Ruffed grouse population dynamics in the central and southern Appalachians

Abstract

Ruffed grouse (Bonasa urnbellus; hereafter grouse) populations in the central and southern Appalachians are in decline. However, limited information on the dynamics of these populations prevents the development of effective management strategies to reverse these trends. We used radiotelemetry data collected on grouse to parameterize 6 models of population growth to: (1) determine the pattern of growth in these populations, and (2) identify the demographic rates most important to growth. TLend estimates from population models were most similar to trend estimates derived from Breeding Bird Survey and Christmas Bird Count data when models incorporated either a reproductive or survival event. These events randomly increased fecundity or survival, respectively, to their empirical maxima on average once every 5 years. Reproductive events improved estimates on areas dominated by mixed mesophytic forest, while survival events characterized population growth on oak (Quercus spp.)-dominated sites. The finite rate of increase (2) was most sensitive to brood survival followed by adult and juvenile non-breeding sunrival on most sites. However, brood survival was low (~0.3f5e male chickshen survived to week 51, and elasticity analyses indicated 1 responded more strongly to proportionate change in non-breeding and breeding survival rates of adults and juveniles than any reproductive variable. Life stage analyses corroborated this result. At baseline values, survival of adults and juveniles may be the main determinants of growth in these populations, and reproduction may not be adequate to compensate for these losses. Therefore, population growth above baseline levels may be

Citation

Tirpak, John M. Giuliano, William M.; Miller, C. Allan; Allen, Thomas J.; Bittner, Steve; Buehler, David A.; Edwards, John W.; Harper, Craig A.; Igo, William K.; Norman, Gary W.; Seamster, M.; Stauffer, Dean F. 2006. Ruffed grouse population dynamics in the central and southern Appalachians. Biological Conservation, Vol. 133: 364-378