Seabird Nests Research Articles

Per- and polyfluoroalkyl substances (PFAS) in little penguins and associations with urbanisation and health parameters

Per- and Polyfluoroalkyl substances (PFAS) are increasingly detected in wildlife and present concerning and unknown health risks. While there is a growing body of literature describing PFAS in seabird species, knowledge from temperate Southern Hemisphere regions is lacking. Little penguins (Eudyptula minor) can nest and forage within heavily urbanised coastal environments and hence may be at risk of exposure to pollutants. We analysed scat contaminated nesting soils (n = 50) from 17 colonies in lutruwita/Tasmania for 16 PFAS, plasma samples (n = 45) from nine colonies, and three eggs for 49 PFAS. We detected 14 PFAS across the sample types, with perfluorooctanesulfonic acid (PFOS) and perfluorohexanesulfonic acid (PFHxS) most commonly detected. Mean concentration of PFOS in plasma was 2.56 ± 4.3 ng/mL (<LOD–22.3), soil was 2.92 ± 5.39 μg/kg (<LOD–29.8) and eggs were 11.89 ± 11.30 μg/kg (0.27–22.84). Mean concentration of PFHxS in plasma was 0.9 ± 0.84 ng/mL (<LOD–5.6), soil was 11.4 ± 39.18 μg/kg (<LOD–213.3) and eggs were 0.27 ± 0.11 μg/kg (<LOD–0.38). Urbanisation of breeding sites was positively associated with PFOS and PFHxS concentrations in soils and blood. Phenology appeared to be an important predictor of PFHxS load, with moulting birds having lower levels compared to non-moulting birds. We investigated PFAS associations with health parameters and found that haematocrit and total plasma proteins in females were negatively associated with PFOS and positively associated in males. The number of erythrocytic nuclear abnormalities in males was positively associated with PFOS. Findings are the first to document the presence of PFAS in this resident seabird nesting and foraging close to anthropogenically modified habitats. We demonstrate that even in low concentrations, PFAS may have detectable relationships with penguin health. Ongoing research is needed to investigate foraging ecology and trophic bioaccumulation pathways, as well as understand sublethal consequences from exposure.

Effectiveness of novel artificial seabird nest modules for reducing ambient temperature transfer in a warming climate

AbstractArtificial habitat for cavity nesting birds can provide excellent opportunities for research and conservation efforts but may expose species to the negative impacts of warming ambient temperatures with climate change. Artificial nest boxes have been successfully used to monitor the breeding activity of the Cassin's auklet (Ptychoramphus aleuticus), a small burrow‐nesting seabird, on Southeast Farallon Island (SEFI) since 1971. Mean monthly ambient air temperatures on SEFI during the summer months have increased at an annual rate of roughly 0.03°C from 1971 to 2022, along with an increase in the number of extreme heat days and average maximum temperature, confirming a warming trend at this seabird colony. Given a projected increase in global temperature, we assessed the effectiveness of traditional wooden nest boxes vs. newer ceramic modules at buffering external ambient air temperatures in normal and extreme heat days across a gradient of microclimates on SEFI. Results from fitting linear mixed effects models indicated that, on average, internal temperatures of wooden and ceramic nests (of comparable size and shape) exhibited similar rates of deviation from ambient air temperature of approximately 0.15°C, even during extreme heat events. Ceramic modules did keep nest chambers cooler by approximately 1.2°C than wooden boxes during extreme events at the warmer, drier southern location of the island. Our results can help guide future efforts to design artificial nests that can effectively provide habitat for seabirds as ambient temperatures increase.

Mercury in Soils of Seabird Nesting Islands in West Iceland

Seabirds are globally recognized vectors of marine-derived materials, which get deposited on land at their breeding colonies, potentially altering local soil chemistry. We studied mercury (Hg) in soil cores on two islands in west Iceland that host thousands of nesting seabirds, predicting that Hg subsidies from nesting birds would result in elevated Hg in local soils. However, despite clear evidence from nitrogen isotopes of marine influence (seabird faeces) on coastal soil cores, O horizon Hg concentrations averaged 223 nanograms per gram (ng/g), were similar between reference and seabird-nesting sites, and were within the range of soils elsewhere in Europe and the Arctic. The concentration of Hg declined for samples deeper in the core, mirroring declines in organic content and concomitant increases in stable isotopes of nitrogen. A more detailed analysis of local pedogenic processes is required to determine the relative contribution of lithogenic, atmospheric, and anthropogenic Hg, but our data do not suggest that seabirds are markedly increasing local soil Hg through ornithogenic subsidies.

