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Articles 21661 - 21690 of 732827

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Birds Depredating Stingrays And Skates (Chondrichthyes: Batoidea): New Observations And A Review Of Records, James A. Fitzsimons Jul 2025

Birds Depredating Stingrays And Skates (Chondrichthyes: Batoidea): New Observations And A Review Of Records, James A. Fitzsimons

Marine Ornithology

Gulls (Larus spp.) have a diet that includes fish, but they are also often dietary generalists. A limited number of dietary studies have been undertaken on the Pacific Gull Larus pacificus, which are endemic to Australia. Here, an observation of depredation by a Pacific Gull on a Southern Fiddler Ray Trygonorrhina dumerilii is described. Prior to this observation, rays and skates had not been recorded in the diet of Pacific Gulls, and there are few records in the literature of depredation by gulls (Laridae) or other bird families on species of cartilaginous fishes from the superorder Batoidea. However, there is …

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Hatching Success Of Common Murres Uria Aalge Is Linked To The Number Of Neighbours And Resource Availability, Amy L. Irvine, Julia E. Gulka, Gail K. Davoren Jul 2025

Hatching Success Of Common Murres Uria Aalge Is Linked To The Number Of Neighbours And Resource Availability, Amy L. Irvine, Julia E. Gulka, Gail K. Davoren

Marine Ornithology

When breeding within densely populated colonies, seabirds benefit from increased offspring protection from predators, but intraspecific competition for resources may outweigh these benefits. We tested whether the number of breeding-site neighbours and days of predator presence influenced the breeding performance of Common Murres Uria aalge at two different-sized colonies off the northeastern Newfoundland coast: Cabot Island (10000 breeding pairs; < 10 km offshore) and Funk Island (500000 breeding pairs; ~60 km offshore). Gulls, the main predators of murre eggs/chicks, inhabit both islands in similar numbers. During July–August 2018, camera traps placed at topographically similar plots on each colony recorded breeding performance metrics (i.e., hatching, fledging, reproductive success), number of breeding-site neighbours, and daily presence of gulls. Hatching success was lower at Funk Island (64.7%) than Cabot Island (96.2%), but nearly all hatched chicks fledged at both colonies. Lower hatching success at Funk Island was due to higher egg abandonment and predation. It was also associated with fewer breeding-site neighbours, including non-brooding mates and non-breeders, along with higher gull presence (96.6% of all gull sightings at both colonies). Fewer neighbours at Funk Island may have resulted from mates and non-breeding murres spending more time at sea due to longer distances to predictable foraging sites and higher conspecific densities relative to Cabot Island. In turn, with fewer breeding-site neighbours at Funk Island, parents appeared less able to defend against or deter gull predation. Although Funk Island has special conservation status, protection of Cabot Island may also be important for the long-term conservation of murres in Newfoundland.

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Abnormal Plumage Colouration In Spot-Billed Pelicans Pelecanus Philippensis At Pulicat Lake, Andhra Pradesh, India, Vaithianathan Kannan Jul 2025

Abnormal Plumage Colouration In Spot-Billed Pelicans Pelecanus Philippensis At Pulicat Lake, Andhra Pradesh, India, Vaithianathan Kannan

Marine Ornithology

Plumage colour variation is rarely observed in the Pelecaniformes and had not been previously recorded for the Spot-billed Pelican Pelecanus philippensis. Observed at Pulicat Lake, Andhra Pradesh, India, I describe strikingly coloured Spot-billed Pelicans having dark brown plumage, pink coloration on the bill, and black feet, but having normal eye colour

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Unusual Mass Stranding Event Of White-Chinned Petrels Procellaria Aequinoctialis In Santa Catarina State, Southern Brazil, Cristiane K. M. Kolesnikovas, Emanuel C. Ferreira, Cristiana C. A. Assumpção, Patrícia P. Serafini Jul 2025

Unusual Mass Stranding Event Of White-Chinned Petrels Procellaria Aequinoctialis In Santa Catarina State, Southern Brazil, Cristiane K. M. Kolesnikovas, Emanuel C. Ferreira, Cristiana C. A. Assumpção, Patrícia P. Serafini

