Andrew B. Nelson, Shireen D. Alemadi, Brian D. Wisenden
Learned recognition of novel predator odour by convict cichlid embryos
Behavioral Ecology and Sociobiology, May 2013
Predation exerts tremendous selection pressure on all organisms. In this study, we exposed embryos of convict cichlids (Amatitlania siquia) twice daily to one of the following: (1) chemical alarm cues of damaged conspecifics + odour of a novel predator (Polypterus endlicheri), (2) chemical alarm cues of damaged conspecifics + water or (3) blank water. No chemical cues were presented after the eggs hatched. When the larvae were 9 days old (mean total length = 5.7 mm), they were exposed to either predator odour or water. Those larvae that had been conditioned as embryos on alarm cues + predator odour showed a significant reduction in activity (i.e. anti-predator behavioural response) to predator odour relative to the other treatments. This is the first demonstration of acquired predator recognition by fish embryos.
James K. Sheppard, Matthew Walenski, Michael P. Wallace, Juan J. Vargas Velazco, Catalina Porras, Ronald R. Swaisgood
Behavioral Ecology and Sociobiology, May 2013
Hierarchical dominance structure in reintroduced California condors: correlates, consequences, and dynamics
Populations of reintroduced California condors (Gymnogyps californianus) develop complex social structures and dynamics to maintain stable group cohesion, and birds that do not successfully integrate into group hierarchies have highly impaired survivability. Consequently, improved understanding of condor socioecology is needed to inform conservation management strategies. We report on the dominance structure of free-ranging condors and identify the causes and consequences of rank in condor populations by matching social status with the behavioral and physical correlates of individual birds. We characterized the hierarchical social structure of wild condor populations as mildly linear, despotic, and dynamic. Condor social groups were not egalitarian and dominance hierarchies regulated competitive access to food resources. Absence of kin-based social groups also indicated that condor social structure is individualistic. Agonistic interactions among condors were strongly unidirectional, but the overall linearity and steepness of their hierarchies was low. Although one aggressive male maintained the highest dominance rank across the 3-year observation period, there was considerable fluidity in social status among condors within middle and lower rank orders. Older condors were more dominant than younger birds and younger males supplanted older females over time to achieve higher status. Dominance rank did not predict the amount of time that a bird spent feeding at a carcass or the frequency that a bird was interrupted while feeding. Thus, younger, less dominant birds are able to obtain sufficient nutrition in wild social populations.
Livia Wittiger, Christophe Boesch
Female gregariousness in Western Chimpanzees (Pan troglodytes verus) is influenced by resource aggregation and the number of females in estrus
Behavioral Ecology and Sociobiology, May 2013
Among social animals, group size is constrained by competition over resources. Because female reproductive success is limited by access to food resources, and that of males by access to fertile females, chimpanzee females are proposed to be less social than males and to maintain weak intrasexual relations. Findings from Taï National Park, Côte d’Ivoire, challenged this view, as chimpanzee females were described as generally gregarious, and close intrasexual bonds were common. Here, in a new analysis that focuses on the South Group of chimpanzees in Taï forest, we reevaluate the proposed differences in female association patterns between the Taï and East African populations. We find that mean party size and dyadic association index between females has decreased in Taï, although the level of dyadic associations remains high compared with East African chimpanzees. We attribute the decrease in female gregariousness to the decline in community size over the last 10 years. In addition, we use a multivariate approach to analyze social and ecological factors influencing party size in females. We show that female gregariousness increased when the fruit resources were more clumped and with increased number of females in estrus present. Party size of mothers with sons, however, was smaller with increasing number of sexually receptive females. The results of our model and the reviewed findings of other studies support the socioecological model because food distribution affects female gregariousness, but social and demographic aspects are equally influencing female grouping tendencies.
Zootaxa 3646 (4): 336–348 (06 May 2013)
A new species of Duttaphrynus (Anura : Bufonidae) from Northeast India
ABHIJIT DAS, MITALI CHETIA, SUSHIL KUMAR DUTTA & SAIBAL SENGUPTA
A new species of montane toad Duttaphrynus is described from Nagaland state of Northeast India. The new species is diagnosable based on following combination of characters: absence of preorbital, postorbital and orbitotympanic ridges, elongated and broad parotid gland, first finger longer than second and presence of a mid-dorsal line. The tympanum is hidden under a skin fold (in male) or absent (in female). The species is compared with its congers from India and Indo-China. We propose to consider Duttaphrynus wokhaensis as junior synonym of Duttaphrynus melanostictus.
