Mobile Organisms Research Articles

A Network for Scene Processing in the Macaque Temporal Lobe

Spatial navigation is a complex process, but one that is essential for any mobile organism. We localized aregion in the macaque occipitotemporal sulcus that responds preferentially to images of scenes. Single-unit recording revealed that this region, which we term the lateral place patch (LPP), contained a large concentration of scene-selective single units. These units were not modulated by spatial layout alone but were instead modulated by a combination of spatial and nonspatial factors, with individual units coding specific scene parts. We further demonstrate by microstimulation that LPP is connected with extrastriate visual areas V4V and DP and a scene-selective medial place patch in the parahippocampal gyrus, revealing a ventral network for visual scene processing in the macaque.

How does network structure and complexity in river systems affect population abundance and persistence?

Models of habitat connectivity, and how network structure and connectivity affects resident populations, are increasingly being developed for terrestrial habitat networks. Rivers, unlike many terrestrial habitat networks, follow a rigid hierarchical branching structure to form dendritic networks. It has been hypothesised that this unique structure must have implications for population processes. We developed a theoretical model to relate local-scale habitat quality and connectivity to landscape-scale population dynamics of mobile organisms (e.g. fish, aquatic invertebrates). River networks were modelled as directed graphs, with nodes being habitat patches, and edges the connections between them. Using population simulation analyses, we investigated the effects of network structure on population abundance and persistence. Network structural complexity affected landscape-scale population abundance, but the apparent effect depended upon how structure was quantified. There were no noticeable effects of dendritic network structure on population persistence. Previous research on the effects of habitat network structure on population persistence has used metapopulation patch occupancy models, which do not directly consider population dynamics. Our results show that spatially-explicit population modelling is possible, and that it provides information beyond that possible with patch occupancy models (e.g. population abundance). More importantly, it calls into question whether metapopulation models provide an adequate representation of population dynamics in dendritic habitat networks.

Abstract Representations of Location and Facing Direction in the Human Brain

Humans, like other mobile organisms, rely on spatial representations to guide navigation from place to place. Although previous work has identified neural systems involved in wayfinding, the specific spatial codes supported by these systems are not well understood. We use functional magnetic resonance imaging to identify regions within the human medial temporal and medial parietal lobes that encode two fundamental spatial quantities-location and facing direction-in a manner that abstracts away from sensory inputs. University students were scanned while viewing photographs taken at several familiar campus locations. Multivoxel pattern analyses indicated that the left presubiculum, retrosplenial complex, and parietal-occipital sulcus coded location identity even across non-overlapping views, whereas the right presubiculum coded facing direction even across noncontiguous locations. The location and direction codes supported by these regions may be critical to our ability to navigate within the extended environment and to understand its large-scale spatial structure.

Filtering across Spatial Scales: Phylogeny, Biogeography and Community Structure in Bumble Bees

Despite the expansion of phylogenetic community analysis to understand community assembly, few studies have used these methods on mobile organisms and it has been suggested the local scales that are typically considered may be too small to represent the community as perceived by organisms with high mobility. Mobility is believed to allow species to mediate competitive interactions quickly and thus highly mobile species may appear randomly assembled in local communities. At larger scales, however, biogeographical processes could cause communities to be either phylogenetically clustered or even. Using phylogenetic community analysis we examined patterns of relatedness and trait similarity in communities of bumble bees (Bombus) across spatial scales comparing: local communities to regional pools, regional communities to continental pools and the continental community to a global species pool. Species composition and data on tongue lengths, a key foraging trait, were used to test patterns of relatedness and trait similarity across scales. Although expected to exhibit limiting similarity, local communities were clustered both phenotypically and phylogenetically. Larger spatial scales were also found to have more phylogenetic clustering but less trait clustering. While patterns of relatedness in mobile species have previously been suggested to exhibit less structure in local communities and to be less clustered than immobile species, we suggest that mobility may actually allow communities to have more similar species that can simply limit direct competition through mobility.