Marine Ornithology

Bycatch is a significant threat for albatrosses and petrels in general but especially within Brazilian waters. As part of a monitoring program, Projeto de Monitoramento de Praias da Bacia de Santos (PMP-BS), an unusually high number of White-chinned Petrels Procellaria aequinoctialis was recorded at Santa Catarina Island: 72 birds from August 2015 to July 2016 (60 dead and 12 alive) and 31 birds from 29 December 2015 to 05 January 2016 (28 dead and 3 alive). Evaluation of the carcasses showed that 12 birds had external evidence of anthropogenic interaction, and necropsy demonstrated that at least two had perforation of …

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Kidney Lesions Related To Trematode Infestation In A Cabot's Ternâ Thalasseus Acuflavidus Found In Brazil, Rafaela N.R. Cardoso, Hassan Jerdy, Paula Baldassin, Eulógio C.Q. Carvalho, Max R. Werneck Jul 2025

Kidney Lesions Related To Trematode Infestation In A Cabot's Ternâ Thalasseus Acuflavidus Found In Brazil, Rafaela N.R. Cardoso, Hassan Jerdy, Paula Baldassin, Eulógio C.Q. Carvalho, Max R. Werneck

Marine Ornithology

We describe the occurrence of the trematode Renicola sp. associated with kidney lesions in a Cabot’s Tern Thalasseus acuflavidus from Brazil. During necropsy, we observed renal paleness, subpleural hemorrhage at the edges of the organ, and severe dilation of both ureters. Histological analysis revealed distension of the branches of the ureters, with partial obstruction due to the presence of the parasites and compression of adjacent tubules. The infection did not likely cause the tern's death.

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Reviews: The Art Of The Bird: The History Of Ornithological Art Through Forty Artists (Lederer, R.J.); Vanishing Fish: Shifting Baselines And The Future Of Global Fisheries (Pauly, D.); Ta Life On Our Planet: My Witness Statement And A Vision For The Future (Attenborough, D.), Abby Mcbride, Michelle Paleczny, Phillip Taylor Jul 2025

Reviews: The Art Of The Bird: The History Of Ornithological Art Through Forty Artists (Lederer, R.J.); Vanishing Fish: Shifting Baselines And The Future Of Global Fisheries (Pauly, D.); Ta Life On Our Planet: My Witness Statement And A Vision For The Future (Attenborough, D.), Abby Mcbride, Michelle Paleczny, Phillip Taylor

Marine Ornithology

No abstract provided.

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Author Instructions, Pacific Seabird Group Jul 2025

Author Instructions, Pacific Seabird Group

Marine Ornithology

No abstract provided.

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Fishy Tales: Behaviour Of Schooling Fish Escaping From Terns, Kees Hulsman, Gurudeo Anand Tularam Jul 2025

Fishy Tales: Behaviour Of Schooling Fish Escaping From Terns, Kees Hulsman, Gurudeo Anand Tularam

Marine Ornithology

The aim of this study is to develop a better understanding of seabird foraging behaviour and the anti-predator behaviour of their prey. Studies of seabirds’ foraging and prey-capture behaviour, as it relates to the evasive and escape behaviour of schooling fish, are sparse. Our study was carried out at One Tree Reef on the southern end of the Great Barrier Reef, Australia. A school of hardyheads Pranesus capricornensis sheltered in the shallows over the sand flats in front of the research station for 14 non-consecutive days. In that time, Lesser Crested Terns Thalasseus bengalensis were observed for 10 hours from …

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Southern Influx Of The Pantropical Bulwer's Petrel Bulweria Bulwerii Into The Tasman Sea, Simon B. Z. Gorta Jul 2025

Southern Influx Of The Pantropical Bulwer's Petrel Bulweria Bulwerii Into The Tasman Sea, Simon B. Z. Gorta

