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SummaryPelagic seabird populations have declined strongly worldwide. In the North Atlantic there was a huge reduction in seabird populations following the European colonization of the Azores, Madeira and Canary archipelagos but information on seabird status and distribution for the subtropical region of Cabo Verde is scarce, unavailable or dispersed in grey literature. We compiled and compared the historical and current distribution of all seabird species breeding in the Cabo Verde archipelago, updated their relative abundance, investigated their inland habitat preferences, and reviewed their threats. Currently, the breeding seabird community in Cabo Verde is composed of Bulwer’s Petrel Bulweria bulwerii, White-faced Storm-petrel Pelagodroma marina aedesorum, Cape Verde Shearwater Calonectris edwardsii, Cape Verde Storm-petrel Hydrobates jabejabe, Cape Verde Petrel Pterodroma feae, Boyd's Shearwater Puffinus lherminieri boydi, Brown Booby Sula leucogaster, and Red-billed Tropicbird Phaethon aethereus. One breeding species is currently extinct, the Magnificent Frigatebird Fregata magnificens. The relative abundance of Cape Verde Shearwater, Boyd’s Shearwater, Cape Verde Petrel, and Cape Verde Storm-petrel was determined from counts of their nocturnal calls in Santo Antão, São Vicente, Santa Luzia, Branco, Raso and São Nicolau. Cape Verde Petrel occurred only on mountainous islands (Santo Antão, São Nicolau, Santiago, and Fogo) from mid-to high elevations. Larger species such as the Cape Verde Shearwater and Boyd’s Shearwater exhibited a wider distribution in the archipelago, occurring close to the coastline but at lower densities on populated islands. Small procellariforms such as the Cape Verde Storm-petrel occurred at high densities only on rat-free islets and in steep areas of main islands where introduced cats and rats are unlikely to occur. The main threats to seabird populations in Cabo Verde range from predation by introduced predators, habitat alteration or destruction, and some residual human persecution.

French Guiana region is one of the most productive in the world and hosts a wide variety of marine vertebrates. In the same time, anthropogenic activities are a growing concern in French Guiana, both in coastal and offshore areas. However, few studies are published on marine mammals, seabirds and potential interactions. Twenty-three marine mammal species are known to occur in the Exclusive Economic Zone (EEZ) and important seabird breeding sites are located in the area. Most of the existing literature relates to breeding birds and coastal cetaceans, but the continental slope appears to be an essential habitat for marine mammals and seabirds. Between October 22 and November 23, 2017, an oceanographic survey was conducted on the Guiana slope to study the quality of sediments and water. Three marine fauna observers (MFOs) were onboard to record sightings of marine mammals and seabirds opportunistically. During 462 h of visual effort in good sighting conditions, 313 sightings (824 individuals) were recorded: 61 marine mammals (501 individuals) and 252 seabirds (323 individuals). Seven seabird families were observed: Laridae (42%), Fregatidae (26%), Procellariidae (12%), Stercorariidae (10%), Hydrobatidae (4%), Sulidae (2%) and Phaethontidae (1%). 3% concerned wader species. The most frequently observed seabird species was the magnificent frigatebird ( Fregata magnificens ), as well as the common tern ( Sterna hirundo ), Cory’s shearwater ( Calonectris diomedea ) and the pomarine jaeger ( Stercorarius pomarinus ). Many Delphinidae species were observed ( Stenella longirostris , Stenella attenuata , Stenella frontalis , Delphinus delphis , Tursiops truncatus ) in addition to sperm whales ( Physeter macrocephalus ) and humpback whales ( Megaptera novaeangliae ). Only a few sightings of humpback whales have been previously recorded in this area. Sighted individuals were mainly mother-calf pairs suggesting that the area may be an extended part of a calving ground for humpback whales.

Compensating for wind drift can improve goalward flight efficiency in animal taxa, especially among those that rely on thermal soaring to travel large distances. Little is known, however, about how animals acquire this ability. The great frigatebird ( Fregata minor ) exemplifies the challenges of wind drift compensation because it lives a highly pelagic lifestyle, travelling very long distances over the open ocean but without the ability to land on water. Using GPS tracks from fledgling frigatebirds, we followed young frigatebirds from the moment of fledging to investigate whether wind drift compensation was learnt and, if so, what sensory inputs underpinned it. We found that the effect of wind drift reduced significantly with both experience and access to visual landmark cues. Further, we found that the effect of experience on wind drift compensation was more pronounced when birds were out of sight of land. Our results suggest that improvement in wind drift compensation is not solely the product of either physical maturation or general improvements in flight control. Instead, we believe it is likely that they reflect how frigatebirds learn to process sensory information so as to reduce wind drift and maintain a constant course during goalward movement.

Climate change affects every crevice and corner of the ecological world. Already we see seasonal effects on important ecosystems such as the marine habitats of the Galápagos Archipelago. This paper looks at the year 2100 in the IPCC scenario A1B, looking specifically at Chelonia mydas agassizii and seeing whether it will be a “winner” or a “loser” under climate change. We discover that while neonate hatchlings may benefit from a compressed laying period that offers them protection by way of numbers, and speed from the increased ocean temperatures (SST), they lose out many other places. Frigatebird and reef fish predation will increase, hatchling size and fitness may decrease, and a surplus of female hatchlings will be produced, or none at all as nest temperatures rise above the thermal mortality limit. Chelonia mydas agassizii will need serious conservation help if we wish to keep it on this earth by the year 2100 even if we opt for the A1B strategy.

