Gavin Arneill (School of Biological, Earth and Environmental Sciences, University College Cork, Ireland) and colleagues have written for the journal Ibis on the use of recording sound to monitor Manx Shearwaters Puffinus puffinus.

The paper’s abstract follows:

“Passive acoustic monitoring is increasingly used as a cost‐effective way to study wildlife populations, especially those that are difficult to census using conventional methods.  Burrow‐nesting seabirds are amongst the most threatened birds globally, but they are also one of the most challenging taxa to census, making them prime candidates for research into such automated monitoring platforms.  Passive acoustic monitoring has the potential to determine presence/absence, or quantify burrow‐nesting populations, but its effectiveness remains unclear.  We compared passive acoustic monitoring, tape‐playbacks, and GPS tracking data to investigate the ability of passive acoustic monitoring to capture unbiased estimates of within‐colony variation in nest density for the Manx Shearwater Puffinus puffinus.  Variation in acoustic activity across twelve study plots on an island colony was examined in relation to burrow density and environmental factors across two years. As predicted fewer calls were recorded when wind speed was high, and on moon‐lit nights, but there was no correlation between acoustic activity and the density of breeding birds within the plots as determined by tape‐playback surveys. Instead, acoustic indices correlated positively with spatial variation in the in‐colony flight activity of breeding individuals detected by GPS. Though passive acoustic monitoring has enormous potential in avian conservation, our results highlight the importance of understanding behaviour when using passive acoustic monitoring to estimate density and distribution.”

Reference:

Arneill, G.E., Critchley, E.J., Wischnewski, S., Jessopp, M.J. & Quinn, J.L. 2019.  Acoustic activity across a seabird colony reflects patterns of within‐colony flight rather than nest density.  Ibis doi.org/10.1111/ibi.12740.

John Cooper, ACAP Information Officer, 25 June 2019

The ACAP-listed globally Vulnerable Pink-footed Shearwater Ardenna creatopus migrates northwards from its breeding sites on islands off southern Chile as far north as Canadian waters.  Noting that the shearwater has suffered significant declines due to nest predation by introduced predators, exploitation by humans and habitat degradation at its breeding sites, Canada had given the bird a nationally Threatened* status in terms of its Species at Risk Act (SARA).

The purpose of SARA is to protect wildlife species at risk in Canada.  The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) was established as an independent body of experts within SARA responsible for identifying and assessing wildlife species considered to be at risk.  Species that have been designated by COSEWIC may then qualify for legal protection and recovery under SARA.

In November 2016 the shearwater’s national status was re-assessed by COSEWIC as Endangered (defined as facing imminent extirpation or extinction) from its previous 2004 category of Threatened (click here).  The bird was first listed as Threatened in 2005 following a 2004 assessment by COSEWIC.

The order amending Schedule 1 to the Species at Risk Act upgrading the Pink-footed Shearwater from Threatened to Endangered has now been published in the Canada Gazette, Part II Vol. 153 No. 11 on 29 May 2019.  Click here for Canada’s species profile for the Pink-footed Shearwater.

Pink-footed Shearwaters, photographs by Oikonos & Peter Hodum

Canada is not a Party to ACAP but regularly sends an observer to attend and contribute to its meetings.

With thanks to Ken Morgan.

John Cooper, ACAP Information Officer, 24 June 2019

*Note that Canadian national categories of threat do not match those used internationally by BirdLife International and IUCN.  BLI/IUCN ‘Vulnerable’ is approximately the equivalent of COSEWIC ‘Threatened’;  BLI/IUCN ‘Critically Endangered’ and ‘Endangered’ are roughly the same as COSEWIC ‘Endangered’.

The Lord Howe Island Rodent Eradication Project aims to eradicate introduced Ship Rats Rattus rattus and House Mice Mus musculus from Australia’s inhabited and World Heritage Lord Howe Island, inter alia to help protect its breeding populations of petrels and shearwaters (click here).

