ORCID Profile
0000-0001-9146-4318
Current Organisations
University of North Dakota
,
Northland Community and Technical College - East Grand Forks Campus
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Publisher: Wiley
Date: 05-2019
DOI: 10.1111/MEC.15094
Abstract: Identifying the ecological factors that shape parasite distributions remains a central goal in disease ecology. These factors include dispersal capability, environmental filters and geographic distance. Using 520 haemosporidian parasite genetic lineages recovered from 7,534 birds s led across tropical and temperate South America, we tested (a) the latitudinal ersity gradient hypothesis and (b) the distance-decay relationship (decreasing proportion of shared species between communities with increasing geographic distance) for this host-parasite system. We then inferred the biogeographic processes influencing the ersity and distributions of this cosmopolitan group of parasites across South America. We found support for a latitudinal gradient in ersity for avian haemosporidian parasites, potentially mediated through higher avian host ersity towards the equator. Parasite similarity was correlated with climate similarity, geographic distance and host composition. Local ersification in Amazonian lineages followed by dispersal was the most frequent biogeographic events reconstructed for haemosporidian parasites. Combining macroecological patterns and biogeographic processes, our study reveals that haemosporidian parasites are capable of circumventing geographic barriers and dispersing across biomes, although constrained by environmental filtering. The contemporary ersity and distributions of haemosporidian parasites are mainly driven by historical (speciation) and ecological (dispersal) processes, whereas the parasite community assembly is largely governed by host composition and to a lesser extent by environmental conditions.
Publisher: Wiley
Date: 13-01-2019
DOI: 10.1111/ELE.13215
Abstract: Parasites with low host specificity (e.g. infecting a large ersity of host species) are of special interest in disease ecology, as they are likely more capable of circumventing ecological or evolutionary barriers to infect new hosts than are specialist parasites. Yet for many parasites, host specificity is not fixed and can vary in response to environmental conditions. Using data on host associations for avian malaria parasites (Apicomplexa: Haemosporida), we develop a hierarchical model that quantifies this environmental dependency by partitioning host specificity variation into region- and parasite-level effects. Parasites were generally phylogenetic host specialists, infecting phylogenetically clustered subsets of available avian hosts. However, the magnitude of this specialisation varied biogeographically, with parasites exhibiting higher host specificity in regions with more pronounced rainfall seasonality and wetter dry seasons. Recognising the environmental dependency of parasite specialisation can provide useful leverage for improving predictions of infection risk in response to global climate change.
Publisher: The Royal Society
Date: 23-11-2022
Abstract: Birds are highly visually oriented and use plumage coloration as an important signalling trait in social communication. Hence, males and females may have different patterns of plumage coloration, a phenomenon known as sexual dichromatism. Because males tend to have more complex plumages, sexual dichromatism is usually attributed to female choice. However, plumage coloration is partly condition-dependent therefore, other selective pressures affecting in iduals' success may also drive the evolution of this trait. Here, we used tanagers as model organisms to study the relationships between dichromatism and plumage coloration complexity in tanagers with parasitism by haemosporidians, investment in reproduction and life-history traits. We screened blood s les from 2849 in idual birds belonging to 52 tanager species to detect haemosporidian parasites. We used publicly available data for plumage coloration, bird phylogeny and life-history traits to run phylogenetic generalized least-square models of plumage dichromatism and complexity in male and female tanagers. We found that plumage dichromatism was more pronounced in bird species with a higher prevalence of haemosporidian parasites. Lastly, high plumage coloration complexity in female tanagers was associated with a longer incubation period. Our results indicate an association between haemosporidian parasites and plumage coloration suggesting that parasites impact mechanisms of sexual selection, increasing differences between the sexes, and social (non-sexual) selection, driving females to develop more complex coloration.
Publisher: Cambridge University Press (CUP)
Date: 13-10-2022
DOI: 10.1017/S0031182022001469
Abstract: Vector-borne parasites are important ecological drivers influencing life-history evolution in birds by increasing host mortality or susceptibility to new diseases. Therefore, understanding why vulnerability to infection varies within a host clade is a crucial task for conservation biology and for understanding macroecological life-history patterns. Here, we studied the relationship of avian life-history traits and climate on the prevalence of Plasmodium and Parahaemoproteus parasites. We s led 3569 in idual birds belonging to 53 species of the family Thraupidae. In iduals were captured from 2007 to 2018 at 92 locations. We created 2 phylogenetic generalized least-squares models with Plasmodium and Parahaemoproteus prevalence as our response variables, and with the following predictor variables: climate PC1, climate PC2, body size, mixed-species flock participation, incubation period, migration, nest height, foraging height, forest cover, and diet. We found that Parahaemoproteus and Plasmodium prevalence was higher in species inhabiting open habitats. Tanager species with longer incubation periods had higher Parahaemoproteus prevalence as well, and we hypothesize that these longer incubation periods overlap with maximum vector abundances, resulting in a higher probability of infection among adult hosts during their incubation period and among chicks. Lastly, we found that Plasmodium prevalence was higher in species without migratory behaviour, with mixed-species flock participation, and with an omnivorous or animal-derived diet. We discuss the consequences of higher infection prevalence in relation to life-history traits in tanagers.