International audience; Since 2005, we have recorded annual episodes of alphaherpesvirus outbreaks in chicks of magnificent frigatebird Fregata magnificens on the Ile du Grand Connétable Nature Reserve in French Guiana. In 2009, we found sooty terns, Onychoprion fuscatus, that live sympatrically with frigatebirds, with visible clinical signs of a potential viral infection. To determine if the symptoms observed in sooty terns could be associated with an alphaherpesvirus previously identified in frigatebirds, we carried out molecular screening of samples collected from seven individuals. We identified and characterized a novel viral sequence from five birds. BLAST searches, pairwise nucleotide, and amino acid sequence comparisons, as well as phylogenetic analyses confirmed that the sequence belonged to the Herpesviridae family, of the Alphaherpesvirinae subfamily. We observed that it clustered with strains isolated from Podargidae (Caprimulgiformes), Columbiformes, and Falconiformes, but was distinct from the frigatebird herpesvirus. We have tentatively named it Onychoprion fuscatus alphaherpesvirus 1, (OfusAHV1). These two sequences, although found syntopic on the Ile du Grand Connétable, belong to two distinct alphaherpesvirus strains. Thus, the clinical symptoms showed by sooty terns do not likely result from a cross-species transmission event. Future work is needed to better characterize the virus and to investigate herpesvirus prevalence in healthy, free-ranging sooty terns, and to assess the impact of the virus on population viability.

International audience; The early life of animals is a period of high mortality, when foraging capacities are assumed to be improved progressively. In birds, this critical period involves the improvement of the flight. How do young birds gain these capacities has rarely been studied in natural conditions especially in seabirds that spend most of their life at sea. We used detailed GPS and body acceleration data on 37 great frigatebirds (Fregata minor), to test the hypothesis that juveniles starting their first flights have lower flying capacities than adults, but that these capacities will improve during a long learning period, before independence from parents, specific to this seabird that can spend months on the wing at sea. We found that most flight components improved over time to tend towards those of adults, especially the travel speed, range, duration and maximum altitude of trips. However, unexpectedly, juveniles had higher ascent rates, soaring and gliding capacities above the sea than adults. Moreover, energy expenditure of juveniles was similar to adults during low cost travelling movements and during active foraging, but juveniles spent more time foraging actively than adults. Our results suggest that flight tactics based on long‐distance effortless movements specific to this family are acquired during a long period, but soaring and gliding capacities are already inherited by juveniles and possibly favoured by morphological adaptations specific to juveniles. These adaptations might explain the extreme dispersive capacities of juveniles.

Tracking of seabirds has been used to identify foraging hotspots, migratory routes and to assess at-sea threats facing populations. One such threat is the potential negative interaction between sea...

The work on Ascension Island was partly funded by a Darwin Grant (# 19026) to Ascension Island Government and the University of Exeter (A.B. and B.G.), managed on-island by N.W. and S.W. Nigel Butcher and Andrew Asque assisted with preparation of loggers and equipment, and Elizabeth Marsden kindly provided the base station to download data.

Species that inhabit spatially-distinct regions at different stages of their lifecycle pose challenges to conservation managers, particularly when distributions span international or jurisdictional boundaries. Despite the importance of non-breeding habitat to the persistence of individuals and species, there remains limited information on the habitat requirements of many species during the non-breeding period. We used Global Positioning System tracking devices to determine the non-breeding movements of Great Frigatebirds, Fregata minor, and Lesser Frigatebirds, F. ariel, across much of Southeast Asia. These data were analysed with MaxEnt modelling to identify important habitat features for non-breeding frigatebirds and inform priorities for targeted conservation measures. Models with the greatest predictive performance were influenced strongly by bathymetry. Predicted habitat suitability was greatest in shallow waters. Similarly, warmer waters had greater predicted suitability during the wet season. We also identify 45 roosting sites that form an important component of the habitat used by non-breeding frigatebirds in this region. The existing marine protected area (MPA) network contains only a small proportion of habitat identified as suitable or optimum for non-breeding frigatebirds. This is of particular concern given that some parts of the region’s marine environment are among the most heavily human-impacted in the world. Our findings can be used to implement spatially-targeted conservation measures such as education campaigns focusing on bycatch reduction and subsidies for bycatch reduction methods (e.g., streamer lines) for fisheries operating in suitable and optimum habitat. They could also inform placement of additional MPAs to maintain habitat integrity in areas we identified as suitable or optimum habitat, particularly when these habitats occur in close proximity to roosting sites. Such approaches will likely provide benefits to frigatebird populations tracked in the present study as well as those dispersing to the study region from other ocean basins.

