| |
Records |
Links |
|
Author |
Lara D. Shepherd, Colin M. Miskelly, Yves Cherel, Alan J. D. Tennyson |
|
| |
Title |
Genetic identification informs on the distributions of vagrant Royal (Eudyptes schlegeli) and Macaroni (Eudyptes chrysolophus) Penguins |
Type |
Journal |
| |
Year |
2021 |
Publication |
Polar Biology |
Abbreviated Journal |
|
|
| |
Volume |
44 |
Issue |
12 |
Pages |
2299-2306 |
|
| |
Keywords |
Antarctica Eudyptes chrysolophus Eudyptes schlegeli Genetic identification Penguin distribution Predation |
|
| |
Abstract |
Understanding the movements of animals that spend much of their life at sea is difficult but important for effective conservation. Determining the at-sea distributions of Macaroni (Eudyptes chrysolophus) and Royal (Eudyptes schlegeli) Penguins poses particular challenges, including their occurrence in remote locations and difficulties in species identification owing to overlap in morphological characters, particularly in immature birds. Here we use DNA sequencing to examine vagrant Macaroni and Royal Penguins from Antarctica and New Zealand in order to improve understanding of their non-breeding distributions. Our sampling included samples from living birds, museum specimens and scavenged penguin remains recovered from the stomachs of Antarctic toothfish (Dissostichus mawsoni) caught north of the Ross Sea. Mitochondrial control region (HVRI) sequences indicated that the two samples from New Zealand were likely Royal Penguins as were the scavenged penguins. Both Macaroni and Royal Penguins were detected at Terre Adélie, Antarctica, despite the nearest breeding colony of Macaroni Penguins being 4000 km away. We provide the first evidence of Royal Penguins reaching the Ross Dependency. All but one of the vagrants were immature birds, supporting suggestions that this age group is the most likely to disperse large distances from the breeding colonies. Our study demonstrates how DNA sequences can assist in identifying taxa with similar or overlapping morphologies, as well as fragmentary bird remains. |
|
| |
Programme |
109 |
|
| |
Campaign |
|
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN  |
1432-2056 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
yes |
|
| |
Call Number |
|
Serial |
8365 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
G. J. Sutton, C. A. Bost, A. Z. Kouzani, S. D. Adams, K. Mitchell, J. P. Y. Arnould |
|
| |
Title |
Fine-scale foraging effort and efficiency of Macaroni penguins is influenced by prey type, patch density and temporal dynamics |
Type |
Journal |
| |
Year |
2021 |
Publication |
Marine Biology |
Abbreviated Journal |
|
|
| |
Volume |
168 |
Issue |
1 |
Pages |
3 |
|
| |
Keywords |
|
|
| |
Abstract |
Difficulties quantifying in situ prey patch quality have limited our understanding of how marine predators respond to variation within and between patches, and throughout their foraging range. In the present study, animal-borne video, GPS, accelerometer and dive behaviour data loggers were used to investigate the fine-scale foraging behaviour of Macaroni penguins (Eudyptes chrysolophus) in response to prey type, patch density and temporal variation in diving behaviour. Individuals mainly dived during the day and utilised two strategies, targeting different prey types. Subantarctic krill (Euphausia vallentini) were consumed during deep dives, while small soft-bodied fish were captured on shallow dives or during the ascent phase of deep dives. Despite breeding in large colonies individuals seemed to be solitary foragers and did not engage with conspecifics in coordinated behaviour as seen in other group foraging penguin species. This potentially reflects the high abundance and low manoeuvrability of krill. Video data were used to validate prey capture signals in accelerometer data and a Support Vector Machine learning algorithm was developed to identify prey captures that occurred throughout the entire foraging trip. Prey capture rates indicated that Macaroni penguins continued to forage beyond the optimal give up time. However, bout-scale analysis revealed individuals terminated diving behaviour for reasons other than patch quality. These findings indicate that individuals make complex foraging decisions in relation to their proximate environment over multiple spatio-temporal scales. |
|
| |
Programme |
394 |
|
| |
Campaign |
|
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1432-1793 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
yes |
|
| |
Call Number |
|
Serial |
2037 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Karine Delord, Cédric Cotté, Pascal Terray, Charles-André Bost, Henri Weimerskirch, Christophe Barbraud |
|
| |
Title |
Factors affecting adult body condition in the endangered northern rockhopper penguin |
Type |
Journal |
| |
Year |
2021 |
Publication |
Marine Biology |
Abbreviated Journal |
|
|
| |
Volume |
168 |
Issue |
3 |
Pages |
27 |
|
| |
Keywords |
|
|
| |
Abstract |
