Evaluation of methods to estimate gosling survival

Five common approaches hare been used to determine survival of Canada Goose goslings. Two focus directly on broods without marks (mean brood size and total gosling counts), two focus an counting either marked goslings or the goslings of marked adults, and the last is entirely statistical (meta-analy sis). We briefly describe each technique and some inherent problems. We arg ue that comparisons of gosling survival rates based on average brood size o r meta-analysis are likely to result in overestimation, while those based o n total gosling counts may result in either under or overestimation. Surviv al rates based on marked adults or goslings promise results closer to the t rue state of nature, although some problems will still persist.