We present the first record of the Ascension Frigatebird (Fregata aquila) for the Americas by retrieving coordinates from an individual equipped with a satellite transmitting device. As part of a wider study on the spatial and behavioral ecology of this species, we tracked a single juvenile frigatebird that entered into Brazilian waters as defined in the guidelines set forth by the Brazilian Ornithological Records Committee and the South American Checklist Committee. In total, this individual traveled ∼45,000 km over a 3.5-month period before transmissions ceased close to the exclusive economic zone of Sierra Leone. Based on the potential for this species to wander, the Ascension Frigatebird should be considered when attempting to identify any frigatebird in the Atlantic Ocean. Importantly, this record demonstrates the great potential for satellite telemetry to inform national ornithological and conservation organizations on the presence of pelagic seabirds that may otherwise be overlooked by vis...

In this paper, we describe the skulls of Magnificent Frigatebird Fregata magnificens (Fregatidae) and Brown Booby (Sulidae) Sula leucogaster, with focus on the structures associated with the Musculi mandibulae. We discuss the results in the context of the feeding biology of the two species, which feed mainly on flying fish and squids. Frigatebirds capture prey from just above, or just below, the water surface in flight. The hook-shaped Apex maxillae in F. magnificens can be viewed as an adaptation for grasping prey from near the water surface. Boobies catch prey by plunging; thus, the dorsoventrally flattened skull and conical bill of S. leucogaster may reduce water resistance when it dives, or swims underwater. The bill is long in both species, such that it is on average 70% of the whole skull length in F. magnificens and 60% in S. leucogaster. Consequently, the Mm. mandibulae in the two species are more posteriorly positioned relative to the Apex rostri. This results in low mechanical advantage for the mandible opening-closing lever, indicating adaptations for a fast, rather than a strong, bite. Fast-moving mandibles would be advantageous for ‘mandibulating’ prey while swallowing. The Fossa musculorum temporalium and the Palatum osseum in both species provide a broad area for origins of the Musculus adductor mandibulae externus (all parts) and the Musculus pterygoideus. The Processus orbitalis quadrati is longer and thicker in F. magnificens than in S. leucogaster, and so is the Musculus pseudotemporalis profundus. We suggest that Mm. adductores mandibulae are relatively well developed in the two species; therefore, their mandibulae are still probably capable of a powerful adduction. In both species there is a mechanisms that contribute to protect the jaws from disarticulation and damage. Such mechanism involves the incorporation of a ‘flange-like’ Crista intercotylare on the Margo medialis cotylae medialis fossae articularis quadratica that grips the Condylus medialis quadrati. In S. leucogaster, the retractor-stop ‘notch’ formed by Ossa lacrimale et nasale also serves to protect the jaws against sudden external forces when birds are diving or swimming underwater for prey. A more detailed hypothesis for the jaw movements and strength in F. magnificens and in S. leucogaster and their relation with feeding habits should necessarily incorporate data on the jaw and anterior neck musculatures.

Flight traits mediated by symmetry should be constrained by mechanical or aerodynamic effects. Natural asymmetry and external tail feather length could have unfavorable effects on aerodynamic performance and affect the survival of highly aerial birds. The Magnificent Frigatebird, Fregata magnificens , is a long-lived, highly aerial seabird with a deeply forked tail, and an extraordinary division of labor between sexes. Its flight pattern is soaring and dynamic, it also has fast active flight and acrobatic maneuvers. We explore the possible effect of tail streamer asymmetry and tail length on annual apparent survival of Magnificent Frigatebirds by using 6 years (2000-2005) of capture-mark-resighting of live-encounter data analysis. Male frigatebirds showed significant differences between left and right tail streamer length, and tail asymmetry differences between sexes. Models did not find a clear effect of tail streamer asymmetry and tail length, as individual covariates, on annual apparent survival by sex. Natural variation in a secondary sexual trait like those explored here likely does not affect apparent survival. Life-history strategies such as flight pattern, breeding behavior, and tail moult may constrain any negative effects. Longer mark-resighting studies and additional modelling could answer conclusively the association between survival and flight traits in Magnificent Frigatebirds.

International audience; Outbreaks of wildlife diseases are occurring at an unprecedented rate. In French Guiana, recurrent episodes of frigatebird chicks’ mortality due to a viral disease that first appeared in 2005 have recently turned into massive mortality episodes (85–95%) of chicks. One of the suggested hypotheses behind the appearance of the disease is food limitation due to the recent decline of local shrimp fishery boats on which frigatebirds rely for opportunistic feeding. We therefore experimentally fish‐supplemented frigatebird chicks with and without clinical signs of the disease. Food supplementation protected all chicks from the appearance of clinical signs of the disease and increased survival perspectives of sick chicks. These results suggest that food shortage might decrease resistance of chicks to infectious diseases and that using a specifically tailored food supplementation regime could be a complimentary tool to protect frigatebirds and other endangered birds from disease outbreaks threatening them with extinction.