Zootaxa 3646 (4): 426–446 (06 May 2013)
A new treefrog (Hylidae: Litoria) from Kroombit Tops, east Australia, and an assessment of conservation status
CONRAD J. HOSKIN, HARRY B. HINES, ED MEYER, JOHN CLARKE & MICHAEL CUNNINGHAM
The Litoria phyllochroa species-group are small hylid frogs that occur in wet forests of south-east Australia. This group
has had a long history of taxonomic confusion and has received little attention in the last decade. A population of this
species-group at Kroombit Tops, several hundred kilometers north of all other populations, has been recognised for some time as being genetically highly distinct. Here we describe this population as a new species, L. kroombitensis sp. nov. This species is most similar to L. barringtonensis and L. pearsoniana but is readily distinguished based on differences in morphology, colour pattern, mating call and genetics. Litoria kroombitensis sp. nov. is restricted to Kroombit Tops, an isolated area of wet forest in south-east Queensland. The species inhabits slow and intermittently flowing streams in rainforest and adjoining wet sclerophyll forest. The tadpole of L. kroombitensis sp. nov., described herein, is similar in morphology and behaviour to the tadpoles of other species within the Litoria phyllochroa species-group, in particular L. pearsoniana. Litoria kroombitensis sp. nov. has a very small distribution, with all records coming from the headwaters of five streams. Extensive surveys since the mid-1990s have revealed population declines, attributable to amphibian chytrid fungus
(Batrachochytrium dendrobatidis). Other threats include degradation of riparian habitat due to invasive weeds, feral pigs and livestock, and fire. Further, the extent of wet forest habitats at Kroombit Tops is likely to be reduced by climate change impacts. Litoria kroombitensis sp. nov. meets IUCN Red List criteria for critically endangered CR B1ab (i–v) due to its small geographic range, naturally fragmented distribution, and observed and projected decline in populations. In this paper we also assess the validity of the names L. barringtonensis, L. pearsoniana and L. piperata. We conclude that the names L. barringtonensis and L. pearsoniana are valid but the validity of L. piperata requires further investigation.
Zootaxa 3646 (5): 581–586 (07 May 2013)
Description of larvae of the Feather Blenny, Hypsoblennius hentz (Pisces: Blenniidae), from New York Waters
ROBERT E. SCHMIDT & PAUL A. MOCCIO
Hypsoblennius hentz (Lesueur) larvae are described from specimens recently collected in the vicinity of New York Harbor and Raritan Bay. Previous descriptions (Hildebrand and Cable 1938) were erroneous and additionally we provide the first yolk-sac larval descriptions for Western Atlantic Hypsoblennius. H. hentz larvae are distinguished from the other Atlantic species by the size and distribution of preopercular spines.
Smith, K. N., Campomizzi, A. J., Morrison, M. L. and Wilkins, R. N. (2013), Managing Brown-Headed Cowbirds to Sustain Abundance of Black-Capped Vireos. Wildlife Society Bulletin. doi: 10.1002/wsb.277
Brood parasites can appreciably decrease fecundity of susceptible songbird hosts, which can often cause a decrease in host abundance. Wildlife managers use brown-headed cowbird (Molothrus ater) management to reduce parasitism frequency and benefit the conservation of the endangered black-capped vireo (Vireo atricapilla); however, intensity of management needed to increase vireo abundance is not well-understood. We used sensitivity analyses of population models for black-capped vireos to assess effects on abundance of particular changes in parasitism frequency. Our models suggest that the parasitism frequency vireos can tolerate while maintaining abundance in a particular location is ≤30%. If parasitism frequency is high, trapping cowbirds during ≥1 of every 3 years may be sufficient for reducing parasitism enough to maintain abundance at managed locations. Cowbird management programs may need to be intensive in initial years to increase abundance of vireos being managed if the initial abundance is low. Rotating locations of traps each year among managed locations may be effective for maintaining vireo abundance while decreasing overall trapping effort and making more efficient use of management funds. Increasing and restoring habitat concurrent with cowbird management would likely further increase the likelihood of establishing and maintaining vireo abundance in managed locations.
