No abstract

Petrels are highly mobile seabirds that face many threats and whose conservation is frequently hampered by a lack of understanding of their biology at sea. We used a combination of data from burrow monitoring and geolocationimmersion loggers to study the intra-and inter-seasonal distribution and behaviour of the endangered Chatham Petrel (Pterodroma axillaris), breeding on Rangatira Island, New Zealand. Breeding extended from November to June with a prelaying exodus of 35 days; an incubation period of 46 days, with up to five incubation shifts; and a chick-rearing period of 87 days, including a desertion period of 10 days. When breeding, Chatham Petrels foraged between the Subtropical Convergence and Subantarctic Fronts, moving 2000-3000 km to the south-east of the Chatham Islands, during the pre-laying exodus and incubation period, but restricting foraging to the south of the Chatham Islands, around the Bollons Seamount, during chick-rearing. Between April and June birds migrated east and north to core non-breeding distributions~1000 km from the coast of Peru and Chile. Birds spent a greater proportion of time resting and nocturnally active during the nonbreeding period than when breeding, when birds where active during darkness and daylight. These data contribute to the conservation management of the Chatham Petrel and to conservation initiatives to identity marine protected areas for endangered seabirds on the high seas beyond national jurisdictions.

a b s t r a c tConservation of gadfly petrels, some of the most threatened seabirds, is frequently dependent on long-term research and management. We review 20 years of a program preventing the extinction of the Chatham petrel (Pterodroma axillaris), a New Zealand endemic once declining due to intense burrow competition from another native seabird. Breeding success in the early 1990s was unsustainably low (10-30%). Recovery measures started in 1992 when Chatham petrel burrows were converted and artificial entrances blockaded to exclude broad-billed prions (Pachyptila vittata). Pair and burrow fidelity were enhanced, though prions still posed a threat during Chatham petrel chick-rearing. Breeding success improved when prions were culled, however a less intensive and contentious solution was to introduce burrow flaps in 2001 which reduced interference from prospecting prions. Subsequently, breeding success increased to a mean 80% per annum. Finding burrows, primarily using radio-telemetry, increased those under management from eight in 1990 to 217 in 2010 when spotlight surveys indicated 72% of juvenile birds had fledged from managed burrows. Chick translocations to two other islands and increasing population size (from 200-400 birds in 1990 to an estimated 1400 birds by 2010) has improved the species IUCN status from Critically Endangered in 1990 to Endangered in 2013.

No abstract

Context Oil spills cause significant detrimental impacts on many shoreline species. There is limited information in the scientific literature about the management and response of shorebirds to oil spills. Northern New Zealand dotterels (Charadrius obscurus aquilonius) were pre-emptively captured as part of the oiled wildlife response to the container vessel Rena oil spill, to ensure the survival of a regional population should there be a catastrophic release of oil. Previous attempts to hold dotterels in captivity have resulted in high mortality. Aims To describe the captive husbandry and veterinary management of wild-caught adult dotterels, to outline the common problems encountered, and make recommendations for future captive management. Methods The dotterels were caught by noose mat on beaches at risk of further contamination by oil. Initially, dotterels were kept individually indoors and force-fed until they converted to self-feeding on a diet of an artificial insect analogue, ox heart and mealworms. Once self-feeding, the birds were shifted to individual outdoor aviaries. Key results Sixty dotterels were caught. About half of birds had oil contamination of the legs, nine birds had light oil staining of feathers and only three of these birds required washing. The degree of oiling and washing did not affect survival. Dotterels took a median of 5 days (range 1–15 days) to convert to the captive diet. Common problems encountered in captivity included carpal and beak abrasions (61.7%) and pododermatitis (75%); however, these did not affect survival. Seven birds (11.7%) developed respiratory disease and six of these died from aspergillosis. The incidence of aspergillosis increased with length of time in captivity and was largely refractory to treatment. The 54 surviving birds were released at their capture sites after a median time of 49 days in captivity (with a range of 39–61 days). Conclusions The captive management of the dotterels achieved a 90% survival rate over a period of about 2 months. Deaths were solely due to respiratory aspergillosis, but intensive captive husbandry was required to convert the birds to a captive diet, to minimise traumatic injuries and to manage pododermatitis. Implications Although the captive management of shorebird species as a pre-emptive strategy to minimise the effects of oil spills carries significant costs and risks to the birds, it should be considered in the emergency management of high-priority species.

No abstract