The hunting-assisted demise of Campbell Island cattle

Cattle (Bos taurus) were introduced to 11 268 ha Campbell Island/Motu Ihupuku in 1902 as part of a short-lived farming venture that was abandoned by 1931. The cattle were left to fend for themselves and a small feral population of 10–20 animals persisted for 53 years. The population was largely limited to a small area (c. 440 ha) of the island noted for its limestone geology. Ecological damage was pronounced with churning of the soil, damage to vegetation and probable impact on seabird nesting.

Comparing photography and collection methods to sample litter in seabird nests in a coastal archipelago in the Southwest Atlantic

Different methods are used to quantify and classify litter in seabird nests, such as the collection method (CM) and the photography method (PM). We compared the CM and PM in 195 brown booby (Sula leucogaster) nests breeding in a coastal archipelago in the state of Rio de Janeiro, Brazil. Photographs recorded 109 litter items in 44 nests (23% of nests), compared to 416 litter items in 82 nests (42%) by the CM. Pairwise comparison showed a significant difference in the variety and amount of litter items per nest, which was greater for CM (2.1 ± 1.1 categories, 2.13 ± 4.8 items) than for PM (1.5 ± 0.8 categories; 0.56 ± 1.6 items), in addition to a significant difference in the overall litter composition. The CM has been the most often used method to date. Although PM underestimates the amount and frequency of litter, we encourage its use when litter is abundant in nests and for threatened species.

Anthropogenic debris in Kelp Gull and other seabird nests in northern Patagonia, Argentina

Anthropogenic debris is used as nesting material by many seabirds and may result in negative impacts. We assessed the frequency of occurrence of debris (>5 mm) in Kelp Gull (Larus dominicanus) nests at six locations along 2400 km of the Argentine coast, at different distances from urban centres, and in nests of other seven seabird species nesting syntopically. Frequencies in Kelp Gull nests were in general relatively low, ranging between 3.3 and 37.5%, and differed significantly among colonies. No relationship was found between frequency and distance to urban centres. Debris were recorded with frequencies of less than 19.2% in nests of Olrog's Gulls (L. atlanticus), Dolphin Gulls (L. scoresbii), Imperial Cormorants (Leucocarbo atriceps) and Magellanic Penguins (Spheniscus magellanicus), but not in nests of Neotropical Cormorants (Nannopterum brasilianus), Rock Shags (Leucocarbo magellanicus) and Southern Skuas (Catharacta antarctica). This information obtained along a wide coastal sector provides a baseline for future monitoring.

Anthropogenic debris in Kelp Gull and other seabird nests in northern Patagonia, Argentina

Anthropogenic debris in Kelp Gull and other seabird nests in northern Patagonia, Argentina

Stepping Stones to Reproductive Success: The Role of Geomorphology in Seabird Nest Site Choice

Photo 1. Geomorphological features related to seabird nest sites. (A) L’île de l’Amas off Cap-Fréhel, Brittany, France. The island presents several key geomorphological features at various spatial scales, from largest to smallest: small island (~100 × 50 m at low tide), steep slope (north facing, marked with an N), gentle slope (south facing), low degree of enclosure. (B) Detail of a steep slope face with nesting Kittiwakes. Steep slope-nesting seabirds show no requirement for nest site enclosure, and nest indifferently on large or small islands; the steep face deters both land and seaborne predation. Photo credit: Marie Eveillard-Buchoux. These photographs illustrate the article “Between a rock and a large place: the importance of multi-scale geomorphological features to seabird nest site selection” by Marie Eveillard-Buchoux and Peter G. Beninger in Ecology, https://doi.org/10.1002/ecy.3566.

Measuring nest incorporation of anthropogenic debris by seabirds: An opportunistic approach increases geographic scope and reduces costs

Data on the prevalence of anthropogenic debris in seabird nests can be collected alongside other research or through community science initiatives to increase the temporal and spatial scale of data collection. To assess the usefulness of this approach, we collated data on nest incorporation of debris for 14 seabird species from 84 colonies across five countries in northwest Europe. Of 10,274 nests monitored 12% contained debris, however, there was large variation in the proportion of nests containing debris among species and colonies. For several species, the prevalence of debris in nests was significantly related to the mean Human Footprint Index (HFI), a proxy for human impact on the environment, within 100 km of the colony. Collecting opportunistic data on nest incorporation of debris by seabirds provides a cost-effective method of detecting changes in the prevalence of debris in the marine environment across a large geographic scale.

