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Oral baiting is used to deliver vaccines to wildlife to prevent, control, and eliminate infectious diseases. A central challenge is how to spatially distribute baits to maximize encounters by target animal populations, particularly in urban and suburban areas where wildlife like raccoons (Procyon lotor) are abundant and baits are delivered along roads. Methods from movement ecology that quantify movement and habitat selection could help to optimize baiting strategies by more effectively targeting wildlife populations across space. We developed a spatially explicit, individual-based model of raccoon movement and oral rabies vaccine seroconversion to examine whether and when baiting strategies that match raccoon movement patterns perform better than currently employed baiting strategies in an oral rabies vaccination zone in greater Burlington, Vermont, USA. Habitat selection patterns estimated from locally radio-collared raccoons were used to parameterize movement simulations. We then used our simulations to estimate raccoon population rabies seroprevalence under currently used baiting strategies (actual baiting) relative to habitat selection-based baiting strategies (habitat baiting). We conducted simulations on the Burlington landscape and artificial landscapes that varied in heterogeneity relative to Burlington in the proportion and patch size of preferred habitats. We found that the benefits of habitat baiting strongly depended on the magnitude and variability of raccoon habitat selection and the degree of landscape heterogeneity within the baiting area. Habitat baiting improved seroprevalence over actual baiting for raccoons characterized as habitat specialists but not for raccoons that displayed weak habitat selection similar to radio-collared individuals—except when baits were delivered off roads where preferred habitat coverage and complexity was more pronounced. In contrast, in artificial landscapes with either more strongly juxtaposed favored habitats and/or higher proportions of favored habitats, habitat baiting performed better than actual baiting, even when raccoons displayed weak habitat preferences and where baiting was constrained to roads. Our results suggest that habitat selection-based baiting could increase raccoon population seroprevalence in urban-suburban areas, where practical, given the heterogeneity and availability of preferred habitat types in those areas. Our novel simulation approach provides a flexible framework to test alternative baiting strategies in multiclass landscapes to optimize bait distribution strategies.

Vector abundance plays a key role in transmission of mosquito-borne disease. In Hawaii, Aedes albopictus (Skuse) (Diptera: Culicidae), the Asian tiger mosquito, has been implicated in locally-transmitted dengue outbreaks, while Culex quinquefasciatus Say (Diptera: Culicidae), the southern house mosquito, is the primary vector of avian malaria, a wildlife disease that has contributed to declines and extinctions of native Hawaiian birds. Despite the importance of these introduced species to human and wildlife health, little is known about the local-scale drivers that shape mosquito abundance across lowland Hawaii, where forest, agricultural, and residential land uses are prevalent. We examined landscape, larval habitat, and climate drivers of Ae. albopictus and Cx. quinquefasciatus abundance in eight lowland wet forest fragments on the Big Island of Hawaii. We found that the abundance of both species increased with the proportion of surrounding developed land and the availability of larval habitat, which were themselves correlated. Our findings suggest that conversion of natural habitats to residential and agricultural land increases mosquito larval habitats, increasing the abundance of Ae. albopictus and Cx. quinquefasciatus and increasing disease risk to humans and wildlife in Hawaii. Our results further indicate that while source reduction of artificial larval habitats—particularly moderately-sized human-made habitats including abandoned cars and tires—could reduce mosquito abundance, eliminating larval habitat will be challenging because both species utilize both natural and human-made larval habitats in lowland Hawaii.

The small Indian mongoose (Urva auropunctata) is an opportunistic omnivore introduced to sugar producing islands primarily to control rat (Rattus spp.) populations, yet is now considered an invasive pest species on multiple Caribbean islands. Data on home range estimates of mongooses in Puerto Rico and other regions are limited. We fitted 24 mongooses (15 males and nine females) with very high frequency (VHF) radio collars at the Cabo Rojo National Wildlife Refuge in southwestern Puerto Rico and tracked them via radio telemetry for up to six months. The raw mean (SE) minimum convex polygon home range among 24 mongooses was 45.03 (8.30) hectares. The mean (SE) fixed kernel 95% estimate was 38.37 (5.78) hectares, and the 50% core area estimate was 7.89 (1.29) hectares. Our home range estimates are similar to previous estimates in the Caribbean and other islands, but larger than those reported from their native range in India. Our study adds new information to the small body of literature available on mongoose home ranges and is one of the few studies conducted in a lowland dry semi-deciduous forest in southwestern Puerto Rico. Additional research on mongoose home ranges in suburban/rural habitats, as well as in agricultural areas, would provide valuable information for the management of wildlife disease and damage conflicts associated with mongooses in the Caribbean region.

Since the identification and imprisonment of "Typhoid Mary," a woman who infected at least 47 people with typhoid in the early 1900s, epidemiologists have recognized that 'superspreading' hosts play a key role in disease epidemics. Such variability in transmission also exists among species within a community (amplification hosts) and among habitat patches across a landscape (disease 'hotspots'), underscoring the need for an integrative framework for studying transmission heterogeneity. Here, we synthesize literature on human, plant, and animal diseases to evaluate the relative contributions of host, pathogen, and environmental factors in driving transmission heterogeneity across hosts and space. We show that host and spatial heterogeneity are closely linked and that quantitatively assessing the contribution of infectious individuals, species, or environmental patches to overall transmission can aid management strategies. We conclude by posing hypotheses regarding how pathogen natural history influences transmission heterogeneity and highlight emerging frontiers in the study of transmission heterogeneity.