31 research outputs found
Global political responsibility for the conservation of albatrosses and large petrels
Migratory marine species cross political borders and enter the high seas, where the lack of an effective global management framework for biodiversity leaves them vulnerable to threats. Here, we combine 10,108 tracks from 5775 individual birds at 87 sites with data on breeding population sizes to estimate the relative year-round importance of national jurisdictions and high seas areas for 39 species of albatrosses and large petrels. Populations from every country made extensive use of the high seas, indicating the stake each country has in the management of biodiversity in international waters. We quantified the links among national populations of these threatened seabirds and the regional fisheries management organizations (RFMOs) which regulate fishing in the high seas. This work makes explicit the relative responsibilities that each country and RFMO has for the management of shared biodiversity, providing invaluable information for the conservation and management of migratory species in the marine realm
Climate change, phenological shifts, eco-evolutionary responses and population viability: toward a unifying predictive approach
The debate on emission targets of greenhouse gasses designed to limit global climate change has to take into account the ecological consequences. One of the clearest ecological consequences is shifts in phenology. Linking these shifts to changes in population viability under various greenhouse gasses emission scenarios requires a unifying framework. We propose a box-in-a-box modeling approach that couples population models to phenological change. This approach unifies population modeling with both ecological responses to climate change as well as evolutionary processes. We advocate a mechanistic embedded correlative approach, where the link from genes to population is established using a periodic matrix population model. This periodic model has several major advantages: (1) it can include complex seasonal behaviors allowing an easy link with phenological shifts; (2) it provides the structure of the population at each phase, including the distribution of genotypes and phenotypes, allowing a link with evolutionary processes; and (3) it can incorporate the effect of climate at different time periods. We believe that the way climatologists have approached the problem, using atmosphereâocean coupled circulation models in which components are gradually included and linked to each other, can provide a valuable example to ecologists. We hope that ecologists will take up this challenge and that our preliminary modeling framework will stimulate research toward a unifying predictive model of the ecological consequences of climate change
Mobile Incubation in Waved Albatross (Phoebastria irrorata): Associated Hatching Failure and Artificial Mitigation
Waved albatrosses often relocate their eggs during incubation by placing the egg between the tarsi and shuffling forward. This behavior frequently results in eggs becoming lodged between rocks, accounting for at least 10%, and perhaps as much as 80%, of breeding failures. Because albatross populations worldwide are currently threatened, artificial means of augmenting reproductive success may be necessary to mitigate losses caused by anthropogenic effects. We characterize the frequency and extent of egg movement; test several hypotheses related to microhabitat, timing, and incubation location to explain the behavior; and investigate the utility of repositioning lodged eggs in a location in which breeding birds might resume incubation. Egg rescue increased both the likelihood of continued incubation as well as the hatching rate in our experiment, and provides an efficient, low-cost management option for this species
Small range and distinct distribution in a satellite breeding colony of the critically endangered Waved Albatross
To determine the proximate consequences of the limited breeding distribution of the critically endangered Waved Albatross (Phoebastria irrorata), we present continuous breeding season GPS tracks highlighting differences in behaviour, destinations, and distances travelled between three distinct colonies: two in GalĂĄpagos and one closer to the South American continent on Isla de la Plata, where a small number of pairs nest. Accelerometer data paired with GPS locations allowed operational classifications of Waved Albatross behaviour. All birds from GalĂĄpagos travelled eastward to the continental shelf and foraged southward along the Peruvian coast. Birds from Isla de la Plata made more and shorter foraging trips and used habitat north of the destinations of GalĂĄpagos birds. La Plata birds foraged in areas through which GalĂĄpagos birds commuted, and had slower average flight speeds and shorter commutes. Overall, albatrosses from La Plata might operate under a consistently lower return but they also incur lower costs compared to birds from GalĂĄpagos, which take fewer trips involving longer time investment. GalĂĄpagos birds may be able to forage more effectively based on more abundant or more profitable food patches in those highly productive areas. Foraging destinations of birds from the two GalĂĄpagos colonies were similar and overlapped areas that presented localized mortality risk from artisanal fisheries in previous years. This study, performed across the speciesâ breeding range, reveals the different foraging distribution of La Plata albatrosses and the potential conservation value of this small colony in terms of maintenance of spatial diversity and behavioural plasticity
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Comparison of light- and SST-based geolocation with satellite telemetry in free-ranging albatrosses
Light-based archival tags are increasingly being used on free- ranging marine vertebrates to study their movements using geolocation estimates. These methods use algorithms that incorporate threshold light techniques to determine longitude and latitude. More recently, researchers have begun using sea surface temperature (SST) to determine latitude in temperate regions. The accuracy and application of these algorithms have not been validated on free-ranging birds. Errors in both geolocation methods were quantified by double-tagging Laysan (Phoebastria immutabilis Rothschild) and black-footed (P. nigripes Audubon) albatrosses with both leg-mounted archival tags that measured SST and ambient light, and satellite transmitters. Laysan albatrosses were captured and released from breeding colonies on Tern Island, northwestern Hawaiian Islands (23 degrees 52'N, 166 degrees 17'W) and Guadalupe Island, Mexico (28 degrees 31'N, 118 degrees 10'W) and black-footed albatrosses from Tern Island. Studies were carried out between December 2002 and March 2003. For all birds combined, the mean +/- SD great circle (GC) distance between light-based locations and satellite-derived locations was 400 +/- 298 km (n=131). Errors in geolocation positions were reduced to 202 +/- 171 km (n=154) when light-based longitude and SST-based latitude (i.e. SST/light) were used to establish locations. The SST/light method produced comparable results for two Laysan albatross populations that traveled within distinctly different oceanic regions (open ocean vs more coastal) whereas light-based methods produced greater errors in the coastal population. Archival tags deployed on black-footed albatrosses returned a significantly higher proportion of lower-quality locations, which was attributed to interference of the light sensor on the tag. Overall, the results demonstrate that combining measures of light-based longitude and SST-based latitude significantly reduces the error in location estimates for albatrosses and can provide valid latitude estimates during the equinoxes, when light-based latitude measurements are indeterminate
Atâsea behavior varies with lunar phase in a nocturnal pelagic seabird, the swallow-tailed gull
Strong and predictable environmental variability can reward flexible behaviors among animals. We used long-term records of activity data that cover several lunar cycles to investigate whether behavior at-sea of swallow-tailed gulls Creagrus furcatus, a nocturnal pelagic seabird, varied with lunar phase in the GalĂĄpagos Islands. A Bayesian hierarchical model showed that nighttime at-sea activity of 37 breeding swallow-tailed gulls was clearly associated with changes in moon phase. Proportion of nighttime spent on water was highest during darker periods of the lunar cycle, coinciding with the cycle of the diel vertical migration (DVM) that brings prey to the sea surface at night. Our data show that at-sea behavior of a tropical seabird can vary with environmental changes, including lunar phase
Global political responsibility for the conservation of albatrosses and large petrels
Migratory marine species cross political borders and enter the high seas, where the lack of an effective global management framework for biodiversity leaves them vulnerable to threats. Here, we combine 10,108 tracks from 5775 individual birds at 87 sites with data on breeding population sizes to estimate the relative year-round importance of national jurisdictions and high seas areas for 39 species of albatrosses and large petrels. Populations from every country made extensive use of the high seas, indicating the stake each country has in the management of biodiversity in international waters. We quantified the links among national populations of these threatened seabirds and the regional fisheries management organizations (RFMOs) which regulate fishing in the high seas. This work makes explicit the relative responsibilities that each country and RFMO has for the management of shared biodiversity, providing invaluable information for the conservation and management of migratory species in the marine realm