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Tree breeding in holes has been recorded for the Common Swift (Apus apus) mainly in Northern Europe and Siberia. This behaviour, considered as ancestral, has also been noted in Corsican forests. Although marginal in terms of numbers, it is a perennial phenomenon. We present here a synthesis on the distribution and the characteristics of nesting sites, and we compare these breeding sites to the occurrences in continental Europe and Northern Africa. Our data add to the body of arguments in favour of the preservation of mature forests of the Corsican Pine on the island., Thibault Jean-Claude, Armand Thomas, Beuneux Grégory, Cibois Alice, Courtois Jean-Yves, Seguin Jean-François. Common Swifts (Apus apus) nesting in mature pine forests in Corsica. In: Ecologia mediterranea, tome 46 n°1, 2020. pp. 75-82.

The Pacific Ocean is the site of the most important diversification of insular reed warblers (Acrocephalus). In the Marquesas Islands (Eastern Polynesia), reed warblers belong to two distinct lineages that have reached the archipelago independently. We used mitochondrial sequences and microsatellite markers and found evidence of gene flow between the two lineages. One island in particular, Nuku Hiva, seems to act as the main contact zone between the two taxa. We then used reflectance spectrometry to evaluate the variation of carotenoid colouration among all populations. Marquesan reed warblers exhibit convergent evolution in carotenoid-based plumage colouration, but variation among islands was important. Having two different phylogenetic origins, the two lineages acquired their yellow colour independently and there is stochastic variation in plumage among islands. Finally, we analysed the songs of reed warblers from the main islands. Multifactorial analysis showed that vocalisations of Marquesan r...

Islands are separated by natural barriers that prevent gene flow between terrestrial populations and promote allopatric diversification. Birds in the South Pacific are an excellent model to explore the interplay between isolation and gene flow due to the region’s numerous archipelagos and well-characterized avian communities. The wattled honeyeater complex (Foulehaio spp.) comprises three allopatric species that are widespread and common across Fiji, Tonga, Samoa, and Wallis and Futuna. Here, we explored patterns of diversification within and among these lineages using genomic and morphometric data. We found support for three clades of Foulehaio corresponding to three recognized species. Within F. carunculatus, population genetic analyses identified nine major lineages, most of which were composed of sub-lineages that aligned nearly perfectly to individual island populations. Despite genetic structure and great geographic distance between populations, we found low levels of gene flow between populations in adjacent archipelagos. Additionally, body size of F. carunculatus varied randomly with respect to evolutionary history (as Ernst Mayr predicted), but correlated negatively with island size, consistent with the island rule. Our findings support a hypothesis that widespread taxa can show population structure between immediately adjacent islands, and likely represent many independent lineages loosely connected by gene flow.

The patterns of colonisation and phylogenetic relationships of the swiftlets from Oceania, and in particular from the remotest archipelagos of Polynesia, remain a puzzle. In this study we used mito...

We reconstruct the phylogeny of imperial pigeons (genus Ducula) using mitochondrial and nuclear sequence data. We evaluate the most likely biogeographic scenario for the evolution of this group that colonized many islands of the Pacific Ocean. The divergence time analysis suggests that the basal divergences within Ducula occurred more recently than in the fruit doves (genus Ptilinopus), a group that is also well diversified in Oceania. The imperial pigeons colonized the Melanesian region several times independently, and the diversification within this region led to several species in sympatry, in particular in the Bismarck archipelago. Central Polynesia was also colonized several times, first by a lineage during the Miocene that led to the large D. latrans, sister to the New Caledonian endemic D. goliath, then more recently by the widespread D. pacifica, during the Pleistocene. The phylogenetic pattern obtained with the extant Ducula species showed that the Eastern Polynesian endemics do not form a monophyletic group, with the Pacific Imperial Pigeon D. pacifica sister species with good support to the Polynesian Imperial Pigeon D. aurorae. However, the impact of recent anthropic extinctions has been important for the imperial pigeons, more than for the smaller fruit doves, suggesting that several Ducula lineages might be missing today.

We present a recent survey of the vertebrate fauna of Cavallo, a small island belonging to the Lavezzi archipelago located between Corsica and Sardinia. This island is the only inhabited one off the coast of Corsica and underwent deep landscape and ecosystem changes in the past 50 years induced by touristic development. The herpetofauna of the Cavallo island has changed with two recent colonisations, one green frog and one gecko. Two amphibian species and four reptiles live nowadays on this island. Concerning the breeding landbirds, this island has been visited by ornithologists more or less regularly since 1955. Several species have colonized the island while others have left. These changes are due to important modifications of the habitats, such as urbanization, the decline of high matorral and grasslands, but also the development of gardens and the creation of a permanent wetland. Today, 13 species of landbirds breed on Cavallo. Several introduced mammal species recorded in the 1980s seem to have vanished, and today the list is restricted to the introduced Black rat and two or three bat species., Ce travail examine l’évolution des faunes de vertébrés de l’île de Cavallo au cours des cinquante dernières années. Dans l’archipel des Lavezzi, entre Corse et Sardaigne, il s’agit de la seule île para-corse à être habitée. Le développement touristique a engendré de profonds changements dans les paysages et les habitats naturels. Deux introductions d’espèces (une grenouille verte et un gecko) modifient la composition de l’herpétofaune, qui compte aujourd’hui deux espèces d’amphibiens et quatre de reptiles. Des ornithologues ont visité l’île plus ou moins régulièrement depuis 1955. Plusieurs espèces d’oiseaux nicheurs ont colonisé l’île tandis que d’autres ont disparu. Ces changements sont dus aux importantes modifications des habitats, telles que l’urbanisation, la régression du haut maquis et des pelouses et aussi le développement de jardins et la création d’une zone humide permanente. Aujourd’hui, on compte treize espèces d’oiseaux terrestres nicheurs. Plusieurs mammifères introduits notés dans les années 1980 semblent s’être éteints et la liste se limite au rat noir et à deux ou trois espèces de chiroptères., Delaugerre Michel-Jean, Thibault Jean-Claude, Beuneux Grégory. Le renouvellement récent des faunes de vertébrés sur l’île de Cavallo (archipel des Lavezzi, Corse). In: Ecologia mediterranea, tome 43 n°2, 2017. Le patrimoine naturel de l'île de Cavallo (archipel des Lavezzi, Corse) : écologie, biogéographie et conservation. pp. 207-217.