Tahiti Petrel Pseudobulweria rostrata population decline at a nickel-mining site: a critical need for adapted conservation strategies

SummaryNew Caledonia hosts a large part of the world’s breeding population of the Tahiti Petrel Pseudobulweria rostrata. This rare, cryptic and little-studied seabird nests locally in the mountains up to 1,200 m in altitude, particularly in ultramafic (i.e. nickel-rich) areas where mining activity is a major threat. The considerable development of mining activities in New Caledonia over the past decade raises concerns about its potential impacts on breeding populations through both direct habitat destruction and side effects such as pollution or repeated disturbances. This context calls for a dedicated assessment of the persistence of local populations to guide the design of an adapted conservation strategy and potential restoration programmes. We investigated the impact of mining activities on a Tahiti Petrel population when surveyed pre-mining (2004–2007) and following a period of full mining (2017–2018). The vocal activity was assessed at a total of 114 night-call count stations spread over the Koniambo massif. Areas with ground-originated vocal activity were then searched during daytime for nesting evidence. Finally, georeferenced aerial photos were used to estimate habitat degradation as the percentage of bare soil cover (PBSC) within a 400-m radius around each call count station. Our study revealed a dramatic decline in the Tahiti Petrel vocal activity and a desertion of breeding habitats during the full-mining period compared to the pre-mining period. In light of these results, we recommend designing safe breeding areas and combining restoration methods including social attraction, predation control and artificial burrows at mining sites.

The use of social attraction techniques to restore seabird colonies on Desecheo Island, Puerto Rico

Abstract Desecheo Island (117 ha) was historically an important seabird island in the Caribbean with 15 species recorded, of which seven are known to breed, including major populations of brown boobies and red‐footed bobbies. The introduction of invasive mammals, plus the use of the island as a bombing range, contributed to the extirpation of five of the seven known breeding populations of seabird species and vastly reduced numbers of the remaining two species. The island became a National Wildlife Refuge in 1976 and major conservation interventions have included the eradication of invasive goats, rhesus macaques and rats between 1976 and 2016. Removing these critical threats from the island has allowed other active restoration goals to be realized, including restoring seabird colonies to the island. Here, we report on the installation of social attraction equipment in 2018 to augment bridled tern and brown noddy colonies and establish a species of conservation concern, the Audubon's shearwater. We supported these actions through a review of historic seabird nesting and roosting on Desecheo. Motion‐sensing cameras were installed to document activity at each social attraction site and evaluate the effectiveness of our methods. During the 2 years of deployment and monitoring, a total of seven bridled tern nests were documented in new and historic sites for the species, two of them next to a decoy colony; however, no brown noddy visits or nests were detected. In 2018 and 2019, one and two Audubon's shearwaters, respectively, were attracted to one of the sound system speakers, representing the first record for this species on the island. Social attraction efforts on Desecheo appears to be a feasible activity that may help support seabird recolonization and support conservation goals for this National Wildlife Refuge.

Detection of Rickettsia lusitaniae Among Ornithodoros sawaii Soft Ticks Collected From Japanese Murrelet Seabird Nest Material From Gugul Island, Republic of Korea.

In a follow-up to the investigations of soft ticks identified from seabird nest soil and litter collected from coastal islands of the Republic of Korea (ROK), Ornithodoros sawaii and Ornithodoros capensis were assessed for the presence and identification of rickettsiae. Ticks collected from samples of 50-100 g of nest litter and soil from seabird nests were identified individually by morphological techniques, and species confirmed by sequencing of the mt-rrs gene. Subsequently, tick DNA preparations were screened for the presence of rickettsiae using a genus-specific nested PCR (nPCR) assay targeting the 17 kDa antigen gene. The amplicons from the 17 kDa assay and two additional nPCR assays targeting the gltA and ompB gene fragments were sequenced and used to identify the rickettsiae. A total of 134 soft ticks belonging to two species, O. sawaii Kitaoka & Suzuki 1973 (n = 125) and O. capensis Neumann 1901 (n = 9), were collected. Rickettsia lusitaniae DNA was detected and identified among O. sawaii ticks (n = 11, 8.8%) collected from nest litter and soil of the Japanese murrelet (Synthliboramphus wumizusume Temminck 1836) at Gugul Island along the western coastal area of the ROK. This study confirmed for the first time the presence of R. lusitaniae associated with O. sawaii collected from migratory seabird nests in the ROK.

