Raccoon Research Articles

Responses of a federally threatened shorebird to trophic downgrading and expansion of domestic cats (Felis catus)

Along U.S. Atlantic and Gulf Coast barrier islands, red foxes (Vulpes vulpes) are top predators that are thought to impact smaller mesopredators and depredate beach-nesting birds. Starting in 2015, sarcoptic mange epizootics among red foxes led to their eventual temporary extirpation from most of Fire Island, NY, USA. We monitored the subsequent changes to the mammalian predator community on this barrier island and explored the impacts to piping plovers (Charadrius melodus), a federally threatened shorebird. We deployed trail cameras and quantified detection rates of four common shorebird predators (red foxes, northern raccoons Procyon lotor, Virginia opossums Didelphis virginiana, and invasive domestic cats Felis catus), and tested for effects of predator activity and density on piping plover nest and brood survival. Following the loss of red foxes, northern raccoon and Virginia opossum activity remained relatively unchanged, while cat activity increased. The cat population grew from 14 to 42 individuals across the three study areas, and cats later became the most frequently detected mammalian predator. The loss of red foxes was associated with increased plover nest survival (β ± SD = 1.08 ± 0.55), though the increase of cats in later years was associated with a strong, negative decline in nest survival (β ± SD = −3.08 ± 1.28). Plover brood interval survival was negatively correlated with cat density (β ± SD = −0.50 ± 0.14) but not with red foxes. We underscore the importance of monitoring invasive predators during periods of trophic downgrading, which may have delayed impacts to native fauna.

Identification of a novel papillomavirus in oral swabs from giant pandas (Ailuropoda melanoleuca).

To fully characterize papillomavirus diversity in giant pandas (Ailuropoda melanoleuca), we identified a novel papillomavirus (named AmPV5, GenBank accession number MZ357114) in oral swabs from giant pandas with the help of viral metagenomics technology in this study. The complete circular genome of AmPV5 is 7,935 bp in length, with a GC content of 39.1%. It encodes five early genes (E1, E2, E4, E6, and E7), two late genes (L1 and L2), and features conserved zinc-binding domains (CXXC- (X)28/29-CXXC) in E6 and E7 genes. E7 protein has an LxCxE domain (pRB binding) in its N-terminal region. The nucleotide sequence of AmPV5 L1 gene shares < 70% identity with other related sequences available in the GenBank database. Phylogenetic analysis indicated that AmPV5 fell within the Lambdapapillomavirus genus but formed a monophyletic branch away from other papillomaviruses found in Ailuropoda melanoleuca, Canis, Felis catus, Panthera uncia, Enhydra lutris, and Procyon lotor. According to the International Committee on Taxonomy of Viruses (ICTV) classification guidelines, AmPV5 is classified as a new species within the Lambdapapillomavirus genus. The discovery provides valuable insights into the viral diversity in giant pandas and highlights the need for continued surveillance of wildlife pathogens. Future studies should explore the potential role of AmPV5 in the health and disease ecology of this endangered species.

Impervious surface cover and number of restaurants shape diet variation in an urban carnivore

AbstractIn the past decade, studies have demonstrated that urban and nonurban wildlife populations exhibit differences in foraging behavior and diet. However, little is known about how environmental heterogeneity shapes dietary variation of organisms within cities. We examined the vertebrate prey components of diets of coyotes (Canis latrans) in San Francisco to quantify territory‐ and individual‐level dietary differences and determine how within‐city variation in land cover and land use affects coyote diet. We genotyped fecal samples for individual coyote identification and used DNA metabarcoding to quantify diet composition and individual niche differentiation. The highest contributor to coyote diet overall was anthropogenic food followed by small mammals. The most frequently detected species were domestic chicken, pocket gopher (Thomomys bottae), domestic pig, and raccoon (Procyon lotor). Diet composition varied significantly across territories and among individuals, with territories explaining most of the variation. Within territories (i.e., family groups), the amount of dietary variation attributed to among‐individual differences increased with green space and decreased with impervious surface cover. The quantity of anthropogenic food in scats also was positively correlated with impervious surface cover, suggesting that coyotes consumed more human food in more urbanized territories. The quantity of invasive, human‐commensal rodents in the diet was positively correlated with the number of food services in a territory. Overall, our results revealed substantial intraspecific variation in coyote diet associated with urban landscape heterogeneity and point to a diversifying effect of urbanization on population diet.

