Viability of Northern Bobwhite Populations

Abstract

Quail populations are declining in North America. Hence, we modeled tlle \lability of northern bobwhite (Colit~rrsvirgininnus) populations subject to ~veathercatastrophes and harvest to help focus manage- ment and research efforts to reverse the decline. \t7e examined northern-latitude (winter weather catastrophes) and southern-latitude (summer xveather catastrophes) populations separately because winter sunival is lower and densit\.-dependent production is stronger in northern- than in southern-latitude populations. Under a criterion of qnasiextinction at 514 birds (1 co\.ev), the demographic capacit\. required for at least a 95% prol~abilit\.of persistence for 100 years Lvas about 100 birds \\it11 summer weather catastrophes, about 500 birds nith inter weather catastrophes, and about 800 birds with both minter and summer weather catastro- phes. Given assumptions underl>-ing the nioclel, populations subject to sulnrner weather catastrophes were sustainable under a 530% hhan-est rate if demographic capacity in autumn was about 700 birds. Populations subject to \$inter weather catastrophes collld persist at 540% 'charvest rates and a denlographic capacity of about 100 birds. Korthern populations Lvere more wlnerable to extinction in the absence of han-est, whereas southern populations \\.ere more \111nerable to extirictiori in the presence of han-est.