Accounting for data heterogeneity in patterns of biodiversity: an application of linear mixed effect models to the oceanic island biogeography of spore‐producing plants

The general dynamic model of oceanic island biogeography describes the evolution of species diversity properties, including species richness (SR), through time. We investigate the hypothesis that SR in organisms with high dispersal capacities is better predicted by island area and elevation (as a surrogate of habitat diversity) than by time elapsed since island emergence and geographic isolation. Linear mixed effect models (LMMs) subjected to information theoretic model selection were employed to describe moss and liverwort SR patterns from 67 oceanic islands across 12 archipelagos. Random effects, which are used to modulate model parameters to take differences among archipelagos into account, included only a random intercept in the best‐fit model for liverworts and in one of the two best‐fit models for mosses. In this case, the other coefficients are constant across archipelagos, and we interpret the intercept as a measure of the intrinsic carrying capacity of islands within each archipelago, independently of their size, age, elevation and geographic isolation. The contribution of area and elevation to the models was substantially higher than that of time, with the least contribution made by measures of geographic isolation. This reinforces the idea that oceanic barriers are not a major impediment for migration in bryophytes and, together with the almost complete absence of in situ insular diversification, explains the comparatively limited importance of time in the models. We hence suggest that time per se has little independent role in explaining bryophyte SR and principally features as a variable accounting for the changing area and topographic complexity during the life‐cycle of oceanic islands. Simple area models reflecting habitat availability and diversity might hence prevail over more complex temporal models reflecting in‐situ speciation and dispersal (time, geographic connectivity) in explaining patterns of biodiversity for exceptionally mobile organisms.

Burial and exhumation of temperate bedrock reefs as elucidated by repetitive high-resolution sea floor sonar surveys: Spatial patterns and impacts to species' richness and diversity

To understand how chronic sediment burial and scour contribute to variation in the structure of algal and invertebrate communities on temperate bedrock reefs, the dynamics of the substrate and communities were monitored at locations that experience sand inundation and adjacent areas that do not. Co-located benthic scuba-transect surveys and high-resolution swath-sonar surveys were completed on bedrock reefs on the inner shelf of northern Monterey Bay, CA, in early winter 2009, spring 2010, and summer 2010. Analysis of the sonar surveys demonstrates that during the 8 months over which the surveys were conducted, 19.6% of the study area was buried by sand while erosion resulted in the exposure of bedrock over 13.8% of the study area; the remainder underwent no change between the surveys. Substrate classifications from the benthic transect surveys correlated with classifications generated from the sonar surveys, demonstrating the capacity of high-resolution sonar surveys to detect burial of bedrock reefs by sediment. On bedrock habitat that underwent burial and exhumation, species' diversity and richness of rock-associated sessile and mobile organisms were 50–66% lower as compared to adjacent stable bedrock habitat. While intermediate levels of disturbance can increase the diversity and richness of communities, these findings demonstrate that burial and exhumation of bedrock habitat are sources of severe disturbance. We suggest that substrate dynamics must be considered when developing predictions of benthic community distributions based on sea floor imagery. These results highlight the need for predictive models of substrate dynamics and for a better understanding of how burial and exhumation shape benthic communities.

Preference for the Nearer of Otherwise Equivalent Navigational Goals Quantifies Behavioral Motivation and Natural Selection

Navigation and environmental perception precede most actions in mobile organisms. Navigation is based upon the fundamental assumption of a ubiquitous Preference for the Nearest of otherwise equivalent navigational goals (PfN). However, the magnitude and triggers for PfN are unknown and there is no clear evidence that PfN exists. I tested for PfN in human participants on a retrieval task. Results of these experiments provide the first evidence for PfN. Further, these data quantify the three primary PfN triggers and provide an experimental structure for using PfN as a behavioral metric across domains. Surprisingly, PfN exists at a high, but not universal, magnitude. Further, PfN derives most from the absolute distance to the farthest of multiple goals (df), with little influence of the distance to the nearest goal (dn). These data provide previously unavailable quantification of behavioral motivation across species and may provide a measurable index of selection. These methods hold particular import for behavioral modification because proximity is a powerful determinant of decision outcomes across most behaviors.