International audience; The Eurasian treecreeper (Certhia familiaris) comprises two mitochondrial lineages that diverged during the mid-Pleistocene. One palaeoendemic lineage has an allopatric range currently restricted to the island of Corsica and the Caucasus region, whereas the second one has a very large Eurasian range. Here, we used microsatellites (N = 6) and mitochondrial DNA (COI) to assess the genetic structure of insular and mainland populations from Corsica, mainland France and Central Italy (N = 258) and the level of mitochondrial and nuclear gene flow among these populations. Concordant with the mitochondrial DNA signal, the results for microsatellites clearly demonstrate that the Corsican population (Certhia familiaris corsa) is strongly divergent from nearby mainland populations (Certhia familiaris macrodactyla). Microsatellite data also support significant divergence and low gene flow between the Central Italian and mainland French populations. Our results suggest low nuclear gene flow from the mainland into Corsica and no mitochondrial gene flow. Sporadic gene flow from the nearby mainland might explain the presence of continental nuclear alleles in the genome of 5% of sampled insular birds. Our study confirms the existence of an endemic Corsican treecreeper lineage with important conservation value. Our results also imply that Eurasian treecreepers from Central Italy constitute a distinct management unit.

We used a mitochondrial and nuclear DNA phylogeny to evaluate the relationships among all noddies (Anous and Procelsterna, Laridae) and to clarify their classification. The Lesser Noddy Anous tenuirostris and Black Noddy Anous minutus form a pair of closely related sister-species, as do the Blue Noddy Procelsterna albivitta and Grey Noddy Procelsterna cerulea. Blue and Grey Noddies are embedded within the dark noddies and are the sister-clade to the Lesser and Black Noddies, indicating that the genus Anous in its current definition is not monophyletic. Thus, we propose to merge all noddies into the genus Anous Stephens 1826, and to consider Procelsterna Lafresnaye 1842 as a junior synonym.

Molecular studies support the hypothesis that Corsica Island was a glacial refugium for a number of forest birds during the Pleistocene. We focused on the Corsican nuthatch (Sitta whiteheadi), an endemic passerine strongly associated with the laricio pine (Pinus nigra laricio). The range of laricio pine has been impacted by the Pleistocene glacial periods and forest has been recently fragmented by cutting and fires. Using both molecular (mitochondrial and nuclear) and morphological characters, we assessed the variation within the nuthatch population. Our results are consistent with the hypothesis that the Corsican nuthatch endured through the late Pleistocene and Holocene climatic variations, and sustained the subsequent cycles of forests reduction/expansion. The results also suggest that the recent anthropization of the landscape resulted in the isolation of a cluster of populations in the northern part of the island. The fragmentation of the habitat of the nuthatch may impede the future of the bird by creating isolated population units between which the gene flow is reduced.

We investigated the evolutionary history of the spotted flycatcher Muscicapa striata, a long distance migratory passerine having a widespread range, using mitochondrial markers and nuclear introns. Our mitochondrial results reveal the existence of one insular lineage restricted to the western Mediterranean islands (Balearics, Corsica, Sardinia) and possibly to the Tyrrhenian coast of Italy that diverged from the mainland lineages around 1 Mya. Mitochondrial genetic distance between insular and mainland lineages is around 3.5%. Limited levels of shared nuclear alleles among insular and mainland populations further support the genetic distinctiveness of insular spotted flycatchers with respect to their mainland counterparts. Moreover, lack of mitochondrial haplotypes sharing between Balearic birds (M. s. balearica) and Corso-Sardinian birds (M. s. tyrrhenica) suggest the absence of recent matrilineal gene flow between these two insular subspecies. Accordingly, we suggest that insular spotted flycatchers could be treated as one polytypic species (Muscicapa tyrrhenica) that differs from M. striata in morphology, migration, mitochondrial and nuclear DNA and comprises two subspecies (the nominate and M. t. balearica) that diverged recently phenotypically and in mitochondrial DNA and but still share the same nuclear alleles. This study provides an interesting case-study illustrating the crucial role of western Mediterranean islands in the evolution of a passerine showing high dispersal capabilities. Our genetic results highlight the role of glacial refugia of these islands that allowed initial allopatric divergence of insular populations. We hypothesize that differences in migratory and breeding phenology may prevent any current gene flow between insular and mainland populations of the spotted flycatcher that temporarily share the same insular habitats during the spring migration.

Fruit doves of the genus Ptilinopus (Columbidae) form a large group of more than 50 species that have been successful in colonizing most of the Pacific Ocean, with sympatric species on several small oceanic islands. A recent new phylogeny of this genus and allies by Cibois and coworkers showed that all these cases of sympatry derived from multiple independent colonizations, with the exception of the Marquesas Islands (eastern Polynesia), where the two fruit doves that occurred sympatrically are sister species: the Red-moustached Fruit Dove, Ptilinopus mercierii, and the White-capped Fruit Dove, Ptilinopus dupetithouarsii. Both Marquesas fruit doves coexisted on several Marquesas islands until the recent extinction of the Red-moustached Fruit Dove. Here, we analyze their morphology, review their life history, and discuss the two most likely scenarios for the divergence of the two species, in light of the geological history of the Marquesas hot-spot volcanoes (5.5 - 1.1 Ma). The microallopatry scenario takes into account the large initial size of the islands and involves partitioning of the fruit doves' distributions within the same island, whereas in the intra- archipelago scenario, the birds' speciation occurred on different islands, in conjunction with their sequential emergence. We discuss both hypotheses and conclude that esti- mated time of divergence of the two species and known ecology of the birds favor the intra-archipelago scenario.

In this study we investigated the phylogenetics of the Eurasian treecreeper (Certhia familiaris), a forest passerine with a wide Palaearctic range including Corsica, using three mitochondrial genes and three nuclear introns, and its phylogeographic history using the COI gene. Our phylogenetic results, including eight of the ten sub-species currently recognized, support the monophyly of C. familiaris with respect to its Indo-Asian sister species C. hodgsoni. C. familiaris comprises two lineages that diverged during the mid-Pleistocene (c. 1 Myr): one palaeoendemic lineage has an allopatric range nowadays restricted to the Corsica island and the Caucasus region whereas the second one, more recent and widespread, is distributed over most of Eurasia and in northern China. The most likely scenario that may explain such a pattern is a double colonization of the western Palaearctic from the eastern range of the species. During the middle Pleistocene period, a first lineage expanded its range up into Europe but did not persist through glacial cycles except in Corsica and the Caucasus region. Later, during the upper Pleistocene, a second lineage began to diversify around 0.09 Myr, spreading towards the western Palaearctic from a unique refuge likely located in the eastern Palaearctic [correction added on 6 March 2015 after first online publication: 0.9 Myr amended to 0.09 Myr]. Apart from C. f. corsa, our results do not suggest any distinct evolutionary history for other sub-species previously described on morphological grounds in Europe. Our study highlights the important conservation value of the Corsican treecreeper and emphasizes the major role of mature pine forests in the evolution of endemic bird taxa in Corsica. © 2015 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, 115, 134–153.