Marine Ornithology

Seabirds exploit marine habitats for resources, responding to many complex environmental signals that ultimately drive their distributions. Occasionally, influxes of seabird species to regions outside their normal range occur and determining the drivers of these patterns can aid in understanding their ecology and their conservation. I documented five birdwatching observations of Bulwer’s Petrel Bulweria bulwerii in the Tasman Sea between 24 January and 08 March 2020, roughly 2000 km south of their core range. Based on demographic, environmental, and anecdotal observations of seabirds, cetaceans, and bait fish, I suggest that the influx was most likely resource-driven, rather than accidental, age-related, …

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Morphometric Sex Determination Of Breeding Adult Royal Thalasseus Maximus And Sandwich Terns T. Sandvicensis In Louisiana, Megan Nepshinsky, Sabrina S. Taylor, Jeff S. Liechty, Ashlee K. Minor, Eva D. Windhoffer, Aaron R. Pierce Jul 2025

Morphometric Sex Determination Of Breeding Adult Royal Thalasseus Maximus And Sandwich Terns T. Sandvicensis In Louisiana, Megan Nepshinsky, Sabrina S. Taylor, Jeff S. Liechty, Ashlee K. Minor, Eva D. Windhoffer, Aaron R. Pierce

Marine Ornithology

Many seabirds have sex-specific traits, including survival, philopatry, behavior, and diet, information that is essential for effective conservation strategies. The difficulty of sexing monomorphic seabirds, however, has resulted in a lack of information on these important traits and an incomplete understanding of the ecology of many species. We used a polymerase chain reaction (PCR)-based sexing approach to determine if Royal Thalasseus maximus and Sandwich terns T. sandvicensis in Louisiana, USA can be accurately sexed using morphometrics. DNA samples and morphological measurements were obtained from Royal Terns (n = 106) and Sandwich Terns (n = 112) to accurately identify sex and …

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The Rarest Alcid: Status And History Of The Guadalupe Murrelet Synthliboramphus Hypoleucus At Isla Guadalupe, Mexico (1892-2007), Darrell L. Whitworth, Harry R. Carter, Eduardo Palacios, Josh S. Koepke, William R. Mciver, Christine D. Hamilton, Gerard J. Mcchesney, Franklin Gress Jul 2025

The Rarest Alcid: Status And History Of The Guadalupe Murrelet Synthliboramphus Hypoleucus At Isla Guadalupe, Mexico (1892-2007), Darrell L. Whitworth, Harry R. Carter, Eduardo Palacios, Josh S. Koepke, William R. Mciver, Christine D. Hamilton, Gerard J. Mcchesney, Franklin Gress

Marine Ornithology

The Guadalupe Murrelet (GUMU) Synthliboramphus hypoleucus is the rarest alcid in the world (< 5000 pairs), with regular breeding documented only at Islas Guadalupe (hereafter, “Guadalupe”) and San Benito off the west-central coast of Baja California, Mexico. GUMU were discovered at Guadalupe in 1892, but by then feral cats Felis catus had already devastated the population and limited most nesting to predator-free islets just offshore. Despite its status as the only major GUMU breeding island, the population at Guadalupe was never adequately surveyed during the 20th century. In March–April 2007, we used survey techniques developed specifically for Synthliboramphus murrelets to assess the status and distribution of GUMU at Guadalupe. We counted 1511 GUMU during spotlight surveys in waters around the island. GUMU were abundant near the islets, but they were also relatively numerous near suitable breeding habitats off the north and south coasts of Guadalupe proper. Searches on four islets yielded 93 nests, most at Islotes Zapato (66; 71%) and Morro Prieto (21; 23%), where scores of abandoned eggs indicated intense competition for nests. We found seven nests on Guadalupe proper, the first proof of breeding there since 1950, but we also found 68 carcasses that confirmed significant predation by cats and raptors. A spotlight survey correction factor yielded 2418 breeding pairs (95% confidence interval = 1662–4367) at Guadalupe and its islets, which accounted for ~90% of the world breeding population (1822–4789 pairs). About 1150–1750 pairs were estimated on Islotes Zapato and Morro Prieto in 1968, but comparable data were lacking to assess historical or recent changes in population size. Basic studies of GUMU biology have only recently been initiated and should be a continuing priority. Recent conservation actions have benefited the native biota of Guadalupe, but further measures, such as localized rodent control and robust biosecurity on the islets, should be considered to mitigate serious threats to the vulnerable GUMU population and other seabirds.

