Monday, August 13, 2018

The Problem with Pen Raised Quail A Study

Written by Shelby McCay, Texas A&M University, WFSC 15 and MNRD ’19
Edited by Amanda Gobeli, Extension Associate, Texas A&M Natural Resources Institute
Edited by Dr. James Cathey, Associate Director, Texas A&M Natural Resources Institute
Edited by Dr. Dale Rollins, Statewide Coordinator, Reversing the Quail Decline Initiative

The history and practice of releasing pen-raised quail is almost 100 years old. It began in the 1930s as an attempt to bolster declining populations throughout the southeastern U.S., and it was an attractive option for both wildlife biologists and landowners searching for a simple fix to the quail decline problem.  Tens of millions of pen-raised quail were released by state wildlife agencies, with some even building their own hatcheries in the belief that it would take many years for wild populations to recover (Gerstell 1938, Anonymous 1942, Hernández et al. 2012, Whitt et al. 2017).
An example of a state quail hatchery. Photo: California Department of Fish and Wildlife.
However, it soon became apparent that no matter how many quail were released, their survival rate across most areas and habitat types within their U.S. range was abysmally low (Buechner 1950).  In a radio-telemetry study in south Texas, researchers found that half of their pen-raised birds perished only 9 days after release; by 12 weeks, all of them had died (Perez et al. 2002).  But why don’t these pen-raised quail last in the wild?  There are two main theories—let’s explore each further.

One theory is that pen-raised quail are not as genetically vigorous as their wild counterparts due to inbreeding.  Research has shown this is not the case.  A study conducted by Ellsworth et al. (1988), found that the genetic variability in pen-raised bobwhites was not notably deficient, and they did not display high levels of inbreeding compared to wild quail.  But even if pen-raised birds are not lacking genetic diversity, could wild quail have some unknown genetic advantage?  Two studies examined this question by crossing pen-raised quail with wild ones, producing what is known as F1 offspring, and comparing their survival to purebred pen-raised quail.  Both studies found that the survival rates of F1 and pen-raised birds were almost identical (Roseberry et al. 1987, Perez et al. 2002).  It seems there is little evidence for genetic differences causing low survival in pen-raised birds.

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