Does life history shape sexual size dimorphism in anurans? A comparative analysis
Han X, Fu J
BMC Evolutionary Biology 2013, 13:27 doi:10.1186/1471-2148-13-27
The evolution of sexual size dimorphism (SSD) is likely constrained by life history. Using phylogenetic comparative methods, we examined correlations between SSD among anurans and their life history traits, including egg size, clutch size, mating combat, and parental care behaviour. We used sexual dimorphism index (SDI = Body-sizefemale /Body-sizemale -1) as the measurement for SSD. Body size, life history and phylogenetic data were collected from published literature. Data were analysed at two levels: all anuran species and within individual families.
Female-biased SSD is the predominant form in anurans. SSD decreases along with the body size increase, following the prediction of Rensch’s rule, but the magnitude of decrease is very small. More importantly, female body size is positively correlated with both fecundity related traits, egg size and clutch size, and SDI is also positively correlated with clutch size, suggesting fecundity advantage may have driven the evolution of female body size and consequently leads to the evolution of female-biased SSD. Furthermore, the presence of parental care, male parental care in particular, is negatively correlated with SDI, indicating that species with parental care tend to have a smaller SDI. A negative correlation between clutch size and parental care further suggests that parental care likely reduces the fecundity selection pressure on female body size. On the other hand, there is a general lack of significant correlation between SDI and the presence of male combat behaviour, which is surprising and contradictory to previous studies.
We find clear evidence to support the ‚fecundity advantage hypothesis‘ and the ‚parental care hypothesis‘ in shaping SSD in anurans. Nevertheless, the relationships of both parental care and combat behaviour to the evolution of SSD are complex in anurans and the extreme diversity of life history traits may have masked some potential interesting relationships. Our study represents the most comprehensive study of SSD in anurans to date.
Indo-Pacific bottlenose dolphin (Tursiops aduncus) habitat preference in a heterogeneous, urban, coastal environment
Cribb N, Miller C, Seuront L
Aquatic Biosystems 2013, 9:3 (1 February 2013)
Limited information is available regarding the habitat preference of the Indo-Pacific bottlenose dolphin (Tursiops aduncus) in South Australian estuarine environments. The need to overcome this paucity of information is crucial for management and conservation initiatives. This preliminary study investigates the space-time patterns of habitat preference by the Indo-Pacific bottlenose dolphin in the Port Adelaide River-Barker Inlet estuary, a South Australian, urbanised, coastal environment. More specifically, the study aim was to identify a potential preference between bare sand substrate and seagrass beds, the two habitat types present in this environment, through the resighting frequency of recognisable individual dolphins.
Photo-identification surveys covering the 118 km2 sanctuary area were conducted over 2 survey periods May to August 2006 and from March 2009 to February 2010. Sighting frequency of recognisable individual Indo-Pacific bottlenose dolphins established a significant preference for the bare sand habitat. More specifically, 72 and 18% of the individuals sighted at least on two occasions were observed in the bare sand and seagrass habitats respectively. This trend was consistently observed at both seasonal and annual scales, suggesting a consistency in the distinct use of these two habitats.
It is anticipated that these results will benefit the further development of management and conservation strategies.
Biological Sciences – Psychological and Cognitive Sciences:
Ljerka Ostojić, Rachael C. Shaw, Lucy G. Cheke, and Nicola S. Clayton1
Evidence suggesting that desire-state attribution may govern food sharing in Eurasian jays
PNAS 2013; published ahead of print February 4, 2013, doi:10.1073/pnas.1209926110
State-attribution is the ability to ascribe to others an internal life like one’s own and to understand that internal, psychological states such as desire, hope, belief, and knowledge underlie others’ actions. Despite extensive research, comparative studies struggle to adequately integrate key factors of state-attribution that have been identified by evolutionary and developmental psychology as well as research on empathy. Here, we develop a behavioral paradigm to address these issues and investigate whether male Eurasian jays respond to the changing desire-state of their female partners when sharing food. We demonstrate that males feed their mates flexibly according to the female’s current food preference. Critically, we show that the males need to see what the female has previously eaten to know what food she will currently want. Consequently, the males’ sharing pattern was not simply a response to their mate’s behavior indicating her preference as to what he should share, nor was it a response to the males’ own desire-state. Our results raise the possibility that these birds may be capable of ascribing desire to their mates.
