Isolated populations of Northern Bobwhites (Colinus virginianus) have declined causing many landowners to attempt population restoration by releasing captive-reared birds. These attempts have resulted in high mortality rates, which we hypothesised are caused by captive-reared birds exhibiting more naïve predator avoidance behaviour than wild birds. Captive-reared and wild-trapped Northern Bobwhites were subjected to raptorial and terrestrial predator simulations and their responses were recorded on high definition video. We recorded the time to predator detection, time to anti-predator defence, and reaction type for comparative analysis. Captive-reared birds detected simulated predators quicker than wild-trapped birds, but time to mount an anti-predator defence was not different between groups. The response type, however, was different between groups. Captive-reared birds typically flushed when encountering a simulated predator; yet, wild-trapped birds did not flush at all, and typically ran or held when subjected to the simulated predators. We hypothesise that flushing is a naïve anti-predator response that results in revealing of position in the presence of a threat, thereby increasing the individual risk of predation. These results potentially illuminate at least one reason why captive-reared Northern Bobwhite releases have been largely unsuccessful.

No abstract

Northern bobwhite populations are dwindling across their range. Accordingly, in areas with bobwhite habitat restoration and no nearby populations, effective population restoration techniques are needed. Here, we evaluated three bobwhite restoration release strategies: (1) release of captive-reared bobwhites on sites with and without resident populations, (2) translocation of wild-trapped bobwhites from a region of high population density to a region with no population, and (3) release of captive-reared and wild-translocated bobwhites acclimated on site prior to release in year 2. Wild-translocated birds survived longer than captive-reared birds. Mean survival for captive-reared bobwhites was 2.42 weeks, and 4.27 weeks in year 1, and 1.91 and 1.40 weeks in year 2, for study sites without resident and with resident birds present, respectively. Mean survival for wild-translocated birds was 8.50 weeks in year 1, and 11.54 weeks in year 2. Wild-translocated birds dispersed shorter distances than captive-reared birds. Both captive-reared and wild-translocated bobwhites only nested on study sites with conspecifics. Captive-reared birds had 0 nesting attempts on the site with no resident bobwhites, and ⩾8 nests on the site with resident bobwhites. Wild-translocated females nested six times and were subsequently observed with juveniles. On-site acclimation did not increase post-release survival for northern bobwhites. Acclimation increased site fidelity but reduced survival for captive-reared birds and had no impact on survival for wild-translocated bobwhites. Population restoration by release of captive-reared or wild-translocated birds is not irrelevant, but further investigation is needed into the relationship between captive-reared birds and predators, and methods to increase survival and reproduction of released birds.

Sample, recovered from bed of ash near Crater Lake, Oregon, is from a tree burned in the violent eruption of Mount Mazama which created Crater Lake. This eruption blanketed several States with ash, providing geologists with an excellent time zone. Charcoal. _____________________ _______ _______ ___ ___-__-_ _10,130 Sample collected from the "Marmes Man" site in southeastern Washington. This rock shelter is believed to be among the oldest known inhabited sites in North America.

Fi g. 1.-So il-cove red land sown w ith w hea t is show n o n th e ri ght ; th e Chann led Sca bl ands is on th e left.