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Estimating Streaked Shearwater Calonectris Leucomelas Abundance In The Republic Of Korea Using Automated Acoustic Recorders, Kirk A. Hart, Steffen Oppel, Grant R.W. Humphries, Andrew Blackburn, Ki-Baek Nam Jul 2025

Estimating Streaked Shearwater Calonectris Leucomelas Abundance In The Republic Of Korea Using Automated Acoustic Recorders, Kirk A. Hart, Steffen Oppel, Grant R.W. Humphries, Andrew Blackburn, Ki-Baek Nam

Marine Ornithology

Traditional methods to assess population size in seabirds are applicable only to species that nest in visible locations, leaving cryptic nocturnal, burrow-nesting seabirds underrepresented in typical long-term population monitoring programs. Alternative methods to count burrow-nesting birds, however, are extremely labor-intensive and therefore are applicable only to small and possibly unrepresentative areas, and may have negative effects on burrow-nesting populations. We suggest the use of automatic acoustic recorders as a possible survey technique to overcome logistic difficulties of research of seabirds on remote islands in the Republic of Korea, where funding for ecological research is extremely limited but where globally important …

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Changes In The Population Size Of Yellow-Legged Gull Larus Michahellis At Essaouira And Mogador Island, West-Central Morocco, Siham Bellout, Moulay Abdeljalil Ait Baamrane, Ahmed Aamiri, Mohamed Aourir Jul 2025

Changes In The Population Size Of Yellow-Legged Gull Larus Michahellis At Essaouira And Mogador Island, West-Central Morocco, Siham Bellout, Moulay Abdeljalil Ait Baamrane, Ahmed Aamiri, Mohamed Aourir

Marine Ornithology

This study concerns changes in the size and population structure of a Yellow-legged Gull Larus michahellis colony, last assessed in 1985 in the city of Essaouira and on Mogador Island, Morocco. Using point-transect sampling, the average density measured in 2019 was 53.5 ± 2.8 birds/ha (5350 ± 280 birds/km2), which translates to a population size of almost 30 000 birds. The highest density occurred on Mogador Island, with 217.2 ± 28.3 birds/ha, a much higher density than previously recorded. The Yellow-legged Gull breeding population in the Essaouira–Mogador Island area has grown 3.58% per year since 1985, with an annual average …

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Low Prevalence Of Plasmodium And Haemoproteus In Resident Seabirds From Oceanic Islands Off The Brazilian Coast, Philippe N. Mariano, Gisele P. M. Dantas Jul 2025

Low Prevalence Of Plasmodium And Haemoproteus In Resident Seabirds From Oceanic Islands Off The Brazilian Coast, Philippe N. Mariano, Gisele P. M. Dantas

Marine Ornithology

Bird pathogens promote morbidity and mortality that affect bird population stability. In this context, the present study aimed to detect blood intracellular parasites by molecular methods in four species of seabirds, Masked Booby Sula dactylatra, Red-footed Booby S. sula, Brown Booby S. leucogaster, and Magnificent Frigatebird Fregata magnificens, on the Brazilian coast. Blood samples were collected in the Archipelagos of São Pedro and São Paulo, Fernando de Noronha, Atol das Rocas, and Trindade and Martim Vaz. Genomic DNA was extracted with proteinase K digestion and purification with phenol and chloroform. For each sample, three independent polymerase chain reactions were performed …

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Multidecadal Comparison Of Red-Footed Booby Sula Sula Diet At Ulupa'u Crater, O'Ahu, Hawai'i, Sarah E. Donahue, Josh Adams, K. David Hyrenbach Jul 2025

Multidecadal Comparison Of Red-Footed Booby Sula Sula Diet At Ulupa'u Crater, O'Ahu, Hawai'i, Sarah E. Donahue, Josh Adams, K. David Hyrenbach

