scholarly journals Anthropogenic disturbance increases disease emergence risk through predictable changes in parasite community structure

2021 ◽  
Author(s):  
Guha Dharmarajan ◽  
Pooja Gupta ◽  
C. Vishnudas ◽  
VV Robin
Keyword(s):  
Anthropogenic Disturbance ◽  
Emerging Infectious Diseases ◽  
Parasite Prevalence ◽  
Parasite Community ◽  
Disease Emergence ◽  
Free Living ◽  
Bird Populations ◽  
Parasite Communities ◽  
Living Species ◽  
Specialist Species

Niche theory predicts specialists will be more sensitive to environmental perturbation compared to generalists, a hypothesis receiving broad support in free-living species. Based on their niche breadth, parasites can also be classified as specialists and generalists, with specialists infecting only a few and generalists a diverse array of host species. Here, using avian haemosporidian parasites infecting wild bird populations inhabiting the Western Ghats, India as a model system, we elucidate how climate, habitat and human disturbance affects parasite prevalence both directly and indirectly via their effects on host diversity. Our data demonstrates that anthropogenic disturbance acts to reduce the prevalence of specialist parasite lineages, while increasing that of generalist lineages. Thus, as in free-living species, disturbance favors parasite communities dominated by generalist vs. specialist species. Because generalist parasites are more likely to cause emerging infectious diseases, such biotic homogenization of parasite communities could increase disease emergence risk in the Anthropocene

scholarly journals Misinformation tactics protect rare birds from problem predators

2021 ◽  
Vol 7 (11) ◽  
pp. eabe4164
Author(s):  
Grant L. Norbury ◽  
Catherine J. Price ◽  
M. Cecilia Latham ◽  
Samantha J. Brown ◽  
A. David M. Latham ◽  
...  
Keyword(s):  
Decision Making ◽  
Threatened Species ◽  
Prey Availability ◽  
Free Living ◽  
Bird Populations ◽  
New Information ◽  
Mammalian Predators ◽  
Decision Making Processes ◽  
Living Species ◽  
Information Reliability

Efficient decision-making integrates previous experience with new information. Tactical use of misinformation can alter choice in humans. Whether misinformation affects decision-making in other free-living species, including problem species, is unknown. Here, we show that sensory misinformation tactics can reduce the impacts of predators on vulnerable bird populations as effectively as lethal control. We repeatedly exposed invasive mammalian predators to unprofitable bird odors for 5 weeks before native shorebirds arrived for nesting and for 8 weeks thereafter. Chick production increased 1.7-fold at odor-treated sites over 25 to 35 days, with doubled or tripled odds of successful hatching, resulting in a 127% increase in modeled population size in 25 years. We demonstrate that decision-making processes that respond to changes in information reliability are vulnerable to tactical manipulation by misinformation. Altering perceptions of prey availability offers an innovative, nonlethal approach to managing problem predators and improving conservation outcomes for threatened species.

The global biogeography of avian haemosporidian parasites is characterized by local diversification and intercontinental dispersal

Parasitology ◽  
2018 ◽  
Vol 146 (2) ◽  
pp. 213-219 ◽  
Author(s):  
Vincenzo A. Ellis ◽  
Eloisa H. R. Sari ◽  
Dustin R. Rubenstein ◽  
Rebecca C. Dickerson ◽  
Staffan Bensch ◽  
...  
Keyword(s):  
Evolutionary History ◽  
Emerging Infectious Diseases ◽  
Free Living ◽  
Molecular Barcoding ◽  
Haemosporidian Parasites ◽  
Single Region ◽  
Biogeographic Region ◽  
Living Species ◽  
Biogeographic Regions ◽  
Globally Distributed

AbstractThe biogeographic histories of parasites and pathogens are infrequently compared with those of free-living species, including their hosts. Documenting the frequency with which parasites and pathogens disperse across geographic regions contributes to understanding not only their evolution, but also the likelihood that they may become emerging infectious diseases. Haemosporidian parasites of birds (parasite genera Plasmodium, Haemoproteus and Leucocytozoon) are globally distributed, dipteran-vectored parasites. To date, over 2000 avian haemosporidian lineages have been designated by molecular barcoding methods. To achieve their current distributions, some lineages must have dispersed long distances, often over water. Here we quantify such events using the global avian haemosporidian database MalAvi and additional records primarily from the Americas. We scored lineages as belonging to one or more global biogeographic regions based on infection records. Most lineages were restricted to a single region but some were globally distributed. We also used part of the cytochrome b gene to create genus-level parasite phylogenies and scored well-supported nodes as having descendant lineages in regional sympatry or allopatry. Descendant sister lineages of Plasmodium, Haemoproteus and Leucocytozoon were distributed in allopatry in 11, 16 and 15% of investigated nodes, respectively. Although a small but significant fraction of the molecular variance in cytochrome b of all three genera could be explained by biogeographic region, global parasite dispersal likely contributed to the majority of the unexplained variance. Our results suggest that avian haemosporidian parasites have faced few geographic barriers to dispersal over their evolutionary history.

