Raccoon Populations Research Articles

First records of the raccoon roundworm (Baylisascaris procyonis) in Luxembourg: evidence for natural spread and a novel introduction

The raccoon roundworm (Baylisascaris procyonis), a gastrointestinal nematode parasite of the raccoon (Procyon lotor), is the causative agent of a zoonotic disease that can cause severe neurological sequelae and even fatal cases. The parasite is now established in Europe and, while not present in all raccoon populations, it is currently expanding its range. Understanding the geographic distribution of the roundworm is a necessity for public health. Here, we report the first detections of the raccoon roundworm from Luxembourg. We used genetic techniques to test whether the roundworm originated from a distinct introduction event or entered the country by natural dispersal. We detected two roundworms in a raccoon that was road-killed in Echternach, northeastern Luxembourg. Furthermore, in a wildlife rescue centre, roundworms were detected in the latrine of an enclosure containing seven raccoons. Using different genetic techniques, we showed the Echternach roundworms to originate from the nearest German population, while the rescue centre roundworms were genetically distinct. By genotyping the host from a roundworm DNA extract, we identified a raccoon originating from southwest Luxembourg as the host of at least one roundworm. Roundworms are thus colonising Luxembourg both by natural dispersal and from an introduced population. The (potential) hosts all originated from the local population, suggesting that imported/introduced roundworms have already spread to the local raccoon population. Authorities should act as though the parasite is already widespread in the country, raising awareness among the public and individuals with occupational contact with raccoons.

Genetic Tracking of a Rabid Coyote (Canis latrans) Detected beyond a Rabies Enzootic Area in West Virginia, USA.

Wildlife translocation and cross-species transmission can impede control and elimination of emerging zoonotic diseases. Tracking the geographic origin of both host and virus (i.e., translocation versus local infection) may help determine the most effective response when high-risk cases of emerging pathogens are identified in wildlife. In May 2022, a coyote (Canis latrans) infected with the raccoon (Procyon lotor) rabies virus variant (RRV) was collected in Lewis County, West Virginia, USA, an area free from RRV. We applied host population genomics and RRV phylogenetic analyses to determine the most likely geographic origin of the rabid coyote. Coyote genomic analyses included animals from multiple eastern states bordering West Virginia, with the probable origin of the rabid coyote being the county of collection. The RRV phylogenetic analyses included cases detected from West Virginia and neighboring states, with most similar RRV sequences collected in a county 80 km to the northeast, within the oral rabies vaccination zone. The combined results suggest that the coyote was infected in an RRV management area and carried the RRV to Lewis County, a pattern consistent with coyote local movement ecology. Distant cross-species transmission and subsequent host movement presents a low risk for onward transmission in raccoon populations. This information helped with emergency response decision-making, thereby saving time and resources.

A forensic genetic investigation reveals a captive origin for a wild alien population of raccoons in Italy

Invasive alien species have extensively impacted the ecosystems, where they may affect the native biodiversity. The North American raccoon Procyon lotor is one of the most successful invaders in Europe since its introduction in the early twentieth century. In Italy, a wild population was first established in the North at the beginning of the 2000s following a local introduction event. A further self-sustaining population was reported ten years later in Central Italy. To support an official investigation by the authorities, who suspected a captive origin of the free-ranging raccoons in Central Italy, we used nuclear and mitochondrial DNA markers, combined with different statistical approaches, to characterise their gene pool and trace the source of the founders. Results revealed that founders came from a private zoo-park from which they had inadvertently escaped, soon establishing a reproductive population in the wild. Additionally, our mitochondrial DNA data were used to supplement the haplotype variability known to date in captive and wild raccoons from Europe, Asia and their native range. The comparisons allowed us to update previous networks based on the control region with a new mitochondrial lineage, which had not been detected so far.

