Abstract View

Tobias Erik Reiners, Julien Eidenschenk, Karsten Neumann, Carsten Nowak, Preservation of genetic diversity in a wild and captive population of a rapidly declining mammal, the Common hamster of the French Alsace region, Mammalian Biology – Zeitschrift für Säugetierkunde, Available online 24 October 2013, ISSN 1616-5047, http://dx.doi.org/10.1016/j.mambio.2013.10.004.
The Common hamster (Cricetus cricetus) faced massive population declines throughout its western range margin. In France, relict populations remained in the Alsace region. By comparing allelic diversity using microsatellite analysis over a time span of 12 years we investigated if this population decline led to genetic erosion in a French relict population of the species. Genetic diversity was moderate but comparable to other populations from Western Europe. Interestingly, no decline of allelic variation was revealed between 1999 and 2012 in the study region (expected heterozygosity=0.51 in 1999 and 0.5 in 2012, respectively), suggesting a sufficiently high effective population size of ∼500 (179-956 SD). While several alleles were lost in a captive breed maintained for restocking purposes in the region, expected heterozygosity was comparably high (=0.5). Our results show that genetic diversity has been effectively maintained in a relict population of French Common hamsters despite of massive range loss. We recommend the maintenance of intense in-situ conservation effort, along with regular monitoring of genetic diversity and effective population size.

True lemurs…true species – species delimitation using multiple data sources in the brown lemur complex
Markolf M, Rakotonirina H, Fichtel C, von Grumbkow P, Brameier M, Kappeler PM
BMC Evolutionary Biology 2013, 13:233 (26 October 2013)

Species are the fundamental units in evolutionary biology. However, defining them as evolutionary independent lineages requires integration of several independent sources of information in order to develop robust hypotheses for taxonomic classification. Here, we exemplarily propose an integrative framework for species delimitation in the „brown lemur complex“ (BLC) of Madagascar, which consists of seven allopatric populations of the genus Eulemur (Primates: Lemuridae), which were sampled extensively across northern, eastern and western Madagascar to collect fecal samples for DNA extraction as well as recordings of vocalizations. Our data base was extended by including museum specimens with reliable identification and locality information for skull shape and pelage color analysis.
Between-group analyses of principal components revealed significant heterogeneity in skull shape, pelage color variation and loud calls across all seven populations. Furthermore, post-hoc statistical tests between pairs of populations revealed considerable discordance among different data sets for different dyads. Despite a high degree of incomplete lineage sorting among nuclear loci, significant exclusive ancestry was found for all populations, except for E. cinereiceps, based on one mitochondrial and three nuclear genetic loci.
Using several independent lines of evidence, our results confirm the species status of the members of the BLC under the general lineage concept of species. More generally, the present analyses demonstrate the importance and value of integrating different kinds of data in delimiting recently evolved radiations.

Multilocus phylogeny and cryptic diversity in Asian shrew-like moles (Uropsilus, Talpidae): implications for taxonomy and conservation
Wan T, He K, Jiang X
BMC Evolutionary Biology 2013, 13:232 (25 October 2013)

The genus Uropsilus comprises a group of terrestrial, montane mammals endemic to the Hengduan and adjacent mountains. These animals are the most primitive living talpids. The taxonomy has been primarily based on cursory morphological comparisons and the evolutionary affinities are little known. To provide insight into the systematics of this group, we estimated the first multi-locus phylogeny and conducted species delimitation, including taxon sampling throughout their distribution range.
We obtained two mitochondrial genes (~1, 985 bp) and eight nuclear genes (~4, 345 bp) from 56 specimens. Ten distinct evolutionary lineages were recovered from the three recognized species, eight of which were recognized as species/putative species. Five of these putative species were found to be masquerading as the gracile shrew mole. The divergence time estimation results indicated that climate change since the last Miocene and the uplift of the Himalayas may have resulted in the diversification and speciation of Uropsilus.
The cryptic diversity found in this study indicated that the number of species is strongly underestimated under the current taxonomy. Two synonyms of gracilis (atronates and nivatus) should be given full species status, and the taxonomic status of another three potential species should be evaluated using extensive taxon sampling, comprehensive morphological, and morphometric approaches. Consequently, the conservation status of Uropsilus spp. should also be re-evaluated, as most of the species/potential species have very limited distribution.

