Effects of experience and avpr1a microsatellite length on parental care in male prairie voles (Microtus ochrogaster)

Pair-bonded males often make substantial contributions to the care of their offspring. Male parental behavior may be affected by a range of factors, including previous experience (parental or alloparental), genetic influences, and contributions by the female partner. Previous studies have shown that a microsatellite polymorphism in the regulatory region of the avpr1a gene influences aspects of paternal behavior in male prairie voles (Microtus ochrogaster). Specifically, males with longer avpr1a microsatellites groomed offspring more than did males with shorter avpr1a microsatellites. Previous experience with alloparental care also appears to influence subsequent paternal care in prairie voles. We investigated the influence of avpr1a microsatellite length and previous parental experience on paternal behavior in prairie voles two generations from the field and specially bred to exaggerate differences in avpr1a microsatellite length. We found that avpr1a microsatellite length alone did not affect any of the paternal behaviors that we measured. In contrast, males differed in parental behavior between first and second litters. Regardless of avpr1a microsatellite length, males licked/groomed the second litter less, and retrieved pups more quickly during the second compared to the first litter. Our results show that previous paternal experience may play a more important role than the length of the microsatellite in the regulatory region of the avpr1a gene in influencing paternal care.     

Blends of (R)-3-hydroxyhexan-2-one and alkan-2-ones identified as potential pheromones produced by three species of cerambycid beetles

We present data indicating that three species of cerambycid beetles (subfamily Cerambycinae) produce the common cerambycine pheromone component (R)-3-hydroxyhexan-2-one as well as an alkan-2-one component, a possible new motif for cerambycid pheromone components. GC/MS analyses of headspace volatiles produced by male beetles indicated that Cyrtophorus verrucosus (Olivier) produced (R)-3-hydroxyhexan-2-one but also nonan-2-one at ~18 % of the hydroxyketone component, whereas Orwellion gibbulum arizonense (Casey) and Parelaphidion aspersum (Haldeman) produced decan-2-one at ~40 and 7 % of the amount of the hydroxyketone, respectively. In field bioassays, adult C. verrucosus were attracted by (R)-3-hydroxyhexan-2-one alone, but attraction was significantly enhanced by nonan-2-one. This effect was lost if the quantity of nonan-2-one exceeded 100 % of the hydroxyketone, suggesting that beetles could discern ratios of the two chemicals and were most strongly attracted to those approximating the blend produced by males. We suggest that nonan-2-one plays a role in the species specificity of the pheromone signal of C. verrucosus, and that decan-2-one plays a similar role in the semiochemical communication of O. g. arizonense and P. aspersum.     

Biological impacts of ocean acidification: a postgraduate perspective on research priorities

Research into the effects of ocean acidification (OA) on marine organisms has greatly increased during the past decade, as realization of the potential dramatic impacts has grown. Studies have revealed the multifarious responses of organisms to OA conditions, indicating a high level of intra- and interspecific variation in species’ ability to accommodate these alterations. If we are to provide policy makers with sound, scientific input regarding the expected consequences of OA, we need a broader understanding of these predicted changes. As a group of 20 multi-disciplinary postgraduate students from around the globe, with a study focus on OA, we are a strong representation of ‘next generation’ scientists in this field. In this unique cumulative paper, we review knowledge gaps in terms of assessing the biological impacts of OA, outlining directions for future research.     

How wave exposure, group size and habitat complexity influence foraging and population densities in fishes of the genus Halichoeres (Perciformes: Labridae) on tropical rocky shores

Wave exposure and habitat complexity have been used to explain variations in the distribution patterns and behavior of many reef fishes. This study analyzed the influence of both factors on density and foraging activity, and the influence of group size on foraging in three species of the genus Halichoeres (Labridae) on tropical rocky shores. It was shown that initial phases (IP) and terminal phases (TP) Halichoeres, were influenced by wave exposure, although foraging in Halichoeres brasiliensis TP was not influenced by wave exposure. The IP in all three species were positively associated with rugosity and algal cover while the TP was positively associated with depth. Habitat complexity also influences foraging in these species. Group size influenced foraging activity, except in H. brasiliensis TP. We also found variations in microhabitat patches used for foraging between species and differences in the stomach contents between species and phases, showing that functional roles change in response to ontogenetic shifts.     

Room to move? Threatened shorebird habitat in the path of sea level rise—dynamic beaches, multiple users, and mixed ownership: a case study from Rhode Island, USA

Accelerated sea level rise (slr) is expected to transform vulnerable Atlantic coastal habitats in the United States during this century. Low-elevation sandy beaches, important nesting habitat for the continued recovery of the federally threatened piping plover (Charadrius melodus) in Rhode Island, are especially vulnerable. These beaches, under a mix of private and public ownership, exist in a heterogeneous landscape of dunes, rocky headlands, salt ponds, and heavily developed areas. Understanding the extent to which piping plover nesting beaches can retreat landward under projected slr is important for prioritizing future conservation actions across multiple jurisdictions. This research examines habitat change in response to slr (0.5, 1.0, and 1.5 m) under stationary and migration beach responses and whether development blocks habitat migration for five productive piping plover nesting beaches. We found that under the stationary habitat model, all beaches lose area under all slr scenarios. For the habitat migration model, future habitat availability differs by beach depending on elevation, landward topography, and presence of development. However, across the majority of beach area, piping plover habitat will be able to migrate landward if unconstrained by future development. A coalition of public and private stakeholders already supports management efforts to help ensure plover population recovery in the area. With emerging habitat change prediction tools, these stakeholders and other partners can engage in innovative, local-level planning needed to protect wildlife habitat and commercial, residential, and infrastructure assets from sea level rise.     

