Karen Bourgeois

Invasional meltdown potential: facilitation between introduced plants and mammals on French Mediterranean islands.

ABSTRACT In the increasingly important domain of insular invasion ecology, the role of facilitation between different introduced taxa has been mentioned, but rarely studied. This paper outlines facilitation between introduced mammals and the invasive succulents Carpobrotus edulis and C. aff. acinaciformis on offshore islands in southeast France. Rats and rabbits are the primary seed dispersers of Carpobrotus sp. on the islands studied. No such dispersal activity was detected on the adjacent mainland. Seed digestion by rats and rabbits also enhanced percent seed germination and speed, in spite of an associated reduction in seed size. In return, Carpobrotus provides a water/energy-rich food source during the dry summer season, thus demonstrating a clear case of mutualism between invaders.

Invasive rats and seabirds after 2,000 years of an unwanted coexistence on Mediterranean islands

In the Mediterranean, the survival of endemic long-lived seabirds despite the long-standing introduction of one of the most damaging alien predator, the ship rat (Rattus rattus), on most islands constitutes an amazing conservation paradox. A database gathering information on approximately 300 Western Mediterranean islands was analyzed through generalized linear models to identify the factors likely to influence ship rat presence and to account for how ship rat presence and island characteristics may have driven the presence and abundance of seabirds. Our review showed that few Mediterranean islands remain rat-free. At the regional scale, rat presence was only a limiting factor in the abundance of the smallest seabird, the storm petrel (Hydrobates pelagicus), while the distribution and abundance of the three shearwaters were more influenced by island characteristics. We hypothesized that the long-term persistence of these seabirds may have been facilitated by the various biogeographical contexts of Mediterranean islands, likely to provide intra-island refuges.

Colony-Site Selection Drives Management Priorities for Yelkouan Shearwater Populations

Abstract We tested whether colony-site availability could allow for an increase in the unusually small breeding populations of yelkouan shearwater (Puffinus yelkouan) on the islands of the Port-Cros National Park (France) if feral cat eradication were undertaken. Comparisons between colony and noncolony sites indicated yelkouan shearwaters preferred deep-soiled and low-outcrop–covered coastal sites. A substrate cover, light avoidance, and sea proximity model suggested that 17.5% of unoccupied sites are suitable for colony establishment. The low proportion of suitable sites currently used by yelkouan shearwaters suggests that these colonies could be refuges and that feral cat eradication will probably lead to a breeding population increase.

Moulting strategies of the Yelkouan Shearwater Puffinus yelkouan during the breeding season

AbstractBiochemical analyses of feathers are increasingly used to study seabird at-sea distribution, movements, pollutant exposure and trophic level. However, such studies are intrinsically related to the knowledge of the target species moulting strategies. In this study, we analysed the moulting strategies of the Yelkouan Shearwater Puffinus yelkouan at three breeding sites, by scoring the moult of wing, tail and body feathers during the breeding season. While we observed virtually no bird growing its wing feathers, some Yelkouan Shearwaters started moulting their tail and body feathers during late incubation. Moult intensified during chick-rearing. We did not find any significant effect of sex, breeding status or year on moulting patterns. However, moulting strategies varied among individuals, as only a proportion of birds was actively moulting at the various breeding stages and moulting patterns varied among breeding sites. Based on our study, it is evident that factors determining moulting strategies in the Yelkouan Shearwater remain to be elucidated. This study underlines the need to carefully select the most convenient target feathers to ensure the correct development of studies based on the biochemical analysis of feathers as moulting strategies in seabirds can be rather variable.ZusammenfassungMauserstrategien des MittelmeersturmtauchersPuffinus yelkouanwährend der Brutsaison Biochemische Analysen von Federn werden zunehmend herangezogen, um die Verbreitung von Seevögeln auf See, ihre Wanderungen, ihren Kontakt mit Schadstoffen und ihre Trophieebene zu untersuchen. Solche Studien sind jedoch untrennbar mit dem Wissen über die Mauserstrategien der Zielart verbunden. In dieser Untersuchung haben wir die Mauserstrategien des Mittelmeersturmtauchers Puffinus yelkouan in drei Brutgebieten analysiert, indem wir die Mauser von Schwung-, Schwanz- und Körperfedern während der Brutsaison untersucht haben. Während wir so gut wie keinen Vogel mit im Wachstum begriffenen Schwungfedern beobachtet haben, begannen einige Mittelmeersturmtaucher während der späten Bebrütungsphase, ihre Schwanz- und Körperfedern zu mausern. Die Mauser intensivierte sich während der Kükenaufzucht. Wir fanden keine signifikanten Effekte von Geschlecht, Brutstatus oder Jahr auf die Mausermuster. Mauserstrategien unterschieden sich jedoch zwischen Individuen, da nur ein Teil der Vögel in den verschiedenen Stadien des Brutgeschäfts aktiv mauserte und die Mausermuster zwischen den Brutgebieten variierten. Wir müssen noch herausfinden, welche Faktoren Mauserstrategien bei Mittelmeersturmtauchern bestimmen. Schließlich betont diese Studie die Notwendigkeit, die am besten geeigneten Zielfedern sorgfältig auszuwählen, um die korrekte Planung von Studien, die auf biochemischer Analyse von Federn basieren, zu gewährleisten, da Mauserstrategien von Seevögeln recht variabel sein können.

