2016-12-23T18:52:10

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Ambush foragers use a hunting strategy that places them at risk of predation by both visual and olfaction-oriented predators. Resulting selective pressures have driven the evolution of impressive visual crypsis in many ambushing species, and may have led to the development of chemical crypsis. However, unlike for visual crypsis, few studies have attempted to demonstrate chemical crypsis. Field observations of puff adders (Bitis arietans) going undetected by several scent-orientated predator and prey species led us to investigate chemical crypsis in this ambushing species. We trained dogs (Canis familiaris) and meerkats (Suricata suricatta) to test whether a canid and a herpestid predator could detect B. arietans using olfaction. We also tested for chemical crypsis in five species of active foraging snakes, predicted to be easily detectable. Dogs and meerkats unambiguously indicated active foraging species, but failed to correctly indicate puff adder, confirming that B. arietans employs chemical crypsis. This is the first demonstration of chemical crypsis anti-predatory behaviour, though the phenomenon may be widespread among ambushers, especially those that experience high mortality rates owing to predation. Our study provides additional evidence for the existence of an ongoing chemically mediated arms race between predator and prey species.

Vipers are among the most misunderstood and persecuted animals. They occupy most terrestrial ecosystems around the world, often at high population densities. However, certain aspects of their biology (e.g., low fecundity and slow growth) have resulted in vipers being disproportionately threatened by extinction. Despite increased extinction risk, relatively little is known about viper biology, severely limiting the development and implementation of conservation initiatives. Here, we review the conservation status of vipers globally, map species richness, and develop three indices (one reactive; one proactive; one combined index emphasising irreplaceable species facing severe threats) to identify species for which conservation action should be prioritised. Moreover, we map species richness weighted by each index to identify regions for conservation prioritisation. We ranked prioritisation scores for all species for which data were available. In doing so we identify species for which valuable data are missing and that should be prioritised for research. We additionally show that 17 species, currently listed as Not Assessed or Data Deficient by the IUCN, score sufficiently high on our Threat Index to be considered as Threatened in the future. We identify multiple regions for which viper conservation action should be prioritised. These areas broadly correlate with species richness patterns, suggesting that species richness may be an effective proxy for conservation planning. Finally, we discuss the major gaps in knowledge, as well as the major threats facing vipers.

Discrete, ephemeral natural phenomena with low spatial or temporal predictability are incredibly challenging to study systematically. In ecology, species interactions, which constitute the functional backbone of ecological communities, can be notoriously difficult to characterise especially when taxa are inconspicuous and the interactions of interest (e.g., trophic events) occur infrequently, rapidly, or variably in space and time. Overcoming such issues has historically required significant time and resource investment to collect sufficient data, precluding the answering of many ecological and evolutionary questions. Here, we show the utility of social media for rapidly collecting observations of ephemeral ecological phenomena with low spatial and temporal predictability by using a Facebook group dedicated to collecting predation events involving reptiles and amphibians in sub-Saharan Africa. We collected over 1900 independent feeding observations using Facebook from 2015 to 2019 involving 83 families of predators and 129 families of prey. Feeding events by snakes were particularly well-represented with close to 1,100 feeding observations recorded. Relative to an extensive literature review spanning 226 sources and 138 years, we found that social media has provided snake dietary records faster than ever before in history with prey being identified to a finer taxonomic resolution and showing only modest concordance with the literature due to the number of novel interactions that were detected. Finally, we demonstrate that social media can outperform other citizen science image-based approaches (iNaturalist and Google Images) highlighting the versatility of social media and its ability to function as a citizen science platform.

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