Ecological niche segregation among five toothed whale species off the NW Iberian Peninsula using ecological tracers as multi-approach

This study aims to assess niche segregation among the five main toothed whales that frequent the NW Iberian Peninsula waters: the common dolphin, the harbour porpoise, the bottlenose dolphin, the striped dolphin and the long-finned pilot whale. We used cadmium (Cd) and stable isotope ratios (δ¹³C and δ¹⁵N) as ecological tracers to assess degree of segregation in diet/trophic level and in foraging habitat, over various time-scales. δ¹³C values highlighted different habitats, while Cd concentrations highlighted feeding differences between oceanic and neritic species. Moreover, δ¹⁵N values suggest different trophic levels of prey targeted within oceanic and neritic species. Hence, results revealed long-term ecological segregation among five toothed whales that coexist in the NWIP and demonstrated the ability of ecological tracers to discriminate ecological niches among closely related species.     

Natal dispersal in two mice species with contrasting social systems

We compared the natal dispersal behaviour of two mice species under laboratory conditions. Natal dispersal is a movement of an animal from its birthplace to its breeding area. This behaviour is known to be influenced by the mating system. In polygamous species, males are more likely to disperse, while in most of the monogamous species, both sexes disperse. Our subjects, the house mouse (Mus musculus) and the mound-building mouse (Mus spicilegus) are two sympatric species of the genus Mus. Both are native in Hungary, but they differ in their habitat type mating system and overwintering strategy. The house mouse is a polygynous species and adapted to human environment, known for mature and reproduce early. On the contrary, the mound-building mice are monogamous, and they inhabit extensively used agricultural fields, where they spend the unfavourable winter period in nest chambers under mounds, which they construct from soil and plant material. Successful overwintering for this species demands delayed maturity and reduced dispersion during the winter. Our results showed that the natal dispersal of these two species differ; both sexes of the mound-building mice dispersed later than the house mice, where a difference between sexes also occurs; house mice males dispersed earlier than females. The mound-building mice showed no sexual dimorphism in this behaviour.     

Eutrophication alters social preferences in three-spined sticklebacks (Gasterosteus aculeatus)

Algae blooms, which can be caused by eutrophication, drastically influence the ecology and behaviour of aquatic organisms. Such impact is often demonstrated in the context of mate choice and predator–prey interactions. In contrast, the influence of increased turbidity on social behaviour is less well understood, although it may have strong influence, at both the level of the individual and the population. We aimed to address this gap in our knowledge by using the well-described preference of three-spined sticklebacks (Gasterosteus aculeatus) to shoal with the larger of two shoals as model behaviour. In our experiments focal fish had the choice between two shoals of different sizes, either in clear or in turbid water containing green algae. Fish in clear water spent significantly more time near the larger shoal, while fish in algae water showed no significant preferences. Furthermore, fish tested in clear water changed more often between the shoals than fish tested in algae water. These results indicate that eutrophication-induced algae blooms have the potential to alter social decisions of sticklebacks. Such changes of social decisions do not only influence the behaviour of individuals, furthermore it might influence entire populations. This might eventually lead to changes of the structure of the social system.     

Environmental and social determinants of anuran lekking behavior: intraspecific variation in populations at thermal extremes

Environmental and social factors are critical to determine the timing and duration of lekking behavior since they provide species with signs to maximize benefits over costs in sexual displays. However, these factors have rarely been studied under different environmental conditions, and thus, it remains unclear whether exogenous factors affecting group displays show a general species-specific pattern or whether they are population-specific. Using audio-trapping techniques, we compared factors influencing the daily occurrence and duration of lekking behavior in two populations of Hyla molleri and two populations of Hyla meridionalis located at the thermal extremes (coldest vs. hottest) of their Iberian distribution range. From 12,240 hourly recordings over one season, multimodel inference revealed that the major determinants of chorus occurrence were similar between populations and species (i.e., chorus size the previous day, daytime air temperature, relative humidity, and barometric pressure), and accounted for 51–79 % of its deviance. In contrast, the major determinants of chorus duration differed between populations and species (i.e., chorus size, number of day, and air temperature and relative humidity at the onset of the chorus), and accounted for 38–69 % of its variance. Our findings suggest that the decision making related to lek attendance is environment-dependent, takes place at time between lekking events, and is associated with exogenous factors that may be both stable across species ranges and population-specific when populations are under different climatic conditions. This intraspecific variation might be underlain by plasticity mechanisms providing tree frogs with means to cope with changing environments. Moreover, social facilitation related to male-male acoustic competition seems to play a relevant role on the daily time invested by males in lek attendance.     

Macrofaunal responses to structural complexity are mediated by environmental variability and surrounding habitats

Investigating the context that surrounds each habitat is crucial to understand local responses of assemblages of species to habitats. Here, I tested whether responses of benthic macroinvertebrates to the structural complexity of experimental habitats were mediated by the characteristics of their surrounding habitats (i.e. rockpools or emergent-rock surfaces). Each type of surrounding habitat provided particular biotic (e.g. algal growth) and abiotic (e.g. temperature, water movement) conditions that were expected to affect benthic assemblages. The results show that (1) composition of entire assemblages was affected by the matrix and type of habitat; (2) effects of the matrix on the number of species varied depending on the different types of habitats; (3) abundant species showed specific responses to type of habitat, independently of the matrix; and (4) relationships between numbers of species and two major environmental variables (i.e. micro-algal biomass and sediment) varied depending on the type of habitats and the surrounding matrix. Generally, these findings demonstrate that understanding the consequences of the spatial structure of these habitats is essential to advance our knowledge on patterns of abundance and distributions of functionally important species and ultimately the structure of intertidal assemblages.