Presence of Raccoon Roundworm (Baylisascaris procyonis) in Habitat Associated with Allegheny Woodrats (Neotoma magister) in Western Virginia, USA, 2022-24.

Baylisascaris procyonis is a roundworm that does not affect its definitive host, raccoons (Procyon lotor), but may have a devastating effect when ingested by paratenic hosts such as Allegheny woodrats (Neotoma magister). Despite being considered a major factor in woodrat population extirpation and decline in states northward, there have been no large-scale surveys for raccoon roundworm in Virginia, US. From 2022 to 2024, we visited 60 karst or nonkarst rocky habitats known (current or historical) or suspected to be Allegheny woodrat locations in western Virginia. We opportunistically collected raccoon feces as individual piles or subsampled from visible latrines. We used fecal flotation to determine the presence and prevalence of raccoon roundworm eggs in samples collected from 44 sites across 15 counties and 1 independent city. We found evidence of this roundworm at eight (18.2%) sites in six counties. Because woodrats are especially vulnerable to fatal larval infections with B. procyonis, the presence of the parasite at multiple sites suggests conservation measures should be implemented to protect these populations.

Status of Mammals Entrapment in Open Irrigation Canals

Linear infrastructure such as roads, railways, and irrigation canals causes habitat fragmentation and disrupts wildlife movement, negatively impacting ecosystems. This study investigated the physical characteristics of 80 artificial structures across South Korea and analyzed the status of wildlife entrapment prevention facilities and mammal entrapment incidents within irrigation canals. The surveyed structures, including irrigation canals, drainage canals, and roadside ditches, had an average length of 2.57 km, width of 3.34 m, and height of 1.4 m. Most structures (88.8%) were concrete, while 11.3% were mixed concrete and earthen canals. Wildlife entrapment prevention facilities, including escape facilities, cross-movement structures, and avoidance guidance facilities, were installed at low rates. Mammals entrapment incidents were observed 620 cases, with Korean water deer (&lt;i&gt;Hydropotes inermis&lt;/i&gt;) and common raccoon dog (Nyctereutes procyonoides) being the most frequently observed. Additionally, entrapment incidents involving the endangered Eurasian otter (&lt;i&gt;Lutra lutra&lt;/i&gt;) and leopard cat (Prionailurus bengalensis) were also recorded. Escape facilities and guidance facilities showed no significant difference in the average occurrence rates of mammals, but the maximum occurrence rates were lower in sections where these facilities were installed. This study provides essential baseline data for policy development and management strategies aimed at mitigating wildlife entrapments and improving ecological connectivity in artificial linear infrastructure.

Craniology of Nyctereutes procyonoides (Carnivora) based on materials from Ukraine

The article presents the results of a comprehensive craniological analysis of the common raccoon dog (Nyctereutes procyonoides Gray 1834) based on adult skulls from four samples, three of which comprise materials from Ukraine: 1) central and northern oblasts of Ukraine (Kyiv, Chernihiv, and Cherkasy oblasts); 2) eastern oblasts of Ukraine (Luhansk, Zaporizhzhia, and Poltava oblasts); 3) southern oblasts of Ukraine (Kherson Oblast). Additionally, a sample that includes materials from the native range of the species (Khabarovsk Krai, Primorsky Krai, and Chita Oblast of Russia) was also analysed. The research included standard analysis based on craniometric measurements of 19 parameters, and analysis of the skull shape by tools of geometric morphometrics separately for the dorsal and ventral sides of the skull and the buccal surface of the left mandible. The total sample comprised 62 specimens. The results of the analysis of linear characters showed that specimens from the northern, central, and southern oblasts of Ukraine differ from those from the eastern oblasts of Ukraine and from specimens from the Far East, which are characterised by larger dimensions. The analysis of shape differences using MorphoJ demonstrates the greatest morphological distance between the samples from the territory of Ukraine and the sample from the species’ native range. The analysis of the dorsal and ventral surfaces of the skulls showed that the specimens from the native range of the common raccoon dog have more elongated and broader nasal bones, while the braincase is narrowed from the sides, but elongated towards the occipital bones. The greatest level of shape variation is characteristic of the mandible. Specimens from the territory of Ukraine have a more elongated mandibular ramus and a larger area of the coronal, articular, and angular processes, while skulls from the species’ native range have a larger angle between the mandibular ramus and the coronal process, which in turn has a greater inclination relative to the articular process and a smaller area of the angular process. Skull size is often larger in animals in introduced populations, but it also depends on environmental conditions, nutrition, and interspecific competition.

