"Indirect effects of African megaherbivore conservation on bat diversity in the world's oldest desert" was published as an accepted article last week in Conservation Biology, which I coauthored with Joel Berger. This piece assesses whether bat activity and species richness may be affected by local megaherbivore activity in the northern Namib Desert, Namibia, and if these relationships vary seasonally. Feel free to email me if you need assistance accessing the paper. Three hypothesized relationships among megaherbivores, vegetation productivity, and bat communities in northwestern Namibia evaluated through structural equation modeling: (a) direct relationship of megaherbivore use at a site with bat species richness and overall activity, (b) the same model as in (a) but the effects of megaherbivores on bat communities are completely mediated through vegetation productivity, and (c) both the direct and indirect effects of megaherbivores are represented (double-headed arrows, anticipated correlation between bat species richness and overall activity). Figure from Laverty and Berger (2022). Abstract: In extreme environments, temperature and precipitation are often the main forces responsible for structuring ecological communities and species distributions. The role of biotic interactions is typically thought to be minimal. By clustering around rare and isolated features like surface water, however, effects of herbivory by desert-dwelling wildlife can be exacerbated. Understanding how species interact in these environments is critical to safeguarding vulnerable or data deficient species. Consequently, we asked whether large mammalian herbivores—African elephant, black rhinoceros, and southern giraffe—modulate insectivorous bat communities around a limiting resource—bodies of water—in the Namib Desert. We estimated megaherbivore use of sites using dung transects, summarized vegetation productivity from satellite measurements of the Normalized Difference Vegetation Index (NDVI), and described local bat communities using acoustic monitoring. We then designed structural equation models to test for direct and indirect—mediated through NDVI—relationships among megaherbivores and bat species richness and activity during both dry (November 2016 – January 2017) and wet (February – May 2017) seasons. We found site-level megaherbivore use during the dry season to be positively associated with bat activity—particularly that of open-air foraging bats—and species richness through indirect pathways. When resources were more abundant during the wet season, however, these relationships were reduced. Our results indicate that biotic interactions contribute to species distributions in desert habitats and suggest that the conservation of megaherbivores in this arid ecosystem may indirectly benefit insectivorous bat abundance and diversity. Given how misunderstood and understudied most bats are relative to these much larger and heralded mammals, such findings suggest managers pursue short-term solutions (e.g., community game guard programs, waterpoint protection near human settlements, continued ecotourism opportunities) to indirectly promote bat conservation and that research priorities expand beyond charismatic species to better document megaherbivores effects on biodiversity at other trophic levels.
"When we reach… absolute deserts, the struggle for life is almost exclusively with the elements… Not until we reach the extreme confines of life, in the Arctic regions or on the borders of an utter desert, will competition cease." – Charles Darwin, On the Origin of Species (1859)
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I will be giving a talk, coauthored by Kathryn Stoner, at this year's virtual Western Bat Working Group (WBWG) meeting entitled "In search of bachelorettes: Dorsal patches in male Leptonycteris yerbabuenae in the southwestern United States." My presentation will only be available via live-streaming on the meeting's website/program on Wednesday, April 28th from ~11:20-11:40am Mountain Daylight Time. The WBWG 2021 program can be found here.
New paper out: "Listening to bats: Namibian pastoralists' perspectives, stories, and experiences"3/21/2021 "Listening to bats: Namibian pastoralists' perspectives, stories, and experiences" was published this weekend as part of a special issue on the ethnobiology of bats in the Journal of Ethnobiology and coauthored by Tara Teel, Archie Gawusab, and Joel Berger. From semi-structured interviews of Namibian pastoralists, we observed a disconnect between the largely positive attitudes toward bats and the mostly negative cultural representations of bats as bad luck or omens of injuries, death, disease, or lack of rains. Our study illustrates the value of integrating social and ecological research to gain a broader understanding of local human-bat interactions. Feel free to email me if you need assistance accessing the paper. Abstract: While relatively little is known about bats across much of Africa, globally, many bat populations are in decline due to human activities. Successful bat conservation efforts, therefore, depend on both ecological studies and research on human-bat relationships. To address these knowledge gaps about African bats and their interactions with humans, we used semi-structured interviews of pastoralists in northwestern Namibia to assess local experiences with, attitudes toward, and cultural stories about bats. Our research was conducted in conjunction with an ecological study on Namib Desert bat distributions, thus allowing for a broader understanding of the social-ecological dynamics of human-bat interactions in this region. Though only 65% of interviews were able to correctly identify bats from photographs, 100% classified these species as bats when provided with an additional description of “animals that fly at night.” A majority (77%) of interviews expressed positive attitudes toward bats and over a third (38%) provided cultural stories, offering detailed reports of myths and common meanings assigned to bats. Of those stories, 12% indicated that bats brought good luck or good rains, and 84% specified that bats represented bad luck or omens of injuries, death, disease, or lack of rains. While the primary threats of habitat loss and bushmeat hunting were never mentioned in our interviews, the influence of negative cultural stories on individual behavior could pose challenges for future bat conservation initiatives. This qualitative approach combined with ecological research may be valuable for assessing cross-cultural relationships between humans and understudied wildlife in other remote areas.
