Genetic variation in brown trout Salmo trutta across the Danube, Rhine, and Elbe headwaters: a failure of the phylogeographic paradigm?
Lerceteau-Köhler E, Schliewen U, Kopun T, Weiss S
BMC Evolutionary Biology 2013, 13:176 (26 August 2013)
Brown trout Salmo trutta have been described in terms of five major mtDNA lineages, four of which correspond to major ocean basins, and one, according to some authors, to a distinct taxon, marbled trout Salmo marmoratus. The Atlantic and Danubian lineages of brown trout meet in a poorly documented contact zone in Central Europe. The natural versus human mediated origin of the Atlantic lineage in the upper Danube is a question of both theoretical and practical importance with respect to conservation management. We provide a comprehensive population genetic analysis of brown trout in the region with the aim of evaluating the geographic distribution and genetic integrity of these two lineages in and around their contact zone.
Genetic screening of 114 populations of brown trout across the Danube/Rhine/Elbe catchments revealed a counter-intuitive phylogeographic structure with near fixation of the Atlantic lineage in the sampled portions of the Bavarian Danube. Along the Austrian Danube, phylogeographic informative markers revealed increasing percentages of Danube-specific alleles with downstream distance. Pure Danube lineage populations were restricted to peri-alpine isolates within previously glaciated regions. Both empirical data and simulated hybrid comparisons support that trout in non-glaciated regions north and northeast of the Alps have an admixed origin largely based on natural colonization. In contrast, the presence of Atlantic basin alleles south and southeast of the Alps stems from hatchery introductions and subsequent introgression. Despite extensive stocking of the Atlantic lineage, little evidence of first generation stocked fish or F1 hybrids were found implying that admixture has been established over time.
A purely phylogeographic paradigm fails to describe the distribution of genetic lineages of Salmo in Central Europe. The distribution pattern of the Atlantic and Danube lineages is extremely difficult to explain without invoking very strong biological mechanisms.
The peri-alpine distribution of relict populations of pure Danubian lineage brown trout implies that they colonized headwater river courses post-glacially ahead of the expansion of the Atlantic lineage. The recognition of natural as opposed to anthropogenic introgression of the Atlantic lineage into Danubian gene pools is of fundamental importance to management strategies.
Costa, W. J. E. M., Amorim, P. F. and Bragança, P. H. N. (2013), Species limits and phylogenetic relationships of red-finned cryptic species of the seasonal killifish genus Hypsolebias from the Brazilian semi-arid Caatinga (Teleostei: Cyprinodontiformes: Rivulidae). Journal of Zoological Systematics and Evolutionary Research. doi: 10.1111/jzs.12041
Members of the Hypsolebias antenori species group comprise a diverse clade of morphologically similar seasonal killifishes occurring in a vast region of the semi-arid savannah of northeastern Brazil. The present paper focuses on an assemblage of three allopatric cryptic species (H. antenori from isolated coastal river drainages, Hypsolebias igneus from the São Francisco River basin and Hypsolebias coamazonicus sp. nov. from the Parnaíba River basin) sharing almost identical colour patterns, including the presence of an orangish red anal fin in males, thus herein named as the red-finned assemblage. A tree-based approach using mt-DNA (cytochrome b) supports delimitation of all three species, but indicates that the red-finned assemblage is paraphyletic – H. igneus and H. coamazonicus are closely related to Hypsolebias nudiorbitatus, whereas H. antenori is the sister group to a clade comprising all 13 species of the H. antenori group included in the analysis. Morphological characters are useful to diagnose species, but are not informative for most clades highly supported by molecular data. H. coamazonicus is distinguished from all other congeners by the possession of a dark grey or black stripe on the dorsal fin in males. The basal position of H. antenori is related to uplift episodes involving the Araripe-Borborema plateau during the Miocene, which isolated the coastal area inhabited by H. antenori from the remaining areas of the Caatinga. The sister group relationship between H. igneus and H. coamazonicus is attributed to a past connection between the São Francisco and Paranaíba River until the Tertiary.