International audience; 1. Diet quality may have an important effect on the regulation of oxidative statusand the immune system during an infectious disease. However, the relationshipamong intake of specific dietary molecules, an individual’s oxidative status and theoccurrence and progress of a viral disease remains almost unexplored in free‐livingorganisms.2. Here, we study a wild, long‐lived animal, the Magnificent frigatebird Fregata magnificensto investigate: (a) the differences in a number of physiological traits (biomarkersof blood oxidative status, corticosterone (CORT), immunity andinflammation) between sick and healthy nestlings; and (b) whether experimentallyincreased intake of resveratrol (a polyphenol with antioxidant and antiviral properties)affects these physiological markers during the progress of a severe viraldisease.3. Birds with visible clinical signs showed higher oxidative damage, haemolysis andhaemagglutination scores and lower antioxidant defences in comparison withbirds without clinical signs. At the end of the experiment, supplemented birdsshowed the following: (a) increased plasma haptoglobin levels and circulating antioxidantdefences; (b) reduced generation of lipid oxidative damage; and (c) negligibleto no influence on immune markers, baseline CORT levels and activity ofantioxidant enzymes.4. Our work illustrates how the availability of specific organic molecules in the dietmay constrain the individuals’ capacity to cope with viral infections in free‐livinganimals

In recent decades, several seabird populations have declined globally due to anthropogenic activities. In Brazil, 14 seabird species breed at four oceanic islands and one atoll: the Abrolhos, Fernando de Noronha, and Sao Pedro and Sao Paulo (SPSPA) archipelagos; the Trindade/Martin Vaz Islands; and the Atol das Rocas. Seven species are listed as nationally threatened by extinction. This study aimed to present new information on breeding seabird populations in Brazilian oceanic islands, compile all available data previously published and, when possible, to provide updated information on population estimates from censuses carried out sporadically at different islands between 2006 and 2013. Based on new data and the thorough review provided here, of the 35 seabird breeding populations analysed, 14% were increasing (as Red-billed Tropicbird Phaethon aethereus , Magnificent Frigatebird Fregata magnificens and Brown Noddy Anous stolidus in Abrolhos), 11% were decreasing (as Brown Booby Sula leucogaster in Atol das Rocas and Great Frigatebird Fregata minor in Trindade Island), 23% were stable (as White-tailed Tropicbird Phaethon lepturus in Fernando de Noronha and Brown Noddy and Black Noddy Anous minutus in Sao Pedro and Sao Paulo Archipelago), and the remaining 49% were unknown or not possible to evaluate. The Red-footed Booby ( Sula sula ) is locally extinct in Trindade Island, however there are colonies of only a few individuals of other species, such as the Audubon's Shearwater Puffinus lherminieri and Red- billed Tropicbird in Noronha, Black Noddy in Martin Vaz, and Great ( Fregata ariel trinitatis ) and Lesser ( F. m. nicoll i) Frigatebirds in Trindade, that may become extinct soon. Censuses at distinct periods of the breeding cycles and protocols were highly variable, making temporal comparisons difficult. These results indicate an urgent need for long-term studies to improve the scenario to assess seabird population trends based on comparable methodologies, in order to determine trends in the future.

We report a documented record of a Great Frigatebird Fregata minor at Fernando de Noronha, 360 km off the coast of northeast Brazil in the equatorial Atlantic. We presume that the bird at Fernando de Noronha originated from Trindade Island, c.1,800 km to the south, since it is the species' nearest breeding site, and we hypothesise that it moved with the south-east trade winds towards the north-east Brazilian coast.

Las diferentes anormalidades en el plumaje son resultado de múltiples factores ambientales y genéticos. En México se han reportado aberraciones en el plumaje de las aves, no obstante, todas se han clasificado como leucísticas (color blanco del plumaje debido a un gen recesivo). Otros tipos de aberraciones en el plumaje se han identificado, tales como el encanecimiento progresivo, el melanismo o las mutaciones, como la marrón, aún no reportadas para México. Durante trabajo de campo con aves en el estado de Nayarit, observamos individuos de seis especies de aves con plumajes anormales que caracterizamos como no leucísticos. Determinamos encanecimiento progresivo en pijije ala blanca (Dendrocygna autumnalis), zopilote aura (Cathartes aura), playero menor (Calidris minutilla) y golondrina tijereta (Hirundo rustica); plumaje marrón en avoceta americana (Recurvirostra americana) y plumaje ino en fragata magnífica (Fregata magnificens). El plumaje marrón y el ino involucran factores genéticos. El encanecimiento progresivo fue la aberración observada más frecuente, y diversos factores, que pueden ser genéticos, están involucrados en su expresión. Estas aberraciones, sin embargo, no habían sido previamente reportadas para aves en México.

