Gavin Arneill (School of Biological, Earth and Environmental Sciences, University College Cork, Ireland,) and colleagues have published in the open-access journal PLoS ONE on sampling strategies for breeding Manx Shearwaters Puffinus puffinus (Least Concern).

The paper’s abstract follows:

“Sampling approaches used to census and monitor populations of flora and fauna are diverse, ranging from simple random sampling to complex hierarchal stratified designs. Usually the approach taken is determined by the spatial and temporal distribution of the study population, along with other characteristics of the focal species. Long-term monitoring programs used to assess seabird population trends are facilitated by their high site fidelity, but are often hampered by large and difficult to access colonies, with highly variable densities that require intensive survey. We aimed to determine the sampling effort required to (a) estimate population size with a high degree of confidence, and (b) detect different scenarios of population change in a regionally important species in the Atlantic, the Manx shearwater (Puffinus puffinus). Analyses were carried out using data collected from tape-playback surveys on four islands in the North Atlantic. To explore how sampling effort influenced confidence around abundance estimates, we used the heuristic approach of imagining the areas sampled represented the total population, and bootstrapped varying proportions of subsamples. This revealed that abundance estimates vary dramatically when less than half of all plots (n dependent on the size of the site) is randomly subsampled, leading to an unacceptable lack of confidence in population estimates. Confidence is substantially improved using a multi-stage stratified approach based on previous information on distribution in the colonies. In reality, this could lead to reducing the number of plots required by up to 80%. Furthermore, power analyses suggested that random selection of monitoring plots using a matched pairs approach generates little power to detect overall population changes of 10%, and density-dependent changes as large as 50%, because variation in density between plots is so high. Current monitoring programs have a high probability of failing to detect population-level changes due to inappropriate sampling efforts. Focusing sampling in areas of high density with low plot to plot variance dramatically increases the power to detect year to year population change, albeit at the risk of not detecting increases in low density areas, which may be an unavoidable strategy when resources are limited. We discuss how challenging populations with similar features to seabirds might be censused and monitored most effectively.”

A Manx Shearwater chick close to fledging at its burrow mouth, photograph by Jaclyn Pearson

Reference:

Arneill, G.E., Perrins, C.M., Wood, M.J., Murphy, D., Pisani, L., Jessopp, M.J. & Quinn, J.L. 2019.  Sampling strategies for species with high breeding-site fidelity: a case study in burrow-nesting seabirds.  PLoS ONE 14(8): e0221625. doi.org/10.1371/journal.pone.0221625.

John Cooper, ACAP Information Officer, 16 September 2019

The Hawaiian State Department of Land and Natural Resources (DLNR) recently announced that that the population of invasive Pacific Rats Rattus exulans on Lehua Island “remains extremely low” two years after three aerial applications of the rodenticide Diphacinone in 2017 (click here).

Lehua Island from the air

The 126-ha island, designated as a State Seabird Sanctuary, has supported small populations of Black-footed Phoebastria nigripes and Laysan P. immutabilis Albatrosses since at least 2002.  A few rat sightings from fixed cameras were made last year (click here) but no signs of rats eating eggs or chicks have been found since the last bait drop in September 2017.  However, although “no rats have been detected by camera since December 2018, or seen in traps or tracking tunnels ... the monitoring team in early-to-mid 2019 detected what appeared to be rat fecal pellets”.

DLNR field teams will continue to make regular monthly monitoring trips to Lehua and will do spot treatments if rats are detected.

Read more here.

John Cooper, ACAP Information Officer, 13 September 2019

The first World Albatross Day is set to be celebrated on 19 June next year following support expressed by ACAP, as it aligns well with the aim of giving the Agreement greater visibility to address the conservation crisis facing albatrosses and petrels (click here).

Over the years, ACAP Latest News has reviewed half a dozen or so illustrated children’s books that have albatrosses as their central theme; all with an important conservation message.  After reaching out to them, four authors have written quotes in support of the inaugural World Albatross Day.  Their quotes follow.

Heidi Auman - Garbage Guts

“The inauguration of World Albatross Day offers me quiet hope that humanity will turn its eyes skyward to these inspiring seabirds and grant them the protections they need."

Maria Gill - Toroa’s Journey

“Whenever I unfold a three-metre wide life-size picture of an albatross schoolchildren gasp and their mouths drop open; they are utterly amazed and have a newfound respect for the albatross.  World Albatross Day is a fantastic way to bring more awareness for the conservation of these magnificent birds.”

Caren Loebel-Fried - A Perfect Day for an Albatross

“The albatross has long been my muse.  Traveller of vast distances on long, thin, glider wings, passionate dancer, exuberant vocalizer, so committed to a mate and a youngster.  I’ve been lucky to know albatrosses, but their lives are mostly hidden from us humans.  Our lack of awareness makes them even more vulnerable than they already are.  World Albatross Day, a yearly celebration of these incredible creatures, brings the albatross into our lives, and knowledge can spark the desire to protect our natural world.”

Darcy Pattison - Wisdom the Midway Albatross: Surviving the Japanese Tsunami and other Disasters for over 60 Years

"I first learned about albatrosses after the Japanese tsunami when I wrote Wisdom the Midway Albatross, the story of the oldest known wild bird in the world and how she survived the tsunami.  Her survival for over sixty-five years - in spite of storms, pollution, and questionable fishing practices - continues to surprise and inspire scientists.  Wild creatures such as the Laysan Albatross mean our planet is healthy.  We will happily join with others to celebrate World Albatross Day on 19 June 2020."

With thanks to Heidi Auman, Maria Gill, Caren Loebel-Fried and Darcy Pattison.

John Cooper, ACAP Information Officer, 12 September 2019

Last week the Gough Island Restoration Programme got underway to rid the island of its introduced House Mice Mus musculus that attack and kill chicks of the Critically Endangered and near-endemic Tristan Albatross Diomedea dabbenena (and of other of the island's breeding birds).  South Africa's Antarctic ship, the S.A. Agulhas II, sailed from Cape Town on its annual relief voyage to Gough Island on 2 September with a five-person advance party from the UK’s Royal Society for the Protection of Birds (RSPB) and BirdLife South Africa's Seabird Conservation Programme aboard to start setting up for next year's planned eradication of the mice.

Tristan Albatross chick severely wounded by mice, photograph by Karen Bourgeois & Sylvain Dromzee

The team is taking out materials for erecting aviaries for protecting the island’s two species of threatened land birds during the poison bait drop and an emergency hut manufactured by South Africa, as well as needed equipment such as tents.  Listen to a dockside video clip featuring Team Leader Andrew Callender filmed by the Antarctic Legacy of South Africa project.

John Cooper, ACAP information Officer, 11 September 2019