Franks, B., Reiss, D., Cole, P., Friedrich, V., Thompson, N. and Higgins, E. T. (2013), Predicting How Individuals Approach Enrichment: Regulatory Focus in Cotton-Top Tamarins (Sanguinus oedipus). Zoo Biol.. doi: 10.1002/zoo.21075
Evidence is mounting that personality is associated with health and well-being in humans and other animals. In a step towards increasing our understanding of this link, we applied regulatory focus theory, a motivational perspective from social psychology, to the behavior of zoo-housed cotton top tamarins. We tested whether regulatory focus “personality,” that is stable differences in whether an individual is motivated by gains versus safety, would 1) produce individual differences in behavior and 2) predict how individuals interact with enrichment. First, we characterized individuals with respect to several key behaviors: eating in the open, hiding, and time spent near the front of the exhibit. The monkeys were consistent in their behavioral tendencies across the 6-month study, allowing regulatory focus classification. One monkey showed evidence of being a promotion-individual, that is, more motivated by gains than safety. One monkey showed evidence of being a prevention-individual, that is, more motivated by safety than gains. The other monkeys were stable in their behavior and showed evidence of being intermediate-individuals, that is, they favored neither gains nor safety. Using these characterizations, we predicted distinct patterns of individual-object interactions with enrichment. For example, we predicted that a promotion-individual (favoring gains over safety) would approach potential gains faster than a prevention-individual (favoring safety over gains). Counter-intuitively, however, we also predicted that a promotion-individual would approach non-gains slower than a prevention-individual concerned with safety. We found support for our predictions, which suggests that regulatory focus theory could be a useful tool for understanding how and why individuals interact with environmental enrichment.
Andrea Friebe, Andreas Zedrosser, Jon E. Swenson
Detection of pregnancy in a hibernator based on activity data
European Journal of Wildlife Research, May 2013
Pregnancy and parturition are often difficult to detect in wild-living animals, especially in species that give birth to altricial young in burrows or caves. Current methods to detect pregnancy and birth in hibernating animals often entail disturbances that can affect the animals‘ reproductive success. We developed a new method to confirm pregnancy and parturition in hibernating brown bears (Ursus arctos) using activity data recorded in dual-axis motion sensors mounted on GPS–GSM neck collars on 30 brown bears during 52 hibernation seasons in Sweden. We adjusted recorded activity to the individual basal activity level for each bear. Pregnant females showed characteristic activity patterns during the period of pregnancy, with significantly higher daily activity levels and frequency of active periods during pregnancy than nonpregnant bears. Pregnant females were active on average 2.20 times more often during the pregnancy period than during the postpartum period, compared with 0.97 times for nonpregnant females. A pregnancy index was defined as the average of the proportion of mean daily activity levels and the proportion of activity events during the pregnancy period compared with the postpartum period. It averaged 2.61 ± 1.73 (SD) for pregnant females and 0.94 ± 0.24 for nonpregnant females. Using this method, we evaluated a group of adult females that had an unverified reproductive status but were classified as not pregnant because no cubs had been observed after den emergence. The results suggested that 35 % of those females had, in fact, been pregnant.
Fernando Alda, Manuel A. González, Pedro P. Olea, Vicente Ena, Raquel Godinho, Sergei V. Drovetski
Genetic diversity, structure and conservation of the endangered Cantabrian Capercaillie in a unique peripheral habitat
European Journal of Wildlife Research, May 2013
Populations at the rear edge of the species’ range are often at a high risk of extinction due to their isolation, fragmentation and small population sizes. However, these populations also play a relevant role in the conservation of biodiversity since they may represent a valuable genetic resource. The endangered Cantabrian Capercaillie (Tetrao urogallus cantabricus) inhabits deciduous forests of the Cantabrian Mountains of Spain, at the southwestern limit of the species’ range. Recently, nine Cantabrian Capercaillie leks were discovered in Pyrenean oak forests of the southern slope of the Cantabrian range, where the subspecies historically occurred. To elucidate if the origin of this peripheral population nucleus is the result of a historical range contraction or a recent re-colonization from the core population, we sampled moulted feathers from all the known leks in the southern peripheral forests and from the adjacent main core population, based on nine microsatellite loci genotypes. No significant genetic differentiation was detected between main core and peripheral forests suggesting that gene flow is not interrupted between these nuclei. Contrary to expected, peripheral forests did not represent sink populations, since gene flow mainly occurred from southern peripheral to northern main core forests. Therefore, the origin of these birds inhabiting the peripheral nucleus seems not to be a recent colonization but relicts from the former distribution range that have remained unnoticed in a drier and warmer environment than described so far for the species. Cantabrian Capercaillie faces a high risk of extinction in the southernmost forests of its distribution, not only because of its peripheral location but also due to its small population size, low genetic diversity and low incoming gene flow. According to our results, this peripheral nucleus could represent an expanding edge for the population if Pyrenean oak forests continue to spread out southwards and consequently stress the need for conservation programs to preserve habitat availability and forest connectivity.
