Temporal and spatial differences in the post-breeding behaviour of a ubiquitous Southern Hemisphere seabird, the common diving petrel

Abstract

The non-breeding period plays a major role in seabird survival and population dynamics. However, our understanding of the migratory behaviour, moulting and feeding strategies of non-breeding seabirds is still very limited, especially for small-sized species. The present study investigated the post-breeding behaviour of three distant populations (Kerguelen Archipelago, southeastern Australia, New Zealand) of the common diving petrel (CDP) ( Pelecanoides urinatrix ), an abundant, widely distributed zooplanktivorous seabird breeding throughout the southern Atlantic, Indian and Pacific oceans. The timing, geographical destination and activity pattern of birds were quantified through geolocator deployments during the post-breeding migration, while moult pattern of body feathers was investigated using stable isotope analysis. Despite the high energetic cost of flapping flight, all the individuals quickly travelled long distances (greater than approx. 2500 km) after the end of the breeding season, targeting oceanic frontal systems. The three populations, however, clearly diverged spatially (migration pathways and destinations), and temporally (timing and duration) in their post-breeding movements, as well as in their period of moult. Philopatry to distantly separated breeding grounds, different breeding phenologies and distinct post-breeding destinations suggest that the CDP populations have a high potential for isolation, and hence, speciation. These results contribute to improving knowledge of ecological divergence and evolution between populations, and inform the challenges of conserving migratory species.

Contrasting impacts of environmental variability on the breeding biology of two sympatric small procellariiform seabirds in south-eastern Australia

“…This access system reduced the disturbance of the natural tunnel and facilitated rapid access to the birds [45] . unpublished data); post-breeding area of common diving petrels (CDP post-breeding area; [37]).…”

“…The summer period plays a key role in the growth and reproduction of Australian krill (Nyctiphanes australis) in Bass Strait [52], the main prey of both FP and CDP [44]. Additionally, CDP have been observed to migrate during the post-breeding period to subantarctic regions [37] which may provide resources necessary for winter survival and preparation for subsequent breeding. However, FP stay in south-eastern Australia during the inter-breeding period and regularly visit Bass Strait islands during this period [43,53].…”

“…Similarly, low food availability during the non-breeding period can induce low breeding performances through carry-over effects [75]. This period is critical for both study species, as adults need to restore their body reserves and, more importantly, undertake the energetically costly renewal of their plumage [37,76]. In the post-breeding area of CDP in the Southern Ocean, zooplanktonic communities can be affected by warmer sea surface temperatures [77] impacting the body condition and survival of planktivorous seabird species [78].…”

“…Adult CDP do not produce stomach oil and, consequently, are required to feed chicks more regularly, limiting their foraging range during breeding [34,35]. In addition, FP feed on the ocean surface while CDP may forage at depths of up to 30 m [36], potentially facilitating avoidance of interspecific competition for food [37].…”

Contrasting impacts of environmental variability on the breeding biology of two sympatric small procellariiform seabirds in south-eastern Australia

“…Adult CDP do not produce stomach oil and, consequently, are required to feed chicks more regularly, limiting their foraging range during breeding [ 35 , 36 ]. In addition, FP feed on the ocean surface while CDP may forage at depths of up to 30 m [ 37 ], potentially facilitating avoidance of interspecific competition for food [ 38 ].…”