Stereo and serial sniffing guide navigation to an odour source in a mammal
Kenneth C. Catania1
Nature Communications, Volume: 4, Article number:1441, doi:10.1038/ncomms2444
Integration of bilateral sensory information is fundamental to stimulus localization in auditory systems and depth perception in vision, but the role of stereo olfactory cues remains obscure. Here it is shown that blind, eastern American moles combine serial sampling with bilateral nasal cues to localize odorants. Blocking one nostril causes moles to err in the direction of the open nostril with strongest effect within 4–5 cm of the stimulus. Nostril block does not severely disrupt more distant navigation towards odorants in a T-maze nor prevent animals from ultimately locating the odour source. Crossing inputs to the nostrils using plastic tubes causes a local repulsion from the stimulus, whereas uncrossed tubes do not disrupt localization. These findings show that mammals can make use of bilateral chemosensory cues combined with serial sampling to localize odorants and offer insights into the relative contribution of each strategy during different stages of natural search behaviours.
Zootaxa 3613 (1): 1–35 (7 Feb. 2013)
Phylogeny and classification of the New World suboscines (Aves, Passeriformes)
JAN I. OHLSON, MARTIN IRESTEDT, PER G. P. ERICSON & JON FJELDSÅ
Here we present a phylogenetic hypothesis for the New World suboscine radiation, based on a dataset comprising of 219 terminal taxa and five nuclear molecular markers (ca. 6300 bp). We also estimate ages of the main clades in this radiation. This study corroborates many of the recent insights into the phylogenetic relationships of New World suboscines. It further clarifies a number of cases for which previous studies have been inconclusive, such as the relationships of Conopophagidae,Melanopareiidae and Tityridae. We find a remarkable difference in age of the initial divergence events in Furnariida and Tyrannida. The deepest branches in Furnariida are of Eocene age, whereas the extant lineages of Tyrannida have their origin in the Oligocene. Approximately half of the New World suboscine species are harboured in 5 large clades that started to diversify around the Mid Miocene Climatic Optimum (16–12 Mya). Based on our phylogenetic results we propose a revised classification of the New World suboscines. We also erect new family or subfamily level taxa for four small and isolated clades: Berlepschiinae, Pipritidae, Tachurididae and Muscigrallinae.
Zootaxa 3613 (1): 61–82 (7 Feb. 2013)
Validity of Bartram’s Painted Vulture (Aves: Cathartidae)
NOEL F. R. SNYDER & JOEL T. FRY
William Bartram described the Painted Vulture (Vultur sacra) as a new species in his 1791 book on travels in Florida and other southeastern states. However, no specimen of this bird survives, and it has not been reported by any subsequent ornithologist. Bartram’s detailed description is not presently endorsed by the American Ornithologists’ Union and has been widely regarded as a myth, a misdescribed King Vulture Sarcoramphus papa (Linnaeus), a misdescribed Northern Caracara Caracara cheriway (Jacquin), or a garbled mixture of species. In fact, his description bears almost no resemblance to a Northern Caracara, but it does match the King Vulture in all important respects except tail color (which is uniform dark brown in all ages and sexes of King Vultures but was white with a dark brown or black tip in Bartram’s description). Most 20th century ornithologists commenting on Bartram’s bird have been reluctant to accept his description because of the tailcolor discrepancy. Only McAtee (1942) concluded that his description could be fully accurate as written, indicating a bird closely related to, but different from, a typical King Vulture.
Paralleling Bartram’s description is an apparently independent account and painting of a vulture of uncertain geographic origin by Eleazar Albin (1734). Details of Albin’s description, including tail color, are very similar to those of Bartram’s description. The only discrepancies are minor differences in color of softparts and tail that seem explicable as intraspecific variation. Available evidence suggests that Bartram knew nothing of Albin’s description, and if so, Albin’s bird provides quite persuasive support for the validity of Bartram’s bird. Equally important, none of the arguments offered historically against the validity of the Painted Vulture is persuasive when examined closely. Together, these and other factors make a strong case for acceptance of Bartram’s Painted Vulture as a historic resident of northern Florida and likely other adjacent regions.