"Nuclear (18S-28S rRNA) and mitochondrial genome markers of Carios (Carios) vespertilionis (Argasidae) support Carios Latreille, 1796 as a lineage embedded in the Ornithodorinae: re-classification of the Carios sensu Klompen and Oliver (1993) clade into its respective subgenera" was published yesterday in Ticks and Tick-borne Diseases, which I coauthored with Ben Mans, Samuel Kelava, Ronel Pienaar, Jonathan Featherston, Minique de Castro, Juan Quetglas, Will Reeves, Lance Durden, Myrna Miller, Renfu Shao, Ai Takano, Hiroki Kawabata, Mohamed Moustafa, Ryo Nakao, Keita Matsuno, Telleasha Greay, Kimberly Evasco, Dayana Barker, and Stephen Barker. We argue for a reclassification of soft ticks (Argasidae), namely the subfamilies Aragasinae and Ornithodorinae. We used phylogenetic analyses of 18S/28S rRNA sequences and mitochondrial genomes as evidence for this proposed reclassification with new information taken from C. (C.) vespertilionis ticks collected from bats in the Balearic Islands of Spain and Matsumoto, Japan, as well as larval C. (C.) vespertilionis ticks that I collected in January 2017 from a Roberts's flat-headed bat (Sauromys petrophilus) captured over a waterhole along the Hoanib River in Namibia. Feel free to email me if you need assistance accessing the paper. Mitochondrial amino acid phylogenetic analysis. Nodal support is denoted for maximum likelihood analysis, while Bayesian posterior probabilities are represented by black dots (for >95%) and white dots (for >90%). Ticks sequenced in this study were C. (C.) vespertilionis specimens from Menorca, Namibia, and Japan. Accession numbers of the mitochondrial genomes are provided in parentheses. Figure from Mans et al. (2021). Abstract: Argasid systematics remains controversial with widespread adherence to the Hoogstraal (1985) classification scheme, even though it does not reflect evolutionary relationships and results in paraphyly for the main genera of soft ticks (Argasidae), namely Argas and Ornithodoros. The alternative classification scheme, proposed by Klompen and Oliver (1993), has problems of its own: most notably paraphyly of the subgenus Pavlovskyella and the controversial grouping together of the subgenera Alectorobius, Antricola, Carios, Chiropterargas, Nothoaspis, Parantricola, Reticulinasus and Subparmatus into the genus Carios. Recent phylogenetic analyses of 18S/28S rRNA sequences and mitochondrial genomes agree with the scheme of Klompen and Oliver (1993), with regard to the paraphyly of Pavlovskyella, placement of Alveonasus, Ogadenus, Proknekalia and Secretargas in the Argasinae and placement of Carios and Chiropterargas in the Ornithodorinae (Mans et al., 2019). The Carios clade and its constituent subgenera remain controversial, since the phylogenetic position of its type species Carios (Carios) vespertilionis Latreille, 1796 (formerly Argas vespertilionis) has not been determined with confidence. The current study aimed to resolve Carios sensu lato Klompen and Oliver, 1993, and Carios sensu stricto Hoogstraal, 1985, by determining and analysing phylogenetic nuclear and mitochondrial markers for C. (C.) vespertilionis. Both the nuclear and mitochondrial markers support placement of Carios s.s. within the subfamily Ornithodorinae, but to the exclusion of the clade that includes the 6 other subgenera that are part of Carios s.l. Klompen and Oliver (1993), namely Alectorobius, Antricola, Nothoaspis, Parantricola, Reticulinasus and Subparmatus. These 6 subgenera form a monophyletic clade that might be placed as new subgenera within the genus Alectorobius, or elevated to genera. Given the substantial differences in biology among these subgenera, we propose that these 6 subgenera be elevated to genera. Thus, we propose to modify the classification scheme of Mans et al. (2019) so that the subfamily Argasinae now has six genera, Alveonasus, Argas (subgenera Argas and Persicargas), Navis, Ogadenus, Proknekalia and Secretargas, and the subfamily Ornithodorinae has nine genera, Alectorobius, Antricola (subgenera Antricola and Parantricola), Carios, Chiropterargas, Nothoaspis, Ornithodoros (subgenera Microargas, Ornamentum, Ornithodoros, Pavlovskyella and Theriodoros), Otobius, Reticulinasus and Subparmatus (genera indicated in bold).
"New geographical and host record of bat ectoparasite Steatonyssus (Steatonyssus) afer Radovsky and Yunker, 1963 (Mesostigmata: Gamasina: Macronyssidae)" was published today in Acarologia, which I coauthored with Maria Orlova, Will Reeves, Elena Gratton, Mallory Davies, and Nikolay Anisimov. We report the first collections of S. afer from Namibia, expanding the range of the ectoparasite to a new country and further south than it has ever been documented before. These bat mites were discovered on a new host family (Cistugidae) and new host species—the Angolan wing-gland bat, Cistugo seabrae. Mites were collected January and March of 2017 from bats captured over waterholes in the Sesfontein Conservancy. Feel free to email me if you need assistance accessing the paper. Abstract: Steatonyssus afer is recorded for the first time from Namibia and for the first time from Cistugo seabrae (Chiroptera: Cistugidae). Our finding is the southernmost locality for S. afer, expanding the geographical distribution range of this ectoparasite. We give diagnostic illustrations and measurements of the species.
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