Toussaint, S., Reghem, E., Chotard, H., Herrel, A., Ross, C. F. and Pouydebat, E. (2013), Food acquisition on arboreal substrates by the grey mouse lemur: implication for primate grasping evolution. Journal of Zoology. doi: 10.1111/jzo.12073
The use of the hand in food grasping is a shared characteristic of primates. However, the factors involved in the elaboration of this function remain unclear. Grasping hands may have evolved in an arboreal habitat with narrow branches. Interestingly, grasping may also have an association with different types of feeding such as insect predation, fruit and flower exploitation, or both. No study has tested the importance of substrate diameter and food properties on the use of the hand in food grasping. Yet, both of these parameters likely impose important selective pressures on the origin and evolution of manual grasping strategies in the context of food acquisition. Here, we quantified whether (1) substrate diameter (narrow, wide) and (2) food properties (static, slow moving, fast moving) influence food grasping in a small primate, Microcebus murinus. Our results show that narrow substrates increase the use of hands in prey grasping. The mouth is preferentially used to grasp static food (banana), whereas the hands are preferred to grasp moving prey (mealworm and cricket) regardless of the substrate. Thus, the narrow branch niche may be an important selective pressure on the emergence of manual food grasping in primates, but predation likely also played a key role.
Jansen, D. A. W. A. M., Cant, M. A. and Manser, M. B. (2013), Testing for vocal individual discrimination in adult banded mongooses. Journal of Zoology. doi: 10.1111/jzo.12054
The ability to individually recognize conspecifics is acknowledged as one of the prerequisites for the development of sophisticated social relationships in group-living species. It has been hypothesized that the discrimination of individual identities is crucial for the maintenance of social relationships and cooperation based on repeated interactions, and for the evolution of many social behaviours. Previous studies have shown that the close calls of the cooperatively breeding banded mongoose Mungos mungo are individually distinct. For instance, banded mongoose pups are able to distinguish between close calls of their escort and of a non-escort. In this study, we used playbacks based on the recently proposed violation-of-expectation paradigm and a dominance/age class recognition setup to investigate whether adult banded mongooses use the individual signature of close calls to distinguish among adult group members. We found no evidence that the individual signature in close calls is used to discriminate identity in banded mongooses. Based on the previous work, we suggest that this is not because banded mongooses are incapable of using signatures as a means of individual discrimination, but because the benefits of such discrimination are low. The study highlights the importance of understanding the function of a signal (e.g. the expected response), timing and the biology of the species when designing and performing playback experiments.
REHNUS, Maik et al. Seasonal changes in habitat use and feeding strategy of the mountain hare (Lepus timidus) in the Central Alps. Hystrix, the Italian Journal of Mammalogy, [S.l.], v. 24, n. 2, p. 5, aug. 2013. ISSN 1825-5272. Available at: http://www.italian-journal-of-mammalogy.it/article/view/4703. Date accessed: 28 Aug. 2013. doi:10.4404/hystrix-24.2-4703
The mountain hare Lepus timidus (Linnaeus, 1758) is one of the smallest mammals in Alpine environments that stays active year-round without any conspicuous physiological adaptions. Mountain hares thus need to respond to seasonal changes by adaptive habitat and diet choice. We studied seasonal changes in habitat use and feeding strategy in the continental Central Alps during one year. Monitoring of the presence and density of dung and microhistological analysis of faecal pellets revealed that forest habitats, particularly mountain pine shrubs (Pinus mugo ssp.), were used throughout the year, whilst open habitats were avoided during snow-covered seasons. The probabilities of pellet presence and density were positively correlated with the proportion of trees and grass in spring, summer and autumn whereas in winter, they correlated only with the proportion of trees. The observed patterns can be explained by the importance of shelter and food availability which change seasonally and especially due to snow cover. We concluded that the availability of shelter was more important than food because hares selected habitat types that offered security from predators rather than habitat types with high food quality.
Bishop, A. M., Lidstone-Scott, R., Pomeroy, P. and Twiss, S. D. (2013), Body slap: An innovative aggressive display by breeding male gray seals (Halichoerus grypus). Marine Mammal Science. doi: 10.1111/mms.12059
Aggression in male gray seals has been extensively studied; however it is often simplistically assumed that threat signals are mainly cephalic in nature for this species. We report on an undescribed and apparently new kind of threat signal used by male gray seals we term a Body Slap. The behavior has been observed at breeding sites in eastern England since 1993 but has not been studied ethologically or reported elsewhere. The aims of this study were to describe the behavior, test the influence of topographic variation on its frequency of occurrence, examine if it is used to signal dominance or submission, and to place it in intra- and interspecific contexts. Our results show Body Slaps were performed in 66.3% of interactions and by 57.2% of males; it was not performed by females. The Body Slap was positively associated with the Approach and Open-Mouth Threat behaviors but was not related to dominance; nevertheless, display rates were greater for subsequent winners. These findings suggest that the Body Slap carries information about male resource holding potential and does not signal submission. This study furthers our understanding of geographic variants of male threat behaviors and of pinniped nonvocal communication.
