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Louhi, P., Mäki-Petäys, A., Huusko, A. and Muotka, T. (2013), Resource use by juvenile brown trout and Alpine bullhead: influence of interspecific versus intraspecific competition. Ecology of Freshwater Fish. doi: 10.1111/eff.12072
Stream-dwelling salmonids and bullheads occupy similar resource niches in northern rivers. It is therefore tempting to assume that they might be involved in a competitive interaction, with potential implications for the habitat use and growth of brown trout (Salmo trutta). We conducted artificial-stream experiments to test whether a putative competitor, Alpine bullhead (Cottus poecilopus), had an effect on the habitat use of under-yearling (0+) and yearling (1+) trout. We hypothesised that (i) 1+ trout would be competitively superior to 0+ trout, forcing the younger fish to suboptimal habitats, and that (ii) bullhead might affect the habitat use and prey selection of 0+ trout but less so that of 1+ trout. Against our predictions, no effect of bullhead was found on the habitat use of either age class of brown trout. Instead, yearling trout seemed to force bullheads to suboptimal microhabitats with high current velocities. Presence of yearlings also decreased the growth of under-yearling fish and caused a shift in their diet composition. These findings suggest that competitive interactions may not limit the coexistence of brown trout and bullheads in boreal rivers. Intraspecific interactions between trout age classes may be more important, with potentially detrimental effects on the growth and overwintering success of 0+ trout.

Sébastien Bélanger-Deschênes, Patrice Couture, Peter G. C. Campbell, Louis Bernatchez Evolutionary change driven by metal exposure as revealed by coding SNP genome scan in wild yellow perch (Perca flavescens)
Ecotoxicology, May 2013

Pollution can drive rapid evolutionary change in wild populations. This study targets functional polymorphisms of chronically metal-contaminated wild yellow perch (Perca flavescens). A de novo transcriptome scan contrasted subsets of individuals from clean (n = 16) and contaminated (n = 16) lakes to identify 87 candidate annotated coding SNPs. Candidate genotypes and liver [metal] were obtained in 10 populations (n = 1,052) and a genome scan distinguished outliers: one nuclear (cyclin G1 gene) and two mitochondrial (cytochrome b and NADH dehydrogenase subunit 2 genes) also displaying allelic correlation to mean population [cadmium]. Whole mtDNA and 17 kb surrounding cyclin G1 were characterised through 454 sequencing thus revealing two non-synonymous substitutions involving dissimilar amino acids. Based on associated functions and inter-population differentiation, contaminated perch may have been selected for fast life cycle completion (p53 pathway) and memorization impairment mitigation (long-term potentiation pathway). In accordance with predicted evolutionary trajectory for stressed and energy deprived organisms, adapted perch would not compensate for repair mechanism inhibition, instead reallocating energy towards growth and favouring inexpensive impairment mitigation adaptations over costly detoxification. Overall, 85 years of selection could have driven rapid, potentially adaptive evolution by selecting alleles increasing perch fitness in polluted environments.

Marko Haapakoski, Janne Sundell, Hannu Ylönen
Mammalian predator–prey interaction in a fragmented landscape: weasels and voles
Oecologia, June 2013

The relationship between predators and prey is thought to change due to habitat loss and fragmentation, but patterns regarding the direction of the effect are lacking. The common prediction is that specialized predators, often more dependent on a certain habitat type, should be more vulnerable to habitat loss compared to generalist predators, but actual fragmentation effects are unknown. If a predator is small and vulnerable to predation by other larger predators through intra-guild predation, habitat fragmentation will similarly affect both the prey and the small predator. In this case, the predator is predicted to behave similarly to the prey and avoid open and risky areas. We studied a specialist predator’s, the least weasel, Mustela nivalis nivalis, spacing behavior and hunting efficiency on bank voles, Myodes glareolus, in an experimentally fragmented habitat. The habitat consisted of either one large habitat patch (non-fragmented) or four small habitat patches (fragmented) with the same total area. The study was replicated in summer and autumn during a year with high avian predation risk for both voles and weasels. As predicted, weasels under radio-surveillance killed more voles in the non-fragmented habitat which also provided cover from avian predators during their prey search. However, this was only during autumn, when the killing rate was also generally high due to cold weather. The movement areas were the same for both sexes and both fragmentation treatments, but weasels of both sexes were more prone to take risks in crossing the open matrix in the fragmented treatment. Our results support the hypothesis that habitat fragmentation may increase the persistence of specialist predator and prey populations if predators are limited in the same habitat as their prey and they share the same risk from avian predation.