Smith, J. B., Walsh, D. P., Goldstein, E. J., Parsons, Z. D., Karsch, R. C., Stiver, J. R., Iii, J. W. C., Raedeke, K. J. and Jenks, J. A. (2013), Techniques for capturing bighorn sheep lambs. Wildlife Society Bulletin. doi: 10.1002/wsb.360
Low lamb recruitment is a major challenge facing managers attempting to mitigate the decline of bighorn sheep (Ovis canadensis), and investigations into the underlying mechanisms are limited because of the inability to readily capture and monitor bighorn sheep lambs. We evaluated 4 capture techniques for bighorn sheep lambs: 1) hand-capture of lambs from radiocollared adult females fitted with vaginal implant transmitters (VITs), 2) hand-capture of lambs of intensively monitored radiocollared adult females, 3) helicopter net-gunning, and 4) hand-capture of lambs from helicopters. During 2010–2012, we successfully captured 90% of lambs from females that retained VITs to ≤1 day of parturition, although we noted differences in capture rates between an area of high road density in the Black Hills (92–100%) of South Dakota, USA, and less accessible areas of New Mexico (71%), USA. Retention of VITs was 78% with pre-partum expulsion the main cause of failure. We were less likely to capture lambs from females that expelled VITs ≥1 day of parturition (range = 80–83%) or females that were collared without VITs (range = 60–78%). We used helicopter net-gunning at several sites in 1999, 2001–2002, and 2011, and it proved a useful technique; however, at one site, attempts to capture lambs led to lamb predation by golden eagles (Aquila chrysaetos). We attempted helicopter hand-captures at one site in 1999, and they also were successful in certain circumstances and avoided risk of physical trauma from net-gunning; however, application was limited. In areas of low accessibility or if personnel lack the ability to monitor females and/or VITs for extended periods, helicopter capture may provide a viable option for lamb capture.

Nichols, T. C. (2013), Ten years of resident canada goose damage management in a New Jersey tidal freshwater wetland. Wildlife Society Bulletin. doi: 10.1002/wsb.345
Intensive grazing by Atlantic Flyway Resident Population Canada geese (Branta canadensis) has been shown to dramatically reduce wild rice (Zizania aquatica) abundance in tidal freshwater marshes in the Mid-Atlantic Region of the United States. From 2001 to 2010, I implemented an integrated damage management program (IDMP) during spring to abate Canada goose herbivory to wild rice in tidal freshwater marshes of the Maurice River, New Jersey, USA. The IDMP consisted of shooting, rendering goose nests unhatchable, and euthanizing molting geese. With implementation of an IDMP, the number of nests on the study area declined 70% over 10 years and the number of geese declined over time. Consequently, the amount of IDMP effort needed to sustain rice was reduced. Because the study area was a key nesting site for ospreys (Pandion haliaetus), which are state-threatened species, there was concern that disturbance from IDMP activities could have a negative impact on osprey nesting or recruitment. The mean annual number of nesting ospreys doubled and the mean number of young fledged/nest was similar between years prior to and during implementation of the IDMP, suggesting that the IDMP did not have a negative impact on ospreys. Wetland managers should consider damage from excessive herbivory caused by non-native, breeding waterfowl, such as resident Canada geese or mute swans (Cygnus olor), in their suite of wetland mitigation strategies.

Victoria M. Hunt, Seth B. Magle, Chino Vargas, Alison W. Brown, Eric V. Lonsdorf, Allison B. Sacerdote, Evan J. Sorley, Rachel M. Santymire
Survival, abundance, and capture rate of eastern cottontail rabbits in an urban park
Urban Ecosystems October 2013

