Stephanie Borrelle (Institute for Applied Ecology New Zealand, Auckland University of Technology, Auckland, New Zealand) and colleagues have published “pre-press” in the journal Oryx on how New Zealand seabirds islands are recovering after the removal of alien predators.

The paper’s abstract follows:

“Protecting the world’s seabirds is a global conservation priority given that 29% of seabird species are threatened with extinction. One of the most acute threats to seabirds is introduced predators, which depredate seabirds at all life stages from eggs to adults. Consequently, invasive predator eradication has been identified as an effective and commonly used seabird conservation method. Seabird recovery post-eradication is influenced by complex and interacting environmental and demographic factors, though gaps remain in our understanding of species-specific responses. Here, we reflect on the recovery of seabirds to islands cleared of predators by drawing on the equilibrium theory of island biogeography and synthesise key influences on recovery reported in the literature. To illustrate this synthesis, we present a regionally specific case study on the recovery of seabird colonies (n=98) in the Hauraki Gulf, New Zealand; a seabird diversity hotspot (27 species), which has a long history of invasive predator eradications. We found that islands cleared of predators show recovery of seabirds over time, and surprisingly had more diverse seabird assemblages than islands that never had predators. This recovery appears to be influenced by a suite of site- and species- specific factors. Managers may assume that given enough time following an eradication, seabirds will recolonise. While time is a factor, island spatial distribution has a significant effect on the recolonisation of seabirds, in addition to demographic traits, colonizing ability and habitat suitability.  Therefore, integrating expected site and species-specific recovery responses into planning seabird island eradications could help guide post-eradication management actions.”

Vulnerable Black Petrel Procellaria parkinsoni, a Hauraki Gulf breeder and an ACAP-listed species, photograph by David Boyle

Reference:

Borrelle, S.B., Boersch-Supan, P.H., Gaskin, C.P & Towns, D.R. 2016.  Influences on recovery of seabirds on islands where invasive predators have been eradicated, with a focus on Procellariiformes.  Oryx doi:10.1017/S0030605316000880.

Supplementary information.

John Cooper, ACAP Information Officer, 01 March 2017

Lucas Krüger (Marine and Environmental Science Centre, Department of Life Sciences, University of Coimbra, Coimbra, Portugal) and colleagues have published in the journal Animal Conservation on using the at-sea seasonal distribution of 14 procellariform seabird species to choose pelagic MPAs in the in the south-west Atlantic.

The paper’s abstract follows:

“With increasing pressure on the oceans from environmental change, there has been a global call for improved protection of marine ecosystems through the implementation of marine protected areas (MPAs). Here, we used species distribution modelling (SDM) of tracking data from 14 seabird species to identify key marine areas in the southwest Atlantic Ocean, valuing areas based on seabird species occurrence, seasonality and extinction risk. We also compared overlaps between the outputs generated by the SDM and layers representing important human threats (fishing intensity, ship density, plastic and oil pollution, ocean acidification), and calculated loss in conservation value using fishing and ship density as cost layers. The key marine areas were located on the southern Patagonian Shelf, overlapping extensively with areas of high fishing activity, and did not change seasonally, while seasonal areas were located off south and southeast Brazil and overlapped with areas of high plastic pollution and ocean acidification. Non-seasonal key areas were located off northeast Brazil on an area of high biodiversity, and with relatively low human impacts. We found support for the use of seasonal areas depending on the seabird assemblage used, because there was a loss in conservation value for the seasonal compared to the non-seasonal approach when using ‘cost’ layers. Our approach, accounting for seasonal changes in seabird assemblages and their risk of extinction, identified additional candidate areas for incorporation in the network of pelagic MPAs.”

Wandering Albatross - one of the studied species, photograph by John Chardine

Reference:

Krüger, L., Ramos , J.A., Xavier, J.C., Grémillet , D. González-Solıs, J. Kolbeinsson , Y. Militão, T., Navarro , J. Petry, M.V., Phillips, R.A., Ramírez, I., Reyes-González , J.M., Ryan, P.G., Sigurðsson, I.A., Van Sebille, E., Wanless, R.M. & Paiva, V.H. 2017.  Identification of candidate pelagic marine protected areas through a seabird seasonal-, multispecific- and extinction risk-based approach.  Animal Conservation  doi:10.1111/acv.12339.

John Cooper, ACAP Information Officer, 28 February 2017

Graham Parker (Parker Conservation, Dunedin, New Zealand) and colleagues have published in the journal Antarctic Science on the population of Near Threatened and ACAP-listed Grey Petrels Procellaria cinerea at New Zealand’s Campbell Island.

The paper’s abstract follows:

“Populations of grey petrels have declined globally due to both incidental capture in commercial fisheries and predation by introduced mammals at breeding sites. In the New Zealand region, grey petrels only breed on Campbell and Antipodes islands. Rats were successfully eradicated from Campbell Island in 2001.We assessed the spatial extent and conducted the first quantitative population estimate of the grey petrel population on Campbell Island and surrounding islets. There was an estimated c. 96 pairs (95% CI: 83, 109) of breeding grey petrels from the four colonies. Since work was conducted during the middle of the chick-rearing stage, this is an underestimate of the breeding population. The Campbell Island grey petrel breeding population remains small. Our study provides a baseline for future population estimates of grey petrels on Campbell Island.”

Graham Parker surveys Grey Petrels on Campbell Island

Read more on the survey here.

Reference:

Parker, G.C., Rexer-Huber, K. & Thompson, D. 2016.  Grey petrel population on Campbell Island 14 years after rodent eradication.  Antarctic Science  doi:10.1017/S0954102016000626.

John Cooper, ACAP Information Officer, 27 February 2017

ACAP Latest News has previously reported on plans to move Black-footed Albatross Phoebastria nigripes chicks from low-lying Midway Atoll to be artificially reared in the James Campbell Wildlife Refuge on Oahu.  The aim of the project is to create a new breeding colony that will not be at risk to sea-level rise (click here).

Black-footed Albatross, photograph by Lindsay Young

We can now report that 15 chicks were collected on Midway last week from nests close to the sea’s edge and thus deemed to be at risk to wash-over by big waves from storms by members of the environmental NGO Pacific Rim Conservation.  Following a flight and a blessing, the downy chicks are now safely ensconced in their new home.

The chicks will be raised for the next five months in the hopes of starting the first Black-footed Albatross colony on a main Hawaiian island.  The exercise is intended to be repeated for the next three to five years “in order to move enough birds to start a new colony that is safe from sea level rise, and protected from predators within a newly fenced, predator-free area”. Click here for the full story and a suite of illustrations.

Pacific Rim Conservation is already involved in hand-rearing Laysan Albatross P. immutabilis chicks  in the James Campbell Wildlife Refuge that been hatched from eggs collected on the island of Kauai, with the third year of translocations now underway (click here).  In time, if all goes as planned, the refuge will support breeding populations of two albatross species safe from climate change.

John Cooper, ACAP Information Officer, 24 February 2017