This study used feathers of brown booby (Sula leucogaster) and magnificent frigatebird (Fregata magnificens) from Cagarras Archipelago, an area under strong anthropogenic influence, for evaluating the exposure of these seabirds to Cd, Sn, Mn, Cu and Se. Average concentrations (µg.Kg-1, dry weight) in feathers of brown booby were Cd 28.1, Sn 210.6, Cu 8233.4, Se 2343 and Mn 1635.7 and for frigatebird were Cd 82.9, Sn 319.6, Cu 8008.6, Se 3026 and Mn 5143. Regarding brown boobies, no significant difference was found between sexes or age (adults vs. juveniles) considering all measured elements. In addition, no significant correlation was observed between Sn, Cd and Cu concentrations and the following biometric parameters (BPs): body weight (BW) and tarsus (TrL), wing (WL), tail (TiL) and beak length (BL), for both species. However, significant negative correlations were observed between Se concentrations and TrL for magnificent frigatebird and brown booby. Concerning possible interspecific dissimilarities for juveniles, there was no significant difference for Sn, Se and Cd concentrations; however, significantly higher Cu and Mn concentrations were found in brown boobies. When adults were compared, significantly higher Cd and Mn concentrations were found in magnificent frigatebirds. These interspecific differences may occur due to dissimilarities in diet; however, the feeding habits of these seabirds around the study area are unknown. Additional studies on the diet of these species are necessary to shed further light on the interspecific differences verified. The concentrations found in the feathers of the seabirds in question do not denote a risk for the survival of the seabirds of the Cagarras Archipelago. DOI: http://dx.doi.org/10.17807/orbital.v10i2.1050

This study presents important morphometric and health parameters of 55 great frigatebirds from two locations on the Galápagos archipelago. All of the animals were robust, clinically healthy and behaving normally. This data adds to baseline health assessment values and provides reference blood parameter intervals., The great frigatebird, Fregata minor, is a widely distributed seabird native to the Galápagos archipelago. Haematology and blood chemistry parameters have been published for this species but not from the San Cristóbal and North Seymour great frigatebird breeding colonies. Analyses were run on blood samples drawn from 25 great frigatebirds captured by hand at their nests at Punta Pitt on San Cristóbal Island and 30 birds on North Seymour Island, Galápagos Islands. A portable blood analyser (iSTAT) was used to obtain near immediate field results for pH, pO2, pCO2, TCO2, HCO3−, haematocrit (Hct), haemoglobin (Hb), sodium (Na), potassium (K), chloride (Cl), ionized calcium (iCa), creatinine, urea nitrogen, anion gap and glucose. Blood lactate was measured using a portable Lactate Plus™ analyser. Average heart rate, respiratory rate, body weight, body temperature, biochemistry and haematology parameters were comparable to healthy individuals of other Fregatidae. The reported results provide baseline data that can be used for comparisons among populations and in detecting changes in health status among Galápagos great frigatebirds.

In order to protect the unique fauna of the Galapagos Islands, it is critical that we understand how and when parasites spread throughout the archipelago. There are several key components of host-parasite dynamics that influence parasite spread, including the basic reproductive rate of the parasite, host density, transmission mode, and host movement, among other factors. Host movement could be especially important in determining parasite spread in island systems like the Galapagos, because parasites are not always able to move larger distances unaided. Because some hosts (and vectors) show population genetic structure within the Galapagos Islands, we can make inferences about potential parasite spread from knowledge of host population connectivity. In this chapter, we review patterns of population connectivity in Galapagos vertebrates (hosts), arthropod vectors, and parasites, focusing on population genetic studies. Hosts with little to no population genetic structure and high rates of inferred movement (e.g., Galapagos fur seal, Galapagos penguin, great frigatebird, Galapagos dove, small ground finch, small tree finch, large tree finch) are the most likely to spread parasites. More research is needed on parasite spread, particularly studies that simultaneously estimate population connectivity of both host (or multiple hosts, including vectors) and parasite.

— Little information exists on nesting by seabirds and coastal waterbirds in Panama. The present study of the Gulf of Chiriqui complements our previous study of nesting waterbirds of the Gulf of Panama. In April 2012, about 4,000 nests of seven species of seabirds and other colonial waterbirds were identified during a complete survey by small plane and boat within and adjacent to the Gulf of Chiriqui. Seventeen colony sites were found, 12 of which are reported here for the first time. Nesting species included Brown Booby (Sula leucogaster; the most abundant species with nearly 2,500 nests), Brown Pelican (Pelecanus occidentalis), Magnificent Frigatebird (Fregata magnificens), Bridled Tern (Onychoprion anaethetus; second nesting site for Panama), Wood Stork (Mycteria americana; third nesting site for Panama), Great Egret (Ardea alba), and Cattle Egret (Bubulcus ibis). The largest nesting site in the Gulf of Chiriqui was the Islas Ladrones, with 2,200 Brown Booby nests (the largest site for this sp...

A humerus and a coracoid from the Early Eocene Wasatch Formation in the Washakie Basin of south-western Wyoming are the oldest materials (by ~2 million years) of the pelecaniform Limnofregata (Aves) and represent a new large species, Limnofregata hutchisoni sp. nov. This fossil is the oldest known member of the frigatebird lineage. Other than its large size relative to Limnofregata azygosternon and L. hasegawai, the new material is very similar morphologically to other known Limnofregata specimens. The size of this new species is comparable to the largest living species (e.g. Fregata minor and Fregata magnifiscens) and much larger than the two described species of Limnofregata. This fossil indicates that the hard minimum date previously advocated for molecular calibration of the split between Fregatidae and Suloidea is an underestimate by approximately two million years. The presence of early pelecaniform bird lineages (represented by Limnofregata and Masillastega) in limnic ecosystems prior to their known occurrences in marine deposits/habitats appears to indicate that some clades of pelecaniform birds may have undergone an evolutionary transition from freshwater to marine habitats in a pattern reminiscent of what has been suggested during the evolution of pinnipeds or that their palaeoecology included broader niches ranging across a variety of aquatic habitats. That transition in habitat occupation and the origin of many of the characteristic biological aspects present in the crown frigatebird clade likely occurred during a significant temporal gap (> 45 million years) in the fossil record of the frigatebird lineage after these earliest occurrences in the Early Eocene and before the oldest records of the extant Fregata species in the Pleistocene.