Following a number of years of planning and discussions and consultations with the island community, the eradication got underway this austral winter combining the use of poison bait boxes and hand broadcasting of bait in inhabited, cultivated and pastoral areas and aerial baiting by helicopter over the mountainous parts that support natural vegetation (click here).

Different rodent baiting zones on Lord Howe Island

Keith Springer, Technical Advisor for the project has written to ACAP Latest News: “we completed the first bait drop last week, starting on Saturday [8 June] and finishing on Wednesday [12 June] morning.  Tuesday was too windy.  Now we await another window of reasonable weather to get the second application out.”  Hand broadcasting of baiting had commenced around the same time with the filling of some 28 000 bait boxes taking place earlier from 22 May.  Following the first round, project sweep teams have been checking recreational areas, the school, playground, family areas and walking tracks and removing any bait pellets which may have been dropped by rodents overnight as well as any carcasses found.  The bait boxes will be checked and topped up, initially once a week, then at two-week intervals for a further two months. 

The second round of aerial baiting and ground broadcasting are due to take place 10-21 days after the first operation and may take place from this week.  So far results of the first round seem promising, according to news received from an island resident: “the forest has a smell of dead rats; and teams are searching tracks and settlement for signs of any off-target species deaths".   It appears very few have been found so far.  Two Australian Masked Owls Tyto novaehollandiae  have been affected by secondary poisoning; it is hoped that this introduced species can also be eradicated on the island.

.

A pair of Flesh-footed Shearwaters Ardenna carneipes (globally Near Threatened and a proposed candidate for ACAP listing) on Lord Howe Island

Photograph by Ian Hutton

 Read a popular article on the eradication here

ACAP’s Information Officer has had a long-time yen to visit Lord Howe.  If he does he hopes to see the island and its petrels and shearwaters free from introduced rats and mice.

With thanks to Ian Hutton and Keith Springer.

John Cooper, ACAP Information Officer, 21 June 2019

Edin Whitehead (School of Biological Sciences, University of Auckland, New Zealand) and colleagues have published a report that comprehensively reviews and summarizes threats facing seabirds of northern New Zealand, including the Hauraki Gulf region and its many islands.  Among the 15 procellariform species included in the report are the ACAP-listed Near Threatened Buller’s Albatross Thalassarche bulleri (of the northern subspecies platei) and globally Vulnerable Black Petrel Pterodroma parkinsoni.  The Near Threatened Flesh-footed Shearwater Ardenna carneipes, identified as a candidate species for listing within the Agreement (click here), is also considered.  The authors write:

“This report aims to assess current and emerging threats to seabirds in Northern New Zealand, particularly the wider Hauraki Gulf region, and to identify knowledge gaps. In doing so, both research and conservation action can be prioritized to best mitigate threats to seabirds in the region. Consequently, the report aims to answer three basic questions:

What are current threats to seabirds in Northern New Zealand?

What are the knowledge gaps regarding seabird species in Northern New Zealand?

What are the knowledge gaps regarding threats to seabirds in Northern New Zealand?”

Both land-based and at-sea threats are covered, importantly including fishery interactions and introduced terrestrial predators, as well as pollution, disease, human disturbance and climate change.  Knowledge gaps in species’ biology and in the threats they face are also treated in the 76-page, illustrated report.

The illustration on the report's front cover shows a Black Petrel caught on a hookless line during experiments on petrel and shearwater behaviour around fishing vessels

Photograph by Richard Robinson

Reference:

Whitehead, E.A., Adams, N.[J.], Baird, K.A., Bell, E.A., Borrelle, S.B., Dunphy, B.J., Gaskin, C.P., Landers, T.J., Rayner, M.J. & Russell, J.C. 2019.  Threats to Seabirds of Northern Aotearoa New Zealand.  Auckland: Northern New Zealand Seabird Charitable Trust.  76 pp.

John Cooper, ACAP Information Officer, 20 June 2019