The ecology of parasites of freshwater fishes: the search for patterns

Parasitology ◽  
2009 ◽  
Vol 136 (12) ◽  
pp. 1653-1662 ◽  
Author(s):  
C. R. KENNEDY
Keyword(s):  
Community Dynamics ◽  
Parasite Community ◽  
Freshwater Fishes ◽  
Convincing Evidence ◽  
Helminth Parasites ◽  
Parasite Communities ◽  
Space And Time ◽  
Long Time ◽  
Population And Community Dynamics ◽  
Parasite Populations

SUMMARYDevelopments in the study of the ecology of helminth parasites of freshwater fishes over the last half century are reviewed. Most research has of necessity been field based and has involved the search for patterns in population and community dynamics that are repeatable in space and time. Mathematical models predict that under certain conditions host and parasite populations can attain equilibrial levels through operation of regulatory factors. Such factors have been identified in several host-parasite systems and some parasite populations have been shown to persist over long time-periods. However, there is no convincing evidence that fish parasite populations are stable and regulated since in all cases alternative explanations are equally acceptable and it appears that they are non-equilibrial systems. It has proved particularly difficult to detect replicable patterns in parasite communities. Inter-specific competition, evidenced by functional and numerical responses, has been detected in several communities but its occurrence is erratic and its significance unclear. Some studies have failed to find any nested patterns in parasite community structure and richness, whereas others have identified such patterns although they are seldom constant over space and time. Departures from randomness appear to be the exception and then only temporary. It appears that parasite communities are non-equilibrial, stochastic assemblages rather than structured and organized.

Consistent differences in macroparasite community composition among populations of three-spined sticklebacks,Gasterosteus aculeatusL.

Parasitology ◽  
2012 ◽  
Vol 139 (11) ◽  
pp. 1478-1491 ◽  
Author(s):  
JOB DE ROIJ ◽  
ANDREW D. C. MacCOLL
Keyword(s):  
Spatial Variation ◽  
Community Composition ◽  
Gasterosteus Aculeatus ◽  
Parasite Community ◽  
Field Studies ◽  
Habitat Characteristics ◽  
Parasite Communities ◽  
Geographical Distances ◽  
Host Parasite ◽  
Relative Differences

SUMMARYParasite ecologists are often interested in the repeatability of patterns in parasite communities in space and/or time, because of implications for the dynamics of host-parasite interactions. Field studies usually examine temporal and spatial variation in isolation or limit themselves to a small number of host populations. Here, we studied the macroparasite communities of 12 populations of three-spined stickleback,Gasterosteus aculeatusL., on North Uist, Scotland, separated by small geographical distances, during the breeding season in 2 consecutive years (2007 and 2008) to determine: (1) the extent of spatial variation in macroparasite communities, (2) whether this variation is consistent across years, and (3) whether habitat characteristics can explain differences in macroparasite community composition among populations. We found substantial variation in parasite communities among populations. Generally, measures of parasite community composition were higher in 2008 than in 2007, but this effect of year was consistent across populations, such that the relative differences in these measures among populations changed little between years. These data suggest that there is short-term stability in the spatial variation in macroparasite communities of North Uist sticklebacks. However, none of the 5 habitat characteristics measured explained spatial variation in any measure of parasite community composition.

scholarly journals Avian Haemosporidian Diversity on Sardinia: A First General Assessment for the Insular Mediterranean

Diversity ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 75
Author(s):  
Irene Pellegrino ◽  
Luca Ilahiane ◽  
Giovanni Boano ◽  
Marco Cucco ◽  
Marco Pavia ◽  
...  
Keyword(s):  
Linear Models ◽  
Parasite Community ◽  
Breeding Birds ◽  
Lower Probability ◽  
Long Distance ◽  
Breeding Bird ◽  
Bird Populations ◽  
Total Prevalence ◽  
Western Palearctic ◽  
Host Parasite