Marine Ornithology

We describe the diet of Red-footed Boobies Sula sula nesting at Ulupa‘u Crater, O‘ahu, Hawai‘i based on 106 regurgitations collected during 2014 and 2015. We also compare our results to a diet study at this colony five decades earlier. Both studies indicate that flying squid (Ommastrephidae) and flyingfish (Exocoetidae) are important prey for this population while provisioning chicks. In particular, Purpleback Flying Squid Sthenoteuthis oualaniensis occurred in the majority (> 70%) of the recent regurgitation samples, and their size (mantle length < 11 cm) indicates that they were mostly juveniles. Moreover, the size distribution of the squid prey varied by year, indicating inter-annual variability in the phenology of spawning and larval development. This study highlights the reliance of Red-footed Boobies on juveniles of this poorly-studied squid and underscores their value as biological samplers of epipelagic fish and squid within their foraging ranges.

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Non-Breeding Movements And Foraging Ecology Of The Black Guillemot Cepphus Grylle In Atlantic Canada, Julia E. Baak, Marty L. Leonard, Carina Gjerdrum, Mark D. Dodds, Robert A. Ronconi Jul 2025

Non-Breeding Movements And Foraging Ecology Of The Black Guillemot Cepphus Grylle In Atlantic Canada, Julia E. Baak, Marty L. Leonard, Carina Gjerdrum, Mark D. Dodds, Robert A. Ronconi

Marine Ornithology

Understanding the movements of seabirds, which are important ecological indicators, can provide new insights into physical and biological aspects of the marine environment. This information can also be used in planning marine conservation and oil spill response strategies. Though Black Guillemots Cepphus grylle are widely distributed in the coastal waters of eastern and arctic Canada, little is known about their movements during the non-breeding season. We used a combination of global location sensors and stable-isotope analyses on Black Guillemots breeding on Country Island, Nova Scotia, Canada and on Kent Island, New Brunswick, Canada to examine their non-breeding movements and trophic …

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Population Decline And Breeding Distribution Changes Of Magnificent Frigatebirds Fregata Magnificens In Baja California Sur, Gerardo Marrón, Adriana Hernández-Alvarez, Roberto Carmona, Sergio Águila Jul 2025

Population Decline And Breeding Distribution Changes Of Magnificent Frigatebirds Fregata Magnificens In Baja California Sur, Gerardo Marrón, Adriana Hernández-Alvarez, Roberto Carmona, Sergio Águila

Marine Ornithology

The Magnificent Frigatebird Fregata magnificens (MaFr) is a tropical seabird species that is widely distributed along the mid-latitude coasts of the Americas. Historically, its most important breeding location has been Estero Las Tijeras in the Magdalena Lagoon complex (MLC), Baja California Sur, Mexico. Our recent data indicate a severe (~96%) population decline at this location. In 2002–2003, 33535 MaFr were counted in all of the MLC, and historical data (1985–1986) support the maintenance of consistently high numbers of MaFr in this region over time. Yet, MaFr abundance dropped severely—to ~1 200 individuals—in 2015. This low abundance persisted into 2017, when …

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Stable Isotope Analysis Of Multiple Tissues From Chick Carcasses Of Three Pygoscelid Penguins In Antarctica, Yanina A. Ciriani, Mariana A. Juáres, M. Mercedes Santos, Steven D. Emslie Jul 2025

Stable Isotope Analysis Of Multiple Tissues From Chick Carcasses Of Three Pygoscelid Penguins In Antarctica, Yanina A. Ciriani, Mariana A. Juáres, M. Mercedes Santos, Steven D. Emslie

Marine Ornithology

Many types of animal tissues are increasingly being used for stable isotope analysis, with their application dependent on the time frame they reflect and their availability for collection. Here, we investigated the isotopic values (δ13C and δ15N) of four tissues (feather, skin, toenail, and bone) collected from fledgling-period chick carcasses of three species of pygoscelid penguins to compare the variability and accuracy of the data among tissues. Samples were collected at 25 de Mayo/King George Island during the 2017/18 austral summer. Chick carcasses are commonly found at active penguin colonies, and “opportunistic sampling” can easily be performed without disturbing nesting …

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Author Instructions, Pacific Seabird Group Jul 2025

Author Instructions, Pacific Seabird Group

Marine Ornithology

No abstract provided.

