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Mccann N.P.,University of Cardiff | Wheeler P.M.,University of Hull | Coles T.,Operation Wallacea | Bruford M.W.,University of Cardiff
Integrative Zoology | Year: 2012

During the International Tapir Symposium 16-21 Oct 2011, the conservation of Baird's tapir (lapirus bairdu) in Honduras received a boost with the signing of a memorandum of understanding between the Minister Director of the Honduran Institute of Conservation and Forestry (ICF) and the Tapir Specialist Group (TSG). Despite this agreement, accelerating levels of hunting and habitat loss continue to pose a threat to Baird's tapir in Hon-duras. An ongoing study in Cusuco National Park in northwestern Honduras has been monitoring changes in population dynamics of Baird's tapir since 2006 through the collection of occupancy data. The study has identified an increase in hunting pressure, coinciding with a drastic decline in the encounter rate with Baird's tapir spoor. Here, we examine the significance of a range of demographic variables on Baird's tapir occupancy in Cu-suco National Park using the software PRESENCE, and simulate the effects of different management strategies on the future dynamics of the population using the stochastic simulation software VORTEX. The predictions of the theoretical population models are compared to observed changes in occupancy levels. We found that non-' intervention resulted in the local extinction of Baird's tapir within a very short time frame, but that various in-tervention models enabled the population to recover to near carrying capacity. Occupancy and extinction probability were shown to respond markedly to the increase in hunting pressure; and occupancy models supported the future population predictions generated by VORTEX. Our study suggests that immediate intervention is required to reduce hunting pressure to near historical levels to prevent the imminent local extinction of the species. © 2012 Wiley Publishing Asia Pty Ltd, ISZS and IOZ/CAS. Source

Nicholson D.J.,University of Leeds | Hassall C.,University of Leeds | Frazier J.A.,Operation Wallacea | Frazier J.A.,Polytechnic University of Mozambique
Journal of Tropical Ecology | Year: 2015

This study compared the life histories of Hemidactylus frenatus, a significant invasive gecko, and Phyllodactylus palmeus, a Honduran endemic, over 10 wk, June-August 2013 at 12 study sites on the Honduran island of Cayo Menor of the Cayo Cochinos archipelago where H. frenatus arrived in 2008. Three different life-history traits related to invasion success were measured: body size, fecundity and population size. During the study 140 natives and 37 non-natives were captured, weighed, measured and marked uniquely. The number of gravid females and number of eggs were also recorded. Phyllodactylus palmeus was the significantly larger of the two species (60% larger mass, 25% longer SVL) and had higher population abundance at all 12 study sites with some sites yielding no H. frenatus individuals. However, H. frenatus had a larger proportion of gravid females. Observations that the native species is more common despite being sympatric with a known aggressive invader suggest two possibilities: the island is at the start of an invasion, or that the two species co-exist in a more stable fashion. © 2015 Cambridge University Press. Source

Titus B.M.,Ohio State University | Daly M.,Ohio State University | Exton D.A.,Operation Wallacea
Marine Biology | Year: 2015

Dozens of marine species have been identified as “cleaners” and many of these co-occur and have considerable overlap in clientele. Understanding the temporal patterns and processes of these cleaning symbioses can provide insight into differential service provision between cleaner species and the ultimate and proximate causes structuring these interactions. Considerable progress has been made in understanding the ecology and behavior of cleaner fish, yet little basic ecological and behavioral data exist for cleaner shrimp. We deployed remote underwater video cameras on coral reefs in the Bay Islands, Honduras, to explore temporal variation of cleaning interactions at Pederson shrimp (Ancylomenes pedersoni) stations. We recorded more than 650 individual cleaning interactions in over 190 h of video. We find no significant temporal variation in cleaning station usage patterns across 17 families of reef fish. Our findings are in contrast to previously published data for interactions of Caribbean cleaner gobies, which co-occur at the sites we studied and overlap significantly in client pool with A. pedersoni but which are most active at dawn. These data suggest that the services provided by cleaner shrimp and cleaner gobies, rather than client identity, independently structure these interactions and drive the discordance in usage patterns between cleaner type. We propose two non-exclusive hypotheses to explain the differences in the temporal patterns of activity between cleaner gobies and A. pedersoni: (1) the proximate causes driving fish visitation rate (e.g., parasite removal or tactile stimulation) to goby and shrimp stations differ, and (2) each cleaner type targets different ectoparasites that differ temporally in their diel infestation rate on reef fish. Our study provides an important rationale for pursuing these questions and broadens our understanding of cleaning services on Caribbean coral reefs. © 2015, Springer-Verlag Berlin Heidelberg. Source