Intertidal Assemblages On Artifical Structures And Natural Rocky Habitats On Taiwan'S North Coast

Differences in intertidal assemblages between artifi cial structures and natural rocky habitats require further investigation, so that the potential effects of artifi cial structures on coastal intertidal community can be better understood. We examined the intertidal assemblages on breakwaters, seawalls, and natural rocky shores in the Linshanbi and Houcuo fi shing ports on the northern coast of Taiwan. Nine seawater parameters were measured at each sampling site in Dec.2010, Mar.2011, and Jun.2011. Intertidal assemblages on seawalls were largely distinct from those on breakwaters or natural rocky shores. The taxa that contributed most to the differences among habitats were algae, barnacles, oysters, and limpets. Limpets, red algae, and green algae were less abundant on seawalls compared to breakwaters or the natural rocky shore. Fewer intertidal organisms existed on seawalls than on breakwaters and natural rocky shores. The mobile organisms on breakwaters were similar to those on natural rocky shores. However, during the growing season, a greater number of mobile organisms were found on natural rocky shores than on breakwaters. We suggest that differences in seawater quality, which might relate to the presence of artifi cial structures, could affect the abundance of intertidal organisms. Further information is required on important factors in artifi cial structures that affect intertidal assemblages, in various coastal areas, to help conserve intertidal biodiversity.

California spiny lobster (Panulirus interruptus) movement behaviour and habitat use: implications for the effectiveness of marine protected areas

The effectiveness of conservation efforts, including marine protected areas (MPAs), hinges on adequate knowledge of movement patterns, habitat associations and habitat-specific survival rates of mobile organisms. California spiny lobsters (Panulirus interruptus) support commercial and recreational fishing in southern California; however, we lack basic information to determine whether MPAs planned for the region will enhance abundance. Working within and outside a small southern California MPA, we (1) quantified the movement patterns and home ranges of the lobster over two time scales, (2) determined lobster day and night habitat associations and (3) determined habitat-specific predation risk. Lobsters exhibited high site fidelity and small home ranges (geometric mean of 651 m2 and 5912 m2 per week, on the basis of 50% and 95% kernel utilisation distributions, respectively). Lobsters were associated with rocky habitat during the day and with the red algae Plocamium cartilagineum while feeding at night. Relative survival rates of lobsters were high across vegetated and unvegetated habitats at night, and were highest in surfgrass (Phyllopsadix torreyi) habitat during the day. Our results highlight the need to consider how movement patterns vary over short and long time scales, and how habitat use may vary from day to night for nocturnally active species such as lobsters, when planning MPAs.

Complex habitat changes along elevational gradients interact with resource requirements of insect specialist herbivores

Stenothermal habitat specialists such as monophagous insects may be threatened by climate-change induced range shifts, if resource requirements along migration routes or future habitats are not met. Little is known about altitudinal shifts of inconspicuous, less mobile species relative to latitudinal range shifts in prominent, mobile organisms such as butterflies. Here, we address three questions: What are the resource requirements—habitat area, quality and fragmentation—for two specialist herbivores? How do habitat characteristics change with altitude? Do species resource requirements suggest an increased vulnerability towards temporal or spatial bottlenecks under climate change? We mapped the spatial distribution of a riparian shrub, Veronica stricta (Plantaginaceae), at local (300 m elevational gradient, n = 252 patches) and regional scales (600 m gradient; n = 102) in the Tongariro National Park, New Zealand. Patch occupancy and patch-level population dynamics of Trioza obscura (Hemiptera: Triozidae) and an undescribed gall midge (Diptera: Cecidomyiidae) were recorded in 2010 and 2011. Habitat suitability and population dynamics were predicted with generalized linear models, applying information theoretic model averaging. Habitat area had the largest positive influence on insect presence and survivorship, the latter benefitting from larger insect populations. Habitat quality showed a species-dependent effect on occurrence (T. obscura: negative effect of plant shade; cecidomyiid: positive effect of host inflorescences) and survival (T. obscura: positive response to leaf-nitrogen and host size; cecidomyiid: positive response to inflorescence abundance). Only cecidomyiid colonization had a weak negative response to habitat fragmentation. Altitude contributed positively to patch suitability and survivorship of the cecidomyiid, but decreased survivorship of T. obscura. Altitude-related changes in the landscape matrix, such as the transition from forested to subalpine vegetation, positively affected habitat area and fragmentation, which in turn offset a steady decrease in host plant size (i.e., patch quality). Our study revealed that habitat area, quality and fragmentation do not always follow simple linear trends along elevational gradients. We recommend that species distribution models should consider these complex patterns when predicting range shifts. We suggest that species vulnerability to climate change depends on whether resource requirements allow for upward migration and suitable habitats are available in future distribution ranges.