Surveys on Baylisascaris procyonis in two of the three French wild raccoon populations

Human infection by Baylisascaris procyonis can result in larva migrans syndromes, which can cause severe neurological sequelae and fatal cases. The raccoon serves as the definitive host of the nematode, harboring adult worms in its intestine and excreting millions of eggs into the environment via its feces. Transmission to paratenic hosts (such as rodents, birds and rabbits) or to humans occurs by accidental ingestion of eggs. The occurrence of B. procyonis in wild raccoons has been reported in several Western European countries. In France, raccoons have currently established three separate and expanding populations as a result of at least three independent introductions. Until now the presence of B. procyonis in these French raccoon populations has not been investigated. Between 2011 and 2021, 300 raccoons were collected from both the south-western and north-eastern populations. The core parts of the south-western and north-eastern French raccoon populations were free of B. procyonis. However, three worms (molecularly confirmed) were detected in a young raccoon found at the edge of the north-eastern French raccoon population, close to the Belgian and Luxemburg borders. Population genetic structure analysis, genetic exclusion tests and factorial correspondence analysis all confirmed that the infected raccoon originated from the local genetic population, while the same three approaches showed that the worms were genetically distinct from the two nearest known populations in Germany and the Netherlands. The detection of an infected raccoon sampled east of the northeastern population raises strong questions about the routes of introduction of the roundworms. Further studies are required to test wild raccoons for the presence of B. procyonis in the area of the index case and further east towards the border with Germany.

Cerebral baylisascariosis in a rainbow lorikeet (Trichoglossus moluccanus) in a German Zoo

BackgroundThe raccoon roundworm, Baylisascaris procyonis, can cause a meningoencephalitis as neural larva migrans which is known in avian species, including rainbow lorikeets in North America, but has not been described in Old World parrots in Germany yet.Case presentationA 2-month-old, male rainbow lorikeet from a zoo in Germany was submitted for necropsy. Prior to death the animal had progressive neurological signs like apathy and torticollis. In the cerebrum a focally extensive severe granulomatous to necrotizing encephalitis with an intralesional larval nematode was diagnosed. Based on the clinical and pathological findings, the larval morphology and the epidemiological background, the larva was identified as Baylisascaris procyonis.ConclusionsCerebral baylisascariosis should be considered as a differential diagnosis in zoo and pet birds with neurological signs having contact to racoons or rather racoon faeces in Germany due to the high prevalence of Baylisascaris procyonis in the German raccoon population.

Oral Rabies Vaccination of Raccoons (Procyon lotor) across a Development Intensity Gradient in Burlington, Vermont, USA, 2015-2017.

Management of the raccoon rabies virus variant in North America is conducted primarily using oral rabies vaccination (ORV). When a sufficient proportion of the population is vaccinated (∼60%), rabies transmission can be eliminated. To date, ORV programs have successfully controlled and eliminated raccoon rabies in rural areas, but there has been less success in urban areas. We studied the proportions of rabies virus neutralizing antibodies (RVNA) in a raccoon (Procyon lotor) population during a 3-yr ORV trial in developed areas of Burlington, Vermont, US. We used a modified N-mixture model to estimate raccoon abundance, RVNA seroprevalence, and capture rates jointly to examine factors that relate to ORV success to better inform management. We found that raccoon abundance was lower in less-developed areas compared to urban centers. Raccoon RVNA seroprevalence decreased as population abundance increased; it increased as the average age of the population increased. Nontarget opossum (Didelphis virginiana) captures correlated with a decrease in raccoon RVNA seroprevalence in low-development areas, suggesting that they may be competing for baits. The target bait density across the entire study area was 150 baits/km2, but a hand baiting strategy was heavily concentrated on roads, resulting in uneven bait densities within sampling sites (0-484 baits/km2). Uneven bait distribution across the study area may explain low RVNA seroprevalence in some locations. Our results suggest that increases in bait density across the study area may improve RVNA seroprevalence and support annual ORV to account for raccoon population turnover.

Assessing the Efficiency of Local Rabies Vaccination Strategies for Raccoons (Procyon lotor) in an Urban Setting.

