More Like this

1. Large herbivores suppress liana infestation in an African savanna

   https://doi.org/10.1073/pnas.2101676118  

   Coverdale, Tyler C. ; O’Connell, Ryan D. ; Hutchinson, Matthew C. ; Savagian, Amanda ; Kartzinel, Tyler R. ; Palmer, Todd M. ; Goheen, Jacob R. ; Augustine, David J. ; Sankaran, Mahesh ; Tarnita, Corina E. ; et al ( September 2021 , Proceedings of the National Academy of Sciences)

   African savannas are the last stronghold of diverse large-mammal communities, and a major focus of savanna ecology is to understand how these animals affect the relative abundance of trees and grasses. However, savannas support diverse plant life-forms, and human-induced changes in large-herbivore assemblages—declining wildlife populations and their displacement by livestock—may cause unexpected shifts in plant community composition. We investigated how herbivory affects the prevalence of lianas (woody vines) and their impact on trees in an East African savanna. Although scarce (<2% of tree canopy area) and defended by toxic latex, the dominant liana,Cynanchum viminale(Apocynaceae), was eaten by 15 wild large-herbivore species and was consumed in bulk by native browsers during experimental cafeteria trials. In contrast, domesticated ungulates rarely ate lianas. When we experimentally excluded all large herbivores for periods of 8 to 17 y (simulating extirpation), liana abundance increased dramatically, with up to 75% of trees infested. Piecewise exclusion of different-sized herbivores revealed functional complementarity among size classes in suppressing lianas. Liana infestation reduced tree growth and reproduction, but herbivores quickly cleared lianas from trees after the removal of 18-y-old exclosure fences (simulating rewilding). A simple model of liana contagion showed that, without herbivores, the long-term equilibrium could be either endemic (liana–tree coexistence) or an all-liana alternative stable state. We conclude that ongoing declines of wild large-herbivore populations will disrupt the structure and functioning of many African savannas in ways that have received little attention and that may not be mitigated by replacing wildlife with livestock.

    

   more » « less
2. Ecology eclipses phylogeny as a major driver of nematode parasite community structure in a graminivorous primate

   https://doi.org/10.1111/1365-2435.13603  

   Schneider‐Crease, India ; Beehner, Jacinta C. ; Bergman, Thore J. ; Gomery, Megan A. ; Koklic, Lia ; Lu, Amy ; Snyder‐Mackler, Noah ; Barribeau, ed., Seth ( June 2020 , Functional Ecology)

   Understanding how ecology and phylogeny shape parasite communities can inform parasite control and wildlife conservation initiatives while contributing to the study of host species evolution.

   We tested the relative strengths of phylogeny and ecology in driving parasite community structure in a host whose ecology diverges significantly from that of its closest phylogenetic relatives.

   We characterized the gastrointestinal (GI) parasite community of wild geladasTheropithecus gelada, primates that are closely related to baboons but specialized to graminovory in the Ethiopian Highlands.

   Geladas exhibited very constrained GI parasite communities: only two genera (OesophagostomumandTrichostrongylus) were identified across 305 samples. This is far below the diversity reported for baboons (Papiospp.) and at the low end of the range of domestic grazers (e.g.Bos taurus,Ovis aries) inhabiting the same region and ecological niche.

   Using deep amplicon sequencing, we identified 15 amplicon sequence variants (ASVs) within the two genera, seven of which matched toOesophagostomumsp., seven toTrichostrongylussp., and one toT. vitrinus.

   Population was an important predictor of ASV richness. Geladas in the most ecologically disturbed area of the national park exhibited approximately four times higher ASV richness than geladas at a less disturbed location within the park.

   In this system, ecology was a stronger predictor of parasite community structure than was phylogeny, with geladas sharing more elements of their parasite communities with other grazers in the same area than with closely related sister taxa.

   A freePlain Language Summarycan be found within the Supporting Information of this article.

    

   more » « less
3. Factors influencing bacterial microbiome composition in a wild non-human primate community in Taï National Park, Côte d’Ivoire

   https://doi.org/10.1038/s41396-018-0166-1  

   Gogarten, Jan F. ; Davies, T. Jonathan ; Benjamino, Jacquelynn ; Gogarten, J. Peter ; Graf, Joerg ; Mielke, Alexander ; Mundry, Roger ; Nelson, Michael C. ; Wittig, Roman M. ; Leendertz, Fabian H. ; et al ( June 2018 , The ISME Journal)

   Microbiomes impact a variety of processes including a host’s ability to access nutrients and maintain health. While host species differences in microbiomes have been described across ecosystems, little is known about how microbiomes assemble, particularly in the ecological and social contexts in which they evolved. We examined gut microbiome composition in nine sympatric wild non-human primate (NHP) species. Despite sharing an environment and interspecific interactions, individuals harbored unique and persistent microbiomes influenced by host species, social group, and parentage, but surprisingly not by social relationships among members of a social group. We found a branching order of host-species networks constructed using the composition of their microbiomes as characters, which was incongruent with known NHP phylogenetic relationships, with chimpanzees (Pan troglodytes verus) sister to colobines, upon which they regularly prey. In contrast to phylogenetic clustering found in all monkey microbiomes, chimpanzee microbiomes were unique in that they exhibited patterns of phylogenetic overdispersion. This reflects unique ecological processes impacting microbiome composition in chimpanzees and future studies will elucidate the aspects of chimpanzee ecology, life history, and physiology that explain their unique microbiome community structure. Our study of contemporaneous microbiomes of all sympatric diurnal NHP in an ecosystem highlights the diverse dispersal routes shaping these complex communities.

