26 / OutdoorIllinois March 2008

Researchers use satellite

technology in an attempt to

discover why the lesser

scaup population has

taken a nose dive.

Story By Kathy AndrewsPhotos By Adele Hodde

I t has the biological commu-nity scratching their prover-bial heads.

Huge rafts of scaup oncerode the waves of the Missis-sippi River each spring and

fall as the birds winged their waybetween their nesting grounds in the

far northern reaches of North Americaand their wintering grounds inLouisiana. According to Illinois NaturalHistory Survey flight data, in the springof 1958, 465,200 lesser scaup wererecorded on Pool 19, compared with an

average spring peak from 1992-2001 of55,533. Fall numbers don’t fare any bet-ter—from a high in 1948 of 545,000 toa low in the past decade of 20,038.

Two species of scaup occur in NorthAmerica, lesser scaup (Aythya affinis),the most common species in the Mid-west, and their larger cousin the greaterscaup (A. marila). Collectively referredto as bluebills, for obvious reasons,identification of two species requiresclose observation, and is virtuallyimpossible from the traditional researchvessel, an airplane.

Biologists across

North America are

trying to determine why

populations of lesser scaup

have declined.

(© Michael Furtman)

March 2008 OutdoorIllinois / 27

Using satellite technology, biolo-

gists are tracking the migratory

paths of selected female scaup.

During spring migration, traps

placed on Pool 19 of the Mississip-

pi River provide biologists the

opportunity to band bluebills.

Recovered bands provide migra-

tion information.

(Ducks

UnlimitedGIS

Departmentincooperationwith

Dr.AlA

ftonand

theLouisianaStateUniversity

SchoolofR

enew

ableNaturalResources.)

Leading a diverse team of biologistsworking to solve the scaup mystery is AlAfton, a U.S. Geological Survey biologistand adjunct professor at Louisiana StateUniversity. Afton and other researchershave formed three hypotheses for thescaup decline: accumulation of contami-nants, climate and habitat changes onthe boreal forest breeding areas, anddecreased quality and quantity of foodresources on winter and spring migra-tion areas. The latter is the focus of apilot study initiated on Pool 19 of theMississippi River in March 2007.

“Pool 19 is a critical area for scaupbecause of the number of birds passingthrough the area each spring from anumber of different wintering areas,”Afton explained. “Traditionally, foodsupplies there have been very good andthe birds have been able to build fatreserves, which is especially importantfor females to ensure their survivalthrough migration and during the egg-laying and incubation periods.”

Biologists spent several weeks onthe river last March, trapping, bandingand weighing 2,500 scaup. From thatlarge sample, 17 females were selectedfor a state-of-the-art study involvingimplanted radio transmitters.

Thanks to this technologicaladvancement, biologists from through-out the country simultaneouslyreceive—on a nearly daily basis—updat-ed locations of those females.

“The use of satellite technology hastaken the logistics of being on theground, or in the airplane, out of theequation of tracking these birds,” Aftonsaid. “Radios are expensive, with eachone costing approximately $2,750 plusan annual fee of about $800 to obtainthe data, but the batteries last two yearsso we are able to gather considerableinformation with relatively minor effort

in terms of hours in the field.”This month, biologists return to Pool

19 to trap scaup—some will be recap-tures that will provide valuable informa-tion on survival rates while others willbe new birds that will be equippedwith a leg band. And from the sample,20-25 females will be outfitted withradio transmitters, boosting the infor-mation biologists will gather on theirmigration routes.

Collectively, this information willprovide biologists with necessary infor-mation on how to focus managementefforts and prioritize habitat work. It’sall in the name of removing bluebillsfrom a state of jeopardy.

28 / OutdoorIllinois March 2008

F or updated information on theproject, visit www.ducks.org/

scaupstudy.Project partners include: the Upper

Mississippi River and Great Lakes JointVenture; Prairie Pothole Joint Venture;U.S. Fish and Wildlife Service; Minneso-ta, Illinois and Iowa Departments ofNatural Resources; USGS-LouisianaCooperative Fish and Wildlife ResearchUnit; Louisiana State University;Louisiana Department of Wildlife andFisheries; University of Illinois Collegeof Veterinary Medicine; USGS-NorthernPrairie Wildlife Research Center; DucksUnlimited Inc.; North Dakota Game andFish Department; Long Point Waterfowland Wetlands Research Fund; KibbeResearch Station of Western IllinoisUniversity; Ontario Ministry of NaturalResources; Des Moines County Conser-vation Board; Mississippi Valley CallingAssociation; Louisa County Conserva-tion Board; Tri Oak Foods; and, Mis-souri Department of Conservation.

Radio transmitters are implanted

in a small sample of female scaup.

Equipped with a band and

radio transmitter, movements of

this duck can be tracked on

near-daily basis.

(CourtesyLowellW

ashburn,IowaDNR.)