Anous Minutus Research Articles

Multidisciplinary approach to the diagnosis of Contracaecum magnipapillatum infections in Australian black noddies, Anous minutus (Charadriiformes: Laridae)

We provide the incidental necropsy findings associated with anisakid nematode infections of black noddy terns, Anous minutus Boie, 1844 (Charadriiformes: Laridae), from offshore islands in the southern Great Barrier Reef, Queensland, Australia. Specimens collected from the proventriculi were identified morphologically as Contracaecum magnipapillatum Chapin, 1925 (Rhabditida: Anisakidae), using light and scanning electron microscopy (SEM). The entire nuclear ribosomal DNA internal transcribed spacer (ITS) region (ITS1-5.8S-ITS2) was amplified by polymerase chain reaction (PCR) and sequenced to provide reference sequences for morphologically well-identified voucher specimens. Interestingly, after an alignment with closely related taxa using BLAST, sequences of the ITS1 and ITS2 were 100% identical to the sequences assigned to Contracaecum septentrionale Kreis, 1955, from a razorbill, Alca torda Linnaeus, 1758 (Charadriiformes: Alcidae), from Spain. These results either raise questions about the ITS as a genetic marker for some members of Contracaecum, or the identity of the specimens assigned to C. septentrionale, given that no supporting morphological data was associated with them. We highlight the need for a combined morphological and molecular approach to parasite diagnostics and the use of multiple genetic loci to resolve the molecular taxonomy of cryptic species. Morphological identifications should be taxonomically robust, transparent and precede the deposition of molecular barcodes in public repositories. The gross and histopathological findings of our investigation concur with previous reports of widespread Contracaecum infections in black noddies and support the contention that Contracaecum spp. are an unlikely primary cause of mortality.

Toxoplasma gondii antibodies in tropical seabirds from the Rocas Atoll Biological Reserve, Brazil.

Toxoplasma gondii is a coccidian that infects almost all warm-blooded animals, including birds. Rocas Atoll Biological Reserve, located in the northeast of Brazil, is the only atoll in the South Atlantic, and home to the largest population of seabirds in the western Atlantic. In this study the occurrence of T. gondii antibodies in seabirds from Rocas Atoll were determined. Birds were manually captured, blood samples were taken, and antibodies detected by the modified agglutination test (>5). In total, 267 birds of seven species belonging to three families (Sternidae, Fregatidae and Sulidae) and two orders (Charadriiformes and Suliformes) were sampled. Out of the 267 samples, 20 (7.3%) were seropositive: nine out of 48 brown noddies (Anous stolidus), one out of 26 black noddies (Anous minutus), three out of 20 magnificent frigatebirds (Fregata magnificens), five out of 95 sooty terns (Onychoprion fuscatus) and two out of 20 red-footed boobies (Sula sula). None of the 33 masked boobies (Sula dactylatra) and the 25 brown boobies (Sula leucogaster) were seropositive. The antibody titers were 5 (n=6), 10 (n=4), 20 (n=3), 40 (n=6) and 160 (n=1). Due to the uniqueness of this environment, monitoring the seabirds is suggested to maintaining this Conservation Unit.

The marine avifauna of Matthew and Hunter Islands, two remote volcanoes of the New Hebrides chain

