Lehua, an eroded tuff cone, now free of rats

Lehua is a 126-ha crescent-shaped island in the USA’s Hawaiian Islands.  The uninhabited island supports small breeding populations of Black-footed Phoebastria nigripes and Laysan P. immutabilis Albatrosses, as well as of several shearwater and petrel species (click here) and, until now, Pacific Rats Rattus exulans.

Following an over a decade-long effort the island has now been declared free of introduced rodents as recently reported by the Hawaiian Department of Land and Natural Resources.

The department reports: “After extensive on-island monitoring, we’re 99.99% certain there are no more rats on Lehua, which builds on the successful removal of invasive herbivorous rabbits and secures a future for Hawai’i’s wildlife and ecosystems.  Following the [second] eradication attempt in 2017 a monitoring effort using motion sensor cameras to detect rat presence or absence was initiated with a team regularly returning to Lehua to treat small areas with bait and to set traps in response to any rat sightings.  Rats have not been detected on the island for over two years.  April 2021 marks the one-year anniversary since all rat-control treatments were removed from the island, adding to the data that allows us to declare Lehua rat-free.”

Black-footed and Laysan Albatrosses on Lehua, photographs by Lindsay Young

Read more details and comments on the successful eradication by the DLNR and partner Island Conservation and watch a short video entitled Success! Lehua Island is Rat Free.

John Cooper, ACAP Information Officer, 29 April 2021

Orion, a Black-browed Albatross chick about to fledge, is to be tracked at sea; photograph by James Crymble

The satellite-tracking of 19 juvenile Black-browed Albatrosses Thalassarche melanophris (Least Concern) from Bird Island in thge South Atlantic is a collaborative study between the British Antarctic Survey and BirdLife International, with the devices being funded by the South Georgia Heritage Trust and Friends of South Georgia Island.  The project will provide new data on habitat use and fisheries overlap (poorly known for non-adult birds) of the population, which is in steep decline, having nearly halved overall from over 100 000 pairs in 1985 to just 54 000 pairs in 2021.  Although the species is not listed as globally threatened, this decrease has been so rapid that the birds are listed as one of 10 priority populations for conservation, by ACAP (click here).

The movements of fledglings in their first few months at sea can be followed on an online map which updates in near-real time. The first chick has recently fledged as reported by Richard Phillips of the British Antarctic Survey to ACAP Latest News, now followed by others, as shown on the map below.  According to the Albatross Task Force Facebook page “Orion’s bags are almost packed, and a fancy tracker to go with them!  We’re going to be able to follow Orion and his colony mates as they venture from Bird Island.  Orion was a perfect candidate weighing in at a whopping 4.5kg.”

The story so far: the fledglings are moving northwards from Bird Island

Meanwhile Nova, a Vulnerable Wandering Albatross Diomedea exulans chick that was followed from hatching to fledging on Bird Island throughout 2020 and was being tracked at sea after fledging has stopped transmitting and may no longer be alive as reported by the same Facebook page.  This serves as a reminder of the threats albatrosses face at sea from fisheries, especially longlining.

Lost at sea?  Nova the Wandering Albatross prior to fledging; photograph by Alex Dodds

For more details of the at-sea tracking and to view the online map visit the project’s web page.

With thanks to Richard Phillips, British Antarctic Survey.

John Cooper, ACAP Information Officer, 28 April 2021

Taking a dip. The rescued Laysan Albatross at the Hawaii Wildlife Center

A Laysan Albatross or Mōlī Phoebastria immutabilis (globally Near Threatened) was collected from a road in the Mokuleia Beach Park on the Hawaiian island of Oahu in late March by officers of the Honolulu Police Department with an injured wing.  The team at the Feather and Fur Animal Hospital in Kailua on Oahu stitched up the wound and stabilized the bird for transport by air to the Hawaii Wildlife Center (HWC) on the ‘big island’ of Hawaii.  Following a period in care and banding the albatross was released by HWC staff with the help of Kohala Divers, who shuttled the patient out to the release spot (watch a video of the release).

"Somewhere over the rainbow Mōlīs moooo, sending Aloha Friday good vibes, from HWC to youuuu" (Hawaii Wildlife Center)

With thanks to Linda Elliott and Rae Okawa, Hawaii Wildlife Center.

John Cooper, ACAP Information Officer, 27 April 2021

L-R: Atlantic and Indian Yellow-nosed Albatrosses together on Gough Island, photograph by Chris Jones (click here)

Dilini Abeyrama (University of Lethbridge, Alberta, Canada) and colleagues have published in the journal Conservation Genetics on the genetics of two species of Atlantic Thalassarche chlororhynchos and Indian T. carteri yellow-nosed albatrosses.

The paper’s abstract follows:

“The two species of yellow-nosed albatross, Atlantic (Thalassarche chlororhynchos) and Indian (T. carteri), are morphologically similar, but they differ in breeding behaviour and distribution. Both species are listed as endangered by the IUCN due to the limited number of breeding sites, threats from introduced predators and diseases, and impact of commercial fishing. We quantified genetic variation between and within the two species. Using nuclear (microsatellites and two nuclear sequences) and mitochondrial (control region) markers, we analysed 354 samples from four breeding islands (Atlantic: Nightingale, Inaccessible, and Gough; Indian: Amsterdam) and bycatch samples from South Africa and New Zealand. In addition to all markers separating the two species, nuclear markers showed Atlantic yellow-nosed albatrosses from Gough Island are genetically distinct from those breeding at Nightingale and Inaccessible Islands in the Tristan da Cunha archipelago. Nuclear markers confirmed that all bycatch samples were Indian yellow-nosed albatrosses, however, the bycatch birds from South Africa and New Zealand were distinct from each other and from birds breeding on Amsterdam Island, suggesting colony specific dispersal at sea. Our study supports the current recognition of two yellow-nosed albatross species and recognises genetically distinct groups of both Atlantic and Indian yellow-nosed albatross breeding on different islands, which is important for their conservation and management.”
Reference:

Abeyrama, D.K., Dempsey, Z.W., Ryan, P.G. & Burg, T. 2021.  Cryptic speciation and population differentiation in the yellow-nosed albatross species complex. Conservation Genetics doi.org/10.1007/s10592-021-01358-x.

John Cooper, ACAP Information Officer, 26 April 2021