Diversity in the Matrix Structure of Eggshells in the Testudines (Reptilia)
Satoshi Kusuda, Yuichirou Yasukawa, Hiroki Shibata, Tomomi Saito, Osamu Doi, Yutaka Ohya, and Norio Yoshizaki
Zoological Science 2013 30 (5), 366-374
The eggshells of 56 chelonians were examined by electron microscopy and X-ray diffractometry. They were classified into six types in terms of the matrix structure of their calcareous layer; type I was composed of a thin calcareous layer with minerals in an amorphous structure; type II with shell units composed of mammillary cores calcified with aragonite crystals; type III with shell units composed of mammillary cores, plus a single palisade layer also calcified with aragonite crystals, and with each shell unit separated; type IV with shell units the same as type III, but tightly packed together; type V with shell units composed of mammillary cores plus two palisade layers; and type VI with a cuticle layer calcified with calcite crystals over the same structure as that of type V. X-ray diffraction analyses at the outer surface of eggshells showed a gradual change in crystal disposition from the random disposition of type II to the single direction-oriented disposition of type V. The shell height was approximately parallel to the development of the palisade-layer matrix. The limiting membrane of all eggshell types was perforated with canals and that of type I was partially missing. Type I had a parchment shell, types II and III had a pliable shell (some were rigid) and types IV to VI had rigid shells. The present study showed that the hardness of eggshells can be determined by the composition of the shell matrices, as shell matrices are the framework for mineralization.
Divergence of Scent Pheromones in Allopatric Populations of Acanthodactylus boskianus (Squamata: Lacertidae)
Eraqi R. Khannoon, David H. Lunt, Stefan Schulz, and Jörg D. Hardege
Zoological Science 2013 30 (5), 380-385
The evolutionary phenomena associated with divergence in chemical signals between populations of the same species help to understand the process of speciation. Animals detect and react to semiochemicals and pheromones used in communication. Comparison between populations of the same species that are geographically isolated from one another allows us to determine the genetic or environmental factors responsible for chemical differentiation. Acanthodactylus boskianus from the east and west of Egypt were used as an example to compare the geographical diversity in chemical fingerprints of this species‘ femoral gland secretions and its phylogeography. Chemical analysis via GC—MS showed that the two geographically distinct populations‘ odor fingerprints are quantitatively different despite sharing the same components of the secretions. Phylogenetic analysis showed that the eastern and western Egyptian populations are genetically distinct and that chemical divergence of these lizards‘ odor profiles may be an example of signal evolution.
Microhabitat use by Hyla japonica and Pelophylax porosa brevipoda at Levees in Rice Paddy Areas of Japan
Risa Naito, Masaru Sakai, Yosihiro Natuhara, Yukihiro Morimoto, and Shozo Shibata
Zoological Science 2013 30 (5), 386-391
In Japan, rice paddies have acted as substitute habitats for pond-breeding frogs. However, frog populations are declining due to the loss of habitat and environmental changes in rice paddy areas. Frogs need both aquatic and terrestrial habitats to complete their life history; in rice paddy areas, levees that surround rice paddies provide terrestrial habitats for basking, foraging, and shelter from predators. Studying microhabitat use at levees is important to elucidating the ecological roles of levees and to properly managing them to support frog populations. In this study, we conducted surveys in lowland modernized rice paddy areas in Shiga Prefecture in which a common species, Hyla japonica, and an endangered species, Pelophylax porosa brevipoda, were found. We captured frogs at levees and recorded environmental factors related to levee vegetation, rice paddy conditions, and weather. We constructed generalized linear mixed models to examine the effects of environmental factors on juvenile and adult H. japonica and on small and large juveniles, females, and males of P. p. brevipoda. Our results showed distinct microhabitat uses at levees in different species, sexes, and body sizes. In general, abundance was high at levees with vegetation that provided shelter. The water depth in rice paddies negatively influenced juvenile H. japonica and large juvenile and small female P. p. brevipoda, and positively influenced small male P. p. brevipoda. The maintenance of a mosaic structure of levees was important not only to support frog populations but also to maintain frog diversity in the area.