Understanding the factors that drive the dynamics of populations of long‐lived species presents a unique challenge for conservation management. Here, we investigated long-term change in the body condition of adult northern rockhopper penguins Eudyptes moseleyi at Amsterdam Island, southern Indian Ocean, which hosts 5–10% of the global population of this endangered species. Analysis of a long‐term dataset (1994–2016), concurrent to the population's rapid decline, revealed no trend in adult northern rockhopper penguin body condition over time at the stages considered in this study, i.e. breeding and moulting. However, body condition varied between years and sexes and part of this variation was explained by environmental factors. Males were on average in better condition than females whatever the stage and individuals on average were in better condition during the moulting compared to the breeding period. The environmental conditions [sea surface temperature anomaly (SSTa), Subtropical Indian Ocean Dipole (SIOD) and Southern Annular Mode (SAM)] appeared to impact non-linearly the body condition. Overall, females were in better condition for negative values of SAM, SIOD and SSTa. The body condition of males exhibited similar but less complex and more significant patterns, with decreasing body condition for increasing SAM, SIOD and SSTa. The absence of long-term trends in male and female body condition suggests that the very low reproductive output and declining population since 1997 is probably not the result of environmental conditions during pre-breeding and pre-moult and necessitates further research into possible drivers during the breeding season. |
|
| |
Programme |
109,394 |
|
| |
Campaign |
|
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
Bachelor's thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1432-1793 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
yes |
|
| |
Call Number |
|
Serial |
7792 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Richard D. Ray, Bryant D. Loomis, Victor Zlotnicki |
|
| |
Title |
The mean seasonal cycle in relative sea level from satellite altimetry and gravimetry |
Type |
Journal |
| |
Year |
2021 |
Publication |
Journal of Geodesy |
Abbreviated Journal |
|
|
| |
Volume |
95 |
Issue |
7 |
Pages |
80 |
|
| |
Keywords |
Annual geocenter motion Annual land motion Annual/semiannual cycle Satellite altimetry |
|
| |
Abstract |
Satellite altimetry and gravimetry are used to determine the mean seasonal cycle in relative sea level, a quantity relevant to coastal flooding and related applications. The main harmonics (annual, semiannual, terannual) are estimated from 25 years of gridded altimetry, while several conventional altimeter “corrections” (gravitational tide, pole tide, and inverted barometer) are restored. To transform from absolute to relative sea levels, a model of vertical land motion is developed from a high-resolution seasonal mass inversion estimated from satellite gravimetry. An adjustment for annual geocenter motion accounts for use of a center-of-mass reference frame in satellite orbit determination. A set of 544 test tide gauges, from which seasonal harmonics have been estimated from hourly measurements, is used to assess how accurately each adjustment to the altimeter data helps converge the results to true relative sea levels. At these gauges, the median annual and semiannual amplitudes are 7.1 cm and 2.2 cm, respectively. The root-mean-square differences with altimetry are 3.24 and 1.17 cm, respectively, which are reduced to 1.93 and 0.86 cm after restoration of corrections and adjustment for land motion. Example outliers highlight some limitations of present-day coastal altimetry owing to inadequate spatial resolution: upwelling and currents off Oregon and wave setup at Minamitori Island. |
|
| |
Programme |
688 |
|
| |
Campaign |
|
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1432-1394 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
yes |
|
| |
Call Number |
|
Serial |
8610 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Charlène Gémard, Thierry Aubin, Eliette L. Reboud, Francesco Bonadonna |
|
| |
Title |
Call rate, fundamental frequency, and syntax determine male-call attractiveness in blue petrels Halobaena caerulea |
Type |
Journal |
| |
Year |
2021 |
Publication |
Behavioral Ecology and Sociobiology |
Abbreviated Journal |
|
|
| |
Volume |
75 |
Issue |
3 |
Pages |
55 |
|
| |
Keywords |
|
|
| |
Abstract |
In blue petrels (Halobaena caerulea), females are supposed to be particularly choosy and mate choice can take a couple of years. In these lifelong monogamous seabirds, choosing a good mate is crucial and has a strong influence on their fitness. Due to their nocturnal habits, the absence of sexual dimorphism, and the physical barrier between males calling from their burrow and females flying above the colony, vocal signals seem to be one of the main channels for males to communicate with potential mates. In a previous study, we investigated whether acoustic parameters of male calls carry information about morphological characteristics that might be indicators of males’ qualities. Here, we experimentally test whether these acoustic parameters linked to male characteristics are actually attractive to females. To do so, we played back modified calls of males to females in a colony of blue petrels of the Kerguelen archipelago. We found that flying females were more attracted by high-pitched calls, and by calls broadcasted at a high call rate. Previous studies showed a relationship between pitch and bill depth and length. In filter-feeding birds, such as blue petrels, bill morphology influences feeding efficiency. A high call rate is an indicator of sexual motivation and makes the caller easier to locate by potential mates and predators in the hubbub of the colony. We thus hypothesized that producing frequent high-pitched calls appeared to be preferable for a conspicuous sexual signaling although it may increase predation risks. |
