Optimizing Nest Survival and Female Survival: Consequences of Nest Site Selection for Canada Geese

Abstract

We examined the relationship between attributes of nest sites used by Canada Geese (Branta canadensis) in the Copper River Delta, Alaska, and patterns in nest and female survival. We aimed to determine whether nest site attributes related to nest and female survival differed and whether nest site attributes related to nest survival changed within and among years. Nest site attributes that we examined included vegetation at and surrounding the nest, as well as associations with other nesting birds. Optimal nest site characteristics were different depending on whether nest survival or female survival was examined. Prior to 25 May, the odds of daily survival for nests in tall shrubs and on islands were 2.92 and 2.26 times greater, respectively, than for nests in short shrub sites. Bald Eagles (Halieaeetus leucocephalus) are the major predator during the early breeding season and their behavior was likely important in determining this pattern. After 25 May, when eagle predation is limited due to the availability of alternative prey, no differences in nest survival among the nest site types were found. In addition, nest survival was positively related to the density of other Canada Goose nests near the nest site. Although the number of detected mortalities for females was relatively low, a clear pattern was found, with mortality three times more likely at nest sites dominated by high shrub density within 50 m than at open sites dominated by low shrub density. The negative relationship of nest concealment and adult survival is consistent with that found in other studies of ground-nesting birds. Physical barriers that limited access to nest sites by predators and sites that allowed for early detection of predators were important characteristics of nest site quality for Canada Geese and nest site quality shifted within seasons, likely as a result of shifting predator-prey interactions.

Factors affecting the responses of female Canada Geese to disturbance during incubation

“…Incubating female Canada Geese in our study remained on nests longer in the presence of an approaching threat when they were better concealed by vegetation. Concealing vegetation can reduce the likelihood of detection of nests and incubating female Canada Geese by predators (Miller et al 2007). Thus, nest site selection represents an important antipredator strategy (Albrecht andKlvaňa 2004, Osiejuk andKucyński 2007).…”

“…Predation is a major cause of nest loss in ground-nesting birds (Ricklefs 1969), including Canada Geese (Bellrose 1976, Bruggink et al 1994). However, female geese are long-lived and thus rarely risk their lives to protect clutches that can be replaced (Schmutz et al 1997, Ghalambor and Martin 2000, Miller et al 2007. Adult geese must, therefore, determine the degree of risk they are willing to assume at the approach of a predator and adjust their flushing distances and return times accordingly.…”

Patterns and processes in shorebird survival rates: a global review

“…Additional non-reproductive factors could also contribute to the observed variation in shorebird survival rates. For example, in ground-nesting species, levels of nest concealment can also influence adult survival, with species that nest in the open being able to detect predators earlier (Amat & Masero 2004, Miller et al 2007. Variation in survival could also result from differences associated with migratory behaviour, depending on the environmental conditions experienced by individuals on the particular set of locations each uses along the flyway (Duriez et al 2012, Alves et al 2013a.…”

Habitat selection and potential fitness consequences of two early‐successional species with differing life‐history strategies

“…Adults choose a location that not only protects their reproductive investment, but often also their own safety. This choice can carry consequences for survival (Amat & Masero, 2004;Miller, Grand, Fondell, & Anthony, 2007), nest success (Murray & Best, 2014;Stokes & Boersma, 1998), and potentially fitness (Braden, McKernan, & Powell, 1997;Clark & Shutler, 1999;Martin, 1988;Orians & Wittenberger, 1991). Although nest-site selection and its relationship with reproductive success is a widely researched topic (Jones, 2001), incongruences between selection and success are the norm and not the exception (Chalfoun & Schmidt, 2012).…”