Tabatabaei Yazdi, F. and Adriaens, D. (2013), Cranial variation in Meriones tristrami (Rodentia: Muridae: Gerbillinae) and its morphological comparison with Meriones persicus, Meriones vinogradovi and Meriones libycus: a geometric morphometric study. Journal of Zoological Systematics and Evolutionary Research. doi: 10.1111/jzs.12020
Jirds (genus Meriones) comprise a group of rodents, of which the biodiversity is still poorly known. Reason for this is that several species of similar morphologies are known to occur sympatrically. In the north-west of Iran, four such species occur: Meriones tristrami, Meriones persicus, Meriones vinogradovi and Meriones libycus, prone to several issues of taxonomical ambiguity. A proper characterization of morphological distinctiveness between these species, in relation to the variation within species, could provide the required information for species diagnosis and identification. As some cranial characters of M. tristrami, M. persicus and M. vinogradovi are quite similar, demarcations of species-specific phenotypic variation have proven to be difficult. To tackle this problem, this study involves a geometric morphometric analysis of skull shape and size, incorporating a large representative sample of these four species, originating from most parts of their natural distribution range (especially for M. tristrami). It is first tested whether M. tristrami can be distinguished from the other sympatric species, and if so, to what degree the species shows a geoclimatic pattern in its skull shape and size when comparing different populations. The shape and size analyses show that M. libycus can be distinguished because of its largest skull and the relatively largest tympanic bulla, and that M. tristrami can be distinguished from the other species. At an intraspecific level in M. tristrami, the Iranian groups (Qazvin and west Iran) do not differ in shape among them, but do so in skull size. They could, however, be distinguished in skull shape from the non-Iranian populations included (Turkey and Jordan). To what degree this continuous data can now be translated into discrete and diagnostic features, useful for taxonomic purposes, remains to be studied.
Elliser, C. R. and Herzing, D. L. (2013), Social structure of Atlantic spotted dolphins, Stenella frontalis, following environmental disturbance and demographic changes. Marine Mammal Science. doi: 10.1111/mms.12038
Extreme environmental events and demographic changes can have variable effects on the social structure of animal populations. This study compared the social structure of a community of Atlantic spotted dolphins in the Bahamas before and after two hurricanes. Approximately 36% of the individuals were lost, with no subsequent increase in immigration. The majority of the social structure characteristics were consistent with results from a long-term study covering the previous 12 yr, including community structure with definitive social clusters, sex preferences and overall association patterns. However some changes occurred, though still constrained within sex preferences. Posthurricane there was a decrease in social differentiation and increased cohesion within clusters and across age class. Males retained or made new first order alliances, however, only one second order alliance was evident, revealing a simplified alliance structure. Juvenile individuals made alliance level associations, unprecedented from long-term analysis. Although other studies have shown stark restructuring, this study showed that less drastic changes within overall social structure stability can occur. Persistence and evolutionary changes in populations through environmental and/or demographic perturbations may depend on the social structure of a population or community. Understanding the processes involved in social development is paramount for conservation of diverse populations.
