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- Data packageData from: Study "GPS tracking of guanay cormorants"(2025-12-10) van Oordt, Francis; Elliott, Kyle H.Foraging movements are commonly driven by both extrinsic (e.g. climate or food availability) and intrinsic (e.g. breeding status or nutritional state) factors. In the Humboldt Current System (HCS), a highly productive upwelling system, Peruvian boobies (Sula variegata) and guanay cormorants (Phalacrocorax bougainvillii), are the most abundant guano seabirds. They prey mainly on Peruvian anchovy (Engraulis ringens), a cold-water fish species whose availability decreases during El Niño events (warmer conditions). We studied the relationship between extrinsic and intrinsic factors linked with foraging movements by means of biologging and analysis of metabolites, which reflect the nutritional states of both species during two contrasting breeding seasons (2018 [warm, high nest abandonment]; 2019 [normal, low nest abandonment]) at Guañape Norte Island, Peru (8°32’02.0"S 78°57’47.0"W). Peruvian boobies traveled greater distances on average (69.7 +/- 2.90 km) than guanay cormorants (50.5 +/- 2.13 km). Mean foraging trip duration for both species was greater during the warmer year (2.63 h +/- 0.15 in 2018 vs. 1.97 h +/- 0.1 in 2019), as expected due to reduced prey availability. Ketone concentrations were lower in boobies during the warm year, and cholesterol concentrations decreased with search effort. We conclude that Peruvian seabirds respond to warming of the HCS by increasing foraging effort, which is strongly linked to their nutritional status. Therefore, these warming effects on the system may be detrimental for population recovery in the long-term and need to be addressed in conservation planning such as protected area delimitation and fisheries management during the breeding season.
- Data packageData from: Study "GPS tracking of Peruvian boobies"(2025-12-10) van Oordt, Francis; Elliott, Kyle H.Foraging movements are commonly driven by both extrinsic (e.g. climate or food availability) and intrinsic (e.g. breeding status or nutritional state) factors. In the Humboldt Current System (HCS), a highly productive upwelling system, Peruvian boobies (Sula variegata) and guanay cormorants (Phalacrocorax bougainvillii), are the most abundant guano seabirds. They prey mainly on Peruvian anchovy (Engraulis ringens), a cold-water fish species whose availability decreases during El Niño events (warmer conditions). We studied the relationship between extrinsic and intrinsic factors linked with foraging movements by means of biologging and analysis of metabolites, which reflect the nutritional states of both species during two contrasting breeding seasons (2018 [warm, high nest abandonment]; 2019 [normal, low nest abandonment]) at Guañape Norte Island, Peru (8°32’02.0"S 78°57’47.0"W). Peruvian boobies traveled greater distances on average (69.7 +/- 2.90 km) than guanay cormorants (50.5 +/- 2.13 km). Mean foraging trip duration for both species was greater during the warmer year (2.63 h +/- 0.15 in 2018 vs. 1.97 h +/- 0.1 in 2019), as expected due to reduced prey availability. Ketone concentrations were lower in boobies during the warm year, and cholesterol concentrations decreased with search effort. We conclude that Peruvian seabirds respond to warming of the HCS by increasing foraging effort, which is strongly linked to their nutritional status. Therefore, these warming effects on the system may be detrimental for population recovery in the long-term and need to be addressed in conservation planning such as protected area delimitation and fisheries management during the breeding season.
- Data packageData from: Invasive wild pig movement and space use in a mixed-use forest landscape, South Carolina(2025-12-03) Buchholtz, Erin K.; Yarrow, Greg; Jamison, AndrewInvasive wild pigs (Sus scrofa) pose considerable ecological and economic challenges across their introduced range, and understanding their spatial ecology is critical for management. This research and accompanying dataset represents adult wild pig movement in South Carolina, United States based on 16 individuals collared in 2023-2024. Using hourly GPS collar data for 6 males and 5 females, we calculated autocorrelated kernel density estimates (AKDEs) and monthly kernel density estimates (KDEs) to characterize space use. Individual pigs had an average hourly step length of 83 m and average net displacement of 930 m. On average, pigs used 2.32 km2 monthly, while they used 2.95 km2 over their entire tracked period (mean = 111 days). This work aims to support management actions and future research on invasive wild pigs.
- Data packageData from: Study "GPS tracking of honey buzzards in Finland"(2025-10-17) Byholm, Patrik; Mirski, Paweł; Vansteelant, WouterNatal dispersal is a multistep process. It commences when a juvenile departs from its natal site and concludes when it settles to breed for the first time. During this interim period, dispersing individuals of long-lived species often undergo a wandering phase, which may span years. This phase remains one of the least studied aspects of avian life histories. We utilized a unique GPS-telemetry data set on a slow reproducing, long-lived migratory bird of prey, the European honey buzzard, Pernis apivorus, tracked for up to 6 years after fledging. Our aim was to assess how phenology, ranging behaviour and philopatry change as individuals gain experience. Individuals exhibited variability in the age at which they first returned to their breeding range, yet all survivors settled at sites proximate to their natal nests. In subsequent returns, immatures increased the time spent within the breeding range and narrowed down their ranging to smaller areas situated progressively closer to their natal nests. Our study reveals the complexity and extended nature of natal dispersal, emphasizing the importance of individual experi ence and migratory improvement for successful recruitment in long-lived species.
- Data packageData from: Abundance, diet and foraging of Galápagos Barn Owls (Tyto furcata punctatissima)(2025-09-17) Wagner, Hermann; Cruz, Sebastian; Jiménez-Uzcategui, Gustavo; Albán, Katherine; Quezada, Galo; Piedrahita, PaoloWe studied Galápagos barn owls on Santa Cruz Island in the Galápagos Archipelago. We collected and analyzed pellets to determine diet composition. Barn-owl diet consisted—in terms of biomass—of ~89% rodents and ~10% insects. Bird remains occurred in 1% of the pellets. Foraging was studied with data loggers, a method not previously applied to the study of Galápagos barn owls. Owls rested during the day in natural and human-built roosts such as lava holes, trees, or huts. Night-time foraging was characterized by periods during which the bird moved and periods during which the bird stayed within one place, with the latter amounting to ~56% of the time away from the day roost. Birds began foraging shortly after sunset and returned to their day roost before sunrise. The duration of foraging was approximately 11 h per night. Foraging areas were small (median value: 0.28 km2). Although our data demonstrate a continued presence of the subspecies, we regard the situation for this subspecies as labile, as multiple threats, such as road kills, poisoning, and intentional killing by farmers, have increased recently, and suggest the development of a management plan to improve its conservation.