Search

Coyotes (Canis latrans) occur across North America in many types of ecosystems, including urban areas, yet certain aspects of coyote behavior remain obscure. Previous observational studies have provided evidence that coyotes are socially monogamous; however, the degree to which coyotes exhibit genetic monogamy has not previously been determined. We used radiotelemetry and genetic techniques to determine the mating system of an urban coyote population. We obtained samples from 236 coyotes captured during 2000-2006 in the Greater Chicago Metropolitan Area of Illinois. Individuals were genotyped using 12 polymorphic microsatellite markers. Among 18 litters comprising 96 offspring, we found no evidence of polygamy, and detected a single instance of a double litter (pups from different parents sharing the same den). The 2 mated pairs that contributed to the double litter had not interbred. However, the relatedness values shared between 1 mated pair and the pups that were not their offspring suggested that they were closely related, possibly as cousins or grandparents! grandoffspring. Across all radiocollared mated pairs, mean home range overlap for the male and female was 80.1% (SD = 13.4). Among 7 mated pairs, 3 of which were radiotracked over multiple years, there was no evidence of mate abandonment and multiyear monogamy was maintained. Despite the high food resources available and high population density, urban coyotes display no variability in their monogamous mating system. [ABSTRACT FROM AUTHOR]

Understanding population structure can lend insight into the spread of animal-borne disease, and the effects of anthropogenic land use on habitat. Raccoons are highly adaptive to human land development and can persist in a wide range of habitat types, making them ideal subjects for investigating the level of population structure in a highly fragmented area. A total of 323 raccoons were livetrapped from 7 locations encompassing 3 distinct habitat types (agriculture, urban forest preserves, and residential) across the Chicago metropolitan region (maximum distance between 2 sites was 128 km). Genetic analyses of 14 microsatellite loci indicate that although raccoon populations across the region share up to 50% of the allelic diversity, they segregated into at least 2 distinct subpopulations, dividing the Chicago metropolitan region into northern and southern groups with further structure occurring within these larger groups. Incorporating sample sites between the identified north-south groups may provide greater resolution as to where this split occurs. Although there is evidence of population structure between all sample sites, migrant analysis suggests there is enough gene flow to preserve genetic diversity throughout the population. [ABSTRACT FROM AUTHOR]

Spatial dynamics and frequency of interaction between mating individuals are difficult to observe in the wild, and linking behavioral and genetic mating systems is particularly challenging for nocturnal or otherwise cryptic mammals. We monitored 29 (11 male and 18 female) adult raccoons in northeastern Illinois to gain a better understanding of how individuals interacted with one another during the mating season (December-March) of 2005. Adults were monitored with proximity-detecting radiocollars to determine the amount of spatial overlap and rate of contact among members of the local population, including those parent pairs that had mated successfully. We identified successful matings by conducting parentage analyses on 43 juveniles using 15 highly variable microsatellite loci. We were unable to identify parents for 25 of 43 juveniles, which greatly reduced our ability to assess the raccoon mating system. However, we present novel data on contact rates and den-sharing incidents between known parental pairs. We found that 3 of 4 parent pairs shared >35% of their daytime resting areas and >26% of their core resting areas. Contact rates of parent pairs varied, ranging from 0.1 to 0.9 contacts/day. Parent pairs were not observed to share dens during the mating season. However, among the remainder of the adult population, we found a sharp increase in instances of den sharing between unrelated adults that coincided with the peak of the mating season. Finally, male coalitions were not successful at sequestering breeding access to reproductive females; only 38.8% of juveniles were sired by males known to live in groups. [ABSTRACT FROM AUTHOR]

With the continuing spread of urban areas, gaining a greater understanding of the effect of human presence on wildlife species is essential for wildlife managers. We determined the influence of anthropogenic resources on home range size and habitat selection of raccoons (Procyon lotor) during summer (June-August) 1996-2000 for 120 raccoons at three sites exposed to varying levels of urbanization and anthropogenic resources, specifically food. Home range estimates were larger (P<0.05) at the rural site than the suburban and urban sites for both genders. We used compositional analysis to examine raccoon habitat selection at the second-order home range, second-order core area, and third-order home range scales. Woodland was consistently a highly-selected habitat type for both sexes at every spatial scale. Relative to other habitat types, habitat associated with human-related food (human use areas) was selected most often at the urban site, intermediately at the suburban site, and not selected at the rural site. Spatial scale also affected habitat selection. Human use areas were preferentially selected at the second- and third-order level at the urban site, third-order level only at the suburban site, and at neither level at the rural site. Additionally, intersexual differences in habitat selection were reduced at the urban site, with both sexes preferentially selecting for human use areas as well as woodland habitat. Smaller home ranges in urbanized environments are often attributed to the abundant and concentrated anthropogenic resources associated with human activity, but with little empirical support. Our habitat selection analyses followed our predictions that raccoon foraging is strongly influenced by the artificial distribution and abundance of human-related food. Male and female raccoons in urban areas reduce their foraging patterns and focus their foraging activity on anthropogenic foods. [ABSTRACT FROM AUTHOR]

