Pest Management Solutions -- Texas Tech University


Protection of Quail Nests from Mammals to Increase Chick Recruitment in Habitat Occupied by the Red Imported Fire Ant

Principal Investigators:
Brad Dabbert 
Dept. of Range, Wildlife, and Fisheries Management
Box 42125
Texas Tech University
Lubbock, TX 79409-2125

Phone: 806/742-1983; Fax 806/742-2280
Email: Brad.Dabbert@ttu.edu

Rob Mitchell
Dept. of Range, Wildlife, and Fisheries Management
Box 42125
Texas Tech University
Lubbock, TX 79409-2125
Phone: 806/742-1983; Fax 806/742-2280
Email: Rob.Mitchell@ttu.edu

Funding Amount/2Years: $86,500

Relevance\Implication of Project:
A major goal of the Texas Imported Fire Ant Research and Management Plan is to develop methods to reduce red imported fire ant (RIFA) impacts on wildlife. Current methods available to reduce RIFA density in wildlife habitat, such as insecticide treatments, are not economically or environmentally desirable for most landowners.  In some instances landowners may be able to mitigate the impacts of RIFA on wildlife populations by altering ecological processes rather than removing ants.  For instance, landowners may be able to increase northern bobwhite populations subjected to RIFA predation by decreasing loss of nests to mammalian predators.  An increase in nest success should mitigate predation by RIFA and increase chick recruitment into the population.  Predator exclusion or removal may provide managers an economically feasible alternative to the $20/ha required to broadcast insecticide application for red imported fire ant control.  

Summary of Work to be Done:
Our research indicates that protection of hatching chicks from RIFA increases chick survival (54% when protected versus 25% unprotected) to 21 days of age.  Chick survival is related to the number of RIFA captured in a bait cup placed in nests on the day after hatch.  When > 300 RIFA recruit to the bait cup, chick survival approaches zero.  If  < 300 RIFA recruit to the bait cup then survival is similar to that of chicks that hatched from nests protected from RIFA.  Thus not all areas of the landscape harbor RIFA populations that are sufficiently active to kill entire broods.  Protecting nests from other mortality sources may increase chick recruitment into the fall population. Nests can be protected from vertebrate predation using fences.  Other studies have indicated that increasing nest success by altering predator populations initially causes more chicks to hatch.  This increased hatch often does not result in greater numbers of birds in the fall, however, because populations are already at or near their carrying capacity.  In this situation density-dependent factors such as food limitation, act to limit chick survival, preventing a net increase in population size.  We believe the current evidence suggests that northern bobwhite populations cohabiting areas with RIFA are below their carrying capacity. We postulate that if more nests in areas containing low RIFA activity survive to hatch, then more chicks should survive to subadult status.  We suggest nest success can be increased by reducing predator populations in the nesting area or physically protecting nests.   The objective of this study is to determine if hens whose nests are physically protected from mammalian predators will have more chicks survive until fall than hens whose nests are exposed to predation.   Landowners who wish to increase quail populations subjected to RIFA predation may be able to decrease loss of nests to mammalian predators and increase recruitment of chicks into the population.   Reduction of mammalian predation upon nests may be a more economically and environmentally desirable practice than large-scale application of insecticides to reduce RIFA.