Two centuries of human‐mediated gene flow in northern bobwhites

Abstract

The northern bobwhite (Colinus virginianus; hereafter, bobwhite) population decline has prompted several studies over the past decade investigating bobwhite population genetics and overall connectivity. The zeitgeist of current quail conservation is that bobwhite populations have become increasingly fragmented, leading to their decline as a result of reduced fitness associated with effects from small population size. A few studies exploring population-level patterns of genetic connectivity at the local scale have identified some areas possessing limited gene flow likely due to recent anthropogenic landscape changes. Interestingly, however, multiple studies using genetic methods have also suggested that the species has experienced a recent range-wide expansion with few barriers to dispersal, suggesting a large panmictic population. Although the above are both supported by empirical data, we highlight another possibility that has been proposed yet rarely investigated. Millions of wild bobwhites have been transported among populations, and millions more captive-reared bobwhites have been and continue to be released across the species' range. Given the massive scale at which bobwhites have been artificially dispersed, more research is needed to investigate the effects of introgression of nonlocal birds on our ability to understand recent changes in bobwhite population fragmentation, size, and diversity. Such information has important management implications to long-term bobwhite population sustainability. By quantifying the level of human-mediated bobwhite dispersal events, our review cautions against assigning evolutionary or conservation significance to patterns of genetic connectivity among bobwhite populations until a more systematic effort is made to verify that such activities have not affected our ability to identify natural gene-flow patterns at both local and broadscale distributions. Ó 2017 The Wildlife Society.

Efficacy of acclimating and releasing captive-reared and wild-translocated Northern bobwhites

“…Northern bobwhite quail populations (Colinus virginianus) have been in decline for over a century, 1 largely due to climate, habitat loss, and population fragmentation. [2][3][4][5][6][7] For remedy, wildlife managers have typically focused their efforts on quail habitat restoration; however, for declining density-dependent species like northern bobwhite, habitat restoration alone has had mixed results.…”

“…8 Millions of captive-reared and wild northern bobwhites have been released annually across North America and the world, with varying rates of success. 1,9,10 Captive-reared releases have been carried out in large scale with little success in many states, including Texas in the 1950s and 60s. 1,9,[11][12][13][14][15][16][17] Past evaluations of captive-reared quail releases have been laden with biases including stock selection, prerelease handling, release methods, and monitoring.…”

“…1,9,10 Captive-reared releases have been carried out in large scale with little success in many states, including Texas in the 1950s and 60s. 1,9,[11][12][13][14][15][16][17] Past evaluations of captive-reared quail releases have been laden with biases including stock selection, prerelease handling, release methods, and monitoring. 12,14,15,18 Translocating wild birds has also had challenges.…”

“…23 Although the goal of these population restoration techniques has typically been to increase fall hunting encounters, sustained populations have been established by translocation of wild birds to non-native areas of the United States and Europe. 1,10,24 Even when measured by recapture, survival rates of captive-reared birds tend to be lower than those of wild birds. 17,25,26 The discrepancy in survival between captive-reared and wild birds is hypothesized to be caused by genetic inferiority of captive-reared bobwhites.…”

Comparative Analysis of Behavioural Response of Captive-Reared and Wild-Trapped Northern Bobwhites to Simulated Predator Attacks

“…Restocking has typically been done by state agencies and private landowners in an attempt to re-establish or bolster populations for the fall harvest, with likely hundreds of millions of birds released across the USA annually (Whitt et al, 2017). Releases have included both captive-reared and wild birds; however, most releases involved captivereared birds with limited success (Buechner, 1950;Hernández et al, 2012).…”