Eastern cottontail rabbits (Sylvilagus floridanus) are common, conspicuous denizens of urban environments. They are associated with human-wildlife conflict due to vegetation damage. Prior to this study, population dynamics of this species in urban environments remained largely uncharacterized. For three consecutive winters, we used classic field ecology methods (mark-recapture and mark–resight surveys) to estimate demographic parameters of rabbits in a city park in Chicago, Illinois. Rabbits occurred in densities as high as 16.3 rabbits/ha, which is comparatively high for the Midwestern United States. An annual survivorship of 30.4 ± 12.9 % SE was similar to that observed in natural environments in similar climates. This result refuted our hypothesis that urban rabbits would have higher annual survival rates than rabbits in natural settings due to food subsidies supplied by landscaping in parks. Mean distance between trap locations for rabbits trapped three or more times was 43.14 ± 30.01 m SD, suggesting that rabbits in the urban study area had smaller home ranges than rabbits in non-human-dominated habitats. This study contributes to our understanding of population dynamics of a human-wildlife conflict species in urban environments and provides useful information for managers dealing with damage caused by rabbits. The mark-resight method employed here could be used by managers to estimate pre- and post-management population sizes of other conflict species, for example Canada geese (Branta Canadensis), in parks and green spaces, provided that the species is trappable, visible, and individuals have relatively small home ranges.

Rapid evolution of cooperation in group-living animals
Franz M, Schülke O, Ostner J
BMC Evolutionary Biology 2013, 13:235 (29 October 2013)

It is often assumed that evolution takes place on very large timescales. Countering this assumption, rapid evolutionary dynamics are increasingly documented in biological systems, e.g. in the context of predator–prey interactions, species coexistence and invasion. It has also been shown that rapid evolution can facilitate the evolution of cooperation. In this context often evolutionary dynamics influence population dynamics, but in spatial models rapid evolutionary dynamics also emerge with constant population sizes. Currently it is not clear how well these spatial models apply to species in which individuals are not embedded in fixed spatial structures. To address this issue we employ an agent-based model of group living individuals. We investigate how positive assortment between cooperators and defectors and pay-off differences between cooperators and defectors depend on the occurrence of evolutionary dynamics.
We find that positive assortment and pay-off differences between cooperators and defectors differ when comparing scenarios with and without selection, which indicates that rapid evolutionary dynamics are occurring in the selection scenarios. Specifically, rapid evolution occurs because changes in positive assortment feed back on evolutionary dynamics, which crucially impacts the evolution of cooperation. At high frequencies of cooperators these feedback dynamics increase positive assortment facilitating the evolution of cooperation. In contrast, at low frequencies of cooperators rapid evolutionary dynamics lead to a decrease in assortment, which acts against the evolution of cooperation. The contrasting dynamics at low and high frequencies of cooperators create positive frequency-dependent selection.
Rapid evolutionary dynamics can influence the evolution of cooperation in group-living species and lead to positive frequency-dependent selection even if population size and maximum group-size are not affected by evolutionary dynamics. Rapid evolutionary dynamics can emerge in this case because sufficiently strong selective pressures allow evolutionary and demographic dynamics, and consequently also feedback between assortment and evolution, to occur on the same timescale. In particular, emerging positive frequency-dependent selection could be an important explanation for differences in cooperative behaviors among different species with similar population structures such as humans and chimpanzees.

Zootaxa 3731 (1): 171–182 (29 Oct. 2013)
Molecular evidence for taxonomic status of the gudgeon genus Huigobio Fang, 1938 (Teleostei: Cypriniformes), with a description of a new species from Guangdong Province, South China

The gudgeon cyprinid genus Huigobio Fang, 1938 is re-diagnosed. It can be distinguished from all other genera of Armatogobionina Kryzhanovsky, 1947 and the Gobioninae by its uniquely modified lower lip. The lower lip has a small, heart-shaped, longitudinally non-bisected central pad and two lateral lobes expanded as a wing-shaped flap completely covered with papillae. The lobes contact each other posteromedially, but are not completely confluent. Huigobio exilicauda, new species, is described from the Zhu-Jiang drainage of Guangdong Province, South China. It differs from H. chenhsienensis in caudal-peduncle thickness and interorbital width.

Zootaxa 3731 (3): 331–337 (31 Oct. 2013)
Dario kajal, a new species of badid fish from Meghalaya, India (Teleostei: Badidae)

Dario kajal, new species, is described from Seinphoh stream in the Jaintia Hills of Meghalaya, India. It can be distinguished from all other congeners by the presence of a postorbital stripe that continues behind the eye in line with the preorbital stripe and by the presence in males of a series of double bars restricted to the upper half of the body. The discovery of D. kajal in the Meghna River drainage raises the number of Dario species to five and raises interesting questions about the biogeography of the genus.