Detection and phylogenetic analysis of blood-associated pathogens from spleen samples of wild raccoons (Procyon lotor) in Germany

Raccoons (Procyon lotor) originated in North America and have been introduced to Europe. Due to their close contact with human settlements, they are important reservoirs for zoonotic pathogens, such as Baylisascaris procyonis. The relevance and prevalence of vector-borne pathogens have not yet been fully elucidated. In this study, we screened 285 spleen samples of raccoons, collected between 2019 and 2022 in Germany. The samples were analysed by PCR to detect Mycoplasma spp., Anaplasmataceae, Bartonella spp., Babesia spp., Rickettsia spp., Filarioidea, Trypanosomatida and Hepatozoon spp., and positive PCR products were sequenced. In total, 104 samples were positive for Mycoplasma spp. (36.49%), making this the first study to detect Mycoplasma spp. in raccoons outside of North America. Three samples were positive for Babesia spp. (1.05%) and two for Anaplasma phagocytophilum (0.7%). Phylogenetic analysis revealed that the Mycoplasma spp. detected all belong to the haemotrophic mycoplasmas cluster and were grouped within a single phylogenetic clade. Two different Babesia spp. were detected, one of which was closely related to Babesia canis, while the other was more closely related to Babesia sp. from ruminants. It is unclear whether the pathogens detected have an impact on the health of raccoons or whether they may serve as a reservoir for other animals.

Detection of antibodies against H5 subtype highly pathogenic avian influenza viruses in multiple raccoons in Tokachi District, Hokkaido, Japan, from 2022 to 2023.

In recent years, infection cases of H5 subtype highly pathogenic avian influenza viruses (HPAIVs) in wild mammals have increased globally. To obtain recent epidemiological information regarding influenza A virus (IAV) infection in raccoons (Procyon lotor), the prevalence of anti-IAV antibodies in sera was analyzed among raccoons captured in Tokachi District, Hokkaido, Japan, from 2019 to 2023. Screening of serum samples using enzyme-linked immunosorbent assay and agar gel precipitation test detected anti-IAV antibodies in 5 of 114 (4.4%) raccoons. All positive sera were from raccoons captured from 2022 to 2023. The hemagglutination inhibition test revealed that all five serum samples contained anti-H5 subtype HPAIV antibodies, and one also contained anti-H1 subtype antibodies. The neuraminidase inhibition test revealed that all five sera contained anti-N1 subtype antibodies, and one also contained anti-N8 subtype antibodies. In the virus neutralization test, these five sera showed stronger neutralization activity against the H5 subtype clade 2.3.4.4b HPAIV strain recently circulating worldwide compared to the old H5 HPAIV strain isolated in Japan in 2007. Findings suggested that raccoons could be involved in the circulation of H5 HPAIVs in nature.

Lack of host‐associated differentiation in Ixodes scapularis using population genetics

AbstractThe blacklegged tick, Ixodes scapularis (Say) (Acari: Ixodidae), is a vector of pathogens that cause diseases including anaplasmosis, babesiosis, and Lyme disease. It is a generalist vector feeding on a wide variety of vertebrate hosts. The transmission cycles of these pathogens are affected by the tick's host selection because host species differ in their ability to clear, maintain, or amplify these pathogens. Several generalist parasites exhibit host‐associated differentiation (HAD), a process that results in genetically distinct populations associated with different host species. Knowing whether I. scapularis exhibits HAD is important to better understand the ecology of these diseases. To test for HAD in I. scapularis, whole‐genome resequencing was performed on ticks collected directly from six hosts in the southern United States (i.e., cotton mice [Cricetidae: Peromyscus gossypinus Le Conte], opossum [Didelphidae: Didelphis virginiana Kerr], raccoon [Procyonidae: Procyon lotor L.], gray fox [Canidae: Urocyon cinereoargenteus Schreber], wild boar or feral hog [Suidae: Sus scrofa L.], and white‐tailed deer [Cervidae: Odocoileus virginianus Zimmermann]). For the hosts tested, HAD was not found. However, it could not be ruled out if HAD is occurring for ticks associated with lizards in this study. The results of this study contrast with findings from another host generalist, Dermacentor variabilis (Say), that does exhibit HAD. Our results suggest that these two tick species differ in their propensity for HAD. One explanation could be that I. scapularis can mate off‐host, maintaining panmixia, whereas D. variabilis mate only on the host. The lack of HAD in I. scapularis should be confirmed by sampling ticks from lizard and rodent hosts. These results will inform control efforts and the use of area‐wide tick control strategies.