Coral Reef Surveillance: Infrared-Sensitive Video Surveillance Technology as a New Tool for Diurnal and Nocturnal Long-Term Field Observations.

Direct field observations of fine-scaled biological processes and interactions of the benthic community of corals and associated reef organisms (e.g., feeding, reproduction, mutualistic or agonistic behavior, behavioral responses to changing abiotic factors) usually involve a disturbing intervention. Modern digital camcorders (without inflexible land-or ship-based cable connection) such as the GoPro camera enable undisturbed and unmanned, stationary close-up observations. Such observations, however, are also very time-limited (~3 h) and full 24 h-recordings throughout day and night, including nocturnal observations without artificial daylight illumination, are not possible. Herein we introduce the application of modern standard video surveillance technology with the main objective of providing a tool for monitoring coral reef or other sessile and mobile organisms for periods of 24 h and longer. This system includes nocturnal close-up observations with miniature infrared (IR)-sensitive cameras and separate high-power IR-LEDs. Integrating this easy-to-set up and portable remote-sensing equipment into coral reef research is expected to significantly advance our understanding of fine-scaled biotic processes on coral reefs. Rare events and long-lasting processes can easily be recorded, in situ-experiments can be monitored live on land, and nocturnal IR-observations reveal undisturbed behavior. The options and equipment choices in IR-sensitive surveillance technology are numerous and subject to a steadily increasing technical supply and quality at decreasing prices. Accompanied by short video examples, this report introduces a radio-transmission system for simultaneous recordings and real-time monitoring of multiple cameras with synchronized timestamps, and a surface-independent underwater-recording system.

Synergistic effects of reserves and connectivity on ecological resilience

Summary In light of the global extent and cascading effect of our impact on the environment, we design and manage reserves to restore biodiversity and the functioning of ecosystems. Mobile organisms link important processes across ecosystems, however, their roles in providing these services are often overlooked and we need to know how they influence ecosystem functions in reserves. Herbivorous fish play a key role in coral reef seascapes. By removing algae, they promote coral growth and recruitment, and help to increase resilience. We examined how connectivity with mangroves affected herbivore populations and benthic succession on reefs in eastern Australia. We surveyed fish assemblages, examined reef composition and characterised benthic recruitment on reefs at multiple levels of connectivity with mangroves, in a no‐take reserve and areas open to fishing. Our results show that connectivity enhanced herbivore biomass and richness in reserves, and that these connectivity and reserve effects interacted to promote herbivory on protected reefs near mangroves. Connectivity and reserve protection combined to double the biomass of roving herbivorous fish on protected reefs near mangroves. The increase in grazing intensity drove a trophic cascade that reduced algal cover and enhanced coral recruitment and reef resilience. Synthesis and applications. Our findings demonstrate that ecosystem resilience can be improved by managing both reefs and adjacent habitats together as functional seascape units. By understanding how landscapes influence resilience, and explicitly incorporating these effects into conservation decision‐making, we may have greater success with environmental restoration and preservation actions.