Between 2006 and 2013, we salvaged and necropsied 362 seabird specimens from Tern Island, French Frigate Shoals, Northwestern Hawaiian Islands. Plastic ingestion occurred in 11 of the 16 species sampled (68.75%), representing four orders, seven families, and five foraging guilds: four plunge-divers, two albatrosses, two nocturnal-foraging petrels, two tuna-birds, and one frigatebird. Moreover, we documented the first instance of ingestion in a previously unstudied species: the Brown Booby. Plastic prevalence (percent occurrence) ranged from 0% to 100%, with no significant differences across foraging guilds. However, occurrence was significantly higher in chicks versus adult conspecifics in the Black-footed Albatross, one of the three species where multiple age classes were sampled. While seabirds ingested a variety of plastic (foam, line, sheets), fragments were the most common and numerous type. In albatrosses and storm-petrels, the plastic occurrence in the two stomach chambers (the proventriculus and the ventriculus) was not significantly different.

Migratory behavior varies extensively between bird taxa, from long distance migration to purely sedentary behavior. Variability in migratory behavior also occurs within taxa, where individuals within some species, or even populations, show mixed strategies. The same variability occurs in seabird species. We examined the migratory behavior of distinct populations of great frigatebirds Fregata minor in three distant oceanographic basins. Great frigatebird populations showed extensive variation in post-breeding migratory behavior. Birds from Europa Island (Mozambique Channel) made longdistance migration to numerous distinct roosting sites in the Indian Ocean, New Caledonia birds made shorter distance migrations to roosting sites in the southwestern Pacific Ocean, and Galapagos birds were resident within the archipelago year round. Juvenile birds from Europa Is. and New Caledonia dispersed widely whereas Galapagos juveniles were resident year round. The migratory behavior of Europa Is. and New Caledonia resulted in complete separation of foraging grounds between breeding adults, non-breeding adults, and juveniles, whereas in the Galapagos the overlap was complete. We suggest that population variability in migratory behavior may have arisen because of different environmental conditions at sea, and also depends on the availability of suitable roosting sites on oceanic islands. The results also highlight the capacity of frigatebirds to remain airborne most of the time even outside the breeding season when they have to molt.

The Magnificent Frigatebird (Fregata magnificens) is a monogamous, widespread, neotropical, pelagic seabird with low flight costs, high dispersal capacity, sex-biased dispersal, and female mate choice. Here, we adopt an integrative approach to evaluate the influence of behavior, male-biased philopatry, female choice, and geographic distance as non-physical barriers to dispersal acting on the genetic structure of magnificent frigatebirds in the 4 largest Mexican breeding colonies. We integrate ecological dispersal observations from tagging studies, analyses of maternally and biparentally inherited genetic markers, and group-structured population modeling. Mitochondrial DNA (matrilineal) and randomly amplified polymorphic DNA (biparental) data provided evidence of genetic differentiation between ocean basins, as well as among Eastern Pacific breeding colonies, and absence of a genetic pattern of isolation by distance. Our ecological, genetic, and modeling results are concordant with the expected effects of sex-biased philopatry and female mate choice as non-physical barriers to interbreeding, and suggest that geographic distance does not play a significant role in the genetic distinction of breeding colonies. The genetic differentiation found between Eastern Pacific and Caribbean, as well as that among Eastern Pacific breeding colonies is of consequence for the management plans and conservation measures of the Magnificent Frigatebird in the region.

Ecological segregation among coexisting seabird species can occur due to morpho- logical and behavioral differences. This segregation is especially important as it reduces competi- tion during the breeding season, when birds are central-place foragers. Furthermore, seasonal variation in oceanographic processes may change prey availability and shape seabird community trophic structure and species isotopic niche. We used stable isotope analyses of seabird whole blood and prey muscle in 5 tropical seabird communities representing 12 species (Charadri- iformes, Phaethontiformes, Procellariiformes and Suliformes) inhabiting 5 offshore islands off Brazil from 00°55' N to 20° 30' S and 65 to 1160 km from the coast. We evaluated how community trophic structure was correlated with morphology (body mass and bill length), and we verified seasonal variation in isotopic niche in 2 communities. Overall, seabird trophic position (TP) was positively correlated with body size, with frigatebirds and boobies occupying a higher TP than noddies and terns. Structuring of seabird communities according to body size probably occurred due to consumption of prey of different sizes and TP, which contributed to niche segregation by reducing interspecific competition during the breeding season. All species showed isotopic niche segregation at 2 islands, and ~60 to 70% of species segregated at the other islands, except at Atol das Rocas, where 43% of species segregated. Niche overlap occurred mainly among closely related species at Atol das Rocas, Fernando de Noronha and Trindade. The isotopic niche and TP changed across islands for all 3 boobies (red-footed Sula sula, brown S. leucogaster and masked S. dactylatra), brown noddy Anous stolidus and red-billed tropicbird Phaethon aethereus; these factors also changed seasonally in other species, such as in magnificent frigatebird Fregata mag- nificens, brown booby, both the red-billed P. aethereus and white-tailed P. lepturus tropicbirds and both the brown A. stolidus and black Anous minutus noddies. Such changes probably occurred due to differences in prey availability, opportunistic behavior (e.g. feeding on fishery dis- cards) and/or local foraging and diet specialization.