In harvested forests, the bird community is largely determined by stand structure, which itself is determined by forestry practices. This study aimed to identify habitat variables determining the presence of Corsican Nuthatch Sitta whiteheadi – a threatened island endemic – in harvested Corsican Pine Pinus nigra laricio woods, with the aim of mitigating the impact of timber harvest on the bird. Comparison of occupied and unoccupied plots showed that this bird is found mostly in pure Corsican Pine stands, and is absent when more than 50% of trees are not this species. Nests were built in decaying pine snags between 20 and 100 cm diameter at breast height (dbh), but birds avoided stands with live pines 80 cm dbh. Conservation of Corsican Nuthatch therefore depends on maintaining harvest rotations of more than 200 years, reducing the size of felling coupes in clear-cutting systems or, preferably, practising selective cutting, maintaining a sufficient density of old trees and snags, and checking the encroachment of other tree species into Corsican Pine stands.

The Nightingale Reed-Warbler (Acrocephalus luscinius) is known from six islands of the Mariana Archipelago in the Pacific Ocean. A recent phylogeny of the reed-warblers of the Pacific islands suggested however that the species was polyphyletic, the result of at least three independent colonisations. We present here a complete phylogeny of the Mariana reed-warblers that includes two populations, from Alamagan and Aguiguan, not yet studied using molecular techniques. Both of these populations belong to the Pacific Acrocephalus radiation, with birds from Alamagan closely related to the Saipan population, and those from Aguiguan having unresolved relationships within the Micronesian clade. These results suggest that the Mariana Islands experienced multiple colonisations by reed-warblers. We use a combination of molecular phylogeny and biometry of museum specimens to propose a new species-level taxonomy for Acrocephalus of the Marianas. These results have conservation implications for the two remaining populations, on Alamagan and Saipan, which probably belong to the same taxon, Acrocephalus hiwae (Nightingale Reed-Warbler).

With only a single extant representative, endemic to the Tuamotu Archipelago, the Polynesian sandpipers (Aechmorhynchus and Prosobonia) may have had a larger distribution in Eastern Polynesia in the past, with four endemic taxa. Although these aberrant sandpipers' membership to the Scolocapidae has been well supported, finding their closest living taxa has proved difficult and the phylogenetic relationships of these taxa have remained unresolved. We present the first molecular analysis of the Polynesian sandpipers, including sampling of the only known specimen of the extinct Prosobonia leucoptera, collected in 1773. Based on mitochondrial and nuclear gene sequence data, the phylogenetic analyses demonstrate that the Polynesian sandpipers were sister taxa and belonged to the clade that included the other sandpipers (Calidris and allies) and turnstones (Arenaria), although without a close relative among extant genera. Divergence time estimates suggested that the lineage leading to Prosobonia diverged from the other extant sandpipers during the Oligocene and that either the Line Islands or the Tuamotu Archipelago were probably the first archipelagos colonized by the Prosobonia lineage. On the basis of these results, we suggest that Aechmorhynchus parvirostris and Prosobonia leucoptera be regarded as related species within the same genus, and thus that the senior name Prosobonia be used for both taxa.

Located in the South Pacific Ocean, the Gambier Islands are sometimes presented as an example, with Easter Island, of biodiversity collapse provoked by overexploitation of the natural resources by the Polynesian people during the course of several centuries. However, when comparing the list of bird bones obtained from archaeological sites with the data obtained and specimens collected by naturalists from the end of the eighteenth century to the midtwentieth century, we show that land-bird extinction continued uninterrupted, mostly due to introduced predators and the continuous loss of wooded areas. Conversely, the list of breeding seabirds has remained relatively stable, but the number of breeding sites has decreased owing to introduction of predators, especially the cat and black rat. Today these sites are restricted to cliffs on the main islands and to remote islets.

Th e endemic Tahiti reed-warbler Acrocephalus caff er occurs in two distinct morphs, a typical or ‘ yellow ’ morph and a melanic or ‘ dark ’ morph, which are found together in the valleys of the eastern and central parts of the island of Tahiti (Society Islands, French Polynesia). We investigated the molecular basis of the plumage colour polymorphism in this species using sequences of the melanocortin-1 receptor (MC1R), a gene often found associated to melanism in birds. We found that the MC1R genotype was perfectly associated with plumage colour in the Tahiti reed-warbler, with the same nonsynonymous substitution that showed a correlation with phenotype in the Caribbean bananaquit Coereba fl aveola . An heterozygous reed-warbler at this site presented a melanic phenotype, suggesting that the melanic allele is dominant. All other Polynesian reed-warbler species, which do not have a melanic morph, shared the ‘ yellow ’ nucleotide at this position. Th ese results suggested that the same mutation point was linked to a melanic polymorphism in two unrelated passerine birds. Polymorphism in colour is a widespread phenomenon in birds and in other vertebrates: it is generally defi ned by the presence within a species of individuals of the same sex and age that have diff erent genetically determined coloration (Buckley 1987). Th e term ‘ morph ’ was fi rst proposed by Huxley (1955) and is generally used for the discrete categories of plumage. In their review of avian polymorphism, Galeotti et al. (2003) showed that changes in the distribution of the melanic pigments, with the defi nition of a ‘ dark ’ or melanic morph, is the most frequent polymorphism

Aim Deciphering the complex colonization history of island archipelagos is greatly facilitated by comprehensive phylogenies. In this study we investigate the phylogeny and biogeography of the insular reed-warblers (genus Acrocephalus) of the tropical Pacific Ocean, from Australia to eastern Polynesia. Location Oceania. Methods We used sequences of mitochondrial DNA (cytochrome b, ND2 and ATP8 genes) to infer the colonization patterns of reed-warblers endemic to Pacific islands and Australia. We sampled all known taxa of Acrocephalus in the Pacific except A. luscinius nijoi, for which no sample was available. Most taxa were represented by toe-pad samples from museum specimens collected in the 19th and 20th centuries. With a few exceptions, several specimens per taxon were sequenced independently in two institutions (Smithsonian Institution and Natural History Museum of Geneva). Results Our data indicate that Pacific reed-warblers do not form a monophyletic group, because A. luscinius luscinius from Guam falls outside the main Pacific radiation. The remaining Pacific taxa are divided into two clades: one clade includes all the reed-warblers from Micronesia (except Guam) and Australia, and two Polynesian taxa from the Line Islands and the southern Marquesas; the other clade includes all remaining Polynesian taxa. The taxa endemic to three archipelagos (Mariana, Marquesas and Society islands) are polyphyletic, suggesting several independent colonizations. Main conclusions Our results provide evidence for a complex pattern of colonization of the Pacific by reed-warblers. Calibration analyses suggest that reed-warbler lineages are much younger than the ages of the islands they occupy. Several remote archipelagos were colonized independently more than once. Consequently, we infer that the colonization of reed-warblers in the Pacific did not follow a regular, stepping-stone-like pattern. The phylogeny also suggests a previously undetected case of reverse colonization (from island to continent) for the Australian lineage and indicates that A. luscinius, as currently defined, is not monophyletic. We discuss the supertramp strategy of reed-warblers in the Pacific and show that, although Pacific reed-warblers meet some of the supertramp criteria in their aptitude for colonizing remote archipelagos, their life history characteristics do not fit the model.

