Evaluation of artificial nest sites for long-term conservation of a burrow-nesting seabird

Abstract

The persistence of many cavity‐nesting animals is threatened by habitat modification and a shortage of suitable breeding sites. Consequently, provision of alternative breeding sites is a frequently applied short‐ to medium‐term conservation action. However, the effectiveness of provisioning for breeding success and persistence of breeding animals is rarely considered and could lead populations into an ecological trap. We evaluated the effectiveness of providing nest boxes for little penguins (Eudyptula minor) compared with natural nests over 25 years. We assessed nest‐box adoption and occupancy rates, compared breeding success (i.e., hatching and fledging success) and indices of productivity (i.e., observed brood size, total fledged chick mass, and the number of clutch initiations) with nest survival models and log‐linear mixed effects models, and compared long‐term residency patterns with Link–Barker mark‐recapture models between artificial and natural nests. Little penguins readily adopted nest boxes and breeding attempts were recorded in about 92% of nest boxes installed for 7 or more years. Breeding productivity from 6,081 monitored clutches varied by year and was similar across nest types in most years, but in poor breeding seasons nest boxes performed better. Survival rates to hatching and fledging averaged 7.6% and 8.6% greater in nest boxes, respectively. Similarly, the average total observed mass of chicks produced per clutch was 11% heavier in nest boxes. Annual site fidelity of 2,331 breeding penguins was similar in areas with nest boxes and areas with natural burrows, despite an average of 35% of natural burrows collapsing each year. Nest‐box provisioning for little penguins overcomes local nest‐site limitation, improves breeding success, and can result in local population increases, so is not indicative of an ecological trap. However, a self‐sustaining local population in the long term will require management strategies that address the underlying processes inhibiting population recovery and assist the transition from artificial nest sites back to natural nest sites. © 2014 The Wildlife Society.

Integrated population model reveals that kestrels breeding in nest boxes operate as a source population

“…Nest boxes are expected to be advantageous for bird populations for two reasons: first they can relax the constraint related to nesting sites availability (Newton 1994) and second, they can increase breeding performance compared to natural nesting sites which are often more vulnerable to predation, parasite infection and adverse weather events (Møller 1989, Bolton et al 2004, Catry et al 2009, Sutherland et al 2014. The Swiss kestrel population has benefited from the nest boxes probably through both mechanisms (Jeanmonod and Broch 2001).…”

“…Furthermore, nest-site availability could be locally limiting for kestrels in Switzerland (Schimd 1990), a situation which is fairly common for this species (Cavé 1968, Village 1990, Fargallo et al 2001. Following the installation of nest boxes, populations have usually rapidly increased (Bolton et al 2004, Catry et al 2009, Libois et al 2012, Sutherland et al 2014. Such management has been used for seabirds (Libois et al 2012), raptors (Catry et al 2009), passerines (Brazill-Boast et al 2013, ducks (Savard and Robert 2007), parrots (White et al 2005), hoopoes (Arlettaz et al 2010) and even mammals (Harley 2006).…”

“…Nest box deployment has been regularly applied as a conservation measure for populations limited by nest-site availability or quality. Massive local recruitment and immigration are the main drivers of the rapid increase observed in the first couple of years (Bolton et al 2004, Catry et al 2009, Arlettaz et al 2010, Sutherland et al 2014, while the improvement of fecundity contributes more to the lasting population growth (Catry et al 2009, Altwegg et al 2014). Following the installation of nest boxes, populations have usually rapidly increased (Bolton et al 2004, Catry et al 2009, Libois et al 2012, Sutherland et al 2014.…”

“…Such management has been used for seabirds (Libois et al 2012), raptors (Catry et al 2009), passerines (Brazill-Boast et al 2013, ducks (Savard and Robert 2007), parrots (White et al 2005), hoopoes (Arlettaz et al 2010) and even mammals (Harley 2006). Because the positive effect of such a management measure on reproduction is pervasive (Møller 1989, Bolton et al 2004, Catry et al 2009, Sutherland et al 2014 but see Bragin et al 2017), it could be fairly common that birds breeding in nest boxes operate as source population. Massive local recruitment and immigration are the main drivers of the rapid increase observed in the first couple of years (Bolton et al 2004, Catry et al 2009, Arlettaz et al 2010, Sutherland et al 2014, while the improvement of fecundity contributes more to the lasting population growth (Catry et al 2009, Altwegg et al 2014).…”

“…Furthermore, reproductive performance is generally higher in nest boxes than in natural nests, at least in birds (Møller 1989). Several studies have documented the positive effect of such management on local population dynamics (Libois et al 2012, Altwegg et al 2014, Sutherland et al 2014). However, no study has yet investigated if the provision of artificial nests may promote the creation of source populations.…”