First detection of Borrelia and Rickettsia species from Ornithodoros ticks in the Republic of Korea

Ticks are considered important vectors among arthropods and are linked to serious medical and veterinary health problems. In this study, we investigated tick-borne pathogens (TBPs) of Ornithodoros (Carios) sawaii and a newly identified Ornithodoros species from migratory bird nests in the uninhabited islands of the Republic of Korea (ROK). Ticks were collected from seabird nests with soil using a Tullgren funnel. Polymerase chain reaction (PCR) was performed using specific primer sets targeting genes of Borrelia spp., Rickettsia sp., Anaplasma phagocytophilum, Anaplasma bovis, and Bartonella spp. for molecular identification of TBPs, and two pathogens, Borrelia sp. and Rickettsia sp. were detected via PCR. Sequence data were analyzed and a phylogenetic analysis was conducted using the maximum-likelihood method in MEGA v.7. The detection rate of Borrelia sp. in O.(C.) sawaii was 6.8 % (5/74), and that of Rickettsia sp. in O. sawaii and the newly identified Ornithodoros species. was 36.5 % (27/74). Sequencing analysis revealed that the 16S ribosomal (r) RNA and flagellin genes of Borrelia sp., and the citrate synthase (gltA) and 17-kDa antigen gene of Rickettsia sp. were closely phylogenetically related to those of Borrelia turicatae and Rickettsia asembonensis. This is the first report identifying Borrelia sp. and Rickettsia sp. from O. sawaii, and Rickettsia sp. from the newly identified Ornithodoros species in the ROK, and these results imply that soft ticks (O. sawaii, and the newly identified Ornithodoros species) may function as pathogen carriers with important implications for public health throughout their distribution areas in Asia.

Microplastic abundance in gull nests in relation to urbanization

Human activity and urbanization are having profound effects on natural landscapes and ecosystems. The presence and persistence of human-made materials such as microplastics can have major impacts on the health of organisms in both marine and terrestrial environments. We quantified microplastics in herring gull (Larus argentatus) and great black-backed gull (Larus marinus) nests at three colonies in the northeast United States that varied in their degree of urbanization: Jamaica Bay (JB) in New York City, Youngs Island (YI) on Long Island, New York, and Tuckernuck Island (TN) in Massachusetts. Nests in urban colonies contained a higher proportion of microplastics than those in the more remote colony. Our results link urbanization with microplastic accumulation in coastal environments and suggest that assessing microplastics in seabird nests could provide a means of evaluating microplastics encountered by seabirds and other coastal marine animals.

First report of Newly Identified Ornithodoros Species in the Republic of Korea.

Ticks and tick-borne diseases are important issues worldwide because of their effects on animal and human health. The genus Ornithodoros, which is included in the family Argasidae, is typically associated with wild animals, including seabirds. In this study, samples from the nests of seabirds and surrounding soil were collected to investigate Ornithodoros spp. from 9 uninhabited islands in the western, eastern, and southern parts of Korea from April 2017 to October 2018. The islands are known as the breeding places of migratory and resident birds. Ticks were collected from soil and nest material of seabirds using a Tullgren funnel and identified using 16S rRNA and the cytochrome c oxidase 1 gene (COI), and host animals of soft ticks were identified using the mitochondrial DNA cytochrome b gene by a polymerase chain reaction. In the sequence identity of the 16S rRNA gene fragment of Ornithodoros sp., Ornithodoros sawaii was identified as the closest homologous sequence, and the new Ornithodoros sp. was newly identified. We found that the newly identified Ornithodoros sp. in the Republic of Korea was located in uninhabited islands used as breeding places by the black-tailed gull, Larus crassirostris.

Creating a conservation network: Restoration of the critically endangered Chinese crested tern using social attraction

Social attraction techniques have been demonstrated effective in restoring seabird breeding colonies, especially colonies of terns (Subfamily: Sterninae). The Chinese crested tern (Thalasseus bernsteini) is a critically endangered seabird with a global population of about 100 breeding adults and a breeding range restricted to the East China Sea and the Yellow Sea. In order to restore a breeding colony of Chinese crested terns in an archipelago where a former colony had been abandoned, social attraction (decoys and audio playback systems) was deployed on a small, uninhabited island with no history of seabird nesting. The objective was to establish a breeding colony of greater crested terns (T. bergii), a closely-related common species, in the hope that Chinese crested terns would follow. Thousands of greater crested terns and at least 19 Chinese crested terns colonized the island during the first breeding season after deployment of social attraction. After three years of successful breeding, the colony was abruptly abandoned early in the fourth breeding season because of invasive king rat snakes (Elaphe carinata), which consumed all tern eggs. Following removal of all snakes from the colony, terns resumed nesting the subsequent year. Recovery of this critically endangered seabird depends on repeating this process at multiple islands. Careful planning, in conjunction with habitat management, close colony monitoring, and deployment of social attraction, can establish a conservation network of suitable, secure colony sites where most breeding adults can reproduce successfully. This approach can be used to restore a variety of declining seabird species along the Chinese coastline.