    

   more » « less
4. Comparison of Antimicrobial-Resistant Escherichia coli Isolates from Urban Raccoons and Domestic Dogs

   https://doi.org/10.1128/AEM.00484-21  

   Worsley-Tonks, Katherine E. ; Gehrt, Stanley D. ; Miller, Elizabeth A. ; Singer, Randall S. ; Bender, Jeff B. ; Forester, James D. ; McKenzie, Shane C. ; Travis, Dominic A. ; Johnson, Timothy J. ; Craft, Meggan E. ( July 2021 , Applied and Environmental Microbiology)

   Elkins, Christopher A. (Ed.)

   ABSTRACT Wildlife can be exposed to antimicrobial-resistant bacteria (ARB) via multiple pathways. Spatial overlap with domestic animals is a prominent exposure pathway. However, most studies of wildlife-domestic animal interfaces have focused on livestock and little is known about the wildlife-companion animal interface. Here, we investigated the prevalence and phylogenetic relatedness of extended-spectrum cephalosporin-resistant (ESC-R) Escherichia coli from raccoons ( Procyon lotor ) and domestic dogs ( Canis lupus familiaris ) in the metropolitan area of Chicago, IL, USA. To assess the potential importance of spatial overlap with dogs, we explored whether raccoons sampled at public parks (i.e., parks where people and dogs could enter) differed in prevalence and phylogenetic relatedness of ESC-R E. coli to raccoons sampled at private parks (i.e., parks where people and dogs could not enter). Raccoons had a significantly higher prevalence of ESC-R E. coli (56.9%) than dogs (16.5%). However, the richness of ESC-R E. coli did not vary by host species. Further, core single-nucleotide polymorphism (SNP)-based phylogenetic analyses revealed that isolates did not cluster by host species, and in some cases displayed a high degree of similarity (i.e., differed by less than 20 core SNPs). Spatial overlap analyses revealed that ESC-R E. coli were more likely to be isolated from raccoons at public parks than raccoons at private parks, but only for parks located in suburban areas of Chicago, not urban areas. That said, ESC-R E. coli isolated from raccoons did not genetically cluster by park of origin. Our findings suggest that domestic dogs and urban/suburban raccoons can have a diverse range of ARB, some of which display a high degree of genetic relatedness (i.e., differ by less than 20 core SNPs). Given the differences in prevalence, domestic dogs are unlikely to be an important source of exposure for mesocarnivores in urbanized areas. IMPORTANCE Antimicrobial-resistant bacteria (ARB) have been detected in numerous wildlife species across the globe, which may have important implications for human and animal health. Wildlife can be exposed to ARB via numerous pathways, including via spatial overlap with domestic animals. However, the interface with domestic animals has mostly been explored for livestock and little is known about the interface between wild animals and companion animals. Our work suggests that urban and suburban wildlife can have similar ARB to local domestic dogs, but local dogs are unlikely to be a direct source of exposure for urban-adapted wildlife. This finding is important because it underscores the need to incorporate wildlife into antimicrobial resistance surveillance efforts, and to investigate whether certain urban wildlife species could act as additional epidemiological pathways of exposure for companion animals, and indirectly for humans. 

   more » « less
5. The changing ecology of primate parasites: Insights from wild‐captive comparisons

   https://doi.org/10.1002/ajp.22991  

   Herrera, James P. ; Chakraborty, Debapriyo ; Rushmore, Julie ; Altizer, Sonia ; Nunn, Charles ( July 2019 , American Journal of Primatology)

   Host movements, including migrations or range expansions, are known to influence parasite communities. Transitions to captivity—a rarely studied yet widespread human‐driven host movement—can also change parasite communities, in some cases leading to pathogen spillover among wildlife species, or between wildlife and human hosts. We compared parasite species richness between wild and captive populations of 22 primate species, including macro‐ (helminths and arthropods) and micro‐parasites (viruses, protozoa, bacteria, and fungi). We predicted that captive primates would have only a subset of their native parasite community, and would possess fewer parasites with complex life cycles requiring intermediate hosts or vectors. We further predicted that captive primates would have parasites transmitted by close contact and environmentally—including those shared with humans and other animals, such as commensals and pests. We found that the composition of primate parasite communities shifted in captive populations, especially because of turnover (parasites detected in captivity but not reported in the wild), but with some evidence of nestedness (holdovers from the wild). Because of the high degree of turnover, we found no significant difference in overall parasite richness between captive and wild primates. Vector‐borne parasites were less likely to be found in captivity, whereas parasites transmitted through either close or non‐close contact, including through fecal‐oral transmission, were more likely to be newly detected in captivity. These findings identify parasites that require monitoring in captivity and raise concerns about the introduction of novel parasites to potentially susceptible wildlife populations during reintroduction programs.

    

   more » « less