Raccoon rabies virus (RRV) has been managed using multiple vaccination strategies, including oral rabies vaccination and trap-vaccinate-release (TVR). Identifying a rabies vaccination strategy for an area is a nontrivial task. Vaccination strategies differ in the amount of effort and monetary costs required to achieve a particular level of vaccine seroprevalence (efficiency). Simulating host movement relative to different vaccination strategies in silico can provide a useful tool for exploring the efficiency of different vaccination strategies. We refined a previously developed individual-based model of raccoon movement to evaluate vaccination strategies for urban Hamilton, Ontario, Canada. We combined different oral rabies vaccination baiting (hand baiting, helicopter, and bait stations) with TVR strategies and used GPS data to parameterize and simulate raccoon movement in Hamilton. We developed a total of 560 vaccination strategies, in consultation with the Ontario Ministry of Natural Resources and Forestry, for RRV control in Hamilton. We documented the monetary costs of each vaccination strategy and estimated the population seroprevalence. Intervention costs and seroprevalence estimates were used to calculate the efficiency of each strategy to meet targets set for the purpose of RRV control. Estimated seroprevalence across different strategies varied widely, ranging from less than 5% to more than 70%. Increasing bait densities (distributed using by hand or helicopter) led to negligible increase in seroprevalence. Helicopter baiting was the most efficient and TVR was the least efficient, but helicopter-based strategies led to lower levels of seroprevalence (6-12%) than did TVR-based strategies (17-70%). Our simulations indicated that a mixed strategy including at least some TVR may be the most efficient strategy for a local urban RRV control program when seroprevalence levels >30% may be required. Our simulations provide information regarding the efficiency of different vaccination strategies for raccoon populations, to guide local RRV control in urban settings.

Characterisation of pathogenic Leptospira in invasive raccoons (Procyon lotor) in northeast and southwest France.

Leptospirosis is a widespread zoonosis caused by bacteria of the genus Leptospira. Although crucial to mitigate the disease risk, basic epidemiological information is lacking, such as the identities of Leptospira maintenance hosts. The raccoon (Procyon lotor), an alien invasive species in France, could pose a public health risk if it carries pathogenic Leptospira. We investigated the rate and type (selective vs. unselective) of Leptospira carriage in the two main raccoon populations in France. Out of the 141 raccoons collected, seven (5%) tested quantitative PCR positive, targeting lfb1 gene, based on kidney, lung, and urine samples. Phylogenetic analysis revealed the presence of three different L. interrogans clusters. The results suggest that raccoons were more likely accidental hosts and made only a limited contribution to Leptospira maintenance.

Are rabid raccoons (Procyon lotor) ready for the rapture? Determining the geographic origin of rabies virus-infected raccoons using RADcapture and microhaplotypes.

North America is recognized for the exceptional richness of rabies virus (RV) wildlife reservoir species. Management of RV is accomplished through vaccination targeting mesocarnivore reservoir populations, such as the raccoon (Procyon lotor) in Eastern North America. Raccoons are a common generalist species, and populations may reach high densities in developed areas, which can result in contact with humans and pets with potential exposures to the raccoon variant of RV throughout the eastern United States. Understanding the spatial movement of RV by raccoon populations is important for monitoring and refining strategies supporting the landscape-level control and local elimination of this lethal zoonosis. We developed a high-throughput genotyping panel for raccoons based on hundreds of microhaplotypes to identify population structure and genetic diversity relevant to rabies management programs. Throughout the eastern United States, we identified hierarchical population genetic structure with clusters that were connected through isolation-by-distance. We also illustrate that this genotyping approach can be used to support real-time management priorities by identifying the geographic origin of a rabid raccoon that was collected in an area of the United States that had been raccoon RV-free for 8 years. The results from this study and the utility of the microhaplotype panel and genotyping method will provide managers with information on raccoon ecology that can be incorporated into future management decisions.