Guarnizo, C. E. and Cannatella, D. C. (2013), Genetic divergence within frog species is greater in topographically more complex regions. Journal of Zoological Systematics and Evolutionary Research. doi: 10.1111/jzs.12027
Most global hotspots of biodiversity and endemism are in montane regions. One explanation is that montane regions have intrinsically higher speciation rates than lowland regions because complex mountain topography and climate variation facilitate genetic isolation among populations. Here, we ask from an intraspecific perspective whether frog species whose haplotypes are connected by topographically/climatically complex regions display strong genetic isolation (greater scaled genetic distances), compared with species whose haplotypes are connected by less complex regions. We analysed published DNA sequences of several frog species from tropical Central and South America for the mitochondrial cob, cox1 and 16S rRNA genes. Pairwise genetic distances among haplotypes within each species were scaled to the geographic distances between each pair of haplotypes. Topographic complexity was positively correlated with scaled genetic distances, and isolation-by-resistance was supported only in species from more topographically complex regions. This suggests that heterogeneous topographies increase landscape resistance, which in turn favours the appearance of isolation-by-resistance. Moreover, we found that the potential barriers that restrict gene flow within species are more closely related to factors associated with temperature and topography than to precipitation.

AHMAD, S., HUSSAIN, J., AKRAM, M., MEHMOOD, S., USMAN, M., REHMAN, A., MUSTAFA, G., SULAMAN, R.. Body measurements and slaughter parameters in four close bred stocks of japanese quail reared under different levels of dietary lysine. Scientific Journal of Zoology, North America, 2, may. 2013. Available at: <http://www.sjournals.com/index.php/SJZ/article/view/775>. Date accessed: 01 Jun. 2013.
The aim of study was to evaluate body measurements and slaughter parameters in four close bred stock (CBS) of Japanese quail (named as Major (M), Kaleem (K), Saadat (S) and Zahid (Z)) reared under different levels of dietary lysine at Avian Research and Training (ART) Centre, UVAS Lahore, Pakistan. For this purpose 1440 broiler quail chick were procured form ART Centre hatchery, birds were reared at different levels of dietary lysine i.e. 1.3% lysine for 28 days (Phase-I), 1.4% lysine for 1st 14 days and 1.2% lysine for last 14 o (Phase-II), 1.5% lysine for 9 days, 1.3% lysine for next 10 days and 1.1% lysine for last 9 days (Phase-III). A total of 108 birds {4(CBS)×3(Phases)×9 birds}, were slaughtered at the age of 27 weeks and their body measurements and slaughter parameters were recorded. The data thus obtained were statistically analyzed through Randomized Complete Block Design (RCBD). The means were separated out through Duncan’s Multiple Range test using SAS 9.1 for windows. Statistical analysis revealed significant differences (P < 0.05) among different CBS and Phases. In body measurements body, shank and drumstick length and drumstick circumference showed significant difference (P<0.05) while wing spread, keel length and shank circumferences showed non-significant difference. In slaughter parameters carcass, heart and gizzard weight, and intestinal length showed significant differences (P<0.05) whereas body, liver and intestinal weight showed non-significant differences.

Pawel Fedurek, Zarin P. Machanda, Anne M. Schel, Katie E. Slocombe, Pant hoot chorusing and social bonds in male chimpanzees, Animal Behaviour, Available online 31 May 2013, ISSN 0003-3472, 10.1016/j.anbehav.2013.05.010.
Vocal interactions, such as call exchanges or chorusing, are common behaviours in many animal species and their function has often been attributed to social bonding. However, few studies have investigated the effectiveness of vocalizations as bonding signals in comparison to other affiliative behaviours. We tested the hypothesis that male chimpanzee, Pan troglodytes schweinfurthii, pant hoot chorusing, a common behaviour in these primates, is a reliable but also flexible signal of affiliative relationships. The results of our study, conducted on the Kanyawara community of chimpanzees in Uganda, show that males were more likely to join in with the pant hoot of preferred long-term social partners to form a chorus. This supports the hypothesis that this behaviour is a good indicator of strong or long-term social bonds between male chimpanzees. However, our results also show that pant hoot chorusing reliably reflects short-term affiliations between males. For instance, male dyads were more likely to be involved in affiliative behaviours, such as reciprocated grooming, joint nonvocal displays and coalitions, on days when they chorused together, compared to days when they did not. This pattern applied to both preferred and neutral social partners. Moreover, on a short-term basis chorusing was a better indicator of other affiliative behaviours than grooming. We suggest that in male chimpanzees pant hoot choruses are efficient signals of short-term affiliative relationships. We conclude that potentially low-cost bonding behaviours such as coordinated vocal displays might be especially adaptive in highly fluid fission–fusion societies where grouping patterns are often unpredictable.