An implicit assumption of the mesopredator release hypothesis (MRH) is that competition is occurring between the larger and smaller predator. When significant competition exists, the MRH predicts that larger species should affect population size, through direct predation or the elicitation of avoidance behavior, of smaller predators. However, there have been few manipulations designed to test these predictions, particularly regarding avoidance. To test whether striped skunks (Mephitis mephitis) avoid coyotes (Canis latrans), we intensively monitored 21 radiocollared skunks in a natural area in northeastern Illinois. We identified 2 spatially distinct groups and recorded 1,943 locations from September to November 2003. For each group, testing periods consisted of 4 weeks (2 weeks pretreatment, 1 week treatment, and 1 week posttreatment). We simulated coyote activity during the treatment week by playing taped recordings of coyote howls at 1-h intervals at 5 locations. Additionally, we liberally applied coyote urine to several areas within 20 randomly selected 100 x 100-m grid cells, and used the grid to classify cells as urine-treated, howling-treated, or control. We determined changes in home-range size and location, and intensity of cell use in response to treatment. We found no differences in home-range size related to treatment (P ≥ 0.248). Although weekly differences in home-range drift approached significance when individuals from both tests were pooled (P = 0.071), drift was highly correlated with mean weekly low temperatures (P = 0.004). Use of howling- and urine-treated cells did not vary among weeks (P ≥ 0.307), nor did proportions of locations within howling circles with assumed effective broadcast radii of 50--200 m (P ≥ (0.851). Examination of our data did not support the prediction that skunks avoid areas of coyote activity on our study site. [ABSTRACT FROM AUTHOR]

The frequency of interactions among individuals is vital to understanding many aspects of a species' behavioral ecology. This also is a fundamental aspect of infectious disease epidemiology. However, the number of times an individual animal comes into contact with another is an extremely difficult parameter to estimate. This paper describes radiocollars (proximity detectors) capable of recording close contacts among radiocollared individuals. We conducted laboratory tests using collars alone (i.e., not fitted on an organism) and field tests of collar performance with collars fitted on 42 free-ranging raccoons (Procyon lotor) within a 20-ha portion of the Ned Brown Forest Preserve in northeastern Illinois, USA. During laboratory tests, we determined variation in detection distance within and among collars, effect of collar orientation on detection distances, and accuracy of recorded duration of proximity and identification of contacted collar. Overall variation in detection distance both within and among collars was relatively low, although we observed intrinsic variation in collar strength. We found little variation in horizontal detection distances with collar orientation, although mean distances for vertical tests were greater than most horizontal means. Recorded contact duration deviated from actual time by ≤3 seconds for short-duration (10-300 sec), and by ≤30 seconds for extended-duration (8-14 hr) contacts recorded as a single event. However, there was a tendency for the collars to record extended-duration contacts as multiple events, with the frequency dependent on settings. Identification number of the contacted collar was correctly identified in all cases (n = 1,537). We downloaded 35 of the 42 proximity detectors deployed on free-ranging raccoons. Of these, approximately 57% were functioning properly, 9% exhibited problems apparently correctable in the field, and 34% exhibited problems not correctable in the field. For random pairs of raccoons, daily contact duration and number of contacts (omitting 1-sec contacts) recorded by both detectors did not differ (P ≥ 0.066). Overall, collars produced accurate information in terms of detection range, duration of contact, and contacted collar identification, and represented a promising improvement over previous methods to assess intraspecific contact rates of secretive, nocturnal, or otherwise unobservable species. Because accurate determination of contact rates requires that a population be saturated with detectors, their use may be most appropriate for species readily trapped. [ABSTRACT FROM AUTHOR]