|
| |
Programme |
354 |
|
| |
Campaign |
|
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1432-0762 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
yes |
|
| |
Call Number |
|
Serial |
7055 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Yushiro Fujii, Kenji Satake, Shingo Watada, Tung-Cheng Ho |
|
| |
Title |
Re-examination of Slip Distribution of the 2004 Sumatra–Andaman Earthquake (Mw 9.2) by the Inversion of Tsunami Data Using Green’s Functions Corrected for Compressible Seawater Over the Elastic Earth |
Type |
Journal |
| |
Year |
2021 |
Publication |
Pure and Applied Geophysics |
Abbreviated Journal |
|
|
| |
Volume |
178 |
Issue |
12 |
Pages |
4777-4796 |
|
| |
Keywords |
2004 Sumatra–Andaman earthquake far-field tsunami waveform phase-corrected Green’s function slip distribution tsunami data inversion |
|
| |
Abstract |
We re-examined the slip distribution on faults of the 2004 Sumatra–Andaman (M 9.1 according to USGS) earthquake by the inversion of tsunami data with phase-corrected Green’s functions applied to linear long waves. The correction accounts for the effects of compressibility of seawater, elasticity of solid earth, and gravitational potential variation associated with the motion of mass to reproduce the delayed arrivals and the reversed phase of the first tsunami waves. We used sea surface height (SSH) data from satellite altimetry (SA) measurements along five tracks, and the tsunami waveforms recorded at tide gauges (TGs) and ocean bottom pressure gauges (OBPGs) in and around the Indian Ocean. The inversion results for both data sets for different rupture velocities (Vr) show that the reproducibility of the spatiotemporal SSHs and tsunami waveforms is improved by the phase corrections, although the effects are not so significant within the Indian Ocean. The best slip distribution model from joint inversion of SA, TG and OBPG data with Vr of 1.3 km/s shows the largest slips of 16–25 m off Sumatra Island, large slips of 2–11 m off the Nicobar Islands, and moderate slips of 2–6 m in the Andaman Islands. The inversion results reproduce the far-field tsunami waveforms well at distant stations even more than 13,000–25,000 km from the epicenter. The total source length is about 1400 km and the seismic moment is Mw 9.2, longer and larger than that of our previous estimates based on TG records. |
|
| |
Programme |
688 |
|
| |
Campaign |
|
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1420-9136 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
yes |
|
| |
Call Number |
|
Serial |
8411 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Jana Maresova, Alena Suchackova Bartonova, Martin Konvicka, Toke T. Høye, Olivier Gilg, Jean-Claude Kresse, Nazar A. Shapoval, Roman V. Yakovlev, Zdenek Faltynek Fric |
|
| |
Title |
The story of endurance: Biogeography and the evolutionary history of four Holarctic butterflies with different habitat requirements |
Type |
Journal |
| |
Year |
2021 |
Publication |
Journal of Biogeography |
Abbreviated Journal |
|
|
| |
Volume |
48 |
Issue |
3 |
Pages |
590-602 |
|
| |
Keywords |
COI Ef-1α insect Lepidoptera mammoth steppe Pleistocene Quaternary RpS5 species distribution modelling |
|
| |
Abstract |
Aim Biogeographical studies on the entire ranges of widely distributed species can change our perception of species’ range dynamics. We studied the effects of Pleistocene glacial cycles on current butterfly species distributions, aiming to uncover complex biogeographic patterns in the Holarctic, a region dramatically affected by Cenozoic climate change. Location Eurasia and North America. Taxon Boloria chariclea, Agriades optilete, Carterocephalus palaemon, Oeneis jutta. Methods We reconstructed the biogeographic history of four butterfly species differing in habitat preferences (B. chariclea – tundra, A. optilete – bogs, C. palaemon – temperate grasslands, O. jutta – taiga), using one mitochondrial and two nuclear DNA markers and species distribution modelling. Results Except for B. chariclea, all species originated in Eurasia. The open habitat species A. optilete and C. palaemon formed widely distributed east-west genetic clusters in continental Asia and clusters separated from them in Europe. Genetic clusters of the taiga species O. jutta were not geographically separated in Eurasia, suggesting Pleistocene fragmentation and recent reconnection. The glaciated North America was recolonized from Beringian and southerly situated refugia by all four species. Main