Stephanie Borrelle (Institute for Applied Ecology New Zealand, Auckland University of Technology, Auckland, New Zealand) and colleagues has published in the journal Oryx on how well seabirds recover after their islands are freed of invasive predators.

The paper’s abstract follows:
“Protecting 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 the presence of introduced predators, which depredate seabirds at all life stages, from eggs to adults. Consequently, eradication of invasive predators has been identified as an effective and commonly used approach to seabird conservation. Seabird recovery following the eradication of predators is influenced by complex and interacting environmental and demographic factors, and there are gaps in our understanding of species-specific responses. We reflect on the recovery of seabirds on islands cleared of predators, drawing on the equilibrium theory of island biogeography, and synthesize key influences on recovery reported in the literature. We present a regionally specific case study on the recovery of seabird colonies (n = 98) in the Hauraki Gulf, New Zealand, which is a hotspot of seabird diversity (27 species), with a long history of eradications of invasive predators. We found that on islands cleared of predators seabirds recover over time, and such islands have more diverse seabird assemblages than islands that never had predators. Recovery appears to be influenced by a suite of site- and species-specific factors. Managers may assume that given enough time following eradication of predators, seabirds will recolonize an island. Although time is a factor, proximity to source populations and human activities has a significant effect on recolonization by seabirds, as do demographic traits, colonizing ability and habitat suitability. Therefore, integrating expected site and species-specific recovery responses in the planning of eradications should help guide post-eradication management actions.”

House Mice have killed this Atlantic Petrel chick on Gough Island, photograph by Ross Wanless

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.org/10.1017/S0030605316000880.

John Cooper, ACAP Information Officer, 30 December 2016

ACAP Latest News reported a year ago on the killing of Laysan Albatrosses Phoebastria immutabilis breeding in the Ka'ena Point Natural Area Reserve on the Hawaiian island of Oahu by intruders entering the fenced area at night.  Eggs were also smashed and recording and attracting equipment removed (click here).

One of the Laysan Albatrosses found dead after the event next to its egg, photograph from Pacific Rim Conservation

The miscreant?  A trail-side camera catches an intruder on the night of the killings

News is now in that after a year a 19-year-old man has been arrested in connection with the incident. He turned himself in, was booked and released on [US]$25,000 bail.  He faces 19 criminal counts.  They include 14 counts of animal cruelty, as well as criminal property damage, theft and engaging in a prohibited act in a state nature reserve.

The accused albatross killer pleaded not guilty in his first court appearence this week (click here).  The trial date has been set for 27 February.  The accused's defence attorney has stated that my client "was camping at Kaena Point with schoolmates from Punahou.  He was there when this happened but he did not injure any birds. He didn’t do it. He didn’t maim or touch the animals, period.”  The attorney said another of the accused's schoolmates was responsible for the albatross slaughter.

Two other suspects, then schoolmates of the adult accused and who were minors at the time of the incident, have also been arrested.  Their cases are to be handled in a juvenile court.

Pacific Rim Conservation which monitors Kaena Point's albatrosses and was responsble for the Kaena Point Ecosystem Restoration Project which resluted in the erection of a predator-proof fence reports on a positive outcome of the incident:

"In many ways our hearts are no less broken than they were last year and we are still grieving. But there have been some silver linings to this. We have seen a change in all of you who regularly hike out to Kaena - bad behavior is not tolerated out there anymore and we see folks regularly taking it upon themselves to teach good behavior to others. We receive a lot more questions when we are working out there which is good. We encourage you to always ask questions, even of the folks who appear to be working off trail- anyone working in the reserve will always come over to talk to you and explain what they are doing if asked. If you see something you don’t feel comfortable with addressing- call DOCARE- their number is 643-DLNR. Those of you who hike out to Kaena are the eyes and ears and together we can work together to try and keep that area safe for our wildlife. Aloha and Mahalo you for all of your support over the last year."

Read more here.  ACAP Latest News will report on the outcome of the trial.

Kaena Point predator-proof fence, photograph by Lindsay Young

Laysan Albatrosses at Kaena Point in happier times, photograph by Lindsay Young

John Cooper, ACAP Information Officer, 29 December 2016

Dominic Rollinson (FitzPatrick Institute, University of Cape Town, South Africa) and colleagues submitted a meeting document to the 19th Session of the Indian Ocean Tuna Commission’s Scientific Committee, held recently in the Seychelles.  The document reviews seabird bycatch mitigation measures, including experimental work, within South Africa’s tuna longline fishery.

The document’s abstract follows:

“Both foreign and domestic pelagic longline fleets operate in South Africa’s Exclusive Economic Zone (EEZ) and adjacent international waters. Roughly 360 birds are killed each year by the longline fleets operating off South Africa; this includes bycatch from observed Japanese vessels, observed South African vessels and extrapolations of observed to unobserved South African vessels, between 2010 and 2013. This rate was even higher for the entire period between and 2013 when seabird bycatch averaged c. 450 birds per year. Permit conditions apply equally to domestic and foreign longline vessels, and are aligned with IOTC Resolution 12/06. Specifically, vessels must use two of three measures: bird-scaring lines, night setting or line-weighting. The domestic fleet typically uses 60-80 g swivels and sets exclusively at night, therefore they seldom use bird-scaring lines. Japanese-flagged vessels employ line weighting (60 g within 2.8 m of the hook) and bird-scaring lines, with most sets partially conducted at night and part during daylight (in international waters only). Encouragingly, concurrent with 100% observer coverage, significant reductions in seabird bycatch rates have occurred in this fleet after 2007, and the resultant bycatch rates now approximate the national target (0.05 birds per 1000 hooks). South Africa has also encouraged significant research into new or improved seabird bycatch mitigation options. These include research into sliding leads, hook pods and smart tuna hooks. Through the FAO’s Common Oceans Tuna Project (or ABNJ project), South Africa is piloting port-based outreach to foreign-flagged tuna longline vessels that offload, refuel or revictual in Cape Town harbor. The outreach is specifically to provide information to skippers on Regional Fisheries Management Organisation (RFMO) regulations and to explain available bycatch mitigation options.”

A Black-browed Albatross succumbs to a longline hook and drowns, photograph by Graham Robertson 

Reference:

Rollinson, D.P., Wanless, R.M., Makhado, A.B. & Crawford, R.J.M. 2016.  A review of seabird bycatch mitigation measures, including experimental work, within South Africa’s tuna longline fishery.  IOTC-2016-SC19-13 Rev_1.  9 pp.

John Cooper, ACAP Information Officer, 28 December 2016

The Smithsonian Magazine has published an article on line that discusses seabird mortality from three types of fishing: longlining, trawling and gill netting.  “Changes as basic as adding a colorful streamer to commercial longline fishing boats could save thousands of seabirds a year”.

The article, written by Emily Eng and Whitney Pipkin, comes with three clear and well-drawn graphics by Emily that illustrate the problem – and what can be done to mitigate it – for each fishing type, and serves as a good introduction to the issue to share with friends and colleagues who may not be well informed.  Mitigation measures described include the use of bird-scaring lines by both longliners and trawlers, line weighting and night setting.  The longline fishing graphic is given as an example.

With thanks to Mi Ae Kim, Office of International Affairs and Seafood Inspection, National Marine Fisheries Service, USA.

Reference:

Eng, E. & Pipkin, W. 2016.  These simple fixes could save thousands of birds a year from fishing boats.  Smithsonian Magazine 22 August 2016.

John Cooper, ACAP Information Officer, 27 December 2016