Is There a Positive Relationship Between Body Size and Fecundity in Lesser Snow Geese?

Lack (1967) proposed that egg production in nidifugous waterfowl is ultimately limited by availability of nutrient resources (fat, protein, minerals) during the egg-laying period. In some species, there is considerable variation in the extent that egg production depends upon stored nutrient reserves and reserves acquired during laying (Krapu 1981, Alisauskas and Ankney 1985, Drobney and Fredrickson 1985, Robwet 1986, Ankney et al. 1991, Arnold and Robwet 1991, Drobney 1991). In Arctic-nesting geese the relationship between endogenous nutrient reserves and egg production probably is less complex. It has been traditionally believed that little food is available during the prelaying and laying period (Ryder 1970, Raveling 1979), and that geese subsist exclusively on stored nutrient reserves for maintenance and egg production (Ryder 1970, Ankney and Macinnes 1978). The potential impact of feeding by the geese during the prelaying and laying periods at some colonies on this traditional view is considered later in this paper. Ryder (1970) suggested the amount of nutrient reserves that could be stored by Arctic-nesting geese might be limited in part by the structural size of the bird; the larger the bird, the greater the absolute mass of nutrients that could be carried to the breeding ground and used for egg production. Ankney and Macinnes (1978) and Alisauskas (1988) have shown significant positive correlations between structural size and nutrient reserves in Lesser Snow Geese (Chen caerulescens caerulescens). Although this led to predictions of a significant direct association between structural size and clutch size, results of such analyses have been contradictory. Ankney and Macinnes (1978) found that Lesser Snow Geese with longer culmens (used as a univariate index of structural size) had greater absolute levels of reserves and laid larger clutches in two consecutive years. In contrast, Davies et al. (1988) found no significant relationship for Lesser Snow Geese between a multivariate index of structural size and clutch size using data from La P6rouse Bay pooled over several years. They suggested the difference between their results and those of Ankney and Macinnes (1978) may have been due to a lack of control for covariation of age and structural size in their sample. Davies et al. (1988) showed that older females in the La P6rouse Bay sam-