Amélie N. Dreiss, Charlène A. Ruppli, Fréderic Oberli, Sylvain Antoniazza, Isabelle Henry, Alexandre Roulin, Barn owls do not interrupt their siblings, Animal Behaviour, Available online 31 May 2013, ISSN 0003-3472, 10.1016/j.anbehav.2013.04.019.
Animals communicate with conspecifics to resolve conflicts over how resources are shared. Since signals reflect individuals‘ resource-holding potential and motivation to compete, it is crucial that opponents efficiently transmit and receive information to adjust investment optimally in competitive interactions. Acoustic communication is particularly flexible as it can be quickly modulated according to background noise and audience. Diverse mechanisms have evolved to minimize acoustic signal interference, one being the avoidance of signal overlap by adjusting the timing of call production to alternate calls with those of competitors. However, the occurrence and function of overlap avoidance in the resolution of competition among relatives have barely been studied. Using young barn owl siblings, Tyto alba, which vocally negotiate over who will have priority access to food provided by parents, we investigated the extent to which nestlings avoid calling simultaneously and the function of this behaviour. We found that nestlings overlapped both their live siblings‘ calls and experimentally broadcast calls at least five times less often than expected at random. Furthermore, a focal nestling engaged more intensely in vocal negotiation when competing with nestmates that called simultaneously compared to those that did not overlap their respective calls. This suggests that barn owl nestlings avoid calling simultaneously, as overlapped calls are less efficient at deterring siblings from competing. Overlap avoidance reduces signal interference and, as a consequence, would improve the efficiency of communication among kin.

Bezawork Afework Bogale, Shoei Sugita
Animal Cognition, June 2013
Shape discrimination and concept formation in the jungle crow (Corvus macrorhynchos)

We investigated whether jungle crows can learn concepts by using printouts of shapes in a simultaneous two-alternative task. Jungle crows were first trained with a red triangle and red square until they reached the discrimination criterion (80 % of correct choices in two blocks of 10 trials each). Then, we tested crows with successive transfer tests to investigate both the discrimination cues being used and concept formation ability, by using novel triangular and non-triangular stimuli. All of the jungle crows learnt to discriminate between the triangle and square during training. The discrimination performance was generally not affected either by changes in the colour of the stimuli or when both shape and colour cues conflicted, with the previously non-rewarded shape but matching colour (red square) versus rewarded shape but non-matching colour (green triangle). The use of only outlines of the familiar stimuli also did not affect discrimination behaviour of crows. In addition, crows significantly discriminated novel triangular shapes during the limited trials given, suggesting their ability to form the concept of triangularity. However, failure to discriminate when the novel stimuli size deviated from the original suggests that there is a limit to shape concept formation in a familiar–novel context in the jungle crow.

NELSON, M. R. and ANDERSEN, D. E. (2013), Do singing-ground surveys reflect American woodcock abundance in the western Great Lakes region?. Wildlife Society Bulletin. doi: 10.1002/wsb.288
The Singing-ground Survey (SGS) is the primary monitoring tool used to assess population status and trends of American woodcock (Scolopax minor). Like most broad-scale surveys, the SGS cannot be directly validated because there are no independent estimates of abundance of displaying male American woodcock at an appropriate spatial scale. Furthermore, because locations of individual SGS routes have generally remained stationary since the SGS was standardized in 1968, it is not known whether routes adequately represent the landscapes they were intended to represent. To indirectly validate the SGS, we evaluated whether 1) counts of displaying male American woodcock on SGS routes related to land-cover types known to be related to American woodcock abundance, 2) changes in counts of displaying male American woodcock through time were related to changes in land cover along SGS routes, and 3) land-cover type composition along SGS routes was similar to land-cover type composition of the surrounding landscape. In Wisconsin and Minnesota, USA, counts along SGS routes reflected known American woodcock-habitat relations. Increases in the number of woodcock heard along SGS routes over a 13-year period in Wisconsin were related to increasing amounts of early successional forest, decreasing amounts of mature forest, and increasing dispersion and interspersion of cover types. Finally, the cover types most strongly associated with American woodcock abundance were represented along SGS routes in proportion to their composition of the broader landscape. Taken together, these results suggest that in the western Great Lakes region, the SGS likely provides a reliable tool for monitoring relative abundance and population trends of breeding, male American woodcock. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