Zootaxa 3731 (3): 345–370 (31 Oct. 2013)
Rediscovery of the Earless Microteiid Lizard Anotosaura collaris Amaral, 1933 (Squamata: Gymnophthalmidae): A redescription complemented by osteological, hemipenial, molecular, karyological, physiological and ecological data

More than a century after its discovery by Ernest Garbe, and almost 80 years after its original description, we obtained a series of specimens of the earless gymnophthalmid Anotosaura collaris, the type species of the genus, up to now known only by a single specimen. On the basis of the material obtained at and close to the type locality we redescribe the species, adding information about the external and hemipenial morphology, osteology and karytoype. Molecular data confirm its sister relationship with Anotosaura vanzolinia as well as the close relationship of Anotosaura with the Ecpleopodini Colobosauroides and Dryadosaura. We supplement this information with thermophysiological, ecogeographical, karyotypic and ecological data.

Zootaxa 3731 (2): 201–211 (30 Oct. 2013)
A new species of Pristimantis (Amphibia: Anura: Strabomantidae) from the Río Abiseo National Park, Peru

We describe a new species of Pristimantis from the Río Abiseo National Park in the Andes of northern Peru. Specimens were collected from 2650 to 3000 m elevation. The new species has a snout–vent length of 24.9–34.2 mm (n = 7) in adult females, and 15.3–23.5 mm (n = 29) in adult males. It differs from other species of Pristimantis in having the snout with a broad, slightly upwards curved, fleshy process. The most similar species, P. phoxocephalus has the snout with a vertical fleshy keel, but differs from the new species by being larger (female SVL up to 38.4 mm vs. 34.2 mm), by having prominent dentigerous processes of vomers (minute in the new species), by lacking an inner tarsal fold (present), by lacking heel tubercles (present), and by having the dorsum in life grey, red or brown and the groin with black and orange or yellow mottling, whereas in the new species the dorsum is rusty reddish-brown with lighter blotches or tannish-brown chevrons, and the groin tan with pale brown flecks.

Zootaxa 3731 (2): 255–266 (30 Oct. 2013)
A new species of Brycon (Characiformes: Characidae) from Nicaragua and Costa Rica, with a key to the lower Mesoamerican species of the genus

A new species of Brycon is described from the Atlantic slope of Nicaragua and Costa Rica. Brycon costaricensis n. sp.
differs from all other Central American Brycon species by the following combination of characters: 49 to 54 scales in the lateral line; 5 or 6 rows of scales between lateral line and pectoral fin base; 9 to 11 rows of scales between lateral line and dorsal fin base; 5 to 7 rows of scales between lateral line and anal fin base; anal fin notably longer than head, with 33 to 37 total rays; and a elongated and shallow caudal peduncle, whose length is 1.78 to 2.35 times its depth. A key to lower Mesoamerican species of the genus is also presented.

Zootaxa 3731 (2): 279–286 (30 Oct. 2013)
Geophagus crocatus, a new species of geophagine cichlid from the Berbice River, Guyana, South America (Teleostei: Cichlidae)

We describe a new Geophagus from the Berbice River of Guyana, bringing the total number of described species in the
genus to 19, and of Guianese species to six.. Geophagus crocatus, new species, is distinguished from all species of Geophagus outside of the G. surinamensis group by the presence of an incomplete suborbital stripe (vs. complete), and the presence of six lateral bars, with bars 2 and 3 slightly sloping toward each other and fusing dorsally at the base of the dorsal fin. Geophagus crocatus is the only Geophagus species known from the Berbice River, and it is present above and below the Itabru Falls.

Zootaxa 3731 (2): 287–294 (30 Oct. 2013)
Channa andrao, a new species of dwarf snakehead from West Bengal, India (Teleostei: Channidae)

Channa andrao, new species, from Lefraguri swamp, West Bengal, India, differs from all its congeners except, C. asiatica, C. bleheri and C. burmanica and the recently described C. hoaluensis and C. ninhbinhensis by the absence of pelvic fins. It can be distinguished from all other pelvic fin-less species of snakeheads by its colour pattern, and differs further in its number of vertebrae, dorsal- and anal-fin rays, and lateral-line scales from individual snakehead species in this complex. Channa andrao raises the number of snakehead species endemic to the Eastern Himalaya biodiversity hotspot to ten, representing almost one third of the known species in the genus.

