1 ̀

Background

• Scavenging is a widespread yet understudied foraging strategy

• Vultures are ubiquitous scavengers that often carry heavy

contaminant burdens due to high trophic position

• Incidental poisoning is causing vultures declines worldwide

• Fate of vulture carcasses is currently unknown, but they are

a potential source of contaminant and

poison redistribution within the vertebrate

community via scavenging

Objective 1

• Lead chamber with gamma detector measured radiocesium levels of

carcasses, 28 of which were acquired from outside of the SRS and

3 of which came from on site

Objective 2

• 31 black vulture carcasses monitored for vertebrate scavenging

activity over 14 days with Reconyx HyperFire remote cameras

15 in open and 16 in forested areas

Objective 1

• One vulture from the SRS had a slightly above background

radiocesium level of 5.04 Bq/kg

• The other thirty vultures had normal background levels

Objective 2

Objective 2

• High vertebrate scavenging rates in both habitat types

~60% vs. 49.4% of rabbit carcasses in same landscape

Scavenging communities identical in

both habitat types but lower diversity

than prior study with rabbit carcasses

• Potential for contaminants in vulture

carcasses to re-enter food web at

middle and high trophic levels

What Scavenges the Ultimate Scavenger? The Fate of Black

Vulture Carcasses on the Savannah River Site

Methods

Study Area

Introduction

Lauren Laatsch1, 2, Joshua B. Smith1, James C. Beasley1, 2

1. University of Georgia, Savannah River Ecology Lab 2. Warnell School of Forestry and Natural Resources

Results

Conclusions and Discussion

Objectives

1. Measure radiocesium levels in black vulture carcasses

2. Determine the proportion of vulture carcasses scavenged by

vertebrates within open and forested habitats and the community

composition of vertebrates utilizing vulture carrion

Savannah River Site (SRS)

• Department of Energy facility

• 800 square kilometers near Aiken, SC

• Built in early 1950’s to produce materials

for nuclear weapons

• Many studies conducted on site have

analyzed the behavior and ecological

impacts of radionuclides Figure 1. Map of the SRS with locations of experimentally

placed vulture carcasses represented by red dots

13.33%

26.67%

20.00%

6.67% Open

30%

35%

40%

45%

50%

55%

60%

65%

Open Forest

Pe

rce

nta

ge

of

Carc

as

se

s S

ca

ve

ng

ed

Habitat Type

18.75%

37.50%

18.75%

6.25% Forest

Figure 2. The

proportion of

carcasses scavenged

in each habitat type.

60% of the carcasses

placed in open areas

and 62.5% of those

placed in forested

areas were scavenged

by vertebrates.

Figure 3. The three dominant scavengers were coyotes, opossums, and turkey vultures. These graphs show the percentage

of scavenged carcasses that each of the dominant scavengers at least partially scavenged in both open and forested areas.

Acknowledgements: This research was funded through the National Science Foundation’s Radioecology Research

Experience for Undergraduates program hosted at the Savannah River Ecology Lab (UGA). This work was also

supported through funding by the U.S. Department of Energy through Cooperative Agreement number DE-FC09-

07SR22506 with the University of Georgia Research Foundation. We would like to thank Noel Myers of USDA-APHIS

Wildlife Services for providing black vulture carcasses. Special thanks to Bobby Kennamer and Kelsey Turner for their

help.

Objective 1

• All radiocesium levels were at background except for one

vulture from the SRS that was slightly above background

Legal limit for human consumption in Europe is 600 Bq/kg

Future studies should measure levels in other black

vultures and turkey vultures from the SRS

Because vultures migrate, these substances could disperse

widely from points of origin