Haemosporidian parasites, which require both a vertebrate and invertebrate host, are most commonly studied in the life stages occurring in the vertebrate. However, aspects of the vector's behaviour and biology can have profound effects on parasite dynamics. We explored the effects of a haemosporidian parasite, Haemoproteus iwa, on a hippoboscid fly vector, Olfersia spinifera. Olfersia spinifera is an obligate ectoparasite of the great frigatebird, Fregata minor, living among bird feathers for all of its adult life. This study examined the movements of O. spinifera between great frigatebird hosts. Movement, or host switching, was inferred by identifying host (frigatebird) microsatellite genotypes from fly bloodmeals that did not match the host from which the fly was collected. Such host switches were analysed using a logistic regression model, and the best-fit model included the H. iwa infection status of the fly and the bird host sex. Uninfected flies were more likely to have a bird genotype in their bloodmeal that was different from their current host's genotype (i.e. to have switched hosts) than infected flies. Flies collected from female birds were more likely to have switched hosts than those collected on males. Reduced movement of infected flies suggests that there may be a cost of parasitism for the fly. The effect of host sex is probably driven by differences in the sex ratio of bird hosts available to moving flies.

We examined persistent organic pollutant and trace element concentrations in eggs of magnificent frigatebirds (Fregata magnificens), a species of conservation concern breeding in the West Indies. Despite that frigatebirds feed at high positions in tropical marine food chains, we detected low levels of most contaminants, suggesting limited contamination of their prey.

In the last two decades, more than 35% of coastal wetlands in the tropics and subtropics have been destroyed, mangrove forest being the most affected habitat. However, mangroves have been poorly studied around the world, particularly in the Neotropics. The spatio-temporal diversity of the mangrove bird community in the Jambeli archipelago, in southwestern Ecuador, was studied. Between 2 August 2015 and 25 July 2016, a total of 118 species (35 migratory and 83 resident species) belonging to 44 families were documented. Nine of the 83 resident species are endemic to the coasts of Ecuador and northwestern Peru; six are threatened species. The most abundant species in the archipelago were Magnificent Frigatebird (Fregata magnificens) and Neotropic Cormorant (Phalacrocorax brasilianus), while the best represented family was Laridae (n = 12 species). No spatial or temporal differences in bird diversity were detected (P > 0.35). The Jambeli archipelago has a high diversity of bird species, particularly as a wintering and stopover site for boreal migratory species. A long-term monitoring program for bird populations in the area has been proposed as an effective tool to assess the conservation status of this important and threatened ecosystem.

In the present study, trace elements and persistent organic pollutants (POPs) were quantified from Magnificent frigatebirds (Fregata magnificens) breeding at a southern Atlantic island. Stable isotope ratio of carbon (delta C-13) and nitrogen (delta N-15) were also measured to infer the role of foraging habitat on the contamination. For another group from the same colony, GPS tracks were recorded to identify potential foraging areas where the birds may get contaminated. Fourteen trace elements were targeted as well as a total of 40 individual POPs, including organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs). The concentration of Hg in the blood was up to 6 times higher in adults (5.81 +/- 1.27 mu g g(-1) dw.) than in nestlings (0.99 +/- 0.23 mu g g(-1) dw.). A similar pattern was found for POPs. Sigma PCBs was the prevalent group both in adults (median 673, range 336 -2801 pg g(-1) ww.) and nestlings (median 41, range 19-232 pg g(-1) ww.), followed by the sum of dichlorodiphenyltrichloroethanes and metabolites (Sigma DDTs), showing a median value of 220 (range 75 -2342 pg g(-1) ww.) in adults and 25 (range 13-206 pg g(-1) ww.) in nestlings. The isotope data suggested that the accumulation of trace elements and POPs between adults and nestlings could be due to parental foraging in two different areas during incubation and chick rearing, respectively, or due to a shift in the feeding strategies along the breeding season. In conclusion, our work showed high Hg concentration in frigatebirds compared to non-contaminated seabird populations, while other trace elements showed lower values within the expected range in other seabird species. Finally, POP exposure was found generally lower than that previously measured in other seabird species. (C) 2016 Elsevier Ltd. All rights reserved.

We induced three adoptions during the period of biparental care by placing orphaned chicks of magnificent frigatebirds (Fregata magnificens) into nests of foster parents whose chick had died. Indirect parent-offspring recognition seemed to occur during the period of biparental care. A chick was adopted in one of our three trials; thus, adoption of orphaned chicks potentially could be used as a conservation strategy.

