The Husting dilemma: A methodological note

Recently, Gill (1985) discussed the interpretation of capture history data resulting from his own studies on the red-spotted newt, Notophthalmus viridescens , and work by Husting (1965) on spotted salamanders, Ambystoma maculatum. Gill (1985) noted that gaps in capture histories (years in which individuals were not captured, preceded and followed by years in which they were) could result from either of two very different possibilities: (1) failure of the animal to return to the fenced pond to breed (the alternative Husting (1965) favored), or (2) return of the animal to the breeding pond, but failure of the investigator to capture it and detect its presence. The authors agree entirely with Gill (1985) that capture history data such as his or those of Husting (1965) should be analyzed using models that recognize the possibility of 'census error,' and that it is important to try to distinguish between such 'error' and skipped breeding efforts. The purpose of this note is to point out the relationship between Gill's (1985:347) null model and certain capture-recapture models, and to use capture-recapture models and tests to analyze the original data of Husting (1965).