Zootaxa 3731 (4): 473–494 (1 Nov. 2013)
Phylogeography of the reed frog Hyperolius castaneus (Anura: Hyperoliidae) from the Albertine Rift of Central Africa: Implications for taxonomy, biogeography and conservation

We examine the systematics of multiple populations of the Albertine Rift endemic amphibian Hyperolius castaneus,
which currently incorporates four subspecies. Standard morphometric data were analyzed with principal components analyses and analyses of covariance. Phylogenetic analyses of two mitochondrial (16S, cyt b) and one nuclear (RAG1) genes were analyzed from 41 samples representing three subspecies. Results indicated some significant morphometric differences between the nominate subspecies H. c. castaneus and the Itombwe Plateau subspecies H. c. constellatus, and phylogenetic analyses of molecular data recovered these taxa as reciprocally monophyletic groups. We recognize these two allopatric populations as recently diverged, but distinct species, H. castaneus and H. constellatus. The subspecies H. c. submarginatus from the Kabobo Plateau is transferred to the synonymy of H. constellatus, but the status of the unsampled subspecies H. c. rhodogaster, described from mid-elevations of the western Itombwe Plateau, remains problematic. The phylogeographic pattern of our study resembles some, but not all, Albertine Rift vertebrates that have been examined with molecular data. Hyperolius constellatus is restricted to the Itombwe and Kabobo plateaus, which are of special conservation concern because of high levels of amphibian diversity and endemism, and multiple threats from deforestation, mining activities and road construction.

Zootaxa 3731 (4): 533–551 (1 Nov. 2013)
Bioacoustics reveals two new syntopic species of Adenomera Steindachner (Anura: Leptodactylidae: Leptodactylinae) in the Cerrado of central Brazil

In this paper, we describe two syntopic species of Adenomera from the Chapada dos Veadeiros microregion, northern State of Goiás, central Brazil, recognized based on morphology, color patterns, and bioacoustics. Specimens and calls were obtained in the Municipality of Teresina de Goiás, central Brazil. Adenomera cotuba sp. nov. is diagnosed from the other 16 congeneric species by its 1) small size (adult male SVL 18.6–20.5 mm) and very robust body; 2) dorsum glandular/granular with no distinctive dorsal granular rows or dorsolateral folds; 3) black or very dark dorsal coloration with no distinctive color patterns (e.g., dorsolateral or vertebral stripes); 4) toe tips not developed into flattened disks; 5) presence of antebrachial tubercle; and 6) advertisement call consisting of a well-defined series of pulsed calls (7–32 calls/series) with progressive increment in amplitude in the first third of each call series when it reaches a sustained plateau. Adenomera juikitam sp. nov. is diagnosed from the other 16 congeneric species by its 1) dorsum profusely glandular/granular with no distinctive dorsal granular rows or dorsolateral folds; 2) dorsum with a marble-like and red coloration with no distinctive color patterns (e.g., dorsolateral or vertebral stripes); 3) toe tips not developed into flattened disks; 4) small size (adult male SVL 19.1–19.5 mm) and very robust body; and 5) long (148–202 ms) advertisement call composed of 16–21pulses. Both new taxa occur in syntopy, and our data allow us to differentiate them both in temporal (pulses/call) and spectral (frequency peaks) traits of their advertisement calls. Besides, dorsal coloration is distinctive, Adenomera cotuba sp. nov. has a black or very dark-colored dorsum, whereas Adenomera juikitam sp. nov. has a marble-like and red-colored dorsum, in addition to the presence (A. cotuba sp. nov.) or absence (A. juikitam sp. nov.) of antebrachial tubercle.

Zootaxa 3731 (4): 552–560 (1 Nov. 2013)
A new species of Crossodactylodes (Anura: Leptodactylidae) from Minas Gerais, Brazil: first record of genus within the Espinhaço Mountain Range

