Linking diet switching to reproductive performance across populations of two critically endangered mammalian herbivores.

Optimal foraging theory predicts that animals maximise energy intake by consuming the most valuable foods available. When resources are limited, they may include lower-quality fallback foods in their diets. As seasonal herbivore diet switching is understudied, we evaluate its extent and effects across three Kenyan reserves each for Critically Endangered eastern black rhino (Diceros bicornis michaeli) and Grevy's zebra (Equus grevyi), and its associations with habitat quality, microbiome variation, and reproductive performance. Black rhino diet breadth increases with vegetation productivity (NDVI), whereas zebra diet breadth peaks at intermediate NDVI. Black rhino diets associated with higher vegetation productivity have less acacia (Fabaceae: Vachellia and Senegalia spp.) and more grass suggesting that acacia are fallback foods, upending conventional assumptions. Larger dietary shifts are associated with longer calving intervals. Grevy's zebra diets in high rainfall areas are consistently grass-dominated, whereas in arid areas they primarily consume legumes during low vegetation productivity periods. Whilst microbiome composition between individuals is affected by the environment, and diet composition in black rhino, seasonal dietary shifts do not drive commensurate microbiome shifts. Documenting diet shifts across ecological gradients can increase the effectiveness of conservation by informing habitat suitability models and improving understanding of responses to resource limitatio

Unusual mortalities of the eastern black rhinoceros (Diceros bicornis michaeli) due to clostridial enterotoxaemia in Ol Jogi Pyramid Sanctuary, Kenya

Nine eastern black rhinoceroses (Diceros bicornis michaeli) developed clinical clostridial enterotoxaemia between May and July 2010 in the Pyramid Black Rhino Sanctuary within the Ol Jogi Conservancy, Laikipia, Kenya. The rhinos presented with a peracute syndrome characterised by severe abdominal pain manifested by struggling and rolling on the ground, laboured breathing and died within three hours after being sighted sick. Necropsy and histopathology revealed severe pathology in the gastro-intestinal tract (GIT). Grossly, the small and large intestines were congested and oedematous. All the rhinos had variable amounts of hemorrhagic fluid in the intestines. Microscopically, the most characteristic lesion was severe necrotising-haemorrhagic enteritis. Numerous gram-positive rod-shaped bacterial colonies that were identified to be Clostridium spp were occasionally seen in the intestinal mucosa. Clostridium perfringens type A was isolated from the stomach contents. C. perfringens was postulated as the aetiological agent with the infection triggered probably by change of habitat following a prolonged period of drought that was followed by above normal rainfall

Gonad structure and gamete morphology of the eastern South Pacific chiton Acanthopleura echinata Barnes, 1824

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Effects of herbivores, wave exposure and depth on benthic coral communities of the Easter Island ecoregion

The Easter Island ecoregion includes Rapa Nui (Easter Island; RN), with a human population of ~5600, and the uninhabited Salas y Gómez (SyG). Although the culture and terrestrial ecology of RN have been well studied, we know little about the marine environment of these islands, particularly the interplay among herbivores, algae, and corals, and how coral reef communities differ between islands, by wave energy exposure, and between depths. To address the potential roles of herbivores, wave-energy exposure, and depth on the sessile benthic communities, we examined herbivorous fish biomass, sea urchin (Diadema savignyi) density, and algal and coral cover to identify patterns and relationships among these groups. We found significant differences between islands. For example, turf and macroalgae were nearly absent from SyG, whereas D. savignyi density and Kyphosus sandwicensis biomass were ~28- and ~3-fold greater respectively at SyG. Benthic cover of coral and algae and density of D. savignyi significantly differed among levels of wave exposure, especially between wave-protected stations and semi-exposed and exposed stations. Likewise, community structure significantly differed at protected stations. Concordant patterns between herbivores and algae were observed. Therefore, herbivores and wave energy likely play important roles in structuring these benthic communities, especially for algal groups

Protected areas in Chile: are we managing them?

Abstract Background Human population growth since the mid-1900s has been accompanied by an unsustainable use of natural resources and a corresponding impact on terrestrial and marine biota. In response, most states have established protected areas as tools to decrease biodiversity loss, being Chile one of the signatories of international conservation agreements such as the Convention on Biological Diversity (CBD) and the 2010 Aichi Targets. This study reviews the Chilean protected areas that have been created to date, with an emphasis on the existence and effectiveness of management plans for all terrestrial and marine protected areas. Effectiveness was individually evaluated using two filters: 1) the age of the management plan and 2) the first four steps of the Protected Areas Management Effectiveness (PAME) methodology recommended by the IUCN. Results We show that 84 out of a total of 145 protected areas (PAs), and only five out of a total of 20 marine protected areas (MPAs), have management plans. Only 12% (N = 16) of PAs are effectively managed; while in the marine realm, no MPA has an effective plan. Conclusions Our results show the lack of both the effectiveness of and updates to the management plans for the vast majority of the national territory and raise the following question: is it sustainable to continue adding protected areas to the national system even though it is clear that the existing support is insufficient to meet the minimum requirements for full implementation