Spread of the Zoonotic Nematode Baylisascaris procyonis into a Naive Raccoon Population

The raccoon roundworm (Baylisascaris procyonis), a gastrointestinal nematode of the raccoon (Procyon lotor), may cause a severe form of larva migrans in humans, which can lead to death or permanent neurological damage. Although roundworms were inadvertently introduced to Europe alongside their raccoon hosts, the parasite is not present in every raccoon population. It is important to understand the geographic distribution of B. procyonis, as early and rapid treatment can prevent severe pathologies in humans. We present evidence for the roundworm spreading into a naive raccoon population through natural dispersal of infected raccoons. We sampled 181 raccoons from Saxony-Anhalt, a German federal state containing contact zones of different raccoon populations, two of which were previously free of the parasite. We screened the raccoons for roundworms and used microsatellite-based assignment tests to determine the genetic origin of the raccoons and their parasites. We detected roundworms in 16 of 45 raccoons sampled in a previously roundworm-free area in the northern part of the state. The largest proportion of the genetic ancestry (≥ 0.5) of the 16 raccoon hosts was assigned to the previously naive raccoon population. Conversely, the genetic ancestry of almost all the roundworms was assigned to the nearest roundworm population in the southern part of the state. Infected raccoons have, therefore, spread to the north of the state, where they interbred with and infected local raccoons. It seems likely that the roundworms will continue to spread. Health authorities should consider continuous surveillance programmes of naive populations and raise public awareness.

Demographic, environmental and physiological predictors of gastrointestinal parasites in urban raccoons.

Raccoons are host to diverse gastrointestinal parasites, but little is known about the ecology of these parasites in terms of their interactions with each other during coinfections, their interactions with host physiology and environmental factors, and their impact on raccoon health and survival. As a first step, we investigated the patterns of parasite infection and their demographic distribution in an urban-suburban population of raccoons trapped in the summers and autumns of 2018 and 2019. We collected faecal samples, demographic data, morphometric measurements, and blood smears, and used GPS data to classify trapping location by land cover type. Faecal floats were performed to detect and quantify gastrointestinal nematode eggs and coccidia oocysts, and white blood cell differentials were performed on blood smears to characterise white blood cell distributions. Data were analysed cross-sectionally and, where possible, longitudinally, using generalised linear models. Overall, 62.6% of sampled raccoons were infected with gastrointestinal nematodes, and 82.2% were infected with gastrointestinal coccidia. We analysed predictors of infection status and faecal egg count for three different morphotypes of nematode-Baylisascaris, strongyle, and capillariid nematodes-and found that infection status and egg count varied with Year, Month, Age class, Land cover, and coinfection status, though the significance of these predictors varied between nematode types. Gastrointestinal coccidia prevalence varied with Year, Month, Age class, strongyle infection status, and capillariid infection status. Coccidia oocyst counts were lower in adults and in October, but higher in females and in raccoons trapped in areas with natural land cover; furthermore, coccidia oocysts were positively associated with capillariid faecal egg counts. We found no evidence that gastrointestinal parasites influenced raccoon body condition or overwinter mortality, and so conclude that raccoons, though harbouring diverse and abundant gastrointestinal parasites, may be relatively tolerant of these parasites.

Trypanosoma cruzi infection in mammals in Florida: New insight into the transmission of T. cruzi in the southeastern United States.