The marine avifauna of Matthew and Hunter Islands, two remote volcanoes of the New Hebrides chain Breeding birds recorded on Matthew and Hunter Islands in the tropical southwestern Pacific between 1973 and 2018 are summarised from a compilation of reports, for which various methods were used for counting seabirds. These methods included line transects, or direct observations using telescope or binoculars, or exhaustive counts, depending on the species observed and its nesting habitat. Population size estimates and reproductive periods are given. The total number of seabird species recorded breeding on the two islands was n = 14. This total includes seabird species breeding on both islands (n = 7): black-winged petrel Pterodroma nigripennis, wedge-tailed shearwater Ardenna pacifica, red-tailed tropicbird Phaethon rubricauda, masked booby Sula dactylatra, brown booby S. leucogaster, brown noddy Anous stolidus, and grey noddy A. albivitta. Hunter island also harbours a small colony of Herald petrel Pterodroma heraldica, and colonies of lesser and great frigatebirds (Fregata ariel and F. minor), red-footed booby S. sula and, black noddy A. minutus and white tern Gygis alba. Matthew Island harbours a large colony of sooty tern Onychoprion fuscatus; an undetermined storm petrel may also breed there. Differences between the two islands regarding community composition of seabirds are explained by the absence of trees on Matthew Island and the presence of the Polynesian rat Rattus exulans on Hunter Island. Brown noddies bred exclusively during the austral summer, as did black-winged petrels and wedge-tailed shearwaters, while the Herald petrel and the two frigatebirds seemed to preferentially breed in the winter. The red-tailed tropicbird, the three boobies, the grey noddy and the sooty tern appeared to reproduce year-round. Disturbance caused by human activities was irregular but devastating to seabird colonies. The diversity and abundance of seabird species breeding on these islands makes them regionally important sites for conservation. Key words: Seabird, Population, Reproduction, Threats, Polynesian rat; Helicopters

Persistent organic pollutant patterns in seabirds from marine protected areas in the tropical Atlantic Ocean

Persistent organic pollutants were investigated in the blood of living seabirds (Pterodroma arminjoniana, Onychoprion fuscatus, Sula dactylatra, Anous minutus, Anous stolidus and Sula leucogaster) from two Brazilian Conservation Units - Trindade Island and São Pedro and São Paulo Archipelago. ∑PCBs (0.55 to 55.09 ng/g wet weight (ww), ∑DDTs (0.01 to 17.36 ng/g ww) and Mirex (0.01 to 5.53 ng/g ww) were predominant in all samples. Trindade petrel Pterodroma arminjoniana presented higher values than other seabirds, which is potentially related to diet and migratory behavior. Fluctuations in the trophic ecology data, through carbon and nitrogen stable isotope ratios, warn of temporal variation in diet and foraging and highlight the importance of using a nondestructive matrix to allow long-term monitoring of POP contamination in seabirds from Brazilian Conservation Units. In addition, the data will fill the gaps in the POP baselines for seabirds from the tropical Atlantic Ocean.

Avifauna of the Ninigo, Hermit, Sae and Kaniet Islands, and adjacent seas, Papua New Guinea

One of us (SMH) surveyed the Ninigo and Hermit Islands (27 January–13 February and 2–14 October 2019), providing the first observations of birds on these islands for c.50 years. KDB collated data from the unpublished diaries of W. F. Coultas, a member of the Whitney South Sea Expedition, including observations from the nearby Kaniet and Sae Islands. Four new landbirds, in addition to six new shorebirds and five new seabirds, were added to the list of birds for these poorly known islands, bringing the total list to 59 species. We also document significant extensions of the known breeding ranges of Brown Noddy Anous stolidus, Black Noddy A. minutus and Red-footed Booby Sula sula. The biological importance of the West Melanesian Trench is further emphasised by our seabird observations.

An updated assessment of the seabird populations breeding at Príncipe and Tinhosas

The Príncipe Autonomous Region is recognised as a marine biodiversity hotspot, although little is known about the status of its marine fauna. It holds most breeding seabirds of the tropical eastern Atlantic Ocean. Based on anecdotal accounts of increased fishing and seabird harvesting, regular monitoring of seabird populations is considered a priority. Therefore, a survey of Príncipe’s seabird colonies was conducted in 2017. The results revealed that the more accessible seabird colonies have disappeared. Around Príncipe, Boné de Joquei is the present main stronghold for Brown Boobies Sula leucogaster and White-tailed Tropicbirds Phaethon lepturus. The Tinhosas islands hold an estimated 300 000 seabirds, predominantly Sooty Terns Onychoprion fuscatus, but also Brown Boobies, Black Noddies Anous minutus and Brown Noddies Anous stolidus. Long-term multi-annual monitoring is needed to understand the breeding phenology of each species and to better assess population trends. Ensuring a protective status for both Tinhosas and the seabirds under national legislation is a key priority for future conservation policy in São Tomé and Príncipe.

