geological Survey, and the California Waterfowl Association.

Missing Prairie Pintails
Dr. Bruce Batt, chief biologist at Ducks Unlimited, says Pintails were once the second most abundant ducks, after mallards. In the 1950s, they peaked at 10.3 million birds, versus 10.4 million mallards. Theyve gone down to about 3 million in four decades. We need to find out what has happened. If you look at the common ducks, the pintail is one of just two species thats seriously below population goals." Typically, pintails that winter in California migrate to the Canadian prairies and to Alaska to breed in the spring. In recent years, fewer and fewer have arrived on the prairies, while the arctic population has been relatively stable. Scientists suspect the pintails may be overshooting the prairies in search of more hospitable breeding habitat.    

Breeding Habitat Matters Most
Dry conditions, intensive farming, avian disease, and predation all put stress on the pintail population and limit the species reproductive success. Says Dr. Batt, Breeding habitat conditions matter more than any other factor. The reproductive tactics and courtship rituals of pintails are fascinating. During courtship, many males will gather around a female and its up to her to select the best suitor. The males will encircle the female and become quite vocal, uttering a flute like whistle, which is followed by a head-up-tail-up movement."    

How the Data Relay Works
Michael Miller, a scientist at the Western Ecological Research Center of the U.S. Geological Survey in Dixon, California, leads the data management team of Bill Perry and Joan Daugherty. Together, they are analyzing data collected during the study, which began in January. The satellite transmitters send signals to environmental satellites owned by the National Oceanic and Atmospheric Administration (NOAA).    A second company, Argos, is facilitating the transmission process by attaching receivers to the NOAA satellites. The receivers enable Argos to download data and send the results via email to Miller and his team in California.

What Twenty Grams Can Do
Each transmitter, weighing about 20 grams (less than 3 percent of a female pintails body mass), relays a broad spectrum of information, including date, time and location (latitude/longitude) of the ducks, as well as estimates of location quality (not all locations are reliable), the temperature of the transmitters, and activity levels of the ducks. Once we determine migration routes and spring-use areas that link the Central Valley wintering areas with specific nesting areas, we hope to design field studies that address the issue of whether or not winter habitat, and its effect on pintail body conditions, influences productivity of nesting hens," says Miller. The information also may allow managers to determine the proportion of pintails exposed to perennial botulism, a serious population stressor.

Long Term Recovery Underway
In 1998, the pintail breeding population was estimated at 2.5 million. Says Dr. Bruce Batt: The scientific community has agreed on a population goal of 5.6 million.     Part of the recovery process is under way in the Central Valley, where Ducks Unlimited has more than 250 projects to restore wetland habitats. The Valley has lost more than 95 percent of its wetlands, and with that loss you have the deterioration of the pintails most significant wintering area. So far, DU projects, under the auspices of the Valley/Bay Care program, have restored and enhanced more than 80,000 acres of this critical winter habitat."    Dr. Batt oversees DUs science arm, the Institute for Wetland and Waterfowl Research (IWWR), which has been studying pintails in the Central Valley of California since 1993. Right now," Batt explains, we have a lot of information about pintails and the key aspects of their biology. With the satellite technology, we can build upon that knowledge. Were going to pursue these and other studies until we figure out whats wrong. Until then, well continue our work on the ground, restoring and enhancing habitat that pintails use throughout the annual cycle."

Discovery for Recovery" can be viewed at www.werc.usgs.gov/pinsat/plan.html.
Or link to Discovery" by clicking on www.ducks.org. Visitors can also visit the Ducks Unlimited sound and picture gallery to learn more about pintails and other ducks.
For more information, contact Tildy La Farge at 901-758-3859 or mlafarge@ducks.org.