The Tuamotu Reed-Warbler (Acrocephalus atyphus) is a small insectivorous passerine endemic to eastern Polynesia in the Pacific Ocean. To complement a previous study of the phylogeography of this species based on molecular data, we undertook an analysis based on morphological characters taken from study skins and live birds and propose a new classification for the Tuamotu Reed-Warbler. Three of the six subspecies previously recognised, eremus, palmarum and niauensis, can be diagnosed by both morphological and genetic characters and all are found on uplifted coral islands with a peculiar geomorphology (a shallow or absent lagoon) and elevations higher than average for Tuamotu atolls. Conversely, morphological and molecular analyses suggest that all low-lying atoll populations should be merged into a single taxon, atyphus. Finally, we suggest priorities for conservation for this endemic bird. This study provides an evaluation of the morphological variation of a terrestrial bird across the largest chain of atolls in the world.

SummaryEndemic to the island of Corsica in the western Mediterranean, the Corsican NuthatchSitta whiteheadionly occupies mature stands of Corsican PinePinus nigra lariciowhich cover a very small area. We present estimates of the distribution and population size of the Corsican Nuthatch, based on both field investigation and analysis of vegetation maps for the 103 county and municipality forests identified. Between spring 1997 and summer 2008, 48 forests were systematically investigated to map nuthatch territories, requiring 20 months of fieldwork. In the 55 forests not explored, we estimated the number of territories from analysis of digital maps with a calculated mean density from six spot-mapping censuses previously made in mature forests. The total estimated number was estimated to be 1,557-2,201 territories, distributed across 45 forest fragments (= group of connected stands) totalling 185 km2. At distances varying from 250 m to 16 km from each other, fragments were separated by unfavourable vegetation (shrubs, trees other than pines) or rocky outcrops. The area of these fragments varied from seven to 3,159 ha. Of the 45 fragments, 19 held fewer than 10 nuthatch pairs, 20 had 10–99 territories, and only six had more than 100 territories. We suggest that nuthatch numbers have declined by 10% in the past 10 years because of a reduction in suitable habitat due to fires and logging. The Corsican Nuthatch currently fulfils the criteria established by IUCN to qualify as “Vulnerable”.

Little is known about the effect of quaternary climate variations on organisms that inhabited carbonate islands of the Pacific Ocean, although it has been suggested that one or several uplifted islands provided shelter for terrestrial birds when sea-level reached its highest. To test this hypothesis, we investigated the history of colonization of the Tuamotu reed-warbler (Acrocephalus atyphus) in southeastern Polynesia, and found high genetic structure between the populations of three elevated carbonate islands. Estimates of time since divergence support the hypothesis that these islands acted as refugia during the last interglacial maximum. These findings are particularly important for defining conservation priorities on atolls that endure the current trend of sea-level rise owing to global warming.

The Phoenix Petrel (Pterodroma alba) is classified as Endangered and its population is declining on most of its breeding islands. However, the exact population size is not clearly known and data are sometimes old and inaccurate, such as for the Marquesas Archipelago, French Polynesia. Hatuta'a Island, Marquesas, was visited for three days in March 2007 to determine whether P. alba was still breeding on this island. The population size was estimated to be more than 200 pairs, compared with the one individual seen 20 years ago. Thus, Hatuta'a's importance for bird conservation in the region has increased.

The Corsican Nuthatch Sitta whiteheadi is a bird endemic to Corsica Island and has a very small population. Its habitat, Corsican pine Pinus nigra laricio forest, is currently restricted to less than 16,000 ha and is threatened by forest fires. In this article, we aim (1) to evaluate the effects of a large wildfire on a Nuthatch population, and (2) to identify the habitat features that influence the presence/absence of the Nuthatch after fire, so as to promote appropriate forestry practices after fire. The study has been conducted on a study plot of 300 ha which is part of a larger area severely burnt in August 2003. Habitat characteristics have been investigated on 39 plots of 1,225 m2 occupied by the bird, and 22 randomly chosen plots without the Nuthatch. We observed a decrease of 37.5% in Nuthatch abundance the first spring after the fire, but the impact showed great local variation as a function of fire severity. Logistic modelling showed that the presence of Nuthatch mainly depended on the degree of crown alteration: the Nuthatch tended to be present when at least one pine had less than 2.5 m of crown burned. We have no evidence of any direct fire-induced mortality, but several effects of fire can explain this population decrease, namely, the reduction of canopy volume, the decrease of the amount of pine seeds, and the reduction of nest-site availability. These results permit us to propose a simple criterion that can help in choosing the plots to be cut where salvage logging is necessary.

The Citril Finch Serinus citrinella breeds in several mountains of central and southern Europe and on Corsica, Sardinia and Tuscany islands. Several studies have emphasized differences in phenotype and vocalization, and some authors consider mainland and insular forms to be two distinct species. A genetic approach based on the sequences of a mitochondrial DNA fragment was used to estimate genetic distance separating several populations. Individuals from the Alps and the Pyrenees belong to one group and the individuals from Corsica to the second. These results, discussed together with data on ecology, biometrics and vocalization, suggest keeping only one polytypic species which includes two distinct forms.

This paper describes the diet of young Lammergeiers Gypaetus barbatus during the nesting period on the island of Corsica. From 1985 to 1990, food items were collected from 10 nests after the young had fledged. These nests were from five territories where the potential food supply was estimated using a range of ‘large mammal’ counts. Feathers, bones and isolated hooves were used to identify prey. For each nest, the minimal number of food portions was quantified, ignoring material that provided no food value. The diet consisted mainly of limb extremities of domestic ungulates (c. 36% by number of portions of sheep and goat; 33% of cattle, mostly calves). Pigs, both wild and domestic, yielded c. 16% of the items. Where present on the territory, mouflon occurred frequently in nests (c. 12% of items). Birds and small mammals were scarce in the diet. For three territories, samples varied less among years than among territories. There was a strong association between the diet of the young and the food available in the territories. We examined the possible links between known 20th century changes in stock rearing activities and the Corsican Lammergeier's diet.

In the Society archipelago (French Polynesia), Acrocephalus reed warblers are known only from four islands: Tahiti, Mo’orea, Huahine and Raiatea. All populations are now extinct except on Tahiti. Our knowledge of these birds is based on a small number of specimens preserved in museums, collected mostly during the 19th century. We present here a review of the past and present distribution, habitat and threats to the Society Islands reed warblers, including details on the specimens in museum collections. We compare the external morphology of the different populations, and use samples from museum specimens to propose a molecular phylogeny of all taxa based on partial cytochrome b gene sequences. The genetic data do not support the monophyly of the Society Islands reed warblers, which probably derived from three different lineages, found in Tahiti, Mo’orea and in the cluster Raiatea–Huahine. We outline the taxonomic consequences of this phylogeny. Our results support the hypothesis that evolutionary pattern, not distance between islands, shaped the long-distance colonization of oceanic islands by reed warblers.