Gut travellers: internal dispersal of aquatic organisms by waterfowl

AbstractAimPatterns of high biodiversity among less mobile organisms throughout isolated locations suggest that passive dispersal importantly contributes to biodiversity. We examined the contribution of waterbirds to the dispersal of plant seeds and macroinvertebrates between aquatic wetlands. Birds are renowned vectors for seeds of terrestrial plants, but less is known about their role in more dispersal‐dependent aquatic systems. We therefore performed a meta‐analysis on bird‐mediated endozoochorous dispersal of aquatic species.LocationOur review included studies that collected data world‐wide.MethodsWe analysed data from 81 peer‐reviewed publications on endozoochorous dispersal of aquatic plant seeds and macroinvertebrates by waterbirds.ResultsIn total, 36% of 1581 waterbird droppings collected in the field contained one or more intact propagules, with macroinvertebrates found almost as frequently as plant seeds. Positive droppings contained on average 3.3 intact propagules, of which one‐third were viable. In 728 trials from 17 published feeding experiments 24% of the ingested propagules were retrieved intact, with c. 6.5% both viable and intact. As many as 17 species of Anatidae and Rallidae were involved in the dispersal of at least 39 species of macroinvertebrates and seeds from 97 species of plants across a wide taxonomic range. Smaller propagules seemed less affected by digestion than larger ones. We provide a first quantitative model that can be used to estimate waterbird‐mediated dispersal of propagules between wetlands. This model indicates that an average waterbird has the potential to disperse five viable propagules after flying more than 100 km, and one additional propagule after flying 300 km.Main conclusionsWe demonstrate that waterbirds have the potential to transport a wide variety of aquatic plants and animals over several hundreds of kilometres. High survival of propagules might be explained by propagule adaptations or by the digestive adaptations of birds, whereby energy absorption is thought to be maximized rather than assimilation efficiency. Our meta‐analysis suggests that waterbirds might contribute significantly to wetland biodiversity around the world, despite several limitations to our current knowledge. We outline avenues for future research to address these knowledge gaps.

Measuring Natural Pest Suppression at Different Spatial Scales Affects the Importance of Local Variables

The role biodiversity plays in the provision of ecosystem services is widely recognized, yet few ecological studies have identified characteristics of natural systems that support and maintain ecosystem services. The purpose of this study was to identify landscape variables correlated with natural pest suppression carried out by arthropod natural enemies, predators and parasitoids. We conducted two field experiments, one observational and one experimental, where landscape variables at broad and local scales were measured and related to natural pest suppression. The first experiment measured natural pest suppression at 16 sites across an urban to rural landscape gradient in south central Wisconsin. We found natural enemy diversity positively affected natural pest suppression, whereas flower diversity negatively affected pest suppression. No relationship was found between natural pest suppression and broad scale variables, which measured the percentage of different land cover classes in the surrounding landscape. In the second experiment, we established small (2- by 3-m) replicated plots that experimentally varied flower diversity (0, 1, or 7 species) within a plot. We found no significant relationship between natural pest suppression and the different levels of flower diversity. The fact that we only found differences in natural pest suppression in our first experiment, which measured natural pest suppression at sites separated by larger distances than our second experiment, suggests the more appropriate scale for measuring ecosystem services performed by mobile organisms like insects, is across broad spatial scales where variation in natural enemies communities and the factors that affect them become more apparent.

Movement and phenology of bees in a subtropical Australian agricultural landscape

AbstractBees are mobile organisms that seek food and nesting opportunities from a range of habitats. It is important to understand the way they move in agricultural landscapes if we are to conserve them and benefit from their activity as pollinators. We surveyed bees using directional flight interception (Malaise) traps over a 1‐year period in two agricultural landscapes in south‐east Queensland, Australia. We placed traps at the ecotone between crops and remnant vegetation to establish the pattern of movement between these habitats. Species richness in these landscapes (70) was high relative to that in comparable studies. Some bees were active year round, but most were caught in the period September to March. Across the whole assemblage there was a significant pattern where more species were detected leaving rather than entering remnant vegetation. The same bias was true for the number of individuals of the two most abundant species (Homalictus urbanus and Apis mellifera). Species exclusively found in crops were smaller on average (and therefore have smaller foraging range) than their non‐crop counterparts. Together, these patterns indicate that while bees are abundant in crop habitat, the remnant vegetation is important as the point of origin for bee movements, and the riparian remnant in particular is richer than the dry native remnant. Compositional similarity among samples was significantly explained by landscape but also movement direction (i.e. to or from the riparian remnant) because different species showed different patterns of response. The landscape with greater native vegetation cover supported more species in and around crops than the landscape with less native vegetation.

