Four Minnesota pelicans are taking backpacks with them on their annual migration trip to the Gulf of Mexico.

The American White Pelicans are part of a large colony that nests in west central Minnesota. First-year birds – those hatched this past spring – will spend a full year on the gulf once they reach it. Mature pelicans winter there, migrating back here for nesting.

Minnesota pelicans were on the gulf when that BP oil rig went bad, spilling millions of gallons of oil into the water. The dispersant chemicals used in the cleanup effort probably just added to the problem for birds.

Early this summer researchers took blood samples from adult pelicans in the Minnesota colony, and collected about two dozen eggs for scientific examination. Traces of oil and dispersant were found in both birds and eggs.

To learn more about the birds' habits on their winter visit south, five pelicans were equipped with solar-powered geolocators – radio transmitters. Four of the birds have been followed since as they make wander toward the gulf.

A transmitter weighs about three ounces. It is four inches long and an inch and a half wide. Think of it as an iPod for birds. The transmitters are fastened to the birds' backs with what you would call shoulder straps if you think of birds having shoulders.

This is not an inexpensive project. Each transmitter costs $3,500. They have a life expectancy of about five years. It will cost about $1,000 per year to process the data collected. The transmitters have GPS units that take a reading every 24 hours.

The information goes first to a satellite, which in turn sends it to a ground station. There, someone converts that info to email and sends a message to Mark Martell, director of bird conservation for Audubon Minnesota. Martell posts regular updates on the pelicans to one of Minnesota's birding email networks.

The project is a joint effort involving Audubon, North Dakota State University, and the Minnesota DNR Nongame Wildlife program.

At last report (Oct. 9) the birds continued movement began in July, although each bird seems to have its own idea of how to get to the Gulf. One bird was in Mississippi, moving over 300 miles in the previous 26 hours from a location in Missouri. A second bird was near Des Moines, Iowa. A third bird flew from North Dakota into South Dakota, its transmitter reporting in from near Watertown. The fourth bird flew 40 miles north of its previous location to a spot on the Illinois River near Peoria. All of the birds began their trips at Marsh Lake, an impoundment of the Minnesota River located near Appleton.

The photo of the pelican with the backpack transmitter was taken by Carrol Henderson of the Minnesota Department of Natural Resources.