Aim Remote oceanic islands often provide good illustrations of adaptive radiations, but phylogenetic studies have also demonstrated unexpected multiple colonization events for a given archipelago. In this study we investigate the relationships among endemic populations of the Marquesas reed-warbler, Acrocephalus mendanae Tristram, 1883, which have colonized nearly all islands of this remote Polynesian archipelago, and which exhibit a very uniform plumage pattern. We study the phylogeny and morphology of all subspecies in the Marquesas, providing an examination of the position of the Marquesas lineages in relation to reed-warblers distributed across multiple Polynesian archipelagos. Location This study focused on all the main islands of the Marquesas archipelago, along with samples from other Polynesian archipelagos (Society, Tuamotu, Austral, Cook, Kiribati) and Australia. Methods We used mitochondrial DNA markers (cytochrome b and ND2 genes) to develop a phylogeny of the main eastern Polynesian taxa. All subspecies for the Marquesas were investigated, including multiple individuals per island. Phylogenetic analyses using maximum-likelihood and Bayesian approaches were employed to infer relationships among A. mendanae populations and between the main Polynesian archipelagos. Morphometric analyses based on 110 specimens from museum collections were performed on external characters to investigate the differences between islands, and these results were compared to the phylogeny. Results Our data indicate that the Marquesas reed-warbler is in fact a polyphyletic taxon including two independent lineages: the northern Marquesas reed-warbler, closely related to the Tuamotu reed-warbler, and the southern Marquesas reed-warbler, sister taxon to that endemic to the Kiribati. Analyses of morphological characters show that the size and shape features of the Marquesas reed-warblers exhibit high plasticity linked to adaptation to ecological factors, particularly habitat richness (the diversity of vegetation structure that provides suitable resources and habitat for reed-warblers, simplified here as the number of indigenous plant species). Main conclusions Our results suggest that reed-warblers have successfully colonized the Marquesas archipelago, one of the most remote groups of islands in the Pacific Ocean, at least twice. Both events occurred more or less simultaneously at ca. 0.6 Ma, and are more recent than the islands' formation. We outline the taxonomic consequences of our phylogeny and discuss the supertramp strategy of reed-warblers in the Pacific.

Todiramphus chlorisis the most widely distributed of the Pacific's ‘great speciators’. Its 50 subspecies constitute a species complex that is distributed over 16 000 km from the Red Sea to Polynesia. We present, to our knowledge, the first comprehensive molecular phylogeny of this enigmatic radiation of kingfishers. Ten PacificTodiramphusspecies are embedded within theT. chloriscomplex, rendering it paraphyletic. Among these is a radiation of five species from the remote islands of Eastern Polynesian, as well as the widespread migratory taxon,Todiramphus sanctus. Our results offer strong support that PacificTodiramphus, includingT. chloris, underwent an extensive range expansion and diversification less than 1 Ma. Multiple instances of secondary sympatry have accumulated in this group, despite its recent origin, including on Australia and oceanic islands in Palau, Vanuatu and the Solomon Islands. Significant ecomorphological and behavioural differences exist between secondarily sympatric lineages, which suggest that pre-mating isolating mechanisms were achieved rapidly during diversification. We found evidence for complex biogeographic patterns, including a novel phylogeographic break in the eastern Solomon Islands that separates a Northern Melanesian clade from Polynesian taxa. In light of our results, we discuss systematic relationships ofTodiramphusand propose an updated taxonomy. This paper contributes to our understanding of avian diversification and assembly on islands, and to the systematics of a classically polytypic species complex.

We examined the relationship between the Corsican nuthatch Sitta whiteheadi, a passerine endemic to the island of Corsica and Corsican pine Pinus nigra laricio forest, its virtually exclusive habitat, currently restricted to inland mountains. The Corsican nuthatch prefers older Corsican pine stands with tall, large trees, and avoids younger stands, both in the breeding and wintering seasons. This preference is explained by the greater availability of pine seeds from older trees. Territorial adults are almost completely sedentary, a trait that is influenced by seed hoarding behaviour. From late autumn to early spring (i.e., when cones are mature), and during sunny weather (i.e., when cones are open), nuthatches remove pine seeds from cones and cache them on branches and under the bark of trunks. The birds retrieve the cached seeds in cold and wet weather. The presence of old Corsican pine stands appears to be a key-factor in the survival of the Corsican nuthatch, whose habitat is currently threatened by logging and fires.

The endemic Corsican Nuthatch Sitta whiteheadi population is small and currently restricted to mountain forests of Corsican Pine Pinus nigra laricio. An estimate of annual survival rate is an important parameter to allow evaluation of extinction risk. Adult Corsican Nuthatches were colour‐ringed and resighted on territory in the Ascu Valley, central Corsica, from 1998 to 2005. Mark–recapture methods were used to estimate the annual apparent survival rate of male Corsican Nuthatches as 0.616 (95% CI 0.524–0.700), the best model being independent of time. The longest lifespan recorded for any individual was five years and seven months. During the study, there was no strong evidence that annual survival was affected by the variation in a key food source, Corsican Pine seeds.

Capsule Food availability determines date of clutch initiation, and predation is the main cause of clutch failure. Aims To describe several aspects of the breeding biology of Corsican Nuthatch (mating system, occupation of territories, fecundity, breeding period, levels and impact of predation), in relation to abiotic parameters (altitude, rain, temperature) and feeding resources. Methods The reproductive ecology of the endemic Corsican Nuthatch was studied from 1998 to 2003 in the Ascu forest, central Corsica, using an infrared camera for nest controls. Results The annual rate of re-occupation of territories was high and the birds often used the same nesting tree. The dates of clutch completion ranged from 5 April to 16 June. There were no genuine second clutches, but sometimes a replacement clutch was laid. Clutch size varied from four to six eggs (x = 5.1, n = 21) and brood size at fledging from three to six young (x = 4.3, n = 28). We found a correlation between the abundance of pine cones and the ons...