Offshore surprises: new at-sea bird records for Suriname (2013\u20132015)

Bird observations were collected from various types of survey vessels in Suriname’s territorial waters between 2013 and 2015. Dedicated, effort-related surveys were carried out from geophysical seismic survey vessels within an area located 80–110 km offshore (in 2013) and 165–290 km (in 2015). Opportunistic observations were recorded during fisheries surveys on a shrimp trawler operating along the 30 m depth contour, approximately 40–60 km offshore (in 2014). In total, 10 bird (sub-)species were observed during these surveys that previously were not recorded for Suriname, including Manx Shearwater Puffinus puffinus, Ruff Calidris pugnax, South Polar Skua Stercorarius maccormicki, Long-tailed Jaeger Stercorarius longicaudus, Sandwich Tern Thalasseus sandvicensis (ssp. acuflavidus), Roseate Tern Sterna dougallii, Bridled Tern Onychoprion anaethetus, Black Noddy Anous minutus, Scarlet Tanager Piranga olivacea and Black-and-white Warbler Mniotilta varia. In addition, Lesser Black-backed Gull Larus fuscus and Bulwer’s Petrel Bulweria bulwerii were photographed for the first time in Suriname. A Sooty Shearwater Ardenna grisea was recorded just outside the Exclusive Economic Zone (EEZ), and therefore does not count as a new country record. This paper contributes to a better understanding of the avifauna frequenting the waters off Suriname, which historically has been poorly studied. Most of the species reported here are migratory. The timing of our sightings therefore also helps in a better understanding of their at-sea distribution and migration patterns.

First record of Anous minutus in the state of Amapá, Brazil

We present the first record of Anous minutus for the state of Amapa, Brazil, and only the second for the whole Amazonian region. Within Brazil A. minutus is restricted as a breeder to Fernando de Noronha, Atol das Rocas, Sao Pedro and Sao Paulo and Martin Vaz/Trindade archipelagos, with records of vagrants from the states of Ceara and Sao Paulo. We photographed a single bird at the Maraca-Jipioca Ecological Station, on 10 December 2015, west of the Maraca do Sul Island in an area known as Ponta Sul. To our knowledge this is the first record from Amapa and only the second from northern Brazil and the Amazon region.

Population estimates of the breeding birds of the Tinhosas islands (Gulf of Guinea), the only major seabird colony of the eastern tropical Atlantic

The Tinhosas islands, in São Tomé e Príncipe, host the most important seabird breeding colony in the Gulf of Guinea, but information on its conservation status was hitherto unpublished or anecdotal, the last assessment having been performed in 1997. A two-day expedition to the Tinhosas islands was undertaken to estimate the status of breeding seabirds in 2013. Four of the five seabird species known to breed in São Tomé e Príncipe, namely Brown Booby Sula leucogaster, Sooty Tern Onychoprion fuscatus, Brown Noddy Anous stolidus and Black Noddy Anous minutus, occur on the Tinhosas. A decrease of 80% in Brown Booby numbers, possibly due to occasional exploitation, and a 30% increase in Sooty Tern and Black Noddy numbers, were found compared to 1997 data although survey methods differed. Breeding of Brown Noddy and Madeiran Storm-petrel Hydrobates castro remains unconfirmed. Our estimates confirmed that BirdLife International Important Bird and Biodiversity Area criteria are met for at least one species, the Sooty Tern. The islands are not legally protected, nonetheless, apart from moderate levels of disturbance by fishermen who land on Tinhosa Grande, no alien species were seen, and no immediate threats to the Tinhosas colony were detected. Multiple visits within and between years are recommended, to census breeders, monitor threats and establish breeding phenologies.

