At risk to cats: a breeding Galapagos Petrel in its burrow

Floreana is the sixth largest (at 17 250 ha) of Ecuador’s Galapagos Islands. The island has a population of 160 inhabitants and is an important tourist destination, notably to its historic Post Office Bay. It is also severely impacted by alien species, notably Black Rats Rattus rattus, House Mice Mus musculus and feral cats Felis sylvestris catus.

An example of this impact is for the Critically Endangered Galapagos Petrel Pterodroma phaeopygia which is endemic to the Galapagos Islands, breeding on Floreana, Isabela, San Cristóbal, Santa Cruz and Santiago. Floreana supports over 60% of the species’ global population. One study found almost 50% of Galapagos Petrel nests on Floreana were preyed upon by feral cats (and likely also by Black Rats) despite local control efforts.

A view of Floreana Island; photograph from Island Conservation

After nearly 12 years of planning, the Floreana Ecological Restoration Project has this month commenced restoring Floreana’s many native and endemic species by removing introduced Black Rats, House Mice and feral cats. According to the project’s operational plan the “combination of methods will include aerial- and ground-dispersed toxic rodent and cat baits (resulting in primary and secondary poisoning), trapping, and hunting with and without dogs”. Feral cattle, donkeys, goats and pigs have all previously been removed from Floreana by the Galapagos National Park Directorate.

“Every action has a reaction, and it has been well established that removing invasive species from islands paves the way for ecosystem recovery,” says Chad Hanson, Deputy Vice President Conservation at Island Conservation, and Implementation Advisor for the project. “The vision is for Floreana Island to not only recover but that the community, wildlife, as well as the immediate marine environment thrive as a result of this holistic intervention. As the restoration project moves from imagination to implementation, we’re excited to demonstrate what can be achieved by a community committed to their island home’s well-being.”

On 3 October, two Mosquito ultralight helicopters, adapted to be able to fly unmanned with suspended spreader buckets each able to lift 130-180 kg, began dispersing cereal bait pellets containing the rodenticide brodifacoum at predetermined transects from low altitude to ensure precise distribution over the island. Flights are scheduled to continue through the night. Both the use of unmanned helicopters and night baiting are thought to be novel for an island eradication. The initial bait application is set to span 10 days, covering the entire island, including its coastal cliffs. Three spaced applications are planned to achieve eradication. Aerial baiting targeting cats will commence using meat-based “sausages” containing Para-aminopropiophenone (PAPP) thereafter, scheduled for three applications using the Mosquito helicopters during daylight hours only. This is scheduled to continue until mid-December 2023. Ground baiting against rodents by hand-broadcasting and use of bait stations will occur in selected localities, such as around buildings, freshwater ponds, livestock pens, and in known caves and lava tunnels. Cage and leg-hold traps will also be used to target cats.

A Mosquito ultralight helicopter

“The Floreana Ecological Restoration Project represents the most significant endeavour in the history of the Galapagos National Park. Its success [will symbolize] a global conservation milestone that exemplifies the synergy between conservation and sustainable development, serving as an inspiring model for protected areas worldwide,” emphasized José Antonio Dávalos, the Ecuadorian Minister of Environment, Water, and Ecological Transition.

A Giant Tortoise on Floreana; photograph from Island Conservation

Once free of rodents and cats the project partners plan to reintroduce twelve locally extinct species to the island, phased over at least seven years and commencing with hybrid individuals of the Floreana Giant Tortoise Chelonoidis niger niger in early 2024. Reintroduction of terrestrial birds and a snake are set to follow as the island’s ecosystem recovers.

The Floreana Ecological Restoration Project is directed by the Ecuador Ministry of Environment, through the Galapagos National Park Directorate, in collaboration with the Floreana community and Agency for Biosecurity for Galapagos. It is being executed in collaboration with Fundación de Conservación Jocotoco (Jocotoco Conservation Foundation) and Island Conservation. The project is part of the Island-Ocean Connection Challenge, an ambitious campaign to restore 40 globally significant islands from ridge-to-reef by 2030. Read the complete media release on project initiation by Island Conservation here.

References:

Cruz, J.B. & Cruz, F. 1987. Conservation of the Dark-rumped Petrel Pterodroma phaeopygia in the Galápagos Islands, Ecuador. Biological Conservation 42: 303-311.

Hanson, C. & Campbell, K. 2013. Floreana Island Ecological Restoration: Rodent and Cat Eradication Feasibility Analysis. Santa Cruz: Island Conservation. 85 pp.

Hanson, C. & Campbell, K. 2020. Floreana Island Ecological Restoration: Rodent and Cat Eradication Operational Plan. Puerto Ayora: Island Conservation and Galapagos National Park Directorate. 93 pp.