The passerine genus Pomarea (monarchs, Monarchidae) is endemic to eastern Polynesia, where it is distributed on high volcanic islands of the Cook, Society, and Marquesas archipelagos. Recent extinctions of these birds have been documented on several islands, and most of the remaining forms are threatened by introducted rats (Rattus rattus) and habitat loss. We used mitochondrial DNA markers to develop a phylogeny of the entire genus Pomarea, including extinct taxa. This phylogeny was compared to geological data of the eastern Polynesian islands, with emphasis on the Marquesas archipelago where Pomarea has undergone its most extensive diversification. The phylogeny of Pomarea monarchs is consistent with the sequential appearance of the Marquesas islands. We approximated the ages of the lineages using molecular-clock and Bayesian methods that incorporate geological data. Both analyses showed differences of 1 to 2 million years between the ages of most islands and the ages of the nodes. We suggest that these differences are due to a latent period during which the islands were emergent but not successully colonized by Pomarea taxa. Phylogenetic hypotheses suggest that several species are polyphyletic. We outline the taxonomic consequences of our tree as well as implications for the evolution of sexual dimorphism in monarchs. Biogeografía de Pomarea: Un Género Endémico del Este de Polinesia Cercano a la Extinción Resumen. El género de aves paserinas Pomarea (Monarchidae) es endémico del este de Polinesia, donde se distribuye en las islas volcánicas de gran elevación de los archipiélagos Cook, Society y Marquesas. En varias islas se han documentado extinciones recientes de estas aves y la mayoría de las formas remanentes están amenazadas por ratas introducidas (Rattus rattus) y por la pérdida de hábitat. Empleamos marcadores de ADN mitocondrial para determinar la filogenia de todo el género Pomarea, incluyendo los taxones extintos. Esta filogenia fue comparada con datos geológicos de las islas polinésicas del este, poniendo énfasis en el archipiélago Marquesas donde Pomarea ha experimentado la diversificación más amplia. La filogenia de Pomarea es consistente con la aparición secuencial de las islas Marquesas. Estimamos las edades de los linajes usando los métodos de reloj molecular y Bayesiano que incorporan datos geológicos. Ambos análisis mostraron diferencias de 1 a 2 millones de años entre las edades de la mayoría de las islas y las edades de los nodos. Sugerimos que estas diferencias se deben a un período de latencia durante el cual las islas estuvieron emergidas pero no fueron colonizadas exitosamente por taxones de Pomarea. Las hipótesis filogenéticas sugieren que varias especies son polifiléticas. Destacamos las consecuencias taxonómicas de nuestro árbol así como las implicancias para la evolución del dimorfismo sexual en Pomarea.

The Corsican Nuthatch is a passerine endemic to Corsica island. Its habitat mostly consists in old stands of Corsican pine and locally of Maritime pine. Large fires affected several mountain forests during the summer of 2000. Our objective is to estimate the impact of these fires on Corsican nuthatches population. Among the forest stands occupied by this bird, 848 ha of Corsican pines and 275 ha of Maritime pines were either totally “charred” or simply “browned”. The ranges considered as “charred” amounted to 20.1 % for the Corsican pine and 14.6 % for the Maritime pine. Considering densities measurements obtained from several mapping censuses in unburned forests, we estimate at 25-38 the number of territories eliminated because the stands were completely burned, and at 47-80 the number of territories more or less affected by fire or salvage cutting, the total representing about 4 % of the Corsican nuthatch population. However, data on burnt surfaces did not take into account forest mosaic where nuthatches are able to survive. We then discuss the direct effects of fires on the nuthatches (disappearance from territories owing to the fires itself , or to postfire logging) and the secondary effects (delayed mortality of pines, difficulties for the birds to find new nesting sites and/or to obtain food from the cones during the following winter.), Endémique de Corse, la sittelle corse est un passereau dont l’habitat est constitué par les peuplements matures de pin laricio, très localement de pin maritime. Après les incendies qui ont parcouru ou brûlé plusieurs massifs forestiers d’altitude (forêts de Corte, Tavignanu, Ghisoni, Rospa sorba, Vizzavona, Noceta, Muracciole, Vivario et de Pineta) au cours de l’été 2000, nous tentons une évaluation de l’impact sur la population de cette espèce en tenant compte de l’intensité du passage du feu et de la qualité des peuplements forestiers concernés. Parmi les types de peuplements fréquentés par les sittelles corses, on a relevé 848 ha de pins laricio (75,5 %) et 275 ha de pins maritimes (24,5 %) calcinés et plus ou moins roussis. Les superficies considérées comme «calcinées» représentaient 20,1 % des surfaces parcourues par le feu pour le pin laricio et 14,6 % pour le pin maritime, et les superficies «roussies» représentaient 55,6 % pour le pin laricio et 9,6 % pour le pin maritime. En se basant sur des densités moyennes mesurées dans différents quadrats en forêt non brûlée, on estime à 25-38 le nombre des territoires de sittelle corse désertés à la suite des feux car les peuplements ont calciné ou ont été coupés, et à 47-80 , le nombre des territoires affectés à des degrés divers pouvant aller jusqu’à l’abandon. Nous estimons que les seuls incendies de 2000 auraient pu affecter environ 4 % de l’effectif de l’espèce. Cependant, les données sur les superficies brûlées ne prennent pas en compte les mosaïques dans les lesquelles les sittelles pourraient se maintenir. Nous examinons les effets des incendies sur les sittelles en considérant les effets directs (disparition des territoires par le feu et les coupes de récupération) et les effets indirects ou différés (mortalité différée des pins, difficultés pour les oiseaux à trouver des sites de reproduction suite à la combustion des arbres morts, et à s’alimenter suite à une diminution des cônes accessibles en hiver)., Thibault Jean-Claude, Prodon Roger, Moneglia Pasquale. Estimation de l’impact des incendies de l’été 2000 sur l’effectif d’un oiseau endémique menacé : la sittelle corse (Sitta whiteheadi). In: Ecologia mediterranea, tome 30 n°2, 2004. pp. 195-203.

Understanding the decline and extinction of species has become critical to conservation biology. The five monarch species of the genus Pomarea, endemic to the southeastern Pacific, are all listed as threatened. Introduced mammals and birds are believed to be responsible for their rarefaction. We analyzed the historical and current distribution of monarchs and introduced animals and found no relation between presence of Polynesian rats (Rattus exculans) and monarch distribution. There was a highly significant correlation between the arrival of the black rat (Rattus rattus) and the decline and extinction of monarch populations. The extinction of monarch populations after colonization by black rats tended to take longer on larger islands than on smaller ones. On islands without black rats, monarchs persisted even where forests have been reduced by more than 75%. After an island was colonized by black rats the number of monarch pairs with young decreased dramatically. Eggs in artificial nests placed in sites used by monarchs were only preyed upon by black rats. No eggs were preyed upon by Polynesian rats (Rattus exulans) or introduced birds. Monarch nests were mainly placed on horizontal branches inside the canopy and were more accessible than nests of Polynesian warbler (Acrocephalus caffer), a species still locally abundant. Warbler nests were placed higher up on vertical branches near the top of trees. These studies suggest that nest predation by black rats has been the main cause of monarch decline. However observations of direct aggression of adult monarchs by introduced red-vented bulbuls (Pycnonotus cafer), especially when monarchs raise their young, suggest that introduced birds could aggravate the decline of monarch populations already weakened by black rats. We discuss the practical implications of these findings for monarch conservation.