Breeding seabird populations in Brazilian oceanic islands: historical review, update and a call for census standardization

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.

Molecular phylogeny and systematics of Blue and Grey Noddies (Procelsterna)

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 , and to consider Procelsterna Lafresnaye as a junior synonym.

Assessment of the Birds of Swains Island, American Samoa

ABSTRACT Swains Island is an uninhabited 210 ha former copra plantation 360 km North of American Samoa. The island, dominated with coconut palm (Cocos nucifera), was last surveyed in 1976. The goal of this 17–26 September 2012 survey was to identify the bird species present, and document relative abundance, distribution, and breeding activity across the island. Two shoreline surveys recorded a seabird community dominated by Black Noddy (Anous minutus), White Tern (Gygis alba), and Brown Noddy (Anous stolidus), while the reef flat community was dominated by Pacific Golden Plover (Pluvialis fulva) and Wandering Tattler (Tringa incana). Inland surveys revealed four roosting or breeding species, including Black Noddy, White Tern, Brown Noddy, and Red-footed Booby (Sula sula). Seabird densities were highest in the northwest section of the island, furthest from former settlements. Although feral pigs (Sus scrofa) were recently eradicated, feral cats (Felis cattus) remain present, and Pacific rats (Rattus exulan...

Segregation in Diet between Black Noddy (Anous minutus) and Brown Noddy (A. stolidus) from the Southern Lagoon of New Caledonia

Abstract: The Black Noddy (Anous minutus) and the Brown Noddy (A. stolidus) occur sympatrically in the Southern Lagoon of New Caledonia, breeding on islets located at the edge of a wide, productive coral-reef lagoon next to oceanic waters enriched by a seasonal upwelling. The diets of the two species were determined from regurgitations from birds nesting at Kouare Islet during two consecutive breeding seasons (2002/2003 and 2003/2004) and compared. The average prey load in the Brown Noddy was heavier than that in the Black Noddy, as expected from its larger body size and from a predicted longer foraging distance. Fish prey dominated the diet of both species (100% and 81.8% biomass in Black and Brown Noddies, respectively); the remainder consisted of squid. Black Noddy ate small pelagic fishes inhabiting the reef and the lagoon, mainly round herrings (Spratelloides spp.), and Brown Noddy mainly preyed on offshore species including buccaneer anchovy (Encrasicholina punctifer) and larger pelagic fishes (Exoc...

Community of chewing lice (Phthiraptera: Amblycera and Ischnocera) parasites of resident birds at the Archipelago of São Pedro and São Paulo in northeast Brazil.

The current study describes the chewing lice community associated with seabird populations resident at the São Pedro and São Paulo Archipelago in the Atlantic Ocean in Pernambuco State, Brazil. Adults of three species of seabirds were captured using hand-nets for the collection of biometric data and specimens of ectoparasites. In total, 320 birds were examined (120 Sula leucogaster (Boddaert), Brown Booby; 120 Anous stolidus (L.), --Brown Noddy; and 80 Anous minutus Boie, Black Noddy) of which 95% were infested with 8,625 chewing lice, representing eight species of the genera Actornithophilus, Austromenopon, Eidmanniella, Pectinopygus, Quadraceps, and Saemundssonia. On S. leucogaster, Pectinopygus garbei (Pessôa & Guimarães) was more prevalent and had a mean and median intensity of infestation significantly greater than those recorded for Eidmanniella albescens (Piaget). On the two Noddies, the species of Actornithophilus and Quadraceps were significantly more prevalent and abundant than Austromenopon atrofulvum (Piaget) and Saemundssonia remota Timmermann Most of the louse species had a highly aggregated distribution, with k exponent of the negative binomial distribution ranging from 0.04 to 3.06. A weak but significant correlation was found between the abundance of chewing lice and morphometric variables (body weight, wing, beak, tail, and tarsus lengths). It is possible that high rates of infestation have a negative effect on the morphological characteristics of the hosts, including the health of the plumage. All the lice species collected--except for P. garbei (ex S. leucogaster)--were reported for the first time from Brazilian populations of these seabird species.