Managementstrategies and Animalwelfare of Captive Capuchin Monkeys Genus CebusErxleben 1777 (Primates: Cebidae)
Aluane Silva Ferreira, Rafaela Nascimento Almeida and Romari Alejandra Martinez
World Applied Sciences Journal 21 (1): 42-48, 2013, ISSN 1818-4952
Handling can compromise the quality of life of wild animals in captivity. Welfareincaptive animals
canbe assessed through recording of abnormal behaviors. The relationship betweentwomanagement strategies and animal welfare (measured as frequency of abnormal behaviors) for5 Cebus monkeys of three species (4 males and 1 female) captive at a biological station in ElísioMedrado, Bahia, Brazil is analyzed. This is relevant because capuchin monkeys areveryabundant in captivity worldwide and different species are often housed togetherdue to taxonomic uncertainties. Also, many zoos lack an animal welfare program and simple management practices might help welfare improvement.Stereotyped behaviors werequantified undertwo management strategies: a) daily-movement and b) social-housing. Furthermore, an environmental enrichment was added under the social-housing strategy to test its effect on abnormal behaviors.Frequencies were compared through a Wilcoxon test, which did not show statistical differences intotalabnormal behaviors between different management strategies. However, there was a tendency towards improvement in social
behaviors following the social-housingstrategy.Food enrichmentwas useful to diminish stereotyped behaviors, but represented a source of stress for the most subordinate animals. Betterenclosure quality is not enough to promote animal well being, but environmental enrichments are good alternatives for reducing stress in non subordinates.
Jürges V., Kitzler J., Zingg R., Radespiel U.
First Insights into the Social Organisation of Goodman’s Mouse Lemur (Microcebus lehilahytsara) – Testing Predictions from Socio-Ecological Hypotheses in the Masoala Hall of Zurich Zoo
Folia Primatol 2013;84:32–48 (DOI: 10.1159/000345917)
Following current socio-ecological hypotheses, the social organisation of a species is mainly determined by resource quality and distribution. In the case of Microcebus spp., a taxon-specific socio-ecological model was formulated earlier to explain their variable social organisation. The aim of this study was to test predictions from this model in Goodman’s mouse lemur based on a data set from animals living in the semi-free colony of Zurich Zoo. During a 2-month study, we observed 5 females and 5 males using radiotelemetry. We collected data on space use and social behaviour, on sleeping sites and on sleeping group composition. Predictions were only partly confirmed. As expected, Goodman’s mouse lemurs were solitary foragers with an increased level of sociality due to crowding effects at the feeding stations. In contrast to the prediction, females and males formed unisexual sleeping groups, which were stable in females and of a fission-fusion type in males. Whereas the formation of sleeping groups by both sexes may be triggered by thermoregulatory benefits, the formation of unisexual sleeping groups may result from divergent interests of the sexes. We conclude that the existing model for the evolution of mouse lemur social organisation needs to be refined.
Nathan F. Putman, Kenneth J. Lohmann, Emily M. Putman, Thomas P. Quinn, A. Peter Klimley, David L.G. Noakes, Evidence for Geomagnetic Imprinting as a Homing Mechanism in Pacific Salmon, Current Biology, Available online 7 February 2013, ISSN 0960-9822, 10.1016/j.cub.2012.12.041.
In the final phase of their spawning migration, Pacific salmon use chemical cues to identify their home river, but how they navigate from the open ocean to the correct coastal area has remained enigmatic. To test the hypothesis that salmon imprint on the magnetic field that exists where they first enter the sea and later seek the same field upon return, we analyzed a 56-year fisheries data set on Fraser River sockeye salmon, which must detour around Vancouver Island to approach the river through either a northern or southern passageway. We found that the proportion of salmon using each route was predicted by geomagnetic field drift: the more the field at a passage entrance diverged from the field at the river mouth, the fewer fish used the passage. We also found that more fish used the northern passage in years with warmer sea surface temperature (presumably because fish were constrained to more northern latitudes). Field drift accounted for 16% of the variation in migratory route used, temperature 22%, and the interaction between these variables 28%. These results provide the first empirical evidence of geomagnetic imprinting in any species and imply that forecasting salmon movements is possible using geomagnetic models.