Postfledging Survival of Grasshopper Sparrows in Grasslands Managed with Fire and Grazing

The condor

Torre J. Hovick¹ 

关键词: Ammodramus savannarum;    Grasshopper Sparrow;    patch-burn grazing;    postfledging survival;    prescribed fire;    tallgrass prairie;   

DOI  :  10.1525/cond.2011.100135

学科分类：动物科学

来源: Central Ornithology Publication Office

【 摘 要 】

Abstract. More accurate estimates of survival after nestlings fledge are needed for population models to be parameterized and population dynamics to be understood during this vulnerable life stage. The period after fledging is the time when chicks learn to fly, forage, and hide from predators. We monitored postfledging survival, causespecific mortality, and movements of Grasshopper Sparrows (Ammodramus savannarum) in grassland managed with fire and grazing. In 2009, we attached radio transmitters to 50 nestlings from 50 different broods and modeled their survival in response to climatic, biological, and ecological variables. There was no effect of treatment on survival. The factor most influencing postfledging survival was age; no other variable was significant. The majority of chicks (74%) died within 3 days of radio-transmitter attachment. We attributed most mortality to mesopredators (48%) and exposure (28%). Fledglings' movements increased rapidly for the first 4 days after they left the nest and were...

【 授权许可】

CC BY