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Control of house mice preying on adult albatrosses at Midway Atoll National Wildlife Refuge
Biodiversity Conservation, BRB
Available Online

Duhr,M.

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Flanders, B.

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Flint, E.N.

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Howald, G.

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Hunter, S.A.

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Norwood, D.

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Taylor, R.V.

2019
Sand Island, Midway Atoll National Wildlife Refuge (MANWR), is home to 21% of all nesting black-footed albatross (Phoebastria nigripes) and 47% of all nesting Laysan albatross (P. immutabilis) worldwide. During the 2015–2016 nesting season predation and disturbance by non-native house mice (Mus musculus), here documented for the first time, resulted in 70 abandoned nests, 42 adult birds killed and 480 wounded. In the following nesting season the affected area increased, resulting in 242 dead adults, 1,218 injured birds and 994 abandoned nests. Mouse predation activities triggered a mouse control response to reduce mouse densities in the affected areas using multi-catch live traps, kill traps, and limited use of anticoagulant rodenticides in bait stations. In 2016–2017 we applied a pelleted cholecalciferol rodenticide, AGRID (Bell Laboratories, Madison, WI), at a rate of 20 kg/ha in all affected areas. The purpose of this study was to evaluate the efficacy of using AGRID to reduce mouse density and rate of mouse attacks on nesting albatrosses on Sand Island. Mouse attacks decreased and mouse abundance was reduced following rodenticide applications in the plots treated in December but changes in attack rates in the plots treated in January were not detectable and mouse abundance increased subsequent to treatment. The plots in the December treatments were much larger than those used in January and rainfall rate increased after December. A minimum size of treatment area may be necessary to achieve a reduction in injury rates in albatrosses. No deleterious effects were observed in non-target organisms. The casualties resulting from mouse predation (mostly Laysan albatross) represent a small proportion of the 360,000 pairs nesting on Sand Island. However, the risk to adult breeding albatrosses representing such a large fraction of the global population prompted the United States Fish & Wildlife Service to prioritise mouse control efforts.
The impacts of introduced house mice on the breeding success of nesting seabirds on Gough Island
BRB
Available Online

Bond, Alexander L.

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Caravaggi, Anthony

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Cooper, John

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Cuthber, Richard J.

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Ryan, Peter G.

2018
Invasive species are the main threat to island biodiversity; seabirds are particularly vulnerable and are one of the most threatened groups of birds. Gough Island, a UNESCO World Heritage Site in the South Atlantic Ocean, is an Important Bird and Biodiversity Area, and one of the most important seabird colonies globally. Invasive House Mice Mus musculus depredate eggs and chicks of most seabird species on the island, but the extent of their impact has not been quantified. We used field data and bootstrapped normal distributions to estimate breeding success and the number of surviving chicks for 10 seabird species on Gough Island, and compared estimates with those of analogous species from predator-free islands. We examined the effects of season and nest-site location on the breeding success of populations on Gough Island, predicting that the breeding success of Gough birds would be lower than that of analogues, particularly among small burrownesting species. We also predicted that winter-breeding species would exhibit lower breeding success than summer-breeding species, because mice have fewer alternative food sources in winter; and below-ground nesters would have lower breeding success than surface nesters, as below-ground species are smaller so their chicks are easier prey for mice. We did indeed find that seabirds on Gough Island had low breeding success compared with analogues, losing an estimated 1 739 000 (1 467 000–2 116 000) eggs/ chicks annually. Seven of the 10 focal species on Gough Island had particularly high chick mortality and may have been subject to intense mouse predation. Below-ground and winter breeders had lower breeding success than surface- and summer-breeders. MacGillivray’s Prion Pachyptila macgillivrayi, Atlantic Petrel Pterodroma incerta and Tristan Albatross Diomedea dabbenena are endemic or near-endemic to Gough Island and are likely to be driven to extinction if invasive mice are not removed.
Seabirds enhance coral reef productivity and functioning in the absence of invasive rats
BRB
Available Online

Carr, Peter.

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Graham, Nicholas A. J.

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Hoey, Andrew S.

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Jennings, Simon.

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MacNeil, M. Aaron

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Wilson, Shaun K.