Michael A. Schillaci, J. Margaret Castellini, Craig A. Stricker, Lisa Jones-Engel, Benjamin P. Y.-H. Lee, Todd M. O’Hara
Variation in hair δ13C and δ15N values in long-tailed macaques (Macaca fascicularis) from Singapore
Primates, June 2013

Much of the primatology literature on stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) has focused on African and New World species, with comparatively little research published on Asian primates. Here we present hair δ13C and δ15N isotope values for a sample of 33 long-tailed macaques from Singapore. We evaluate the suggestion by a previous researcher that forest degradation and biodiversity loss in Singapore have led to a decline in macaque trophic level. The results of our analysis indicated significant spatial variability in δ13C but not δ15N. The range of variation in δ13C was consistent with a diet based on C3 resources, with one group exhibiting low values consistent with a closed canopy environment. Relative to other macaque species from Europe and Asia, the macaques from Singapore exhibited a low mean δ13C value but mid-range mean δ15N value. Previous research suggesting a decline in macaque trophic level is not supported by the results of our study.

Carlos R. Brocardo, Valesca B. Zipparro, Renato A.F. de Lima, Roger Guevara, Mauro Galetti, No changes in seedling recruitment when terrestrial mammals are excluded in a partially defaunated Atlantic rainforest, Biological Conservation, Available online 31 May 2013, ISSN 0006-3207, 10.1016/j.biocon.2013.04.024.
One of the most intriguing questions in ecology is how to identify which and how many species will be able to inhabit human-modified landscapes. Large-bodied mammals structure plant communities by trampling, herbivory, seed dispersal and predation, and their local extinction may have pervasive consequences in plant communities due to the breakdown of key interactions. Although much attention has been given to understanding the effects of defaunation on plant communities, information on the potential impacts on plant functional groups (seed dispersal, seed size and seedling leaves defense) inhabiting continuous forests after defaunation is scarce. We conducted mammal surveys (line transects and camera trapping) to determine the defaunation status of a continuous Atlantic forest in Brazil. Then, we evaluated the effects of defaunation on seedling diversity, richness and abundance of functional groups using 15 plot-pairs (each pair with one open and one exclusion plot) monitored over 36 months. We found that the studied area is partially defaunated because it exhibits high abundance of primates, while terrestrial mammals, such as large rodents and ungulates, are rare. We found no significant changes in either seedling richness and diversity or in the seedling composition of plant functional groups in response to mammal exclosure. Seedling mortality and recruitment were similar between plot types. Our findings suggest that at semi-defaunated areas, where arboreal species are still present, terrestrial mammals have low impacts on the plant community reassembly.

Houston, B. E., Rooke, A. C., Brownscombe, J. W. and Fox, M. G. (2013), Overwinter survival, energy storage and reproductive allocation in the invasive round goby (Neogobius melanostomus) from a river system. Ecology of Freshwater Fish. doi: 10.1111/eff.12071
The dynamic nature of population density during the invasion process may compromise how a population is able to cope with challenging environmental conditions within their non-native range. In temperate regions, one of the greatest seasonal environmental challenges is winter. We assess overwinter survival, changes in body condition and lipid content, and reproductive allocation of round goby (Neogobius melanostomus) from the point of introduction and the leading edges of an expanding invasive population in a tributary of Lake Ontario. Autumn lipid content was highest in round goby from the downstream edge and lowest at the centre of the invasive range, likely due to lower population density and reduced intraspecific resource competition at the expanding edges of its distribution. After 142 days of starvation under simulated winter conditions, round goby exhibited 96% survival. Despite the extended starvation period, the majority of females were able to allocate energy into ovarian development, with 60% of females having a gonadosomatic index of >5% at the end of the overwintering period. Individuals originating from the downstream edge allocated significantly more energy towards reproduction compared with individuals from the upstream and centre locations. The results suggest that the position within an expanding invasive range can influence the autumn energy content and consequently the reproductive effort of round goby in early spring. High overwinter survival and greater allocation of energy to reproduction at the expanding edge of an invasion may contribute to the highly successful expansion of the round goby in the Great Lakes Basin.