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Time-Lapse Imagery Of Peruvian Boobies Sula Variegata Reveals Nest Abandonment Caused By Tick Hyperinfestation, Cristina Burga-Domínguez, Diego D. Gonzales-Delcarpio, Carlos B. Zavalaga Jul 2025

Time-Lapse Imagery Of Peruvian Boobies Sula Variegata Reveals Nest Abandonment Caused By Tick Hyperinfestation, Cristina Burga-Domínguez, Diego D. Gonzales-Delcarpio, Carlos B. Zavalaga

Marine Ornithology

Severe tick infestation in seabird colonies causes discomfort in reproductive adults, offspring mortality, and nest abandonment. This study used time-lapse cameras to examine the relationship between Ornithodoros amblus tick infestation and Peruvian Booby Sula variegata nest abandonment in four locations along the Peruvian coast between August 2016 and November 2018. The percent occurrence of discomfort in nesting birds (preening and standing on the nest) recorded by the cameras was used as an indicator of tick infestation. The tick density inside and outside the abandoned colonies was also evaluated. In five of the six colonies, complete nest abandonment occurred over an …

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Seasonal Changes In Diving And Flying Activities Of Rhinoceros Auklets Cerorhinca Monocerata Throughout The Non-Breeding Period, Ui Shimabukuro, Akinori Takahashi Jul 2025

Seasonal Changes In Diving And Flying Activities Of Rhinoceros Auklets Cerorhinca Monocerata Throughout The Non-Breeding Period, Ui Shimabukuro, Akinori Takahashi

Marine Ornithology

To understand how migratory seabirds meet the energetic challenges associated with wing molt and wintering, a full annual cycle behavioral study is needed. We studied the diving and flying activities of three Rhinoceros Auklets Cerorhinca monocerata migrating in the northwestern Pacific. The auklets decreased daily flight time and dive depth for seven weeks from the end of summer, presumably associated with primary feather molt. In winter, they increased dive depth (~81 m) and daily dive time. We suggest that Rhinoceros Auklets adjust their diving and flying behaviors in response to wing molt and energy demands in winter

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Avifauna Associated With An Otter-Trawl Fishery In A Tropical Estuary, Natalie Villar Freret-Meurer, José Vanderli Andreata, Maria Alice S. Alves Jul 2025

Avifauna Associated With An Otter-Trawl Fishery In A Tropical Estuary, Natalie Villar Freret-Meurer, José Vanderli Andreata, Maria Alice S. Alves

Marine Ornithology

Otter trawls are commonly used in fisheries for benthic fishes, and they provide a source of food to many marine birds. This study aimed to quantify the response of birds, by species, attracted to forage at fishing vessels in Ribeira Bay, Angra dos Reis, Rio de Janeiro, Brazil. Sampling was conducted every two months in 2006 at five stations, for a total of 30 trawls; fish were collected for 20 minutes per trawl. Bird counts were recorded just before the trawling started, when it began, 10 minutes after trawling began, and 10 minutes after it stopped. After trawling, 10 fresh …

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Trends In Density, Abundance, And Response To Storm Damage For Westland Petrels Procellaria Westlandica, 2007-2019, Susan M. Waugh, Christophe Barbraud, Karine Delord, Kate L.J. Simister, G. Barry Baker, Georgie K. Hedley, Kerry-Jayne Wilson, Douglas R.D. Rands Jul 2025

Trends In Density, Abundance, And Response To Storm Damage For Westland Petrels Procellaria Westlandica, 2007-2019, Susan M. Waugh, Christophe Barbraud, Karine Delord, Kate L.J. Simister, G. Barry Baker, Georgie K. Hedley, Kerry-Jayne Wilson, Douglas R.D. Rands