The Western Palearctic is one of the most investigated regions for avian haemosporidian parasites (Haemoproteus, Plasmodium and Leucocytozoon), yet geographic gaps in our regional knowledge remain. Here, we report the first haemosporidian screening of the breeding birds from Sardinia (the second-largest Mediterranean Island and a biodiversity hotspot), and the first for the insular Mediterranean in general. We examined the occurrence of haemosporidians by amplifying their mtDNA cytb gene in 217 breeding birds, belonging to 32 species. The total prevalence of infected birds was 55.3%, and of the 116 haplotypes recovered, 84 were novel. Despite the high number of novel lineages, phylogenetic analysis did not highlight Sardinia-specific clades; instead, some Sardinian lineages were more closely related to lineages previously recovered from continental Europe. Host-parasite network analysis indicated a specialized host-parasite community. Binomial generalized linear models (GLMs), performed at the community level, suggested an elevational effect on haemosporidian occurrence probability (negative for Haemoproteus; positive for Leucocytozoon) likely due to differences in the abundance of insect vectors at different elevations. Furthermore, a GLM revealed that sedentary birds showed a higher probability of being infected by novel haplotypes and long-distance migrants showed a lower probability of novel haplotype infection. We hypothesize that the high diversity of haemosporidians is linked to the isolation of breeding bird populations on Sardinia. This study adds to the growing knowledge on haemosporidians lineage diversity and distribution in insular environments and presents new insights on potential host-parasite associations.

scholarly journals Draft Genome Sequence of Piscirickettsia litoralis , Isolated from Seawater

2016 ◽  
Vol 4 (6) ◽  
Author(s):  
Xuehua Wan ◽  
Alex J. Lee ◽  
Shaobin Hou ◽  
Blake Ushijima ◽  
Yen P. Nguyen ◽  
...  
Keyword(s):  
Genome Sequence ◽  
Draft Genome ◽  
Salmonid Fish ◽  
Draft Genome Sequence ◽  
Free Living ◽  
Living Species

One species of Piscirickettsia , a pathogen of salmonid fish, has been described. The genome sequence of a putative second and free-living species may provide insights into the evolution of pathogenicity in the genus.

scholarly journals Bovine tuberculosis disturbs parasite functional trait composition in African buffalo

2019 ◽  
Vol 116 (29) ◽  
pp. 14645-14650 ◽  
Author(s):  
Brianna R. Beechler ◽  
Kate S. Boersma ◽  
Peter E. Buss ◽  
Courtney A. C. Coon ◽  
Erin E. Gorsich ◽  
...  
Keyword(s):  
Community Composition ◽  
Bovine Tuberculosis ◽  
Community Dynamics ◽  
Parasite Community ◽  
Functional Trait ◽  
Taxonomic Composition ◽  
African Buffalo ◽  
Emerging Infections ◽  
Parasite Communities ◽  
Parasite Richness

Novel parasites can have wide-ranging impacts, not only on host populations, but also on the resident parasite community. Historically, impacts of novel parasites have been assessed by examining pairwise interactions between parasite species. However, parasite communities are complex networks of interacting species. Here we used multivariate taxonomic and trait-based approaches to determine how parasite community composition changed when African buffalo (Syncerus caffer) acquired an emerging disease, bovine tuberculosis (BTB). Both taxonomic and functional parasite richness increased significantly in animals that acquired BTB than in those that did not. Thus, the presence of BTB seems to catalyze extraordinary shifts in community composition. There were no differences in overall parasite taxonomic composition between infected and uninfected individuals, however. The trait-based analysis revealed an increase in direct-transmitted, quickly replicating parasites following BTB infection. This study demonstrates that trait-based approaches provide insight into parasite community dynamics in the context of emerging infections.

scholarly journals Untangling the roles of parasites in food webs with generative network models

2015 ◽  
Author(s):  
Abigail Z. Jacobs ◽  
Jennifer A. Dunne ◽  
Cristopher Moore ◽  
Aaron Clauset
Keyword(s):  
Food Web ◽  
Food Webs ◽  
Statistical Physics ◽  
Network Models ◽  
Food Web Structure ◽  
Free Living ◽  
Web Structure ◽  
Living Species ◽  
Parasitic Interactions ◽  
The Impact