conclusions The Pleistocene mammoth steppe allowed a widespread continuous distribution of open habitat butterflies, while in contrast the distribution of a taiga-specialist species was more limited. In the mostly flat and continental North Asia, the butterflies of various types of open habitats survived ice age in widely distributed east-west belts. In the mountainous and oceanic regions of Europe, Beringia and west North America, all four species persisted in contracted areas during the glacials. After deglaciation, they expanded their ranges and formed contact zones among populations. To conclude, the harsh climate of the glacials did not represent an obstacle for butterflies. Instead, different habitat specialists selected their own ways to thrive in the dynamic conditions of Quaternary glacial periods. |
|
| |
Programme |
1036 |
|
| |
Campaign |
|
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1365-2699 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
yes |
|
| |
Call Number |
|
Serial |
7984 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Benjamin Merkel, Sébastien Descamps, Nigel G. Yoccoz, David Grémillet, Francis Daunt, Kjell E. Erikstad, Aleksey V. Ezhov, Mike P. Harris, Maria Gavrilo, Svein-Håkon Lorentsen, Tone K. Reiertsen, Harald Steen, Geir H. Systad, Þorkell Lindberg Þórarinsson, Sarah Wanless, Hallvard Strøm |
|
| |
Title |
Individual migration strategy fidelity but no habitat specialization in two congeneric seabirds |
Type |
Journal |
| |
Year |
2021 |
Publication |
Journal of Biogeography |
Abbreviated Journal |
|
|
| |
Volume |
48 |
Issue |
2 |
Pages |
263-275 |
|
| |
Keywords |
guillemots light-level geolocation murres Uria aalge Uria lomvia |
|
| |
Abstract |
Aim In migratory species, individuals often use fixed and individual-specific migration strategies, which we term individual migration strategy fidelity (IMSF). Our goal was to test if guillemots have flexible or fixed individual migration strategies (i.e. IMSF), if this behaviour is consistent across large parts of the genus’ range and if they were philopatric to geographical sites or a habitat feature. Location North Atlantic. Taxon Uria spp. Methods We quantified consistent individual differences in inter-annual spatial distribution and habitat occupied throughout the non-breeding period using a large geolocator tracking dataset of 729 adult seabirds breeding at 13 colonies across the Northeast Atlantic and repeatedly tracked up to 7 years over a 9-year period. Additionally, we used a similarity index to calculate relative fidelity to either geographical sites or habitats and linear mixed-effects models to assess persistence of spatial site fidelity over multiple years. Results Both guillemot species exhibited IMSF across a large part of the genus’ range which persisted over multiple years. Individuals of both species and almost all colonies showed fidelity to geographical sites and not to specific habitats. Main conclusions Guillemots show IMSF that is best explained by site familiarity (fidelity to specific sites) rather than habitat specialization (fidelity to specific habitats). In the context of rapidly changing environments, favourable habitats may permanently shift locations and hence species displaying IMSF driven by site familiarity—such as the genus Uria—may not be able to adjust their migration strategies sufficiently fast to sustain individual fitness and ensure population persistence. |
|
| |
Programme |
388 |
|
| |
Campaign |
|
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1365-2699 |
ISBN |
1365-2699 |
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
yes |
|
| |
Call Number |
|
Serial |
8025 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
John P. Whiteman, Seth D. Newsome, Paco Bustamante, Yves Cherel, Keith A. Hobson |
|
| |
Title |
Quantifying capital versus income breeding: New promise with stable isotope measurements of individual amino acids |
Type |
Journal |
| |
Year |
2021 |
Publication |
Journal of Animal Ecology |
Abbreviated Journal |
|
|
| |
Volume |
90 |
Issue |
6 |
Pages |
1408-1418 |
|
| |
Keywords |
carbon-13 compound-specific isotope analysis CSIA discrimination fasting fractionation nitrogen-15 |
|
| |
Abstract |
Capital breeders accumulate nutrients prior to egg development, then use these stores to support offspring development. In contrast, income breeders rely on local nutrients consumed contemporaneously with offspring development. Understanding such nutrient allocations is critical to assessing life-history strategies and habitat use. Despite the contrast between these strategies, it remains challenging to trace nutrients from endogenous stores or exogenous food intake into offspring. Here, we tested a new solution to this problem. Using tissue samples collected opportunistically from wild emperor penguins Aptenodytes forsteri, which exemplify capital breeding, we hypothesized that the stable carbon (δ13C) and nitrogen (δ15N) isotope values of individual amino acids (AAs) in endogenous stores (e.g. muscle) and in egg yolk and albumen reflect the nutrient sourcing that distinguishes capital versus income breeding. Unlike