Abundance and distribution of food resources can profoundly affect movements and spatial distribution of solitary carnivores. Food availability and distribution are often altered in urbanized systems due to occurrence of abundant and highly concentrated anthropogenic resources. To address effects of these resources on movements and spatial distribution of raccoons (Procyon lotor), we simultaneously studied populations inhabiting urban (Ned Brown Forest Preserve), suburban (Max McGraw Wildlife Foundation), and rural (Glacial Park) open areas in northeastern Illinois. Estimates of sizes of home ranges were smaller for urban (range, 25.2-52.8 ha, n = 29) and suburban (21.4-37.2 ha, n = 34) than rural (71.2-182.4 ha, n = 39) raccoons during all seasons (P < 0.05). Seasonal changes in sizes of home ranges were least pronounced at the suburban site. Seasonal shifts in activity centers also were small for raccoons at the suburban site and for most raccoons at the urban site. Spatial distribution was aggregated during all seasons at the urban site, and during all seasons except summer 1997 at the suburban site. Abundant and relatively stable artificial resources typical of urbanized systems contributed to reduced size and increased stability of home ranges. Further, concentration of these resources into rich and separated patches resulted in an aggregated distribution. Similar responses to abundant and concentrated resources have been documented for solitary carnivores in other, more natural, systems. [ABSTRACT FROM AUTHOR]

Presents information on a study which described the long-term statewide road-kill indices for raccoons in Illinois. Annual adjusted road-kill indices between 1989 and 1993; Methodology; Results and discussion.

Studies an area, designated as the Bureau, in Princeton, Illinois, in 1932. Occupancy and landscape resulting from the imprint made by occupancy in the region; Land surface and drainage; Roads and railroads.

Social assortativity, preferentially associating with certain individuals, is a widespread behaviour among a diverse range of taxa. Animals often choose to associate with other individuals based on characteristics such as sex, age, body size, rank and genetic relatedness. These preferences can scale up to shape the overall social structure of an animal group or population. We investigated possible factors that might shape the social network structure of common racoons, Procyon lotor, in a high-density urban population in Cook County, Illinois, U.S.A. Racoon associations were recorded using proximity detecting radiocollars that recorded when individuals came within 1–1.5m of each other. In addition, dyadic measures of home range overlap and genetic relatedness were calculated for all individuals included in our study. We used multiple regression quadratic assignment procedures to determine what factors influenced the structure of racoon association networks. The only variable that positively influenced racoon social structure was male–male homophily, which is consistent with previous studies that documented frequent social interactions between adult male racoons. Genetic relatedness had no effect on racoon social networks and there was no evidence that males or females preferentially associated with close relatives, despite the presence of kin in the population. This pattern, that kinship does not play a significant role in shaping social structure, is strikingly unusual among mammals and is not consistent with many socioecological models. Although racoon individuals showed strong social partner preferences, it is unclear what factors drove these choices. This unpredictability in partner choice shaped the structure of the racoon social networks and has important implications for disease transfer in this widespread animal vector. [Copyright &y& Elsevier]

Coyotes (Canis latrans) share urban habitats with domestic dogs (Canis lupus familiaris), providing opportunities for pathogen transmission. In Chicago, Illinois, USA, canine influenza virus (CIV) is prevalent in dogs. Serologic investigation for exposure in 101 coyote samples collected 2000-23 did not detect any antibodies against CIV H3N2 and H3N8., (© Wildlife Disease Association 2024.)

Infectious disease transmission often depends on the contact structure of host populations. Although it is often challenging to capture the contact structure in wild animals, new technology has enabled biologists to obtain detailed temporal information on wildlife social contacts. In this study, we investigated the effects of raccoon contact patterns on rabies spread using network modelling. Raccoons (Procyon lotor) play an important role in the maintenance of rabies in the United States. It is crucial to understand how contact patterns influence the spread of rabies in raccoon populations in order to design effective control measures and to prevent transmission to human populations and other animals. We constructed a dynamic system of contact networks based on empirical data from proximity logging collars on a wild suburban raccoon population and then simulated rabies spread across these networks. Our contact networks incorporated the number and duration of raccoon interactions. We included differences in contacts according to sex and season, and both short-term acquaintances and long-term associations. Raccoons may display different behaviours when infectious, including aggression (furious behaviour) and impaired mobility (dumb behaviour); the network model was used to assess the impact of potential behavioural changes in rabid raccoons. We also tested the effectiveness of different vaccination coverage levels. Our results demonstrate that when rabies enters a suburban raccoon population, the likelihood of a disease outbreak affecting the majority of the population is high. Both the magnitude of rabies outbreaks and the speed of rabies spread depend strongly on the time of year that rabies is introduced into the population. When there is a combination of dumb and furious behaviours in the rabid raccoon population, there are similar outbreak sizes and speed of spread to when there are no behavioural changes due to rabies infection. By incorporating detailed data describing the variation in raccoon contact rates into a network modelling approach, we were able to show that suburban raccoon populations are highly susceptible to rabies outbreaks, that the risk of large outbreaks varies seasonally and that current vaccination target levels may be inadequate to prevent the spread of rabies within these populations. Our findings provide new insights into rabies dynamics in raccoon populations and have important implications for disease control., (© 2015 The Authors. Journal of Animal Ecology © 2015 British Ecological Society.)