Michael, D. R., Cunningham, R. B., Macgregor, C., Brown, D. and Lindenmayer, D. B. (2013), The effects of prey, habitat heterogeneity and fire on the spatial ecology of peninsular Diamond Pythons (Morelia spilota spilota: Pythonidae). Austral Ecology. doi: 10.1111/aec.12056
Understanding an organism’s home range is an important component of effective wildlife management. However, home ranges can vary spatially and temporally within and between populations. Landscape ecology theory can provide a framework for understanding spatio-temporal variability in animal traits. We used radio-telemetry in a population of diamond python Morelia spilota spilota Lacépède (Pythonidae) from a biologically rich and structurally heterogeneous reserve in eastern Australia to explore the relationship between home range size, optimal foraging theory and vegetation mosaic theory. Twelve adult snakes were tracked between September 2004 and February 2008. Male home ranges were significantly larger (P < 0.05) and more variable (41 ± 30 ha) than female home ranges (23 ± 5 ha), and males moved further between observations (123 m c.f. 65 m). Core activity centres varied significantly among habitat (P < 0.05) with larger home ranges observed in heathland, a vegetation community which supported comparatively low mammal diversity. No other variables examined including number of fixes, body length, prey abundance, vegetation heterogeneity or fire history explained home range variability. In this system, relatively high mammalian prey diversity and rapid post-fire vegetation succession may limit prey availability and fire effects as being significant determinants of home range variability in M. spilota.
Heermann, L., Scharf, W., van der Velde, G. and Borcherding, J. (2013), Does the use of alternative food resources induce cannibalism in a size-structured fish population?. Ecology of Freshwater Fish. doi: 10.1111/eff.12060
Cannibalism in fish has various effects at population and individual level. Cannibals derive energetic benefit by feeding on their smaller conspecifics, while at the same time reducing competition for the shared resource. Avoiding intracohort competition can force fish to use alternative feeding strategies, which may subsequently stimulate cannibalism. This study examined diet variation and intracohort cannibalism by young-of-the-year (YOY) European perch (Perca fluviatilis) after hatching in three stocking experiments in ponds based on stomach content and stable isotope analyses. Because zooplankton biomass decreased, YOY perch started to diverge in diet use, suggesting that increased intraspecific competition forced fish to try alternative feeding strategies. Larger YOY perch then fed on energetically richer resources (bream larvae or odonates) and hence outgrew their smaller conspecifics, becoming large enough to enable cannibalism. Thus, the widening of initial size differences by feeding on high-energy resources served as a stepping stone towards cannibalism. This differentiation into two size classes and two different feeding strategies was shown to be a stable pattern within the YOY perch population, as indicated by stable isotope analysis.
Anglin, Z. W. and Grossman, G. D. (2013), Microhabitat use by southern brook trout (Salvelinus fontinalis) in a headwater North Carolina stream. Ecology of Freshwater Fish. doi: 10.1111/eff.12059
Brook trout are the one of the only Salvelinus species native to eastern North America and range from Canada to Georgia. Very little is known, however, about the ecology of the southern form of this species. We quantified microhabitat use of southern brook trout in Ball Creek NC, a third-order stream, during six seasonal samples (summer 2010, autumn 2010, spring 2011, summer 2011, autumn 2011 and spring 2012). In general, trout preferentially occupied deeper microhabitats with lower mean velocities and higher amounts of erosional substrata than were randomly available. Older trout (1+ and 2+) occupied deeper microhabitats with lower mean velocities than yearling trout. These microhabitats typically represent ‘plunge pools’. Southern brook trout also occupied focal point velocities that were statistically indistinguishable from optimal velocities calculated for rainbow trout in the same system and thus may chose microhabitats that maximise net energy gain. Southern brook trout are found in isolated populations, and management strategies should focus on the preservation of plunge pool habitat for conservation of this subspecies.
Welsh, S. A., Smith, D. M. and Taylor, N. D. (2013), Microhabitat use of the diamond darter. Ecology of Freshwater Fish. doi: 10.1111/eff.12062
The only known extant population of the diamond darter (Crystallaria cincotta) exists in the lower 37 km of Elk River, WV, USA. Our understanding of diamond darter habitat use was previously limited, because few individuals have been observed during sampling with conventional gears. We quantified microhabitat use of diamond darters based on measurements of water depth, water velocity and per cent substrate composition. Using spotlights at night-time, we sampled 16 sites within the lower 133 km of Elk River and observed a total of 82 diamond darters at 10 of 11 sampling sites within the lower 37 km. Glides, located immediately upstream of riffles, were the primary habitats sampled for diamond darters, which included relatively shallow depths (