Habitat expansion is a commonly recognized feature of the insular syndrome. It has been explained either by restricted dispersal, intraspecific spillover resulting from density inflation, benign and predictable climate, or by the ecological release that results from species impoverishment. The latter hypothesis has been frequently invoked to explain shifts and/or broadenings of elevational ranges on islands. In this paper, we compared the elevational distribution of 85 terrestrial breeding bird species on a Mediterranean island (Corsica) with their mainland counterparts in a control area of similar altitude, latitude, and climate (Eastern Pyrenees). We calculated specific altitudinal amplitudes in both areas from the upper and lower limits of the bird ranges in the breeding season. We then calculated Island/Mainland Amplitude Ratio (IMAR) for each species. The ratios we found showed an overall trend in favor of range compressions on Corsica, despite a lower number of species on the island than on the main...

Summary: We report numbers and distributions of the breeding seabird community of the Gambier Islands (Eastern Polynesia, South Pacific Ocean), obtained in 1995 and 1996. Comparing these data with those collected in 1922, 1965‐69 and 1971, we assess the extent of changes in distribution and numbers of seabirds. None of the 14 species recorded previously to 1995‐96 has disappeared, but numbers and ranges of all the tern species have decreased. Breeding of three additional species ( Pterodroma spp.) has been discovered or confirmed in 1995‐96, though their numbers are very small. We also identified an unknown Cookilaria petrel, of which a wing was collected in 1922 on Mangareva, but which was not recorded later. Although seabird diversity on Gambier Islands is high, no species breeds in large numbers. Indeed, several species have tiny population sizes, and concern is therefore expressed for the future of this seabird community. Data on seabirds in Eastern Polynesia are scanty, owing to the difficulties of reaching the 141 main island groups, which are spread over more than 4 000 000 km2. Moreover, no breeding site has been monitored regularly during the 20th century. Information related to seabirds comes from a few expeditions mostly led by natural history museums (see Holyoak & Thibault 1982 for details): in the 1920s by the Whitney South Sea Expedition for the American Museum of Natural History, New York (account in several issues of American Museum Novitates); in the 1960s by the Museum National d’Histoire Naturelle (Lacan & Mougin 1974); in the 1970s by the Ecole Pratique des Hautes Etudes (Holyoak & Thibault 1984); and since 1980 by several institutions and the Government of French Polynesia (e.g. Thibault & Varney 1991; Brooke 1995). The aims of this paper are to present comparative data on numbers and distribution of breeding seabirds of the Gambier Islands during the 20th century, using results from previous expeditions as well as recent data collected in 1995 and 1996.

Summary Aim The Mediterranean sea is a winter productive oligotrophic basin where Atlantic water replaces water lost through evaporation, this influx being a major source of productivity and fertility. The long coastlines and the large number of islands cause high oceanographic heterogeneity. Moreover, during its geological history, it has dried out several times. So we describe the consequences of these particular features on species richness, distribution, and breeding ecology of marine birds. Location The Mediterranean sea (including the Black Sea and the Sea of Azov) communicates with the Atlantic Ocean only through a 14 km wide channel (Straits of Gibraltar), and since 1869, with the Red Sea through the Suez Canal. Methods The Mediterranean was subdivided into different areas, according to physical oceanographic entities and productivity, linked to numbers and distribution of both breeding and wintering marine birds (defined as species strongly dependent on marine resources, breeding only on islands and/or the coastline). Results The total marine bird biomass, and species diversity, are lower in the Mediterranean than in the near Atlantic. The eastern Mediterranean, with lowest primary productivity, contains fewer marine bird taxa than the more productive western part. Taxa which mainly occur in the western and southern parts of the Mediterranean migrate through the Straits of Gibraltar to winter in the southern Atlantic, while those inhabiting the northern and eastern parts are sedentary, as a result of differences in species composition. Northern coastal basin communities (i.e. the Tyrrhenian and the Balearic Seas), are composed of less pelagic, and earlier breeding species, that rear chicks during the productive season. These latter taxa are actually the most typical Mediterranean taxa, in terms of endemism. Main conclusions The Mediterranean marine bird community is not tropical, but rather, shows the highest affinity with the Atlantic temperate community. Its level of endemism is however high and comparable to other confined basins such as the Red Sea. Resume Objectif La Mer Mediterranee constitue un bassin oligotrophe, principalement productif en hiver. Les eaux de l’ocean Atlantique y compensent la masse d’eau perdue par l’evaporation, cet afflux constituant egalement une source majeure de productivite et de fertilite. La grande longueur de cotes et le nombre eleve d’iles sont a l’origine de sa forte heterogeneite oceanographique. De plus, elle s’assecha a plusieurs reprises au cours de son histoire geologique. Nous nous proposons de decrire les consequences de ces particularites sur la richesse specifique, la repartition et l’ecologie de la reproduction des oiseaux marins. Localisation du site La Mer Mediterranee (comprenant la Mer Noire et la Mer d’Azov) communique avec l’Ocean Atlantique par un detroit de 14 km de large (Detroit de Gibraltar), et depuis 1869, avec la Mer Rouge par le Canal de Suez. Methodes La Mediterranee a ete divisee en plusieurs regions ou les entites physiques oceanographiques et la productivite ont ete reliees aux effectifs et a la repartition des oiseaux marins (definis comme des especes dependant surtout des ressources marines et nichant seulement dans les iles ou le long des cotes). Resultats La biomasse totale des oiseaux marins, comme la diversite specifique, sont plus faibles en Mediterranee que dans le proche ocean Atlantique. La partie orientale, avec une productivite primaire plus basse, abrite moins de taxons d’oiseaux marins que la partie occidentale. Les principaux taxons rencontres dans les parties ouest et sud migrent par Gibraltar pour hiverner dans la partie sud de l’Atlantique, alors que ceux habitant au nord et a l’est sont sedentaires. Les communautes du nord du Bassin (mers Tyrrhenienne et Baleares) sont composees d’especes moins pelagiques, se reproduisant plus tot, profitant de la periode de productivite de la Mediterranee. Ces derniers taxons sont consideres comme les plus typiquement mediterraneens, en terme d’endemisme. Principales conclusions La communaute des oiseaux marins de Mediterraneen n’est pas tropicale, mais elle montre plutot des affinites avec la communaute de l’Atlantique temperee. Son niveau d’endemisme est cependant eleve et comparable a celui d’autres bassins confines, comme la Mer Rouge.