Resources partitioning by seabirds and their relationship with other consumers at and around a small tropical archipelago

Abstract Seabirds occupy a range of trophic levels in marine foodwebs, and as top predators, they potentially may compete with large fish for prey. Here, we examine trophic segregation among seabird species breeding on São Pedro and São Paulo Archipelago (SPSPA), in the tropical Atlantic Ocean, as well as the trophic relationships between the seabirds and pelagic fish. We used stable isotopes (δ15N, δ13C) combined with a conventional dietary analysis of brown booby (Sula leucogaster), brown noddy (Anous stolidus), and black noddy (Anous minutus) and also analysed stable isotopes in the muscles of tropical two-wing flying fish (Exocoetus volitans), blackfin tuna (Thunnus atlanticus), and common dolphinfish (Coryphaena hippurus). Brown boobies shared a similar trophic level with large predatory fish probably due to their intense consumption of flying fish, but seabirds are most likely not competing with blackfin tuna and common dolphinfish, despite relying on the same prey. Food resources seem to be abundant around SPSPA, minimizing competition. Despite relying mostly on two-wing flying fish, the three seabirds studied had non-overlapping trophic niches during the breeding period, with segregation apparently occurring by prey size. Sex-related trophic differences were not found, but age-related trophic segregation was observed in brown boobies and brown noddies. Overall, although seabirds and marine pelagic fish rely on the same prey species, the overlap in their trophic niches was limited, most likely due to an overabundant food resource, i.e. flying fish, a common prey of large predators in most pelagic tropical oceans.

Role of body size in shaping the trophic structure of tropical seabird communities

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.

Blood parasites in noddies and boobies from Brazilian offshore islands – differences between species and influence of nesting habitat

Seabirds are often free from blood parasites, and a recent review suggested that phylogenetic, ecological and life-history parameters can determine the prevalence of blood parasites in seabirds. However, there is a lack of data available from many seabird groups, and a larger database is needed to understand prevalence patterns of blood parasites. We used a molecular screening approach to detect parasites of the genera Plasmodium, Haemoproteus, Leucocytozoon and Babesia in five species of two genera of seabirds that breed on Atlantic Ocean islands off Brazil. The observed patterns differed between the two bird genera. Like other Laridae, brown noddy, Anous stolidus adults were infected with Haemoproteus with low prevalence. Masked boobies, Sula dactylatra and brown boobies, Sula leucogaster were infected with Babesia. Of the latter, mainly juveniles were infected. In all species, intensity of infection (i.e. number of infected erythrocytes) was so low that parasites remained undetected in blood smears. This may explain the absence of major effects on the body condition of birds, although infected juvenile masked boobies were lighter than juveniles that were not infected with Babesia. Two tree-nesting species; black noddy, Anous minutus and red-footed booby, Sula sula did not have blood parasites, suggesting that tree-nesting may reduce the exposure to arthropod vectors compared with ground nesting in these species.

New records, distribution and status of six seabird species in Brazil

Distribution records of poorly-known species are currently the most explored theme in the Brazilian seabird literature. If properly evaluated, this kind of information can improve our knowledge on distribution, migration and status of occurrence of these species. In this note we present new records for six species of poorly-known seabirds in the Brazilian coast, reviewing distribution records and defining their status of occurrence in the country. We consider Chionis albus (Gmelin, 1789) a pseudo-vagrant in Brazil and define its status as a scarce seasonal visitor from southern South America. We present the first records of Leucophaeus atricilla (Linnaeus, 1758) for Trindade Island, and of Leucophaeus pipixcan (Wagler, 1831) for the state of Rio Grande do Sul, and determined that the former is a vagrant in eastern Brazil and the latter a vagrant across the country. Anous stolidus (Linnaeus, 1758) is a vagrant in southernmost Brazil. We were unable to determine if records of Chlidonias niger (Linnaeus, 1758) for Brazil and southern South America refer to vagrancy or pseudo-vagrancy. Additionally, we verified the occurrence of breeding individuals of Anous minutus Boie, 1844 on Martin Vaz Island and confirmed that there is no evidence of breeding on neighboring Trindade Island.