In Latin America, synanthropic mammalian reservoirs maintain Trypanosoma cruzi, a parasitic protozoan, where they facilitate the transmission of the parasite to humans and other reservoir hosts in peridomestic settings. In the United States, raccoons (Procyon lotor) and Virginia opossums (Didelphis virginiana) are known synanthropic T. cruzi reservoir hosts; however, the role these species have in the peridomestic transmission cycle in the US is not well understood. This study aimed to identify the suite of mammalian reservoirs of T. cruzi in Florida. We also compared infection prevalence in raccoon populations sampled from within and outside of the estimated distribution of the common T. cruzi vector in Florida to gain insight into how the arthropod vector distribution impacts the distribution of infected reservoirs in the state. Finally, to investigate the impact of peridomestic landscapes on parasite prevalence, we compared the prevalence of T. cruzi-infected raccoons and opossums across five paired peridomestic and sylvatic sites. We live-trapped and collected peripheral blood samples from 135 raccoons, 112 opossums, 18 nine-banded armadillos (Dasypus novemcinctus), and nine species of rodents in north central Florida. Using quantitative PCR methods, we found that raccoons (42.2%, 95% CI [34.2-50.7%]) and opossums (50.9%, 95% CI [41.8-60.0%]) were infected with T. cruzi and the prevalence across habitats was similar for both raccoons (peridomestic: n=77, 44.2%, 95% CI [33.6-55.3%], sylvatic: n=58, 39.7%, 95% CI [28.1-52.5%]) and opossums (peridomestic: n=66, 48.5%, 95% CI [36.8-60.3%], sylvatic: n=46, 54.3%, 95% CI [40.2-67.8%]). Raccoons sampled outside the estimated distribution of Triatoma sanguisuga were not infected with T. cruzi (n=73, 0.0%, 95% CI [0.0-5.0%]). Our study did not indicate that peridomestic habitats in Florida maintained a higher infection prevalence than their sylvatic counterparts; however, we did find a difference in prevalence within vs. outside the estimated vector distribution in Florida.

Assessment of habitat‐specific competition for oral rabies vaccine baits between raccoons and opossums

AbstractThroughout the eastern United States, the National Rabies Management Program (NRMP) distributes oral rabies vaccine (ORV) baits to manage rabies virus circulation in raccoon (Procyon lotor) populations. The consumption of vaccine baits by non‐target species including Virginia opossums (Didelphis virginiana) may reduce the effectiveness of ORV programs, but competition for baits remains poorly quantified in many areas of the southeastern United States. We distributed placebo ORV baits injected with a biomarker across 4 land cover types (bottomland hardwood, upland pine, riparian, isolated wetland) on the Savannah River Site in South Carolina, USA, 2017–2019. We then trapped and collected whiskers from 247 raccoons and 78 opossums to assess biomarker presence using fluorescent microscopy. Our data revealed greater bait uptake probability by raccoons (estimated x̅ = 0.30, 95% CI = 0.19–0.44) compared to opossums (estimated x̅ = 0.11, 95% CI = 0.05–0.23) across all cover types surveyed. Probability of bait consumption was not affected by cover type or the abundance of raccoons or opossums. Among raccoons, males were more likely to consume baits than females (estimated x̅ = 0.28, 95% CI = 0.17–0.44 for males and 0.14, 95% CI = 0.05–0.31 for females) and probability of consumption increased by 0.08 with each additional day trapped during the 10‐day trapping session. Uptake rates for raccoons were relatively low compared to other studies and not influenced by competition with opossums. These low consumption rates indicate that additional research addressing the roles of baiting season, bait density, and resource selection will be important to maximize ORV bait uptake by target species in these southeastern landscapes.

Microsatellites and mitochondrial evidence of multiple introductions of the invasive raccoon Procyon lotor in France

Raccoons (Procyon lotor) are worldwide invaders, due to deliberate or accidental releases, and their impacts exceed hundred of billions of Euros in Europe only. In France, raccoons have currently established three separate, expanding populations. Identifying the current spatial genetic structure, dispersal events and phylogeography of these populations is needed to infer the invasion history and identify management units. We used wild and captive individuals sampled in France and Belgium to characterize the genetic diversity and current population genetic structure of French raccoon populations and identify potential genetic connectivity with the Belgium population using both mitochondrial DNA and microsatellite loci. Results confirm that French populations are the result of at least three independent introductions. While the three populations display low genetic diversity and sign of recent bottleneck, they are still expanding, suggesting that in addition to their ecological plasticity, the remaining genetic diversity is sufficient to successfully adapt to their new environment and allow a quick colonization. Particular attention must be given to the North-Eastern population, which shows genetic admixture with the Belgium population, as admixed individuals may exhibit hybrid vigor facilitating their expansion. The comparison of captive and wild individuals did not allow to identify a potential captive origin of the wild populations. The current regulation in France allowing captivity in zoos without enforcement to tighten the biosecurity of detention facilities might dampen any management measure as few introduced founders might be enough to create new populations.