La asimetría de las rectrices exteriores en Fregata magnificens (rabihorcado) influye en su eficiencia de vuelo, mientras que la cola, profundamente bifurcada de esta especie sexualmente dimórfica, juega un papel crucial en su desempeño aerodinámico. Para evaluar la presión de la selección natural en la asimetría de la cola, modelamos el desempeño de rabihorcados machos y hembras simétricos y asimétricos adultos durante el vuelo de planeo en la colonia reproductiva de Isla Isabel, México, mediante la proporción levante:arrastre y las polares y superpolares de planeo. Encontramos diferencias significativas entre rabihorcados machos y hembras, simétricos y asimétricos cuando analizamos su desempeño en el vuelo de planeo y sus costos de compensación asociados. El modelo teórico indicó que la asimetría de la cola tendrá un efecto más grande en los machos que en las hembras durante el vuelo, y que los individuos asimétricos volarán menos eficientemente que los simétricos corrigiendo su asimetría en función de la velocidad al incorporar más costos de arrastre. Investigación futura para estimar las tasas de supervivencia de individuos simétricos y asimétricos, costos de construcción de nido y de éxito reproductivo podría revelar las ventajas de tener una cola simétrica en esta especie y elucidar si la asimetría tiene un costo en la adecuación.

Haemosporidian parasites are widely distributed and common parasites of birds, and the application of molecular techniques has revealed remarkable diversity among their lineages. Four haemosporidian genera infect avian hosts (Plasmodium, Haemoproteus, Leucocytozoon and Fallisia), and Haemoproteus is split into two sub-genera based on morphological evidence and phylogenetic support for two divergent sister clades. One clade (Haemoproteus (Parahaemoproteus)) contains parasites developing in birds belonging to several different orders, except pigeons and doves (Columbiformes), while the other (Haemoproteus (Haemoproteus)) has previously been shown to only infect dove hosts. Here we provide molecular and morphological identification of Haemoproteus parasites from several seabird species that are closely related to those found in dove hosts. We also document a deeply divergent clade with two haemosporidian lineages recovered primarily from frigatebirds (Fregatidae, Pelecaniformes) that is sister to the hippoboscid-(Hippoboscidae) transmitted dove parasites. One of the lineages in this new clade of parasites belongs to Haemoproteus iwa and is distributed in two species of frigatebird (Fregata) hosts from Hawaii, the Galapagos Islands, the eastern Pacific and throughout the Caribbean Basin. Haemosporidian parasites are often considered rare in seabirds due in part to the lack or low activity of some dipteran vectors (e.g., mosquitos, biting midges) in marine and coastal environments; however, we show that H. iwa is prevalent and is very likely vectored among frigatebirds by hippoboscid flies which are abundant on frigatebirds and other seabirds. This study supports the existence of two sister clades of avian Haemoproteus in accord with the subgeneric classification of avian hemoproteids. Description of H. iwa from Galapagos Fregata minor is given based on morphology of blood stages and segments of the mitochondrial cytochrome b gene, which can be used for identification. This study shows that hippoboscid flies warrant more attention as vectors of avian Haemoproteus spp., particularly in marine and coastal environments.

The sometimes-distant association between dispersal movements and mating strategies may govern seabird ecology. Despite their large dispersal capability, pelagic seabirds are subject to the influence of physical and non-physical barriers that may limit the magnitude of realized effective dispersal and gene flow. The Magnificent Frigatebird (Fregata magnificens) is a widespread, tropical, pelagic, sequentially monogamous seabird capable to breach physical barriers, such as land masses. Nevertheless, Mexican frigatebirds have shown movement preferences by sex (female migration and high male site fidelity), which, along with the complex female mate choice behavior, may promote breeding isolation. In order to ascertain if levels of population structure are influenced by physical or non-physical barriers, we analyzed mitochondrial DNA variation of adult Magnificent Frigatebirds breeding in the main nesting colonies in Mexico, three in the eastern Pacific Ocean and one in the Caribbean Sea. Control region sequences revealed significant genetic structure between Pacific and Caribbean frigatebirds (AMOVA, ΦSC = 0.105, P

Annual apparent survival rates from 323 marked immature Magnificent Frigatebirds (Fregata magnificens) were estimated using mark-recapture models for live encounter data in a six-year study (1998–2003) at Isla Isabel, the largest breeding colony in Western Mexico. A time and age immature apparent survival pattern was found: high and variable as yearling-juveniles (mean 1998–2000 = 9.78 ± 0.22) and, later, moderate and constant as juvenile-subadults and subadults (mean = 0.62 ± 0.11). Whereas resighting rate (p) increased with time (range = 0.00 [± 0.04] – 0.87 [± 0.11]). The results suggest variation in true survival and emigration during the juvenile life phase, high true survival and high site fidelity of juvenile-subadults and subadults during the interval after marking, and constant and either low true survival or high emigration in the subsequent intervals. Frigatebird apparent survival was predominantly higher in yearling juveniles than in subsequent age classes, an uncommon occurrence in ...