Caging Four-Toed Salamander Nests Reduces Nest Predation in Northeastern Tennessee

Abstract Four-toed salamanders Hemidactylium scutatum have disjunct populations in the United States and Canada. Increased predation could threaten their populations and cause them to become limited in certain areas. Installing cages to protect threatened populations can reduce the chance of predation. To test the efficacy of cages, we examined the effects of caging four-toed salamander nests in northeastern Tennessee. We randomly selected 65/120 nests to cage from our study sites at the South Holston Weir Dam and Bouton Tract in Sullivan County, Tennessee. Based on photos from a camera trapping survey, we found that raccoons Procyon lotor were the main predators of uncaged four-toed salamander nests. Raccoon damage resulted in portions of moss being ripped away and the disappearance of eggs. Twenty-six percent of uncaged nests were preyed upon, whereas none of the caged nests were preyed upon. Our findings provide a strategy for improving nest success of four-toed salamanders and could be used to protect threatened populations.

Environmental Modulators on the Development of the Raccoon Roundworm (Baylisascaris procyonis): Effects of Temperature on the Embryogenesis

Members of the Ascarididae family are common zoonotic pathogens in humans and play an economic role in domestic and livestock animal husbandry. This family includes the obligatorily parasitic nematodes of the genus Baylisascaris, with the raccoon roundworm Baylisascaris procyonis being the most well-known representative. B. procyonis uses the raccoon (Procyon lotor) as its primary host and can utilize a broad range of mammals as paratenic hosts. Sexual reproduction of the adult nematodes occurs in the small intestine. Eggs are excreted into the environment through feces, where they develop into the infectious stage under suitable conditions within a few days to weeks. Infection of primary and paratenic hosts occurs through the oral ingestion of these infectious eggs. Raccoons can also become infected by ingesting infected paratenic hosts. Humans serve as accidental hosts and can suffer significant damage to organ tissues, the visual system, and the central nervous system after ingesting infectious eggs. The aim of the study was to investigate the effects of ambient temperature on embryonic development and to document the morphological changes during embryogenesis. Live specimens were collected from the raccoon intestine and incubated. Single-celled eggs were collected during this process. The eggs were decorticated and then preserved. To test the effects of ambient temperature, the eggs were incubated at 5°C, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, and 38°C and monitored at 24-hour intervals for their developmental stages. Detailed photographic documentation of the developmental stages was conducted. An increase in ambient temperature led to a reduction in development time. The temperature range within which embryogenesis proceeded to the L1 larval stage was between 10°C and 30°C. Incubation at 5°C did not produce L1 larvae even after 11 months. Incubation at 35°C and 38°C resulted in the complete degeneration of the eggs before reaching the L1 larval stage.

Survey for Babesia spp. in wildlife in the eastern United States

Babesia is a diverse genus of piroplasms that parasitize the red blood cells of a wide variety of mammals and avian species, including humans. There is a lack of knowledge on the Babesia species of carnivores and mesomammals in the eastern United States and the potential impacts of these species on the health of humans and domestic animals. We surveyed 786 wild mammals in the eastern United States by testing blood, spleen, and heart samples with PCR targeting the 18S rRNA region of apicomplexan parasites. We also performed PCR targeting the cytochrome c oxidase subunit 1 (cox1) region of each unique clade identified with 18S rRNA sequencing. We found a high positivity of Babesia spp. infection in raccoons (Procyon lotor), foxes (Vulpes vulpes and Urocyon cinereoargenteus), and striped skunks (Mephitis mephitis), and low positivity in Virginia opossums (Didelphis virginiana). No Babesia infections were detected in coyotes (Canis latrans), black bears (Ursus americanus), groundhogs (Marmota monax), muskrats (Ondatra zibethicus), or mink (Neovison vison). Skunks carried a diverse number of strains including a potential novel species of Babesia related to B. gibsoni, a strain closely related to a B. microti-like species known to cause disease in river otters, as well as a separate B. microti-like strain. Raccoons primarily carried B. microti-like strains, though there was a high diversity of sequences including Babesia lotori, Babesia sensu stricto MA230, and Babesia sp. ‘Coco.’ Foxes exclusively carried B. vulpes. In addition to Babesia spp., a high positivity of Hepatozoon spp. infection was found in mink, while low positivity was found in raccoons and muskrats. Wildlife in the eastern United States carry a diverse range of Babesia species including several novel strains of unknown clinical significance.