D.B. Lindenmayer, W. Blanchard, L. McBurney, D. Blair, S.C. Banks, D. Driscoll, A.L. Smith, A.M. Gill, Fire severity and landscape context effects on arboreal marsupials, Biological Conservation, Volume 167, November 2013, Pages 137-148, ISSN 0006-3207, http://dx.doi.org/10.1016/j.biocon.2013.07.028.
We identified substantial differences among species in response to fire severity and landscape-scale fire. The Sugar Glider (Petaurus breviceps) and the endangered Leadbeater’s Possum (Gymnobelideus leadbeateri) were extremely rare on burned sites irrespective of fire severity. In addition, these two species declined with the amount of burned forest in the surrounding landscape even when their habitat remained unburnt. The Mountain Brushtail Possum (Trichosurus cunninghami) and the Greater Glider (Petauroides volans) both occurred on burned and unburned sites. The Greater Glider responded negatively to fire severity at the site level and also negatively to the amount of forest burned in the surrounding landscape. The abundance of the Mountain Brushtail Possum was lowest on sites subject to moderate severity fire.
On unburned sites, the presence and abundance of virtually all species was characterised by a common positive response to the availability of nesting resources in hollow-bearing trees.
Our findings underscore the importance of management practices to better protect species that decline after fire. These include conserving areas of unburned forest, particularly those with hollow-bearing trees which are critical nest sites for arboreal marsupials. These recommendations are currently the opposite of existing management practices.
Diederik Strubbe, Erik Matthysen
Patterns of niche conservatism among non-native birds in Europe are dependent on introduction history and selection of variables
Biological Invasions August 2013
Recently, the study of niche dynamics using spatial environmental data and species occurrences has become an active field of research. Several studies report niche shifts between native and invasive populations, but it is debated whether these shifts are biologically meaningful or result from methodological artefacts. Using data on the occurrence of non-native birds in Europe, we assess the prevalence of niche shifts along a selected number of climatic variables and find that although niche differences are frequent, biological explanations are often not necessary. Niche shifts occurred more frequently along variables that were of little ecological importance in the non-native range, and about 75 % of the shifts detected do not result from range expansion into different environments but only reflect climatic conditions at introduction locations. Excluding variables exhibiting a niche shift increases the accuracy of predictions of invasion risk generated by native-range based distribution models, evidencing that selection of variables is a crucial step when studying niche changes during biological invasions.
Šmejkal, M., Prchalová, M., Čech, M., Vašek, M., Říha, M., Jůza, T., Blabolil, P. and Kubečka, J. (2013), Associations of fish with various types of littoral habitats in reservoirs. Ecology of Freshwater Fish. doi: 10.1111/eff.12094
Fish associations with different types of littoral habitats were studied in four canyon-shaped reservoirs in the Czech Republic in years 2010 and 2011 by gillnets. Two to three habitats per reservoir–beaches (former meadows), stump fields (former forest) and rubble slopes–were defined and sampled along the longitudinal axis of reservoirs. Effects of reservoir, habitat and locality (position along longitudinal axis) on fish biomass, abundance and species structure were tested for juvenile and adult fish separately. Hierarchical analysis of variance revealed that habitats differed significantly in fish biomass and abundance. Redundancy analysis showed that analysed environmental variables had significant influence on fish community structure. Most variability in community structure was explained by reservoir and then by combination of habitat and slope steepness. Locality position had the smallest influence on community structure. For both adult and juvenile fish total abundance and biomass, the most inhabited habitat was beaches; rubble slopes were the least inhabited. Habitat associations differed among species. Among adults, bream Abramis brama, white bream Blicca bjoerkna and roach Rutilus rutilus were associated with beaches and stump fields, whereas perch Perca fluviatilis, ruffe Gymnocephalus cernuus, asp Aspius aspius and pike Esox lucius were associated with rubble slopes. Bream, white bream, bleak Alburnus alburnus, roach, ruffe and pikeperch Sander lucioperca were associated with beaches among juveniles, whereas the only juvenile associated with rubble slopes was perch. We showed that most common species are associated with distinct habitats and also that utilisation of various littoral habitats differs in general.
Zootaxa 3702 (5): 459–472 (29 Aug. 2013)
A new Crossodactylodes Cochran, 1938 (Anura: Leptodactylidae: Paratelmatobiinae) from the highlands of the Atlantic Forests of southern Bahia, Brazil
MAURO TEIXEIRA JR., RENATO SOUSA RECODER, RENATA CECÍLIA AMARO, ROBERTA PACHECO DAMASCENO, JOSÉ CASSIMIRO& MIGUEL TREFAUT RODRIGUES
A new Crossodactylodes is described from Serra das Lontras, in the highlands of the Atlantic Forests of southern Bahia. The new species can be distinguished from all other Crossodactylodes by having Finger I ending in an acute tip, a larger body size, by cranial features, and by molecular data. Like their congeners, the new species live in bromeliads but is widely geographically disjunct, being apparently restricted to the summit of a mountain range in Northeastern Brazil.