Using photographs to record plastic in seabird nests

The incidence of plastic in seabird nests can be used to track changes in the amounts of marine debris, but large sample sizes are needed for accurate estimates. Surveys of active nests cause disturbance to breeding birds, so we need an efficient way to sample nest plastics. Photographs of brown noddy Anous stolidus nests at Ducie Atoll, southeast Pacific Ocean, allowed rapid characterisation of plastic use with limited disturbance, and showed selection for blue-green items. Plastic was more prevalent in noddy nests at Ducie Atoll (97%) than at Inaccessible Island, South Atlantic Ocean (41%), despite lower debris densities at Ducie. Differences in nesting habitat and the resultant availability of natural nesting material drive this difference in plastic loads. Using photographs to record plastic in seabird nests reduces disturbance to breeding birds and might decrease the risk of missing cryptic debris items. Photographs also provide a permanent record of pollution levels.

Confidence intervals and sample size for estimating the prevalence of plastic debris in seabird nests

Evidence is accumulating about the impacts of plastics on marine life. The prevalence of plastics in seabird nests has been used as an indicator of levels of this pollutant in the ocean. However, the lack of a framework for defining sample sizes and errors associated with estimating the prevalence of plastic in nests prevents researchers from optimising time and reducing impacts of fieldwork. We present a method to determine the confidence intervals for the prevalence of debris in seabird nests and provide, for the first time, information on the prevalence of these items in nests of the Hartlaub’s gull Larus hartlaubii, the African penguin Spheniscus demersus, the great white pelican Pelecanus onocrotalus, and the white-breasted cormorant Phalacrocorax lucidus in South Africa. The method, based on observations and resampling simulations and tested here for nests of 12 seabird species from 15 locations worldwide, allows for straightforward hypothesis testing. Appropriate sample sizes can be defined by combining this method with a Bayesian approach. We show that precise estimates of prevalence of debris in nests can be obtained by sampling around 250 nests. Smaller sample sizes can be useful for obtaining rough estimates. For the Hartlaub’s gull, the African penguin, the great white pelican, and the white-breasted cormorant, debris were present in 0.75%, 3.00%, 6.41%, and 25.62% of the respective nests. Our approach will help researchers to determine errors associated with the prevalence of debris recorded in seabird nests and to optimise time and costs spent collecting data. It can also be applied to estimate confidence intervals and define sample sizes for assessing prevalence of plastic ingestion by any organism.

Past records and current distribution of seabirds at Larsemann Hills and Schirmacher Oasis, east Antarctica

Abstract Seabird populations in Antarctica serve as indicators to assess the impacts of global environmental change. Ecological data on seabirds in Antarctica are scarce due to limited knowledge on their distribution and abundance in most parts of the continent. In this study, we investigated the status of seabird species around the Indian research stations Bharati at Larsemann Hills, Prydz bay and Maitri at Schirmacher Oasis, central Dronning Maud Land located in east Antarctica. We conducted primary surveys during austral summers under the Indian Antarctic Program and compiled published as well as unpublished information on seabird distribution from these areas. We employed intensive area search methods to locate presence of seabird nesting and moulting sites. Ten species were recorded from Larsemann Hills with confirmed breeding of snow petrel, south polar skua and Wilson’s storm-petrel. Only south polar skua and Adélie penguin were reported breeding at Schirmacher Oasis with unconfirmed breeding of Wilson’s storm-petrel. This study presents the first detailed synthesis of status of seabirds from Larsemann Hills and Schirmacher Oasis regions in Antarctica and serves as a strong baseline for future ecological work on seabirds in the sector of operation of Indian Antarctic Program.

Camera traps reveal predators of breeding Black Guillemots Cepphus grylle

The occurrence of predation on Black Guillemots Cepphus grylle, of both adults and chicks, is an important consideration when assessing factors affecting breeding success. However, predators are often cryptic and confirmed interactions are difficult to identify. Through the use of camera traps, we recorded predation by mammalian and avian species on Black Guillemots on Stroma and North Ronaldsay in the 2016 and 2017 breeding seasons. Camera traps recorded two presumed instances of an Otter Lutra lutra predating chicks, one possible instance of an Otter predating an adult, one instance of a Hooded Crow Corvus cornix predating a chick, and the presence of several species of potential predators at nests. Camera traps were deployed concurrently during periods of visual observations, during which, sightings of predators were rare. We found the presence of camera traps to have no effect on breeding success between monitored (mean chicks fledged = 1.05, n = 52) and control (mean chicks fledged = 0.98, n = 98) nests. Here we highlight the potential role of camera traps in monitoring seabird nest success, and positively identifying sources of nest failure.