Urban Prairie Dog Population Management Using Non-Lethal Reproductive Control

Dan Salkeld, Jackson Runte, Douglas Eckery, Gary Witmer, Aaron ShielsColorado State University & National Wildlife Research Center, USDA-APHIS

Photo: Rose Lombardo

Black-tailed prairie dogs (Cynomys ludovicianus)

• One of five species of prairie dogs in North America

• Great Plains habitat

• Keystone species

Photo: M. Lockhart

Burrowing owls

Conservation status: Threatened

“Management efforts directed

toward retention of active prairie

dog towns and cropped vegetation

(

Prairie dog density higher in urban colonies (compared to more natural, unrestricted populations).

Current Solutions

Lethal Control

• Poisoning

• Fumigation

• Raptor perches

Non-lethal Control

• Relocation

• Barriers

Can we use an immunocontraceptive?

GonaCon – a gonadotropin releasing hormone (GnRH) immunocontraceptivevaccine

Injection of GnRH hooked with a foreign protein

Causes the bodies immune system to bind to GnRH and stop production of sex hormones (estrogen, progesterone, testosterone)

Successfully tested on: white tailed deer, California ground squirrels, Norway rats, cats, dogs, swine, horse, and elk

Administration of GonaCon

Individuals captured, Fall 2018

0.4 mL of GonaCon, or sham (saline) injected into upper thigh of adult females

PIT tags for individual recognition

Matched pairs: Gonacon vs sham vaccine (exp. control)

Gonacon: 25Exp. control: 6

Gonacon: 13Exp. control: 14 6

Gonacon: 27Exp. control: 23 6

FORT COLLINS DENVER

Visual count ratiosField scans of juveniles:adults in May/June 2019(corrected by observations of randomly placed colored mason jars)

0

0.5

1

1.5

2

2.5

3

3.5

Hogbacks SoFoCo Bluff Lake

Ratios of juvenile:adult abundance

Gonacon

Exp. Control

Lower abundance of juveniles in Gonacon sites

Visual count ratiosField scans of juveniles

0

0.5

1

1.5

2

2.5

3

3.5

Hogbacks SoFoCo Bluff Lake

Ratios of juvenile:adult abundance

Gonacon

Exp. Control

Sham (Exp. Control) GonaCon

F = 37.95P < 0.0001

Recapture dataCaptures of juveniles

Lower abundance of juveniles in Gonacon sites

0

1

2

3

4

5

6

7

8

9

Hogbacks SoFoCo Bluff Lake

Number of juveniles captured

Caveats

Field-work finished on Friday!

Statistical analyses (population estimates etc.) begin in earnest…

Blood analyses

Potential as management tool? Models (Yoder et al. 2008) suggest approx. 33% annual contraception could work; or 86% every three years…

In combination with culling?

Discrete, urban prairie dog colonies more likely to realistically managed

EPA product registration

Acknowledgements:Funding from:

Brilliant field-assistance:

Jessie Earhart, Jesika Feldman, Kayla Kolber, Gabby Smuts, Linnea Salkeld, Freya Salkeld, Danika Spock, Ben Thomas, Carly Manthei

Permissions from:

Bluff Lake Nature Center

Fort Collins Natural Areas

EPA & Colorado Parks & Wildlife