Plasticity of Noddy Parents and Offspring to Sea-Surface Temperature Anomalies

Behavioral and/or developmental plasticity is crucial for resisting the impacts of environmental stressors. We investigated the plasticity of adult foraging behavior and chick development in an offshore foraging seabird, the black noddy (Anous minutus), during two breeding seasons. The first season had anomalously high sea-surface temperatures and ‘low’ prey availability, while the second was a season of below average sea-surface temperatures and ‘normal’ food availability. During the second season, supplementary feeding of chicks was used to manipulate offspring nutritional status in order to mimic conditions of high prey availability. When sea-surface temperatures were hotter than average, provisioning rates were significantly and negatively impacted at the day-to-day scale. Adults fed chicks during this low-food season smaller meals but at the same rate as chicks in the unfed treatment the following season. Supplementary feeding of chicks during the second season also resulted in delivery of smaller meals by adults, but did not influence feeding rate. Chick begging and parental responses to cessation of food supplementation suggested smaller meals fed to artificially supplemented chicks resulted from a decrease in chick demands associated with satiation, rather than adult behavioral responses to chick condition. During periods of low prey abundance, chicks maintained structural growth while sacrificing body condition and were unable to take advantage of periods of high prey abundance by increasing growth rates. These results suggest that this species expresses limited plasticity in provisioning behavior and offspring development. Consequently, responses to future changes in sea-surface temperature and other environmental variation may be limited.

Breeding Avifauna of the Chesterfield Islands, Coral Sea: Current Population Sizes, Trends, and Threats

This paper reports on post-1991 census data and on the breeding phenology of seabirds of the Chesterfield-Bampton and Bellona groups of coral islets in the Coral Sea. In total, 13 resident bird species were observed [Wedge-tailed Shearwater (Puffinus pacificus), Masked Booby (S. dactylatra), Brown Booby (Sula leucogaster), Red-footed Booby (S. sula), Lesser Frigatebird (Fregata ariel), Great Frigatebird (F. minor), Black Noddy (Anous minutus), Brown Noddy (A. stolidus), Crested Tern (Sterna bergii), Sooty Tern (S. fuscata), Fairy Tern (S. nereis), Black-naped Tern (S. sumatrana), and Buff-banded Rail (Gallirallus philippensis)]. Segregation for nesting habitat was similar to that previously observed on other coral-reef islets of the Coral Sea. Breeding periods were either in the winter (Masked and Red-footed Boobies, Frigatebirds, Fairy Tern) or in the summer (Wedge-tailed Shearwater, Black and Brown Noddies, Crested and Black-naped Terns) or year-round (Brown Booby). Sooty Terns bred twice a year (summer and spring), but this was not consistent across years. Estimates of breeding population sizes for the whole Chesterfield-Bampton and Bellona groups are proposed for Wedge-tailed Shearwater (90,000 to 106,000 breeding pairs), Masked Booby (280–500 pairs), Brown Booby (3,800–5,800 pairs), Redfooted Booby (7,200–7,300 pairs), Lesser Frigatebird (1,600 pairs), Great Frigatebird (350–480 pairs), Black Noddy (29,000–45,000 pairs), Brown Noddy (15,000–23,000 pairs), Crested Tern (80–100 pairs), Sooty Tern (11,000–46,000 pairs), and Black-naped Tern (70–90 pairs). Interannual fluctuation in breeding population size was apparent in Wedge-tailed Shearwater. Over the last 30 yr, an increase in Brown Booby abundance was noted, whereas declines are suspected for the Fairy Tern and Buff-banded Rail. Among the threats to nesting seabirds are stress and other disturbances caused by human frequentation, including poaching of seabird chicks and introduced mice.