Epidemiological Survey of Canine Distemper Virus Infection: Exploring the Link Between Virus Spread and Invasive Raccoon (Procyon lotor) Population Growth in Hokkaido, Japan

ABSTRACTInvasive raccoons (Procyon lotor) naturalized in Hokkaido, Japan, potentially spreading infectious diseases. Canine distemper virus infection is a serious epizootic disease, for which the raccoon is one of the hosts. We investigated the virus's prevalence in Hokkaido's wild raccoons, using 611 serum samples collected from captured raccoons in 2007–2012, 2021, and 2022. Higher seropositivity rates were confirmed in 2007 (32.7%), 2021 (46.4%), and 2022 (46.8%) than in 2008–2012 (0.00%–6.06%), suggesting the occurrence of an epidemic in 2007, 2021, and 2022 and its disappearance in 2008–2012. However, the infection status has recently changed, with high seropositivity rates consecutively confirmed in 2021 and 2022. Logistic regression analysis was performed to investigate the relationships among the catch per unit effort (an index of animal population density), host and environmental factors, and antibody status. The catch per unit effort correlated with seropositivity in 2007. As for environmental factors, the forest area ratio had a weak influence on seroprevalence in 2007; however, the residential area ratio had a clear influence on seroprevalence in 2021 and 2022. The epidemic occurred in forested areas in 2007; nonetheless, recent raccoon population growth and habitat expansion may have caused widespread infections even around residential areas in 2021 and 2022. Continuous monitoring of the infection and reinforcement of raccoon control programs are necessary to avoid serious damage through disease transmission to sympatric native raccoon dog (Nyctereutes procyonoides) and fox (Vulpes vulpes) populations, as well as health consequences for domestic dogs (Canis familiaris).

Climate Extremes in Consecutive Years Impacted the Number and Fate of Duck Nests on Great Salt Lake Marshes.

The number of ground-nesting ducks in the marshes of Great Salt Lake (GSL), Utah has drastically decreased in the past few decades. One potential cause for this decline is the increase in climate extremes caused by global warming. From 2019 through 2023, GSL marshes experienced 1 year of historic spring rainfall (2019), 2 years of historic droughts (2021 and 2022), and 1 year of record snowfall (2023). We used this time period to test the hypothesis that climate extremes impact both the number of duck nests and their fate (i.e., successful, depredated, or abandoned). We counted 563 nests of cinnamon teal (Spatula cyanoptera), 168 mallards (Anas platyrhynchos), and 220 gadwalls (Mareca strepera). Nest numbers varied among years and were positively correlated with the amount of spring rainfall (April and May). Clutch sizes differed among years and were lowest during the drought years. Raccoons (Procyon lotor) and striped skunks (Mephitis mephitis) were the major predators of nests. The percentage of all duck nests that were depredated varied among years and increased from 40% and 46% during the 2 wet years to 75% and 90% during the 2 drought years. The percentage of nests that were successful varied among years and were highest during the wet years. The yearly percentage of successful nests was negatively correlated with the abundance of all predators and positively correlated with snowfall because few skunks and raccoons survived the winter of 2023 with its heavy snowfall. Daily survival rates ( = 0.93), were similar among duck species, but varied among years; DSRs were lowest during the drought years (0.86 and 0.92) and highest during the wet years (0.96 for both years). Our results suggest that climate extremes will have an adverse impact on both the number of duck nests and the percentage of them that are successful.