Food webs represent the set of consumer-resource interactions among a set of species that co-occur in a habitat, but most food web studies have omitted parasites and their interactions. Recent studies have provided conflicting evidence on whether including parasites changes food web structure, with some suggesting that parasitic interactions are structurally distinct from those among free-living species while others claim the opposite. Here, we describe a principled method for understanding food web structure that combines an efficient optimization algorithm from statistical physics called parallel tempering with a probabilistic generalization of the empirically well-supported food web niche model. This generative model approach allows us to rigorously estimate the degree to which interactions that involve parasites are statistically distinguishable from interactions among free-living species, whether parasite niches behave similarly to free-living niches, and the degree to which existing hypotheses about food web structure are naturally recovered. We apply this method to the well-studied Flensburg Fjord food web and show that while predation on parasites, concomitant predation of parasites, and parasitic intraguild trophic interactions are largely indistinguishable from free-living predation interactions, parasite-host interactions are different. These results provide a powerful new tool for evaluating the impact of classes of species and interactions on food web structure to shed new light on the roles of parasites in food webs.

scholarly journals Species composition and structure of parasites component communities of tugun Coregonus tugun (Pallas, 1814) from the Khatanga and Yenisei Rivers

2019 ◽  
Vol 8 (3) ◽  
pp. 72-80
Author(s):  
Kseniya Viktorovna Polyaeva ◽  
Gennady Nikolaevich Dorovskikh ◽  
Yuliya Konstantinovna Chugunova
Keyword(s):  
Species Composition ◽  
Parasite Community ◽  
Shannon Index ◽  
Egg Laying ◽  
Entire Study ◽  
Generalist Species ◽  
Parasite Communities ◽  
Composition And Structure ◽  
Number Of Individuals ◽  
Species Composition And Structure

Tugun Coregonus tugun (Pallas, 1814) is an endemic of Siberia. Information about the species composition and structure of tugun parasite community on the stage of spawning migration is described in this paper. We carried out ichtioparasitologic studies in the Yenisey and the Khatanga Rivers in 2011-2014. Tugun parasite complex from the Khatanga River remains statistically identical in species composition, number of individuals and biomass and differs from those of the Yeniseis tugun over the entire study period. Apparently two different stocks of tugun were investigated in the Yenisei River. One of them lives in the Yeniseis streambed, the other one lives in the Podkamennaya Tunguska River. The composition of the parasitic fauna of tugun from two rivers is formed by generalist species. Tugun parasites component communities from all material collection stations have high values of the Shannon index and two dominant species (by numbers of parasites and by biomass). We found out that the species biomasses differ significantly on the graphic community structure. The description of tugun parasite communities corresponds to characteristic of a climax community on the stage of destruction except the graphic structure. In the analyzed parasitic communities the processes of egg laying and larval appearance, the death of parasites of previous year generation and infection with this year parasites occur simultaneously. The stages of formation and destruction of the community overlap. The described state of tugun parasites communities has an adaptive value. The load on the host body is reduced which ensures the long-term existence of parasites.

scholarly journals What factors explain the geographical range of mammalian parasites?

2019 ◽  
Vol 286 (1903) ◽  
pp. 20190673 ◽  
Author(s):  
James E. Byers ◽  
J. P. Schmidt ◽  
Paula Pappalardo ◽  
Sarah E. Haas ◽  
Patrick R. Stephens
Keyword(s):  
Host Species ◽  
Parasite Species ◽  
Geographical Area ◽  
Complete Information ◽  
Sampling Effort ◽  
Free Living ◽  
Living Species ◽  
Habitat Breadth ◽  
Taxonomic Groups ◽  
Host Characteristics

Free-living species vary substantially in the extent of their spatial distributions. However, distributions of parasitic species have not been comprehensively compared in this context. We investigated which factors most influence the geographical extent of mammal parasites. Using the Global Mammal Parasite Database we analysed 17 818 individual geospatial records on 1806 parasite species (encompassing viruses, bacteria, protozoa, arthropods and helminths) that infect 396 carnivore, ungulate and primate host species. As a measure of the geographical extent of each parasite species we quantified the number and area of world ecoregions occupied by each. To evaluate the importance of variables influencing the summed area of ecoregions occupied by a parasite species, we used Bayesian network analysis of a subset ( n = 866) of the parasites in our database that had at least two host species and complete information on parasite traits. We found that parasites that covered more geographical area had a greater number of host species, higher average phylogenetic relatedness between host species and more sampling effort. Host and parasite taxonomic groups had weak and indirect effects on parasite ecoregion area; parasite transmission mode had virtually no effect. Mechanistically, a greater number of host species probably increases both the collective abundance and habitat breadth of hosts, providing more opportunities for a parasite to have an expansive range. Furthermore, even though mammals are one of the best-studied animal classes, the ecoregion area occupied by their parasites is strongly sensitive to sampling effort, implying mammal parasites are undersampled. Overall, our results support that parasite geographical extent is largely controlled by host characteristics, many of which are subsumed within host taxonomic identity.

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