Publisher: Wiley
Date: 07-09-2021
DOI: 10.1111/GEB.13390
Abstract: Macroecological analyses provide valuable insights into factors that influence how parasites are distributed across space and among hosts. Amid large uncertainties that arise when generalizing from local and regional findings, hierarchical approaches applied to global datasets are required to determine whether drivers of parasite infection patterns vary across scales. We assessed global patterns of haemosporidian infections across a broad ersity of avian host clades and zoogeographical realms to depict hotspots of prevalence and to identify possible underlying drivers. Global. 1994–2019. Avian haemosporidian parasites (genera Plasmodium , Haemoproteus , Leucocytozoon and Parahaemoproteus ). We amalgamated infection data from 53,669 in idual birds representing 2,445 species world‐wide. Spatio‐phylogenetic hierarchical Bayesian models were built to disentangle potential landscape, climatic and biotic drivers of infection probability while accounting for spatial context and avian host phylogenetic relationships. Idiosyncratic responses of the three most common haemosporidian genera to climate, habitat, host relatedness and host ecological traits indicated marked variation in host infection rates from local to global scales. Notably, host ecological drivers, such as migration distance for Plasmodium and Parahaemoproteus , exhibited predominantly varying or even opposite effects on infection rates across regions, whereas climatic effects on infection rates were more consistent across realms. Moreover, infections in some low‐prevalence realms were disproportionately concentrated in a few local hotspots, suggesting that regional‐scale variation in habitat and microclimate might influence transmission, in addition to global drivers. Our hierarchical global analysis supports regional‐scale findings showing the synergistic effects of landscape, climate and host ecological traits on parasite transmission for a cosmopolitan and erse group of avian parasites. Our results underscore the need to account for such interactions, in addition to possible variation in drivers across regions, to produce the robust inference required to predict changes in infection risk under future scenarios.
Publisher: Wiley
Date: 29-10-2019
Abstract: Geographic variation in environmental conditions as well as host traits that promote parasite transmission may impact infection rates and community assembly of vector-transmitted parasites. Identifying the ecological, environmental and historical determinants of parasite distributions and ersity is therefore necessary to understand disease outbreaks under changing environments. Here, we identified the predictors and contributions of infection probability and phylogenetic ersity of Leucocytozoon (an avian blood parasite) at site and species levels across the New World. To explore spatial patterns in infection probability and lineage ersity for Leucocytozoon parasites, we surveyed 69 bird communities from Alaska to Patagonia. Using phylogenetic Bayesian hierarchical models and high-resolution satellite remote-sensing data, we determined the relative influence of climate, landscape, geography and host phylogeny on regional parasite community assembly. Infection rates and parasite ersity exhibited considerable variation across regions in the Americas. In opposition to the latitudinal gradient hypothesis, both the ersity and prevalence of Leucocytozoon parasites decreased towards the equator. Host relatedness and traits known to promote vector exposure neither predicted infection probability nor parasite ersity. Instead, the probability of a bird being infected with Leucocytozoon increased with increasing vegetation cover (NDVI) and moisture levels (NDWI), whereas the ersity of parasite lineages decreased with increasing NDVI. Infection rates and parasite ersity also tended to be higher in cooler regions and higher latitudes. Whereas temperature partially constrains Leucocytozoon ersity and infection rates, landscape features, such as vegetation cover and water body availability, play a significant role in modulating the probability of a bird being infected. This suggests that, for Leucocytozoon, the barriers to host shifting and parasite host range expansion are jointly determined by environmental filtering and landscape, but not by host phylogeny. Our results show that integrating host traits, host ancestry, bioclimatic data and microhabitat characteristics that are important for vector reproduction are imperative to understand and predict infection prevalence and ersity of vector-transmitted parasites. Unlike other vector-transmitted diseases, our results show that Leucocytozoon ersity and prevalence will likely decrease with warming temperatures.
Location: United States of America
No related grants have been discovered for Jeffrey Bell.