The genus Crossodactylodes comprises three species of Atlantic Rainforest endemic frogs strictly dependent on bromeliads where they spend their entire life cycle. The current geographic distribution of the genus covers highland areas of Atlantic Rainforest in the States of Rio de Janeiro and Espírito Santo, Southeastern Brazil. We describe a new species of the genus from Parque Estadual do Pico do Itambé, at Santo Antônio do Itambé municipality, State of Minas Gerais, Southeastern Brazil. Crossodactylodes itambe sp. nov. is characterized by the following combination of traits: male SVL 16.2 ± 1.3 (14.0–17.6 mm, n = 10), female SVL 16.2 ± 1.0 (13.5–18.0 mm, n = 15); snout short, rounded in dorsal view, sloping in lateral view; absence of vocal sac and vocal slits in males; absence of vomerine teeth; males with upper arms and forearms hypertrophied; cloacal flap prominent, simple; dorsal skin coarsely granular. The new species inhabits rupicolous bromeliads in open areas of rocky fields, and is recorded in altitudes between 1836 and 2062 m above sea level. This record extends the genus distribution for about 325 km northwest from where it was known. Crossodactylodes sp. nov. is the only species of the genus that occurs in open field habitats (campos rupestres), in very high altitudes of a non-costal mountain range (the Espinhaço Range).

Zootaxa 3731 (4): 561–576 (1 Nov. 2013)
Two new species of stone loaches of the genus Schistura from the Koladyne basin, Mizoram, India (Teleostei: Cobitoidei: Nemacheilidae)

Two new species of Schistura are described from the Koladyne basin of Mizoram, India. Schistura nebeshwari is distinguished from its congeners by the combination of the following characters: a prominent dorsal adipose crest on the caudal peduncle, 11–14 dark olivaceous bars on the body, the entire ventral surface of head with numerous small melanophores, an incomplete lateral line, three black spots at the dorsal-fin base, a complete prominent black basicaudal bar, lower jaw with a shallow median notch, and no suborbital flaps in males. Schistura scyphovecteta differs from its congeners by the combination of the following characters: six dark brown saddles, each one continuing to the flank, forming globularshaped bars overlaying a background brown stripe along the lateral line, a complete lateral line, two black spots at the dorsal-fin base, an incomplete black basicaudal bar, no median notch on the lower jaw, and a suborbital flap present in males.

Jeffrey D. Wall
Great Ape Genomics
ILAR J (2013) 54 (2): 82-90 doi:10.1093/ilar/ilt048

The great ape families are the species most closely related to our own, comprising chimpanzees, bonobos, gorillas, and orangutans. They live exclusively in tropical rainforests in Central Africa and the islands of Southeast Asia. Due to their close evolutionary relationship with humans, great apes share many cognitive, physiological, and morphological similarities with humans. The members of the great ape family make obvious models to facilitate the further understanding about humans‘ biology and history. This review will discuss how the recent addition of genome-wide data from great apes has furthered humans‘ understanding of these species and humanity, especially in the realm of evolutionary genetics.

Németh, A., Homonnay, Z. G., Krízsik, V., Csorba, M., Pavlíček, T., Hegyeli, Z., Hadid, Y., Sugár, S., Farkas, J. and Csorba, G. (2013), Old views and new insigths: taxonomic revision of the Bukovina blind mole rat, Spalax graecus (Rodentia: Spalacinae). Zoological Journal of the Linnean Society. doi: 10.1111/zoj.12081
As a result of their rather uniform external appearance and gross cranial morphology, the systematics of blind mole rats has been hotly debated over the last century; however, the separation of the large-bodied and small-bodied blind mole rats at the genus level (Spalax and Nannospalax, respectively), suggested earlier on morphological grounds, is strongly supported by recent molecular biological evidence. The species of Spalax have so far been distinguished from each other by cranial traits only, especially the outline of sutures of the cranium, and the shape and relative size of the nasal and parietal bones. Based on mitochondrial DNA sequences (with the widest taxonomic and geographic coverage so far) and detailed anatomical comparisons of museum specimens, we herewith provide a revision of the taxonomic and phylogenetic status of the westernmost representative of the genus, Spalax graecus s.l. We clarify that antiquus and istricus – presently regarded as synonyms of graecus – are well-defined species, and they together form a separate clade within Spalax. The robustness of our conclusions is supported by the combined evidence of morphology, multilocus phylogeny, species distribution, and taxon history (species congruence with past tectonic and climate events).