2018
Biotic connectivity between ecosystems can provide major transport of organic matter and nutrients, influencing ecosystem structure and productivity, yet the implications are poorly understood owing to human disruptions of natural flows. When abundant, seabirds feeding in the open ocean transport large quantities of nutrients onto islands, enhancing the productivity of island fauna and flora. Whether leaching of these nutrients back into the sea influences the productivity, structure and functioning of adjacent coral reef ecosystems is not known. Here we address this question using a rare natural experiment in the Chagos Archipelago, in which some islands are rat-infested and others are rat-free. We found that seabird densities and nitrogen deposition rates are 760 and 251 times higher, respectively, on islands where humans have not introduced rats. Consequently, rat-free islands had substantially higher nitrogen stable isotope (?15N) values in soils and shrubs, reflecting pelagic nutrient sources. These higher values of ?15N were also apparent in macroalgae, filter-feeding sponges, turf algae and fish on adjacent coral reefs. Herbivorous damselfish on reefs adjacent to the rat-free islands grew faster, and fish communities had higher biomass across trophic feeding groups, with 48% greater overall biomass. Rates of two critical ecosystem functions, grazing and bioerosion, were 3.2 and 3.8 times higher, respectively, adjacent to rat-free islands. Collectively, these results reveal how rat introductions disrupt nutrient flows among pelagic, island and coral reef ecosystems. Thus, rat eradication on oceanic islands should be a high conservation priority as it is likely to benefit terrestrial ecosystems and enhance coral reef productivity and functioning by restoring seabird-derived nutrient subsidies from large areas of ocean.
Tuvalu national biodiversity strategy and action plan: fifth national report to the convention on biological diversity.
BRB
Available Online

Alefaio, S

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Falega, E

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Penivao, F

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Saitala, M

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Teakau, F

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Tekenene, M

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Thaman, R

2016
The isolated, small, low-lying resource-poor atolls of Tuvalu are clearly on the frontline against climate change, the escalating impacts natural disasters and declining food, health and energy security.
Special Issue Article: Tropical rat eradication. Seabird recovery and vegetation dynamics after Norway rat eradication at Tromelin Island, western Indian Ocean. Biological Conservation. Volume 185, May 2015
Biodiversity Conservation, BRB
Available Online

Bastien. M

,

Danckwerts. D.K

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M. Le Corre. M

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Micol. T

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Morey Rubio.C

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Orlowski. S

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Pinaud. D

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Ringler. D

2015
Seabirds are notoriously sensitive to introduced mammalian predators and eradication programs have benefitted seabird populations and their habitats on numerous islands throughout the world. However, less evidence is available from the tropics as to the benefits of rat eradication. Here, we report the seabird recovery and vegetation dynamics on a small coralline island of the tropical western Indian Ocean, eight years after Norway rat (Rattus norvegicus) eradication. Two species of seabirds were breeding before rat eradication (red-footed and masked boobies, Sula sula and Sula, dactylatra) and, in both species, the number of breeding pairs had an apparent increase of 22?23% per year after rat eradication. Such a high annual growth rate cannot be achieved by auto-recruitment only and our data suggest that immigration from other source populations never occurred in at least one of these species. We suggest that it is rather due to a rapid increase in breeding success, which rapidly increased the observed number of breeders since birds remained in the available-for-counting-as-breeders group for much longer. Two other species, the white tern (Gygis alba) and the brown booby (Sula leucogaster) were recorded breeding in 2014. The former species has not bred on the island since 1856 and the latter has never bred on the island. Plant cover (monospecific formation of the ruderal herb Boerhavia diffusa) dramatically increased from less than 30% of surface coverage to more than 70%. Although the initial restoration project was to eradicate all introduced mammals of the island simultaneously, house mouse (Mus musculus) eradication failed. Mouse density was high 8 years after rat eradication (32 mice/ha in dry season and 52 mice/ha in rainy season) but not higher than at a comparable tropical island of the region (Juan de Nova) where mice coexist with introduced black rats (Rattus rattus) and feral cats (Felis catus). These results are discussed in terms of the direct positive effects of rat eradication on seabirds and plants and the indirect positive effects of post-eradication seabird increase on soil manuring and vegetation recovery. Overall, our results show that on tropical islands, seabird and habitat recovery can be very rapid after rat eradication and should be implemented as a restoration tool wherever possible.
Special Issue Article: Tropical rat eradication. Trophic roles of black rats and seabird impacts on tropical islands: Mesopredator release or hyperpredation? Biological Conservation. Volume 185, May 2015
Biodiversity Conservation, BRB
Available Online

Le Corre. M.