Raccoon density estimation from camera traps for raccoon rabies management

AbstractDensity estimation for unmarked animals is particularly challenging, yet density estimates are often necessary for effective wildlife management. Raccoons (Procyon lotor) are the primary terrestrial wildlife reservoir for Lyssavirus rabies within the United States. The raccoon rabies variant (RRVV) is actively managed at landscape scales using oral rabies vaccination (ORV) within the eastern United States. To effectively manage RRVV, it is important to know the density of raccoons to appropriately scale the density of ORV baits distributed on the landscape. We compared methods to estimate raccoon densities from camera‐trap data versus more intensive capture‐mark‐recapture (CMR) estimates across 2 land cover types (upland pine and bottomland hardwood) in the southeastern United States during 2019 and 2020. We evaluated the effect of alternative camera configurations and durations of camera trapping on density estimates and used an N‐mixture model to estimate raccoon densities, including covariates on abundance and detection. We further compared different methods of scaling camera‐based counts, with the maximum number of raccoons seen on any given image within a day best explaining density. Camera‐trap density estimates were moderately correlated with CMR estimates (r = 0.56). However, densities from camera‐trap data were more reliable when classifying category of density as an index used to inform management (83% correct when compared to CMR estimates), although the densities in our study fell into the 2 lowest density classes only. Using more cameras reduced bias and uncertainty around density estimates; however, if ≤6 camera traps were used at a site, a line transect approach proved less biased than a grid design. Camera trapping should be conducted for at least 3 weeks for more accurate estimates of raccoon population density in our study area (&lt;5% bias). We show that camera‐trap data can be used to assign raccoon densities to management‐relevant density index bins, but more studies are needed to ensure reliability across a greater range of environmental conditions and raccoon densities.

Klebsiella pneumoniae Complex-Associated Peritonitis, Lymphadenitis, and Pyelonephritis in Juvenile Raccoons (Procyon lotor) under Rehabilitator Care in New York, New Jersey, and Wisconsin, USA.

Klebsiella spp. are gram-negative facultative anaerobic heavily encapsulated bacteria associated with opportunistic and primary infections in a wide range of species. We assessed a series of cases (n=8) of necrosuppurative peritonitis, lymphadenitis, and/or pyelonephritis in wild juvenile raccoons (Procyon lotor) that died under rehabilitator care in New York, New Jersey, and Wisconsin, US, between July 2020 and December 2023, plus a retrospective case of a juvenile raccoon necropsied from New York in August 2011. Gross necropsy (n=9) and histopathology (n=9) were performed to characterize the lesions, whereas bacterial culture (n=8) was used to identify and characterize the bacteria and associated phenotype. We observed gram-negative short rods and coccobacilli (7/9; 78%), fibrinosuppurative peritonitis of variable severity (7/9; 78%) correlated to gross pyoabdomen (5/9; 56%) or abscessation (2/9; 22%), lymphadenomegaly and associated necrosuppurative lymphadenitis (5/9; 56%), and urinary tract disease (3/9; 33%). Aerobic culture of affected tissues isolated Klebsiella pneumoniae (n=4), K. pneumoniae subsp. ozaenae (n=2), Klebsiella variicola (n=1), and Klebsiella sp. (n=1). Our study strongly suggests an association of bacteria within the K. pneumoniae complex with peritonitis, lymphadenitis, and pyelonephritis in raccoons. Disease might be associated with underlying nosocomial infection given that all animals were under rehabilitator care at the time of death.

Environmental and host factors underlying tick-borne virus infection in wild animals: Investigation of the emerging Yezo virus in Hokkaido, Japan

Yezo virus (YEZV) is an emerging tick-borne virus that causes acute febrile illness. It has been continuously reported in patients and ticks in Japan and China since its first identification in Hokkaido, Japan. While serological tests have demonstrated that YEZV infections are prevalent in wild animals, such as raccoons (Procyon lotor), the determinants of infection in wild animals remain largely unknown. We examined the prevalence of YEZV in invasive raccoons, native tanukis (raccoon dogs, Nyctereutes procyonoides albus), and ticks in six study areas in Hokkaido between 2018 and 2023 to identify ecological factors underlying YEZV infection in wild animals. YEZV RNA fragments were detected in 0.22% of the 1,857 questing ticks. Anti-YEZV antibodies were detected in 32 of the 514 (6.2%) raccoon serum samples and in 5 of the 40 (12.5%) tanuki serum samples. Notably, the seroprevalence in raccoons varied significantly in one of the study areas over the years, that is, 0.0%, 60.0%, and 28.6% in 2021, 2022, and 2023, respectively, implying the temporary emergence of YEZV microfoci. By analyzing the tick load and YEZV seropositivity in raccoons in a field-based setting, we found a positive correlation between adult Ixodes ovatus load and YEZV-antibody positivity, highlighting the importance of I. ovatus in YEZV infection in wild animals. We also explored the environmental and host factors influencing YEZV seropositivity in raccoons and tanukis and found that landscape factors, such as the size of forest area around the trap site, were crucial for YEZV seropositivity in these animals. The significant variables for YEZV seropositivity in raccoons were partially different from those affecting tick infestation intensity in raccoons. The present results extend our understanding of tick-borne virus circulation in the field, emphasizing the unique ecology of the emerging YEZV.