John Sullivan, Jansen Zuanon, Cristina Cox Fernandes
Two new species and a new subgenus of toothed Brachyhypopomus electric knifefishes (Gymnotiformes, Hypopomidae) from the central Amazon and considerations pertaining to the evolution of a monophasic electric organ discharge
ZooKeys 327 (2013): 1-34
We describe two new, closely related species of toothed Brachyhypopomus (Hypopomidae: Gymnotiformes: Teleostei) from the central Amazon basin and create a new subgenus for them. Odontohypopomus, new subgenus of Brachyhypopomus, is diagnosed by (1) small teeth present on premaxillae; (2) medialmost two branchiostegal rays thin with blades oriented more vertically than remaining three rays; (3) background color in life (and to lesser extent in preservation) distinctly yellowish with head and sides peppered with small, widely spaced, very dark brown stellate chromatophores that greatly contrast with light background coloration; (4) a dark blotch or bar of subcutaneous pigment below the eye; (5) electric organ discharge waveform of very long duration (head-positive phase approx. 2 milliseconds or longer, head-negative phase shorter or absent) and slow pulse repetition rate (3–16 Hz). The type species of the new subgenus, Brachyhypopomus (Odontohypopomus) walteri sp. n., is diagnosed by the following additional character states: (1) subcutaneous dark pigment at base of orbit particularly prominent, (2) body semi-translucent and nearly bright yellow background coloration in life, (3) a biphasic electric organ discharge (EOD) waveform of very long duration (between 3.5 and 4 milliseconds at 25° C) with head-positive first phase significantly longer than second head-negative phase in both sexes. Brachyhypopomus (Odontohypopomus) bennetti sp. n. is diagnosed by two character states in addition to those used to diagnose the subgenus Odontohypopomus: (1) a deep electric organ, visible as large semi-transparent area, occupying approximately 14–17% body depth directly posterior to the abdominal cavity in combination with a short, but deep, caudal filament, and (2) a monophasic, head-positive EOD waveform, approximately 2.1 milliseconds in duration in both sexes. These are the only described rhamphichthyoid gymnotiforms with oral teeth, and Brachyhypopomus bennetti is the first Brachyhypopomus reported to have a monophasic (head-positive) EOD waveform. Unlike biphasic species, the waveform of its EOD is largely unaffected by tail damage from predators. Such injuries are common among specimens in our collections. This species’ preference for floating meadow habitat along the major channels of the Amazon River basin may put it at particularly high risk of predation and “tail grazing.”
V. Schluessel, H. Kraniotakes, H. Bleckmann
Visual discrimination of rotated 3D objects in Malawi cichlids (Pseudotropheus sp.): a first indication for form constancy in fishes
Animal Cognition August 2013
Fish move in a three-dimensional environment in which it is important to discriminate between stimuli varying in colour, size, and shape. It is also advantageous to be able to recognize the same structures or individuals when presented from different angles, such as back to front or front to side. This study assessed visual discrimination abilities of rotated three-dimensional objects in eight individuals of Pseudotropheus sp. using various plastic animal models. All models were displayed in two choice experiments. After successful training, fish were presented in a range of transfer tests with objects rotated in the same plane and in space by 45° and 90° to the side or to the front. In one experiment, models were additionally rotated by 180°, i.e., shown back to front. Fish showed quick associative learning and with only one exception successfully solved and finished all experimental tasks. These results provide first evidence for form constancy in this species and in fish in general. Furthermore, Pseudotropheus seemed to be able to categorize stimuli; a range of turtle and frog models were recognized independently of colour and minor shape variations. Form constancy and categorization abilities may be important for behaviours such as foraging, recognition of predators, and conspecifics as well as for orienting within habitats or territories.
Lovari, S., Minder, I., Ferretti, F., Mucci, N., Randi, E. and Pellizzi, B. (2013), Common and snow leopards share prey, but not habitats: competition avoidance by large predators?. Journal of Zoology. doi: 10.1111/jzo.12053
Resource exploitation and behavioural interference underlie competition among carnivores. Competition is reduced by specializing on different prey and/or spatio-temporal separation, usually leading to different food habits. We predicted that two closely related species of large cats, the endangered snow leopard and the near-threatened common leopard, living in sympatry, would coexist through habitat separation and exploitation of different prey species. In central Himalaya, we assessed (2006–2010) habitat and diet overlap between these carnivores. The snow leopard used grassland and shrubland, whereas the common leopard selected forest. Contrary to our prediction, snow leopard and common leopard preyed upon similar wild (Himalayan tahr, musk deer) and domestic species (Bos spp., dogs). Dietary overlap between snow leopard and common leopard was 69% (yearly), 76% (colder months) and 60% (warmer months). Thus, habitat separation should be the result of other factors, most likely avoidance of interspecific aggression. Habitat separation may not always lead to the use of different prey. Avoidance of interspecific aggression, rather than exploitation of different resources, could allow the coexistence of potentially competing large predators.