John Cooper, Emeritus Information Officer, Agreement on the Conservation of Albatrosses and Petrels, 17 October 2023

A Southern Giant Petrel takes flight; photograph by Trevor Hardaker

Júlia Finger (PhD candidate Universidade do Vale do Rio dos Sinos, Brazil) and colleagues have published in the journal Antarctic Science on the habitat selection of Southern Giant Petrels in the Southern Ocean and their potential role  in monitoring the Antarctic Peninsula for practices such as illegal fishing.

Writing to ACAP Latest News, Julia said, “Breeding petrels used a large range of areas in the Peninsula, but also travelled to the tip of Tierra del Fuego in an area with fishing activities. This paper highlights how petrels, especially females, are susceptible to impacts of fisheries outside the Antarctic even during the breeding season and also how they connect both regions. We also propose that [Southern Giant Petrels] can be used as platforms to monitor the Antarctic Peninsula."

The paper’s abstract follows:

“The southern giant petrel (Macronectes giganteus) is a widely distributed top predator of the Southern Ocean. To define the fine-scale foraging areas and habitat use of Antarctic breeding populations, 47 southern giant petrels from Nelson Island were GPS-tracked during the summers of 2019–2020 and 2021–2022. Step-selection analysis was applied to test the effects of environmental variables on habitat selection. Visual overlap with seal haul-out sites and fishing areas was also analysed. Birds primarily used waters to the south of the colony in the Weddell and Bellingshausen seas. Females showed a broader distribution, reaching up to -70°S to the west of Nelson Island, while males were mainly concentrated in waters off the northern Antarctic Peninsula. Habitat selection of both sexes was associated with water depth and proximity to penguin colonies. Both overlapped their foraging areas with fishing sites and females in particular overlapped with toothfish fishery blocks in Antarctica and with fishing areas in the Patagonian Shelf. Due to their habitat associations and overlap with fisheries, when harnessed with tracking devices and animal-borne cameras, giant petrels can act as platforms for monitoring the condition and occurrence of penguin colonies, haul-out sites and unregulated fisheries on various temporal and spatial scales in Antarctica.”

An article on the paper has been published in the Polar Journal, here.

Reference:

Finger, J., Krüger, L., Corá, D., & Petry, M. (2023). Habitat selection of southern giant petrels: Potential environmental monitors of the Antarctic Peninsula. Antarctic Science, 35(4), 256-269. doi:10.1017/S0954102023000147

16 October 2023

Nicaraguan artist, Augusto Silva created the artwork for this year’s World Migratory Bird Day to reflect the campaign’s theme, “Water: Sustaining Bird Life”.

The first peak day for WMBD was celebrated earlier this year on 13 May, and this Saturday, 14 October, marks the second peak day for World Migratory Bird Day (WMBD). The observance of two celebratory days for WMBD reflects the seasonal nature of bird migration and differing migration patterns between the northern and southern hemispheres. This year's campaign, under the theme, “Water: Sustaining Bird Life”, is raising awareness of the growing water crisis facing migratory birds.

Water is critical for life on Earth, however increasing human demand for water, poor management, as well as pollution and climate change are threatening water quality and ecosystems across the globe. These threats are not only confined to fresh water, with saltwater ecosystems, which albatrosses and petrels are reliant, facing similar challenges.

“World Migratory Bird Day 2023 spotlights the vital role that water plays in the survival of our shared birds. The focal species illustrated on the campaign poster depict the intricate bond each bird shares with water. The diminutive Rufous Hummingbird thrives on nectar-producing flowers that rely on water for their blooms, and the Dickcissel scours the grasslands for seeds that hold the moisture they need. White Pelicans and Ospreys seek their prey in freshwater lakes, while the magnificent Wandering Albatross and Atlantic Puffin remain at sea. WMBD is an opportunity to unify our voices for the conservation of migratory birds and to celebrate their spectacular journeys". Dr. Susan Bonfield, Executive Director at Environment for the Americas (EFTA).

International cooperation is key to protecting the world’s water resources, and vital for the conservation of migratory birds. The recent adoption of a new global framework for the integrated management of chemicals and waste at the recent fifth International Conference on Chemicals Management (ICCM5) is one such example of the collaboration required to tackle these threats. 

Events celebrating World Migratory Bird Day are being held worldwide and can be found at the official World Migratory Bird Day website. Coinciding with WMBD is BirdLife International's Global Bird Weekend – a worldwide birdwatching and citizen science event organised with partners, Global Birding and eBird. More information about the Global Bird Weekend can be found, here.

WMBD is organised through a partnership between: The Convention on the Conservation of Migratory Species of Wild Animals (CMS), the African-Eurasian Migratory Waterbird Agreement (AEWA), the non-profit organization, Environment for the Americas (EFTA) and new partner, the East Asian-Australasian Flyway Partnership (EAAFP).