Trait‐dependent occupancy dynamics of birds in temperate forest landscapes: fine‐scale observations in a hierarchical multi‐species framework

AbstractSilvicultural practices lead to changes in forest composition and structure and may impact species diversity from the overall regional species pool to stand‐level species occurrence. We explored to what extent fine‐scale occupancy patterns in differently managed forest stands are driven by environment and ecological traits in three regions in Germany using a multi‐species hierarchical model. We tested for the possible impact of environmental variables and ecological traits on occupancy dynamics in a joint modelling exercise while taking possible variation in coefficient estimates over years and plots into account. Bird species richness differed across regions and years, and trends in species richness across years were different in the three regions. On the species level, forest management affected occupancy of species in all regions, but only 3–5% of the total assemblage‐level variation in occurrence probability was explained by either forest type and successional stage and < 1% by forest edge. On the assemblage level, bird occurrence decreased with body mass in all regions. Species with smaller breeding ranges had lower occurrence probabilities in one region, while later spring arrival decreased occurrence probabilities in the two other regions. Spatial variation in the effect size of trait covariates such as species phylogeny and breeding strata showed that variation in patch occupancy due to fine‐scale differences in forest management is, to some extent, predictable from ecological traits. Our results show that environmental factors and ecological traits jointly predict variation in bird occupancy patterns and their response to forest management. Observations at the fine scale of forest stands, at which conservation efforts can be arranged along with forest management practices in heterogeneous environments, have been shown to provide meaningful insights despite the difficulties involved in monitoring mobile organisms such as birds at the plot level.

Interaction between hydrocarbon seepage, chemosynthetic communities, and bottom water redox at cold seeps of the Makran accretionary prism: insights from habitat-specific pore water sampling and modeling

Abstract. The interaction between fluid seepage, bottom water redox, and chemosynthetic communities was studied at cold seeps across one of the world's largest oxygen minimum zones (OMZ) located at the Makran convergent continental margin. Push cores were obtained from seeps within and below the core-OMZ with a remotely operated vehicle. Extracted sediment pore water was analyzed for sulfide and sulfate concentrations. Depending on oxygen availability in the bottom water, seeps were either colonized by microbial mats or by mats and macrofauna. The latter, including ampharetid polychaetes and vesicomyid clams, occurred in distinct benthic habitats, which were arranged in a concentric fashion around gas orifices. At most sites colonized by microbial mats, hydrogen sulfide was exported into the bottom water. Where macrofauna was widely abundant, hydrogen sulfide was retained within the sediment. Numerical modeling of pore water profiles was performed in order to assess rates of fluid advection and bioirrigation. While the magnitude of upward fluid flow decreased from 11 cm yr−1 to <1 cm yr−1 and the sulfate/methane transition (SMT) deepened with increasing distance from the central gas orifice, the fluxes of sulfate into the SMT did not significantly differ (6.6–9.3 mol m−2 yr−1). Depth-integrated rates of bioirrigation increased from 120 cm yr−1 in the central habitat, characterized by microbial mats and sparse macrofauna, to 297 cm yr−1 in the habitat of large and few small vesicomyid clams. These results reveal that chemosynthetic macrofauna inhabiting the outer seep habitats below the core-OMZ efficiently bioirrigate and thus transport sulfate down into the upper 10 to 15 cm of the sediment. In this way the animals deal with the lower upward flux of methane in outer habitats by stimulating rates of anaerobic oxidation of methane (AOM) with sulfate high enough to provide hydrogen sulfide for chemosynthesis. Through bioirrigation, macrofauna engineer their geochemical environment and fuel upward sulfide flux via AOM. Furthermore, due to the introduction of oxygenated bottom water into the sediment via bioirrigation, the depth of the sulfide sink gradually deepens towards outer habitats. We therefore suggest that – in addition to the oxygen levels in the water column, which determine whether macrofaunal communities can develop or not – it is the depth of the SMT and thus of sulfide production that determines which chemosynthetic communities are able to exploit the sulfide at depth. We hypothesize that large vesicomyid clams, by efficiently expanding the sulfate zone down into the sediment, could cut off smaller or less mobile organisms, as e.g. small clams and sulfur bacteria, from the sulfide source.