Warnings alone won’t protect New Caledonia wildlife from cruises

We understand the concerns of Philippe Borsa and colleagues over the New Caledonia government’s plans to open the Chesterfield reefs to ecotourism cruise ships (Nature 558, 372; 2018). In our view as conservation affecting the Antarctic ecosystem properly engage with the ATS from the outset. Antarctic geoengineering proposals would not “require global consent” as Moore et al. state, but instead would need the approval of the 29 consultative parties to the 1959 Antarctic Treaty. The Scientific Committee on Antarctic Research is an important independent contributor to the ATS. However, it is actually the Committee for Environmental Protection (CEP), created by the 1991 Madrid Protocol to the Antarctic Treaty, that formally advises the consultative parties about proposals affecting the Antarctic environment. The Madrid Protocol bans mining and declares Antarctica a natural reserve. We think that the CEP is likely to advise that the “major disturbances to local ecosystems” arising from Moore and colleagues’ proposals — particularly quarrying of local rock and dredging — would infringe Madrid Protocol protections. Geoengineering that affects marine ecosystems might also require separate permission under the 1982 ATS Convention on the Conservation of Antarctic Marine Living Resources. Any discussion of geoengineering in Antarctica needs to preserve and strengthen Antarctic governance, not weaken it. This is a task for international lawyers and policymakers as well as scientists. Brendan Gogarty* University of Tasmania, Hobart, Australia. brendan.gogarty@utas.edu.au *On behalf of 6 correspondents (see go.nature.com/2kjaady for full list). Political pressures on Romania’s research

Sex and Geographic Variation in Grey-Faced Petrel (Pterodroma gouldi) Morphometrics

Abstract. Sexual size dimorphism and geographic variability in external measurements of the Grey-faced Petrel (Pterodroma gouldi) were investigated on the west and east coasts of the North Island of New Zealand. The applicability of morphometrics to distinguish the sex of individuals in the two geographic areas and assign a geographic origin to individuals was evaluated. Low geographic variation in morphometry was found, with discriminant function analysis failing to develop an efficient function to assign a geographic origin (55.9% accuracy). In contrast, sexual size dimorphism was marked (up to 6.6% different), with males being significantly larger than females in all measurements but wing length. A discriminant function combining bill depth at nostrils and head length correctly predicted sex of adult breeders with 80.9% accuracy (78.9% for males, 82.7% for females). Despite its apparent applicability across the entire range of the species, this discriminant function was not sufficiently accurate on its own. Alternatively, the use of bill depth at the base or a bill size index increased sexing accuracy to 92.1% when both mates of pairs were considered. Thus, Grey-faced Petrels can be reliably sexed by taking only one measurement on both mates of a pair.