Detection of Endoparasites in Non-Native Raccoons from Central Italy.

The raccoon (Procyon lotor) is a carnivore native to North and Central America, gradually introduced into Asia and Europe, including Italy. It is an important carrier of multiple endoparasites, both Protozoa and Helminths, some of them being zoonotic. The aim of this study was to investigate the endoparasites of the non-native raccoon population of Central Italy. Sixty-two raccoons were collected by local competent authorities (sixty trapped and euthanized, two found dead) and subjected to necroscopic examination. Carcasses underwent a broad parasitological investigation, including coprological techniques (macroscopic examination of the gastrointestinal tract, lungs, trachea, and heart, Flotac®, Baermann test, and immunofluorescence for Giardia duodenalis and Cryptosporidium spp.), research on respiratory/urinary capillariosis and artificial digestion for Trichinella spp. larvae, and a histopathological examination of the ileum. Ascarid parasites were further identified at the species level using a next-generation sequencing-based amplicon sequencing approach. The results showed the presence of different Protozoa and Nematodes: Baylisascaris procyonis (26/62; 41.9%), Pearsonema sp. (6/62; 9.6%), Capillariidae (6/62; 9.6%), Eimeria sp. (2/62; 3.2%), Cryptosporidium sp. (2/62; 3.2%), and Ancylostomatidae (2/62; 3.2%). B. procyonis is an emerging helminthic zoonotic agent considered a serious concern for public and animal health, given the possibility of its transmission to paratenic hosts, including humans and pets. The demonstrated role of the raccoon as a multi-parasite carrier should be an incentive to continuing the eradication/control of this alien species, and supports the need to implement related disease surveillance programs.

The Raccoon (Procyon lotor) as a Neozoon in Europe.

The raccoon (Procyon lotor) is a North American half-bear that is present in much of Europe and Asia as a result of both accidental and planned releases. In Europe, raccoons were introduced primarily as a source of fur for the fur industry. In the 1930s, raccoons were released into the wild in Central Europe. At the same time, animals from fur farms and private holdings continued to enter the wild. In the following decades, the raccoon spread over large parts of Europe. In addition to the invasive spread of the Central European initial population, individual releases of raccoons occurred frequently, mainly in Southern Europe. The high adaptability of the raccoon favors its expansion into new habitats. It has a high reproductive rate, is very mobile, and encounters few predators in Europe. Raccoons have recently become a topic of interest when large raccoon populations have colonized suburban and urban areas. Despite the proximity of raccoons and humans, however, there have been hardly any conflicts to date, unlike in North America. A significant negative impact on the native fauna has been suspected but not proven. Raccoons have been identified as vectors of zoonotic diseases. Nevertheless, monitoring of the increasing numbers of raccoons in Europe seems advisable.

Surveillance for gastrointestinal, subcutaneous, and ectoparasites of invasive North American raccoons (Procyon lotor) in central Spain.

The American raccoon (Procyon lotor) is an invasive meso-carnivore which has been introduced and established in many European countries. Although the presence of the raccoon in the Iberian Peninsula was confirmed around 20years ago, there are few data on pathogens of these animals in this region. For this work, 72 American raccoons from two subpopulations in the central region of the Iberian Peninsula were examined for selected parasites. Ectoparasite species richness (both fleas and ticks) increased during the sampling season and was highest in the Henares subpopulation and on males. Similarly, ectoparasite abundance increased during the sampling season and was highest in Henares and on adult raccoons. Four species of ticks were detected including Rhipicephalus pusillus (71%), followed by R. sanguineus sensu lato (24%), Ixodes ventalloi (3%), and Dermacentor marginatus (1.4%). Four species of fleas were detected including Pulex irritans (44%), Ctenocephalides felis (3%), C. canis (1.4%), and Paraceras melis (1.4%) infestations. A subset of raccoons (n=56) was examined for intestinal parasites; low prevalence and diversity were found including Strongyloides procyonis (4%), Dilepis sp. (5%), Plagiorchis sp. (2%), and Moniliformis moniliformis (2%). Importantly, Baylisascaris procyonis was not found. Finally, no subcutaneous nematodes (i.e., Dracunculus and Dirofilaria spp.) were found in the 56 raccoons examined. The results of this work show that the invasive North American raccoons currently are infected with few endoparasites but are commonly infested with native ectoparasites, several of which can transmit pathogens relevant for public and veterinary health. However, the geographically distinct populations of raccoons in Spain have different introduction histories, thus additional surveillance for parasites is warranted.