Marine Ornithology

The density and distribution of Westland Petrel burrows was assessed over a 12-year period (2007–2019). During that time, burrow density increased while occupancy remained stable, commensurate with an annual population growth rate of 1.022 (95% confidence interval: 0.971–1.076), as estimated using mark recapture data. From our surveys, we estimated a 2019 baseline population of ~6200 breeding pairs and a world population of 13 800–17600 individuals, covering around 95% of the population. Transects were conducted to establish the location and density of 17 petrel sub-colonies in rugged, untracked terrain in Paparoa National Park, West Coast, New Zealand. Major storms in 2014–2018 …

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Nightly Colony Attendance Patterns Of Provisioning Cassin's Auklet Ptychoramphus Aleuticus Are Consistent And Synchronous, Laura Mcfarlane Tranquilla, John L. Ryder, Louise K. Blight, Patrick D. O’Hara, Douglas F. Bertram Jul 2025

Nightly Colony Attendance Patterns Of Provisioning Cassin's Auklet Ptychoramphus Aleuticus Are Consistent And Synchronous, Laura Mcfarlane Tranquilla, John L. Ryder, Louise K. Blight, Patrick D. O’Hara, Douglas F. Bertram

Marine Ornithology

We conducted a multi-year (1999–2001) radio telemetry study to determine patterns of colony attendance among breeding Cassin’s Auklets Ptychoramphus aleuticus during the chick-rearing period on Triangle Island in British Columbia, Canada. A total of 1 625 detections were obtained for 80 individual birds (24–28 birds per year), each detected 20.3 times on average. We found that colony attendance (arrival times, departure times, in-burrow shift duration) and foraging trip duration (i.e., time away from the colony) were remarkably synchronous among individuals and years. On average, birds arrived in a pulse after darkness, with 67% of returns between 23h15 and 00h15 and …

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Responses Of Sympatric Shearwaters To Supplemental Food Under Varying Natural Prey Availability On The Wintering Grounds Of Coastal Newfoundland, Canada, Paloma C. Carvalho, Laurie D. Maynard, Gail K. Davoren Jul 2025

Responses Of Sympatric Shearwaters To Supplemental Food Under Varying Natural Prey Availability On The Wintering Grounds Of Coastal Newfoundland, Canada, Paloma C. Carvalho, Laurie D. Maynard, Gail K. Davoren

Marine Ornithology

Species tend to concentrate in areas with high prey availability, which could lead to competitive interactions within a feeding assemblage as resources become depleted. In coastal Newfoundland, Canada, capelin Mallotus villosus is the focal forage fish species that many top predators feed on during the summer; however, inshore availability varies throughout the boreal summer when abundant aggregations migrate inshore to spawn. We investigated the interactions and responses of Great Shearwaters Ardenna gravis and Sooty Shearwaters A. grisea during their non-breeding season to supplemental food supply under changing natural prey availability (higher and lower capelin availability) by conducting an at-sea experiment …

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Wedge-Tailed Shearwater Ardenna Pacifica Fallout Patterns Inform Targeted Management, Brooke Friswold, Keith Swindle, David Hyrenbach, Melissa R. Price Jul 2025

Wedge-Tailed Shearwater Ardenna Pacifica Fallout Patterns Inform Targeted Management, Brooke Friswold, Keith Swindle, David Hyrenbach, Melissa R. Price

Marine Ornithology

Seabird fledglings are often attracted to artificial, bright lights, leading to their grounding. This phenomenon is termed “fallout” and is associated with an increased risk of mortality from land-based threats. This study evaluated temporal trends and spatial factors, such as fallout clustering near lights and proximity to colonies, to inform targeted management actions. Standardized surveys were conducted from 2002 to 2010 for Wedge-tailed Shearwater Ardenna pacifica (WTSH) fallout on the island of O‘ahu, Hawai‘i, USA. First, yearly fallout counts along the transect showed a two-year cycle and identified 25 November as the date with the highest fallout across years. Second, …