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Ringler. D

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Russell. J.C

2015
Rats contribute to the decline of tropical seabird populations by affecting their breeding success through direct predation of eggs and chicks. When they coexist with other predators, invasive rats may also generate indirect interactions via the changes they impose on the structure of communities and trophic interactions following invasion (‘hyperpredation process’), or when apex predators are eradicated from the ecosystem (‘mesopredator release effect’). Understanding these effects is necessary to implement restoration operations that actually benefit threatened seabird populations. We investigated these processes on two French tropical seabird islands of the western Indian Ocean, Europa and Juan de Nova, where black rats coexist with two different apex predator species (introduced cats and potentially native barn owls). The parallel use of several methods (diet analysis, stable isotopes, seabird monitoring) to identify trophic roles of rats revealed that the direct impact of rats on seabirds was particularly high on Europa where only rats and owls occur, with high consumption of chicks resulting in low breeding success for several seabird species. We also suggested that hyperpredation associated with top-down regulation of cats is occurring on Juan de Nova, although territoriality of cats may buffer this process. Conversely we found evidence that mesopredator release effect is unlikely, irrespective of the apex predator identity. Considering the most likely effects on both islands we provided recommendations on eradication priorities to mitigate the risk of local extinction that seabirds are currently facing.
Reinstatement of customary seabird harvests after a 50-year moratorium
Biodiversity Conservation
Available Online

Anderson, Alice

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Davis, Joe

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Hohapata-Oke, John

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Hughes, Beverly

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Jones, Christopher J.

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Lyver, Philip O'B

2014
Seabird eggs, chicks and adults have significant value for many cultures, but delayed maturation, low reproductive rates and ease of exploitation at breeding colonies make these species especially vulnerable to over harvest.
Programme régional océanien sur les espèces marines 2013-2017 / Pacific Islands Regional Marine Species Programme
SPREP Publications, Biodiversity Conservation
Available Online

Secretariat of the Pacific Regional Environment Programme (SPREP)

,

Secrétariat du Programme régional océanien de l’environnement (PROE)

2013
The Marine Species Programme of the Secretariat of the Pacific Regional Environment Programme (SPREP) outlines a regional strategy for the cooperative conservation and management of dugongs, marine turtles, whales and dolphins. Other marine species of conservation concern will be added as the need arise. The strategy, which will be implemented through Action Plans during 2013–2017, will enable Pacific Islanders to take a primary role in achieving the following vision: A healthy Pacific Ocean with sustainable populations of whales, dolphins, marine turtles, dugongs and other species, and meets the aspirations of Pacific Island peoples and protects their natural and cultural heritage.
SPREP Marine Species Action Plan Review - Proceedings of Meetings 8-14 March, 2012
Biodiversity Conservation
Available Online

SPREP

2012
The review of the SPREP Regional Marine Species Action Plans (MSAP) 2008 – 2012 was conducted from the 8 – 14 March, 2012, at the Hexagon International Hotel, Nadi, Fiji Islands. The SPREP MSAPs are a composite of individual plans for whales and dolphins, marine turtles and dugongs.
Pacific islands regional marine species programme : 2013 - 2017 (action plan) - Dugong, Turtle, Whale and Dolphin
Biodiversity Conservation
Available Online

Secretariat of the Pacific Regional Environment Programme (SPREP)

2012
The Pacific Islands region that is served by SPREP covers 32 million km2 and is in the middle of the largest continuous marine habitat on the planet, the Pacific Ocean. This region is home to a diverse range of large marine animals, including cetaceans (whales and dolphins), sirenians (dugongs), and marine turtles etc. Over half of the world’s known species of cetaceans are found in the region. The area also supports the world’s largest remaining populations of dugongs, and green, hawksbill and loggerhead turtles.

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