Hassrick, J. L., Crocker, D. E., Costa, D. P. (2013), Effects of maternal age and mass on foraging behaviour and foraging success in the northern elephant seal. Functional Ecology. doi: 10.1111/1365-2435.12108
Animals that show indeterminate growth and put relatively constant proportions of stored body reserves towards annual reproductive effort are confronted with a problem of meeting ever-increasing energetic demands in unpredictable environments.We examined how intrinsic traits, mass and age, as well as extrinsic environmental features impact diving and movement behaviour in a marine capital breeder, the northern elephant seal, Mirounga angustirostris. We assessed the impact of this behavioural variation on foraging success, measured as energy gained at sea.We used principal component analysis to reduce behavioural variables into three principal components that described time in foraging zones (PC1), foraging distance (PC2) and bout structure of dive shapes (PC3).Both intrinsic traits and extrinsic environmental features influenced behaviour and foraging success. Body mass was the sole predictor of residence time in foraging zones (PC1), which, in turn, was the strongest behavioural predictor of foraging efficiency and success over the short postbreeding season. Foraging distance (PC2) significantly varied with year. Since foraging distance is an index of the horizontal and vertical distances seals travel while foraging, we suggest that it was impacted by inter-annual variation in marine prey distribution. Age had a negligible impact on most aspects of behaviour, except for the structure of dive shapes on the postmoult foraging trip.All principal components significantly impacted rates of energy gain for postbreeding foraging trips when maternal body stores must be recovered quickly before returning to shore to moult. Age impacted the bout structure of dives in pregnant females in a way that influenced success, suggesting a role for previous experience during the long postmoult foraging migration.Strong impacts of body mass on diving ability, foraging success and reproductive effort suggest a proximate mechanism for trade-offs in the cost of reproduction. Mass lost to current investment in offspring impacts a mother’s ability to accrue resources for future offspring.

Wallace, E. K., Kingston-Jones, M., Ford, M. and Semple, S. (2013), An Investigation Into the Use of Music as Potential Auditory Enrichment for Moloch Gibbons (Hylobates moloch). Zoo Biol.. doi: 10.1002/zoo.21074
The use of music as enrichment has rarely been explored in zoos, despite evidence that music has a positive effect on a range of laboratory housed animals. In this study of moloch gibbons, Hylobates moloch, at Howletts Wild Animal Park (Kent, England), instrumental classical music was played to eight individuals in two family groups. Music was played 7 hr a day during three of six study weeks for each group, alternating with control weeks in which no music was played. In focal watches, data were recorded on a measure of activity, brachiation, and on two rates of affiliative behavior, giving and receiving grooming. In addition, to assess potential impacts on emotional state, data were recorded on self-scratching and self-grooming, two widely used indices of anxiety or stress. Analyses were carried out for each individual separately, as previous studies of primates indicate animals may differ in their response to enrichment. Results revealed little evidence for effects of music on gibbons‘ behavior. During the music compared to control weeks, the adult male from one group showed higher rates of self-scratching and higher durations of both self-grooming and grooming others. The adult female from the same group was groomed more during the music weeks than control weeks. For the six other animals, no significant differences in behaviors were seen between music and control conditions. Our findings suggest music may not be an effective enrichment for captive gibbons, and further highlight the importance of considering individual differences when assessing the effects of potential enrichment.

Evolutionary Origin of the Turtle Shell
Tyler R. Lyson, Gabe S. Bever, Torsten M. Scheyer, Allison Y. Hsiang, Jacques A. Gauthier
Current Biology – 30 May 2013

The origin of the turtle shell has perplexed biologists for more than two centuries. It was not until Odontochelys semitestacea was discovered, however, that the fossil and developmental data could be synthesized into a model [9] of shell assembly that makes predictions for the as-yet unestablished history of the turtle stem group. We build on this model by integrating novel data for Eunotosaurus africanus—a Late Guadalupian (∼260 mya) Permian reptile inferred to be an early stem turtle. Eunotosaurus expresses a number of relevant characters, including a reduced number of elongate trunk vertebrae (nine), nine pairs of T-shaped ribs, inferred loss of intercostal muscles, reorganization of respiratory muscles to the ventral side of the ribs, (sub)dermal outgrowth of bone from the developing perichondral collar of the ribs, and paired gastralia that lack both lateral and median elements. These features conform to the predicted sequence of character acquisition and provide further support that E. africanus, O. semitestacea, and Proganochelys quenstedti represent successive divergences from the turtle stem lineage. The initial transformations of the model thus occurred by the Middle Permian, which is congruent with molecular-based divergence estimates for the lineage, and remain viable whether turtles originated inside or outside crown Diapsida.

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