To learn more about this year’s World Migratory Bird Day campaign and to download posters and WMBD resources, visit www.worldmigratorybirdday.org.

13 October 2023

Lord Howe Island; photograph by Ian Hutton

UPDATE:  An early-review publication, recently available open access, details the success of taking two non-target land birds into temporary captivity on Lord Howe while the rodent eradication was underway.

O’Dwyer, T.W., Carlile, N., O’Neill, L., Fairlamb, H. & Bower, H. 2023.  Protection and mortality of non‑target terrestrial bird species during the eradication of rodents on Lord Howe Island.  Biological Invasions.  doi.org/10.1007/s10530-023-03161-w.

13 October 2023

Lord Howe Island is a World Heritage natural property situated some 600 km off the coast of New South Wales, Australia, in the Tasman Sea. The 1 455-ha island is inhabited by a resident population of 455 (in 2020), which can nearly double with the presence of tourists. The island supports important breeding populations of several species of shearwaters and petrels (click here).

Following a 15-year period of research and planning, in 2019 the Lord Howe Island Rodent Eradication Project conducted a combined aerial and ground-baiting operation to rid the island of its introduced Ship or Black Rats Rattus rattus and House Mice Mus musculus.

Roofed rodent bait stations spread across a field on Lord Howe Island in July 2019; photograph by Ian Hutton

The prevailing “rule of thumb” is that two years should elapse before declaring a treated island rodent free, allowing for any survivors to breed up to detectable levels. However, although it looked promising that success had been achieved in the 18 months following the baiting operation, in April 2021 a male and a pregnant female rat were caught on the island, only a few months before the two years was up. A quick response followed with ground baiting, use of detection dogs and monitoring camera stations, resulting in a total of 96 rats (44 adults and 52 juveniles) being caught by August 2021, with no further records of live animals being made since then. All rats caught were within the Settlement part of the island.

With the two-year wait then deferred until mid-2023 as a consequence of these rodents being detected, it is now pleasing to report that following a two-week survey conducted in July 2023 there has been no sign of rats or mice on Lord Howe Island for over two years. This was reported in the monthly Lord Howe Island Board’s Community News of 25 September 2023.

More than 950 detection device checks were undertaken during the survey, using 140 tracking tunnels, 32 trail cameras, and 300 wax tags and chew cards, along with sweeps with detection dogs. The results were then analysed and confirmed by independent experts from the New Zealand Department of Conservation’s Island Eradication Advisory Group. The formal check followed regular checks with dogs and camera surveillance throughout the past two years in that part of the island where the inhabitants live. In contrast, no live mice have been recorded on Lord Howe since early July 2019.

Now thankfully safe from rodents: a pair of Flesh-footed Shearwaters Ardenna carneipes on Lord Howe Island; photograph by Ian Hutton

Breeding success of Black-winged Petrels Pterodroma nigripennis increased dramatically from as little as 2.5% to 67% within one year of removal of Lord Howe Island’s rodents, showing the undoubted conservation value of the eradication project. Similarly, abundances of other bird species and of endemic invertebrates on Lord Howe have increased by orders of magnitude since 2019 (click here). For example, the endemic and Endangered Lord Howe Woodhen Hypotaenidia sylvestris has increased in population size from fewer than 500 prior to 2019 to 1147 in the last (incomplete) survey conducted in November 2022 – and in the 1970s there only 20-30 birds! In another success, the Masked Booby Sula dactylatra is now breeding on the main island for the first time since the rodents were eradicated.

On the invertebrate front, the endemic Lord Howe Island Wood-feeding Cockroach Panesthia lata (click here) and several species of pinwheel snails Pseudocharopa sp. (click here), all thought to be extinct on the main island, have been rediscovered following the rodent eradication. Vegetation changes have also been dramatic, with the forest floor on Mount Gower and Mount Lidgbird now carpeted with flourishing seedlings of the endemic Kentia Palm Howea forsteriana and the two mountain palms, whereas previously most seeds had been eaten by the rodents. On the other hand, introduced weedy plants are also increasing, necessitating their control.

The flightless Lord Howe Woodhen; photograph from the Lord Howe Island Board

For further reading, access a detailed report by Grant Harper of the Lord Howe Island Rodent Eradication Project submitted to the Lord Howe Island Board here.

With thanks to Darcelle Matassoni, Project Officer, Lord Howe Island Board and Keith Springer, Operations Manager, Mouse-Free Marion Project for information.

Reference:

Harper, G.A. 2023. The Lord Howe Island Rodent Eradication Project: Rodent Eradication Checkpoint 2023. Lord Howe Island, Australia: Lord Howe Island Board. Unpublished Report. 19 pp.

John Cooper, Emeritus Information Officer, Agreement on the Conservation of Albatrosses and Petrels, 10 October 2023

Note: Amended from a news story first published by the Mouse-Free Marion Project on 05 October 2023.