A report on the Butterflies in Jhansi (U.P.) India

The city Jhansi is famous for the fort, gardens and surrounding hilly areas. These gardens and hilly areas have supported for butterflies and other insects. The butterflies are essential part of any natural ecosystem as their adults performs pollination. They are highly mobile organism and are able to maintain connectivity between the fragmental habitats. The larval stages are herbivorous and cause economic damage but adult are beneficial as pollinators of several trees and herbaceous flora. They are vulnerable to changes in flower supply resulting fromdeforestation and environmental pollution hence they are the biological indicators of pollution. The present study was conducted regarding the different selected sites visited by butterflies, their foraging activity and abundance at different sites of Jhansi. During the visit some species of butterflies were collected as flower visitors on different species of flowering plants (garden, cultivated, semi wild and wild) in selected areas. The species of collected butterflies were showed the most common and highly active species throughout the day. Some species namely Pieris canidia indica, lxias mrianne (Cramer), Catopsilia crocale (Cramer), Catopsilia pyranthe (Linn.), Eurema hecabe fimbriata (Wallace) Colias electo fieldi and Colias erate (Esper) were observed mostly on the flowering plants of each site during the study. The nymphalids were found to be very common in the plane areas of Jhansi as flower visitors and only one species Papilio demoleus could be collected from only two sites.

The low O2 avoidance strategy of the Cape silverside Atherina breviceps (Teleostei)

Aquatic low O2 (hypoxia) is not uncommon but mobile organisms do not have to suffer low O2 stress if they engage in a safe avoidance strategy by moving away early and quickly. Within a behavioural choice chamber system at 20°C, the Cape silverside (Atherina breviceps), a common species from South Africa, was found to seek out and select high O2 saturated water when water O2 saturations declined to 23% saturation. Atherina breviceps also avoided low O2 with a modest increase in swimming speed but no correlation between hypoxic swimming speed and avoidance could be found implying that heightened swimming speed does not necessarily lead to faster avoidance on an individual basis. The overall low O2 response of A. breviceps was seen to reflect an effective avoidance strategy that is compatible with the survival of this species facing low O2 challenge in the wild.

Use of molecular genetics for understanding seabird evolution, ecology and conservation

Information on genetic variation within and among populations of highly mobile organisms such as seabirds is necessary for understanding their evolution and ecology, and can be a tool for conservation. Recent developments in molecular genetics, including efficient mutationdetection methods and automated sequencing, are providing detailed genetic information for non-model organisms. Furthermore, theoretical advances such as coalescent theory and molecular assignments are providing powerful tools to determine species’ historical and contemporary abundance, distributions and movements. We review advances for studying phylogenetics, population genetics, hybridization, ecology and conservation in seabirds and summarize recent studies in each field. All fields will benefit from larger data sets and more sophisticated analytical methods. Phylogenetic studies will provide a more robust determination of evolutionary history, while studies of population genetics and hybridization will be elevated to genomic-level avenues of inquiry. Ecological studies may benefit from improved molecular assignments, and conservationfocussed studies will benefit from an increased understanding of seabird evolution and ecology. In addition, we highlight that combination of new molecular and analytical tools with data on morphology, behaviour and movements is especially powerful for understanding seabird evolution and ecology, and for aiding conservation.