Tick abundance and life-stage segregation on the American black bear (Ursus americanus)

Abstract

Tick abundance and diagnosed cases of tick-borne diseases have been increasing in the United States. American black bear ( Ursus americanus ) populations have also been increasing in the eastern United States. As a competent host of several species of ticks and a mammal capable of traveling long distances, the role of black bears as hosts for ticks requires further evaluation. Ectoparasite surveys were conducted on black bears in Pennsylvania to evaluate tick presence, abundance, spatial distribution, and association with Sarcoptes scabiei, the etiological agent of sarcoptic mange , on bears to better understand their role in tick ecology and to improve on-host surveillance techniques. Tick burden was evaluated using standard area sampling (10.16 × 10.16 cm squares) on pre-designated body regions on black bears from June 2018–December 2019. In total, 278 unique individual black bears were evaluated, with all ticks identified as Ixodes scapularis ( n = 1976; 76.7% adults, 23.3% immatures). Tick presence differed by body region on bears, with the highest percentage of tick observations located on bear ears and muzzle. Ticks also partitioned on black bears by life-stage, with immature ticks primarily recorded on the lower extremities of bears and adult ticks primarily recorded on the front-quarters of bears. This includes the first known record of I. scapularis larvae parasitizing black bears, and observations of all three mobile life-stages concurrently parasitizing bears. Tick abundance was also statistically significant dependent on season, with the highest abundance of ticks recorded in spring and lowest abundance in fall. Adult ticks were less likely to be present on bears with mange. These data reveal the important role black bears may serve in tick ecology and dispersal as all three mobile life-stages of I. scapularis were found parasitizing a mammal capable of traveling far distances in a region with high numbers of Lyme disease cases.

Human attachment site preferences of ticks parasitizing in New York

“…Cats were more successfully parasitized by I. scapularis which preferred the head and A. americanum, which preferred the tail and perianal region 19 . This is similar to a study of tick distribution on wild black bears ( Ursus americanus ) in Pennsylvania, indicating that the primary tick present was I. scapularis and that the greatest numbers were found in association with the ears and muzzle 20 . In these cases, the ability for ticks to attach to specific areas is most likely a result of the grooming habits and abilities of the animals in question.…”

A snapshot of climate drivers and temporal variation of Ixodes ovatus abundance from a giant panda living in the wild

“…Although there were multiple tick species frequently reported on animals, a number of cases found that animals can be infested by a single tick species. For example, a survey of tick abundance on American black bears ( Ursus americanus ) found that all 1976 ticks collected from multiple areas of 278 black bears were identified as I. scapularis ( Tiffin et al, 2021 ). An early case reported more than 2000 ticks as Haemaphysalis warburtoni from a two-year old giant panda in a natural reserve in Sichuan, China ( Wu and Hu, 1985 ).…”

“…Regarding the life stage of ticks, according to previous studies, adult ticks were usually found from mammals with medium to large body size ( Bouchard et al, 2013 ). For example, 98% and 100% of I. scapularis collected from the ear area and upper spine of black bears were adults ( Tiffin et al, 2021 ). In our study, all the ticks were collected from the ear area of the giant panda and identified as adults.…”

All for One Health and One Health for All: Considerations for Successful Citizen Science Projects Conducting Vector Surveillance from Animal Hosts

“…from harvested game animals at check stations, so providing these data and ectoparasites to researchers would require little additional effort on their part. Furthermore, since they are quickly processing through many animals to satisfy their clientele, having professional wildlife accessors search for ectoparasites using an efficient systematic method (timed or by body section) may help them prioritize ectoparasite collection within their normal data collection or processing duties [ 22 , 73 , 76 ].…”

“…This does not necessarily mean that the researcher finds and pursues the wildlife themselves, although researchers have reported harvesting animals for research in some cases [ 82 ]. Instead, most studies sampled game animals at hunter check stations, deer processors, and other high-volume recreational user areas to collect ectoparasites [ 60 , 63 , 76 , 83 , 84 , 85 , 86 , 87 , 88 , 89 , 90 , 91 , 92 , 93 , 94 , 95 , 96 , 97 , 98 , 99 , 100 , 101 , 102 , 103 , 104 , 105 ]. In this case, hunters would bring harvested animals to a central location and, then, as part of the animal checks or processing, researchers could search the animal for ectoparasites using an established systematic method.…”