Polar bear predatory behaviour reveals seascape distribution of ringed seal lairs
Nicholas W. Pilfold, Andrew E. Derocher, Ian Stirling, Evan Richardson
Population Ecology August 2013
Ringed seal (Pusa hispida) breeding distribution has been extensively studied across near-shore habitats, but has received limited attention at a seascape scale due to the difficulty in accessing offshore sea ice environments. Employing highly visible predation attempts by polar bears (Ursus maritimus) on ringed seals in subnivean lairs observed by helicopter, the spatial relationship between predatory behaviour and ringed seal breeding habitat was examined. Resource selection functions were used to determine the relative probability of predation attempts on ringed seals in lairs as a function of habitat during a period of low ringed seal natality (2004–2006). Ringed seal pup kill locations were compared between years of low (2003–2006) and high (2007–2011) natality to assess the effect of reproductive output on habitat use. During years of low natality, polar bear hunting attempts were more likely in near-shore fast ice, and pup kills were observed predominately in fast ice (fast = 65 %, pack = 29 %, P = 0.002) at a median distance of 36 km from shore. In years of high natality, pup kills were observed farther from shore (median = 46 km, P = 0.03), and there was no difference in the proportion of observations in fast ice and pack ice (fast = 43 %, pack = 52 %, P = 0.29). These results suggest that the facultative use of adjacent offshore pack ice by breeding ringed seals may be influenced by natality. This study illustrates how documenting the behaviour of a predator can facilitate insight into the distribution of a cryptic prey.
Aaron C. Hendersona and Megan Nasha
Confirmation of recent hawksbill turtle Eretmochelys imbricata nesting activity on South Caicos, Turks and Caicos Islands
Marine Biodiversity Records/Volume 6/2013
DOI: http://dx.doi.org/10.1017/S1755267213000729 (About DOI)
Sea turtle nesting had thought to be extirpated from South Caicos decades ago, but in December 2012 hatchling hawksbill turtles Eretmochelys imbricata were discovered emerging from the sand on a small beach in Shark Bay. Nest emergence was asynchronous and was spread out over at least two weeks. The nest was subsequently excavated and was found to contain the remains of 142 eggs, 128 of which appeared to have hatched successfully. It is unclear if Shark Bay is a regular nesting site, or if this nesting event was a transient occurrence.
Rayner, L., Lindenmayer, D. B., Wood, J. T., Gibbons, P. and Manning, A. D. (2013), Are protected areas maintaining bird diversity?. Ecography. doi: 10.1111/j.1600-0587.2013.00388.x
Evaluating the effectiveness of protected areas for sustaining biodiversity is crucial to achieving conservation outcomes. While studies of effectiveness have improved our understanding of protected-area design and management, few investigations (< 5%) have quantified the ecological performance of reserves for conserving species. Here, we present an empirical evaluation of protected-area effectiveness using long-term measures of a vulnerable assemblage of species. We compare forest and woodland bird diversity in the Australian Capital Territory over 11 yr on protected and unprotected areas located in temperate eucalypt woodland and matched by key habitat attributes. We examine separately the response of birds to protected areas established prior to 1995 and after 1995 when fundamental changes were made to regional conservation policy. Bird diversity was measured in richness, occurrence of vulnerable species, individual species trajectories and functional trait groups. We found that protected areas were effective in maintaining woody vegetation cover in the study region, but were less effective in the protection of the target bird species assemblage. Protected areas were less species rich than unprotected areas, with significant declines in richness across sites protected prior to 1995. Small, specialised and vulnerable species showed stronger associations with unprotected areas than protected areas. Our findings indicate that recently established reserves (post-1995) are performing similarly to unprotected woodland areas in terms of maintaining woodland bird diversity, and that both of these areas are more effective in the conservation of woodland bird populations than reserves established prior to 1995. We demonstrate that the conservation value of protected areas is strongly influenced by the physical characteristics, as well as the landscape context, of a given reserve and can diminish with changes in surrounding land use over time. Both protected areas and off-reserve conservation schemes have important roles to play in securing species populations.