Close inbreeding is known in several bird species, although it is seldom observed (Greenwood et al. 1978, Craig and Jamieson 1988, Gibbs and Grant 1989, Bensch et al. 1994). Inbreeding can have important evolutionary consequences because it may carry both costs and benefits to fitness (Mayr 1963, Shields 1983, Greenwood 1989). However, the seemingly low rate of inbreeding in nature may result from the fact that documenting inbreeding requires long-term monitoring of marked individuals. Colonial waterbirds are good candidates for studies of inbreeding because they often exhibit high natal philopatry (Greenwood and Harvey 1982). Moreover, long-term studies allowing individual identification and monitoring are relatively easy and widespread in this group (Wooller et al. 1992). Curiously, however, only two cases of inbreeding have been reported for colonial waterbirds: Yellow-eyed Penguin (Megadyptes antipodes; Richdale 1957), and Mute Swan (Cygnus olor; Coleman et al. 1994). Here, we report two cases of close inbreeding in Cory's Shearwater (Calonectris diomedea) documented during an 18-year study. We also consider philopatric behavior in this species and its possible relationships with inbreeding. Cory's Shearwaters are highly philopatric (Ristow et al. 1990, Thibault 1993, Borg and Cachia-Zammit 1997), breeding only on islands in the Mediterranean Sea (C. d. diomedea), and along the west coast of Africa from the Cape Verde islands (C. d. edwardsii) to the Macaronesian and Berlenga islands (C. d. borealis). The biology of this species has been well documented, and geographic variation in biometric (Massa and Lo Valvo 1986), vocal (Bretagnolle and Lequette 1990), and genetic (Randi et al. 1989, Wink et al. 1993) traits tend to confirm this extreme philopatric behavior. Methods.-Our study was conducted on the Lavezzi Islands, south Corsica (300 to 400 breeding pairs). All adults and fledglings were banded and recaptured annually between 1978 and 1996 in five subcolonies totaling 104 to 133 nests (Thibault 1993); 1,045 chicks were banded during this period. Prospecting birds also have been recaptured, albeit irregularly (but more thoroughly since 1992; see Thibault 1993). Recaptured birds were sexed using bill dimensions that have about 95% predictive power (Ristow and Wink 1980, Granadeiro 1993, Thibault 1993).

We reconstruct the phylogeny of fruit doves (genus Ptilinopus) and allies with a dense sampling that includes almost all species, based on mitochondrial and nuclear sequence data. We evaluate the most likely biogeographic scenario for the evolution of this group that colonized many islands of the Pacific Ocean. We also investigate the evolution of one of the main plumage character of fruit doves (the color of the crown), and we propose several revisions of the group's systematics. All Ptilinopus taxa formed a monophyletic group that includes two morphologically distinct genera, Alectroenas and Drepanoptila, confirming a previous result found with less species and genes. The divergence time analysis suggests that the basal divergences within Ptilinopus dated to the Early Oligocene, and the biogeographic analysis indicates that fruit doves originated most probably from the proto New Guinea region. The earliest dispersals from the New Guinea region to Oceania occurred with the colonization of New Caledonia and Fiji. A large group of Polynesian species (Central and Eastern), as well as the three taxa found in Micronesia and four species from the Guinean-Moluccan region, form the "purpuratus" clade, the largest diversification of fruit doves within Oceania, which also has a New Guinean origin. However, the eastbound colonization of fruit doves was not associated with a significant increase of their diversification rate. Overall, the Melanesian region did not act as a cradle for fruit doves, in contrast to the New Guinea region which is found as the ancestral area for several nodes within the phylogeny.

Dispersal is critically linked to the demographic and evolutionary trajectories of populations, but in most seabird species it may be difficult to estimate. Using molecular tools, we explored population structure and the spatial dispersal pattern of a highly pelagic but philopatric seabird, the Cory's shearwater Calonectris diomedea. Microsatellite fragments were analysed from samples collected across almost the entire breeding range of the species. To help disentangle the taxonomic status of the two subspecies described, the Atlantic form C. d. borealis and the Mediterranean form C. d. diomedea, we analysed genetic divergence between subspecies and quantified both historical and recent migration rates between the Mediterranean and Atlantic basins. We also searched for evidence of isolation by distance (IBD) and addressed spatial patterns of gene flow. We found a low genetic structure in the Mediterranean basin. Conversely, strong genetic differentiation appeared in the Atlantic basin. Even if the species was mostly philopatric (97%), results suggest recent dispersal between basins, especially from the Atlantic to the Mediterranean (aprox. 10% of migrants/generation across the last two generations). Long-term gene flow analyses also suggested an historical exchange between basins (about 70 breeders/generation). Spatial analysis of genetic variation indicates that distance is not the main factor in shaping genetic structure in this species. Given our results we recommend gathering more data before concluded whether these taxa should be treated as two species or subspecies. © 2013 Genovart et al.

We studied the coexistence of four species of Sylvia warblers living in Mediterranean matorral in order to identify the respective role of ecological segregation and of interspecific territoriality in explaining the local distribution of these four species. Data on habitat use, foraging behaviour and interspecific spacial segregation were collected on Corsica and on Spargi (Sardinia) islands. Despite large overlap in patch selection and in foraging behaviour the four species did segregate ecologically and behaviourally while foraging (differences in the choice of plant species used for foraging, in the height of the plant selected, in the selection of the portion of the plant volume used and in the selection of the plant structure explored). Complementarity in foraging behaviour was observed in the morphologically and ecologically closest species: the Dartford (Sylvia undata) and the Marmora's (Sylvia sarda) warblers. We did not observe any evidence of direct interspecific interactions in song, alarm, or aggressive behaviour. Nor did we observe patterns of spatial distribution that would support the idea of coexistence by interspecific territorial exclusion. These results contrast with the results of Cody & Walter (1976) suggesting interspecific territoriality in Mediterranean Sylvia warblers. They are consistent with other published results emphasizing ecological differences as explanation for species coexistence.

SummaryThe distribution of Tahitian landbirds in the early twentieth century and at presented here together with maps. Three categories may be recognized: (1) species with a declining distribution owing to changes in habitats (Green-backed Heron), (2) stable or increased species, including local and earlier introduced species, and (3) newly introduced species (Zebra Dove, Red-vented Bulbul, Silvereye and Crimson-backed Tanager). Moreover, owing to their low population numbers, two species, the Pacific Pigeon and the Tahiti Monarch, are on the verge of extinction even if their distribution has not changed notably during this century.Les repartitions des oiseaux terrestres reproducteurs de Tahiti, au début et à la fin du 20e siècle, sont présentées sous forme de cartes. Trois catégories d'espèces sont dis-tinguées: (1) espèce dont la répartition est en déclin a la suite des modifications d'habitats (Héron vert), (2) espèces stable ou en légère augmentation, chez qui on trouve des oiseaux locaux et des oiseaux introduits, et enfin (3) les espèces introduites durant le 20e siècle (Tourterelle striée, Bulbul à ventre rouge, Zosterops à poitrine grise et Tangara cramoisi). II apparaît que deux espèces, le Carpophage du Pacifique et le Monarque de Tahiti, sont aujourd'hui très menacées, même si leur répartition n'a pas régressé d'une façon significative.