other methods, this approach does not require untested assumptions or diet sampling. We found that over half of essential AAs had δ13C values that did not differ between muscle and yolk or albumen, suggesting that most of these AAs were directly routed from muscle into eggs. In contrast, almost all non-essential AAs differed in δ13C values between muscle and yolk or between muscle and albumen, suggesting de novo synthesis. Over half of AAs that have labile nitrogen atoms (i.e. ‘trophic’ AA) had higher δ15N values in yolk and albumen than in muscle, suggesting that they were transaminated during their routing into egg tissue. This effect was smaller for AAs with less labile nitrogen atoms (i.e. ‘source’ AA). Our results indicate that the δ15N offset between trophic-source AAs (Δ15Ntrophic-source) may provide an index of the extent of capital breeding. The value of emperor penguin Δ15NPro-Phe was higher in yolk and albumen than in muscle, reflecting the mobilization of endogenous stores; in comparison, the value of Δ15NPro-Phe was similar across muscle and egg tissue in previously published data for income-breeding herring gulls Larus argentatus smithsonianus. Our results provide a quantitative basis for using AA δ13C and δ15N, and isotopic offsets among AAs (e.g. Δ15NPro-Phe), to explore the allocation of endogenous versus exogenous nutrients across the capital versus income spectrum of avian reproduction. |
|
| |
Programme |
109 |
|
| |
Campaign |
|
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1365-2656 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
yes |
|
| |
Call Number |
|
Serial |
7945 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Florian Orgeret, Ryan R. Reisinger, Tegan Carpenter-Kling, Danielle Z. Keys, Alexandre Corbeau, Charles-André Bost, Henri Weimerskirch, Pierre A. Pistorius |
|
| |
Title |
Spatial segregation in a sexually dimorphic central place forager: Competitive exclusion or niche divergence? |
Type |
Journal |
| |
Year |
2021 |
Publication |
Journal of Animal Ecology |
Abbreviated Journal |
|
|
| |
Volume |
90 |
Issue |
10 |
Pages |
2404-2420 |
|
| |
Keywords |
bio-logging central place foraging ecological niche theory intraspecific competition kernel density estimates resource selection functions sexual segregation wandering albatross |
|
| |
Abstract |
Sexual competition is increasingly recognized as an important selective pressure driving species distributions. However, few studies have investigated the relative importance of interpopulation versus intrapopulation competition in relation to habitat availability and selection. To explain spatial segregation between sexes that often occurs in non-territorial and central place foragers, such as seabirds, two hypotheses are commonly used. The ‘competitive exclusion’ hypothesis states that dominant individuals should exclude subordinate individuals through direct competition, whereas the ‘niche divergence’ hypothesis states that segregation occurs due to past competition and habitat specialization. We tested these hypotheses in two populations of an extreme wide-ranging and sexually dimorphic seabird, investigating the relative role of intrapopulation and interpopulation competition in influencing sex-specific distribution and habitat preferences. Using GPS loggers, we tracked 192 wandering albatrosses Diomedea exulans during four consecutive years (2016–2019), from two neighbouring populations in the Southern Ocean (Prince Edward and Crozet archipelagos). We simulated pseudo-tracks to create a null spatial distribution and used Kernel Density Estimates (KDE) and Resource Selection Functions (RSF) to distinguish the relative importance of within- versus between-population competition. Kernel Density Estimates showed that only intrapopulation sexual segregation was significant for each monitoring year, and that tracks between the two colonies resulted in greater overlap than expected from the null distribution, especially for the females. RSF confirmed these results and highlighted key at-sea foraging areas, even if the estimated of at-sea densities were extremely low. These differences in selected areas between sites and sexes were, however, associated with high interannual variability in habitat preferences, with no clear specific preferences per site and sex. Our results suggest that even with low at-sea population densities, historic intrapopulation competition in wide-ranging seabirds may have led to sexual dimorphism and niche specialization, favouring the ‘niche divergence’ hypothesis. In this study, we provide a protocol to study competition within as well as between populations of central place foragers. This is relevant for understanding their distribution patterns and population regulation, which could potentially improve management of threatened populations. |
|
| |
Programme |
109,394 |
|
| |
Campaign |
|
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
Bachelor's thesis |
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1365-2656 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
yes |
|
| |
Call Number |
|
Serial |
8093 |
|
| Permanent link to this record |