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Spatiotemporal Characterization Of Non-Breeding Great Shearwaters Ardenna Gravis Within Their Wintering Range, Kevin D. Powers, David N. Wiley, Anna R. Robuck, Zachary H. Olson, Linda J. Welch, Michael A. Thompson, Les Kaufman Jul 2025

Spatiotemporal Characterization Of Non-Breeding Great Shearwaters Ardenna Gravis Within Their Wintering Range, Kevin D. Powers, David N. Wiley, Anna R. Robuck, Zachary H. Olson, Linda J. Welch, Michael A. Thompson, Les Kaufman

Marine Ornithology

Movements of Great Shearwaters Ardenna gravis wintering in the Northwest Atlantic showed age-based spatial and temporal flexibility, with foraging tactics linked to a defined physical preference of their primary prey. From 2013 to 2018, we tracked 58 Great Shearwaters during their wintering season using platform terminal transmitters deployed in the same area of the southwest Gulf of Maine. Utilization distributions (UDs) for individual birds were created from convex hulls, which were then combined for spatial and temporal analyses. Of the 95% kernel UDs, 55% were contained within the Gulf of Maine and the remainder extended to the Scotian Shelf off …

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Population Status Of The Kermadec Petrel (Pterodroma Neglecta Juana) At San Ambrosio Island, Chile, Manuel Marín, Rodrigo González, Sergio Trucco Jul 2025

Population Status Of The Kermadec Petrel (Pterodroma Neglecta Juana) At San Ambrosio Island, Chile, Manuel Marín, Rodrigo González, Sergio Trucco

Marine Ornithology

We visited San Ambrosio Island off northern Chile (26°21′S, 079°47′W) on 10–12 December 2019. We found a large population of Kermadec Petrel Pterodroma neglecta juana that appeared to be healthy. In the area that we could survey, we estimated at least 22686 breeding pairs, which is an underestimate of the entire population as we could not access some steep areas. Introduced mammals, which have since been eradicated, caused a loss of island vegetation that might be a drawback for this population, as shading from the sun appears to be important for nest-site selection. Egg-laying started by early December. We assessed …

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Manx Shearwaters Puffinus Puffinus Breeding In The Western Atlantic Follow A Different Migration Route From Their Eastern Atlantic Conspecifics, Annette L. Fayet, Paula Shannon, Donald E. Lyons, Stephen W. Kress Jul 2025

Manx Shearwaters Puffinus Puffinus Breeding In The Western Atlantic Follow A Different Migration Route From Their Eastern Atlantic Conspecifics, Annette L. Fayet, Paula Shannon, Donald E. Lyons, Stephen W. Kress

Marine Ornithology

Manx Shearwaters are transequatorial migrants, and most of the world’s population breeds in Britain and winters off the Patagonian Shelf in the western South Atlantic. The migration route of British birds follows a well-known clockwise movement between the North and South Atlantic, taking advantage of the winds. Whether this main Manx Shearwater migration corridor is used by the smaller populations breeding in the western North Atlantic is unknown. Here, we report our findings from tracking two adults from a newly-established colony of Manx Shearwaters in Maine, USA using miniature geolocators. The tracked shearwaters followed a post-breeding migration route southward along …

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Camera Trapping Reveals Cooperative Breeding In The Red-Footed Booby Sula Sula, Matthieu Le Corre, Morgane Manoury, Sabine Orlowski, Florent Bignon, Gabrielle Dicque Jul 2025

Camera Trapping Reveals Cooperative Breeding In The Red-Footed Booby Sula Sula, Matthieu Le Corre, Morgane Manoury, Sabine Orlowski, Florent Bignon, Gabrielle Dicque

Marine Ornithology

Cooperative breeding occurs in only 9% of bird species and is particularly rare among seabirds. We provide evidence that cooperative breeding occurs in a tropical seabird, the Red-footed Booby. Through camera monitoring of active nests, we found one nest in which a chick was raised by a trio of birds: its two parents and an immature bird. The immature bird fed the chick, guarded it, and preened it. The parents did not behave aggressively towards the immature bird when it approached the chick, suggesting that this trio was stable and composed of birds that knew each other. The growth of …

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