The evolutionary and ecological convergence of the raccoon and raccoon dog: A perfect storm of invasive species in Europe

AbstractThis paper initially describes the evolution of body shape in the raccoon (Procyon lotor) and the raccoon dog (Nyctereutes procyonoides). I explain how their similarities are the result of convergent evolution, the process by which unrelated organisms come to resemble one another in form, function, or both. This is the first examination of this phenomenon in these two species. In addition, I consider how their convergent traits and habits as omnivores have contributed to their astounding success as invasive species in Europe. Problems have arisen from these introductions, including impacts on prey species. Considering their broad adaptability as “stout” shaped mesocarnivores should aid in understanding their behavior and ecology, and could assist in addressing their management in Europe. Last, I offer suggestions for the control of raccoons given their compensatory versus additive mortality patterns, a practice that may also have implications for the regulation of raccoon dog populations.

Human-derived food shrinks home ranges and alters resource selection of mammals at the urban-wild interface

Protected lands are an important source of food, shelter, and reproductive opportunities for wildlife, especially in urban landscapes. When urban development abuts the edges of undisturbed ecosystems, synanthropic species can alter their foraging behaviors and movement to utilize human-supplemented resources throughout the urban-wild interface. Therefore, urban development on the edges of protected lands can have pronounced effects on animal movement and ecosystem functions. Iconic urban adaptive mesopredators such as northern raccoons (Procyon lotor) and Virginia opossums (Didelphis virginiana) often benefit from human-supplemented food sources such as unsecured garbage, pet food, and fresh water when available. To investigate how urban edges affect the movements of urban-adapted omnivores within conservation lands, we estimated home ranges and third-order resource selection of 27 raccoons and 12 opossums with GPS collars throughout the protected areas of northern Key Largo, FL, USA between April 2022–October 2023. The proportion of urban development in an individual's home range was the most influential factor associated with home range size, followed by species and sex. Individuals with greater proportions of residential neighborhoods and commercial areas in their home ranges exhibited smaller home ranges. Third-order resource selection functions identified both mesopredator species using residential and commercial land use areas more than they were available on the landscape. These results indicate that urban areas attract urban-adapted mesopredators from protected areas and result in smaller home ranges in the face of abundant human-derived food. Reduced home ranges on edges can support higher densities of animals, which may increase rates of disease transmission, especially when the urban borders support populations of feral domestic species. Shifting foraging behaviors from the protected areas to urban edges could have cascading downward effects if seed-dispersing roles are diluted. As urbanization increases and the distance between wild lands and human disturbance decreases, it is increasingly important to study the mechanisms of how urban development on the edges of protected areas affect the movement of wildlife.

Rabies situation in the Moscow Oblast in 2011–2023 and the role of oral vaccination of wild carnivores against rabies

Rabies is a zoonotic viral disease of all warm-blooded animals caused by a neurotropic virus, member of the Lyssavirus genus of the Rhabdoviridae family. About 59,000 people die from hydrophobia globally every year. According to the World Health Organization, the red fox (Vulpes vulpes) and the common raccoon dog (Nyctereutes procyonoides) are the main reservoirs and vectors among carnivores of the rabies virus in Europe. The paper describes animal rabies situation in 2011–2023 and the role of oral vaccination of wild carnivores against rabies in the Moscow Oblast. The region is a part of the Central Federal District and located in the center of the Russian plain bordering seven Oblasts (Tver, Smolensk, Kaluga, Tula, Ryazan, Vladimir and Yaroslavl Oblasts), which are also rabies infected. Notwithstanding the metropolis growth, the number of wild carnivores in the Moscow Oblast remains high. Comprehensive preventive measures to control the population of the wild carnivores are taken to stabilize the rabies situation and decrease the incidence, innovative achievements in laboratory diagnosis are introduced, population immunity of wild carnivores by oral vaccination is improved and the epidemic situation in neighboring regions is analyzed. In 2017 the systemic, consistent and thoroughly organized campaign was started – the oral vaccines were distributed by light aircrafts. The research revealed the correlation between the decrease in annual number of reported rabies cases and increase in the amounts of oral vaccines distributed. The use of controlling devices (camera traps) confirmed that oral rabies vaccines are consumed by the target animals (red foxes). The onward systemic, methodical approach to rabies prevention will mitigate the risks of rabies occurrence in the Moscow Oblast.