Ana M.M. Sequeira, Camille Mellin, Laurent Floch, Peter G. Williams, Corey J.A. Bradshaw, Inter-ocean asynchrony in whale shark occurrence patterns, Journal of Experimental Marine Biology and Ecology, Available online 1 November 2013, ISSN 0022-0981, http://dx.doi.org/10.1016/j.jembe.2013.10.019.
The whale shark (Rhincodon typus, Smith, 1828) is a migratory species (classed as Vulnerable by the IUCN) with genetic and circumstantial evidence for inter-ocean connectivity. Given this migratory behaviour, population-wide occurrence trends can only be contextualized by examining the synchrony in occurrence patterns among locations where they occur. We present a two-step modelling approach of whale shark spatial and temporal probability of occurrence in the Atlantic and Pacific Oceans using generalized linear mixed-effects models. To test the hypothesis that the probability of whale shark occurrence is asynchronous across oceans, as expected if inter-ocean migration occurs, we used long-term datasets of whale shark sightings derived from tuna purse-seine logbooks covering most of the central-east Atlantic (1980–2010) and western Pacific (2000–2010). We predicted seasonal habitat suitability to produce maps in each area, and then evaluated the relative effect of time (year) on the probability of occurrence to test whether it changed over the study period. We also applied fast Fourier transforms to determine if any periodicity was apparent in whale shark occurrences in each ocean. After partialling out the effects of seasonal patterns in spatial distribution and sampling effort, we found no evidence for a temporal trend in whale shark occurrence in the Atlantic, but there was a weak trend of increasing probability of occurrence in the Pacific. The highest-ranked model for the latter included a spatial predictor of occurrence along with fishing effort, a linear term for time, and a random temporal effect (year), explaining 15% of deviance in whale shark probability of occurrence. Fast Fourier transforms revealed a prominent 15.5-year cycle in the Atlantic. The increase in the probability of occurrence in the Pacific is concurrent with a decrease previously detected in the Indian Ocean. Cyclic patterns driven by migratory behaviour would better explain temporal trends in whale shark occurrence at the oceanic scale. However, despite cycles partially explaining observations of fewer sharks in some years, overall reported sighting rate has been decreasing. As a result, we suggest that the current IUCN status of the species should be re-assessed, but more data are needed to examine the flow of individuals across oceans and to identify possible reasons for asynchronous occurrences.

Henri Weimerskirch, Yves Cherel, Karine Delord, Audrey Jaeger, Samantha C. Patrick, Louise Riotte-Lambert, Lifetime foraging patterns of the wandering albatross: Life on the move!, Journal of Experimental Marine Biology and Ecology, Available online 31 October 2013, ISSN 0022-0981, http://dx.doi.org/10.1016/j.jembe.2013.10.021.
Wandering albatrosses are large long-lived seabirds that inhabit the Southern Ocean. This species uses wind to move at low energetic costs and probably represents one of the best studied life-history models in animals. Here, using both tracking and isotopic data, we report on the lifetime distribution of wandering albatrosses at sea, constructing a synthesis about how their distribution, foraging movements and feeding ecology change throughout all life-history stages (i.e. juvenile, immature, pre breeding adults, breeding adults, sabbatical adults and senescent birds). Males and females exhibit different foraging strategies that change throughout their life. For instance, as males mature from young to old stages, they progressively move from subtropical waters to Antarctic waters. In comparison, females remain in subtropical waters throughout their lives, but increase their speed of travel with age. For both sexes, the first year at sea is a critical period, when the highest mortality occurs. At this stage, juveniles have already fledged and are able to use the wind optimally to maximise movement, but require several months to reach the travelling speed of adults. Immature albatrosses remain in warm subtropical waters, before returning to their birth place and future breeding grounds from where they move as central place foragers. When recruited into the breeding population, they breed every other year. In one year they invest in one long breeding season when males and females use separate foraging zones in the subtropics and sub-Antarctic, respectively. In the subsequent year (termed “sabbatical” year), both sexes disperse across the Southern Ocean, with reduced segregation between sexes. In total, throughout the approximate 50year lifetime of a wandering albatross, an individual is estimated to travel a mere 8.5millionkm. We show that the changes in habitats and foraging strategies observed though the life time of wandering albatrosses are the results of behavioural adjustment to the successive constraints encountered, such as learning processes, breeding or ageing, and have profound consequences on survival and nesting success.

Dieser Beitrag wurde unter Wissenschaft/Naturschutz abgelegt und mit , , , , , , , , , , , , , , , , , verschlagwortet. Setze ein Lesezeichen auf den Permalink.

Kommentar verfassen