Exton D.A.,Operation Wallacea | Exton D.A.,University of Essex | Mcgenity T.J.,University of Essex | Steinke M.,University of Essex | And 3 more authors.
Global Change Biology | Year: 2015

Biogenic volatile organic compounds (BVOCs), in particular dimethyl sulphide (DMS) and isoprene, have fundamental ecological, physiological and climatic roles. Our current understanding of these roles is almost exclusively established from terrestrial or oceanic environments but signifies a potentially major, but largely unknown, role for BVOCs in tropical coastal marine ecosystems. The tropical coast is a transition zone between the land and ocean, characterized by highly productive and biodiverse coral reefs, seagrass beds and mangroves, which house primary producers that are amongst the greatest emitters of BVOCs on the planet. Here, we synthesize our existing understanding of BVOC emissions to produce a novel conceptual framework of the tropical marine coast as a continuum from DMS-dominated reef producers to isoprene-dominated mangroves. We use existing and previously unpublished data to consider how current environmental conditions shape BVOC production across the tropical coastal continuum, and in turn how BVOCs can regulate environmental stress tolerance or species interactions via infochemical networks. We use this as a framework to discuss how existing predictions of future tropical coastal BVOC emissions, and the roles they play, are effectively restricted to present day 'baseline' trends of BVOC production across species and environmental conditions; as such, there remains a critical need to focus research efforts on BVOC responses to rapidly accelerating anthropogenic impacts at local and regional scales. We highlight the complete lack of current knowledge required to understand the future ecological functioning of these important systems, and to predict whether feedback mechanisms are likely to regulate or exacerbate current climate change scenarios through environmentally and ecologically mediated changes to BVOC budgets at the ecosystem level. © 2014 John Wiley & Sons Ltd. Source

Kolby J.E.,James Cook University | Ramirez S.D.,Operation Wallacea | Ramirez S.D.,Ramapo College of New Jersey | Berger L.,James Cook University | And 4 more authors.
PLoS ONE | Year: 2015

Dispersal and exposure to amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd) is not confined to the aquatic habitat, but little is known about pathways that facilitate exposure to wild terrestrial amphibians that do not typically enter bodies of water. We explored the possible spread of Bd from an aquatic reservoir to terrestrial substrates by the emergence of recently metamorphosed infected amphibians and potential deposition of Bd-positive residue on riparian vegetation in Cusuco National Park, Honduras (CNP). Amphibians and their respective leaf perches were both sampled for Bd presence and the pathogen was detected on 76.1% (35/46) of leaves where a Bd-positive frog had rested. Although the viability of Bd detected on these leaves cannot be discerned from our quantitative PCR results, the cool air temperature, closed canopy, and high humidity of this cloud forest environment in CNP is expected to encourage pathogen persistence. High prevalence of infection (88.5%) detected in the recently metamorphosed amphibians and frequent shedding of Bdpositive residue on foliage demonstrates a pathway of Bd dispersal between aquatic and terrestrial habitats. This pathway provides the opportunity for environmental transmission of Bd among and between amphibian species without direct physical contact or exposure to an aquatic habitat. © 2015 Kolby et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Source

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