Toxoplasma gondii in raccoons (Procyon lotor) in Germany: a serosurvey based on meat juice

Toxoplasma gondii seroprevalence was determined in meat juice samples of 820 free-living raccoons from Germany. The animals were collected between December 2017 and April 2021. Using a commercial enzyme linked immunosorbent assay (ELISA), the overall seroprevalence was found to be 48.5%. Statistical analysis revealed significant seroprevalence differences between seasons, sex, and weight of analysed raccoons. The prevalence in late winter/spring (57.7%) was significantly higher than in autumn (38.4%) (p < 0.0003). Male raccoons (50.5%) were more often seropositive than females (41.0%) (p = 0.028). Increasing animal weight had a significant impact on the relative probability of a positive serostatus (odds ratio: 1.783, p < 0.0001). Furthermore, we found regional differences in seroprevalence, but there was no statistically significant difference resulting from animal age, degree of habitat urbanization and hunting year. Meat juice is a suitable medium for serological surveys for T. gondii in meat producing animals, as sampling is even possible after slaughter or during meat inspection when blood is no longer available. The observed high seroprevalence indicates that T. gondii infection is widespread among the German raccoon population providing a potentially relevant source of T. gondii transmission to humans upon consumption or handling of animal products.

Environmental, individual and social traits of free-ranging raccoons influence performance in cognitive testing.

Cognitive abilities, such as learning and flexibility, are hypothesized to aid behavioral adaptation to urbanization. Although growing evidence suggests that cognition may indeed facilitate persistence in urban environments, we currently lack knowledge of the cognitive abilities of many urban taxa. Recent methodological advances, including radio frequency identification (RFID), have extended automated cognitive testing into the field but have yet to be applied to a diversity of taxa. Here, we used an RFID-enabled operant conditioning device to assess the habituation, learning and cognitive flexibility of a wild population of raccoons (Procyon lotor). We examined how several biological and behavioral traits influenced participation and performance in testing. We then compared the cognitive performance of wild raccoons tested in natural conditions with that of wild-caught raccoons tested in captivity from a previous study. In natural conditions, juvenile raccoons were more likely to habituate to the testing device, but performed worse in serial reversal learning, compared with adults. We also found that docile raccoons were more likely to learn how to operate the device in natural conditions, which suggests a relationship between emotional reactivity and cognitive ability in raccoons. Although raccoons in both captive and natural conditions demonstrated rapid associative learning and flexibility, raccoons in captive conditions generally performed better, likely owing to the heightened vigilance and social interference experienced by raccoons in natural conditions. Our results have important implications for future research on urban carnivores and cognition in field settings, as well as our understanding of behavioral adaptation to urbanization and coexistence with urban wildlife.

Survival rates of two nesting aggregations of diamondback terrapins at neighboring sites in New York City

AbstractThe diamondback terrapin (Malaclemys terrapin) is a charismatic and long‐lived species of the United States eastern coast, and the only North American turtle that exclusively inhabits coastal brackish waters. Many terrapin populations are declining, and these declines have been largely linked to human activities; however, few studies have documented human and natural factors affecting terrapin population demography. Jamaica Bay, an urban estuary located in southern New York City, USA, is home to 2 nesting aggregations of terrapins, located at Ruler's Bar Hassock (RBH) and John F. Kennedy Airport (JFK). We analyzed mark‐recapture data for RBH from 2003–2018 and JFK from 2011–2018 to estimate annual survivorship of female diamondback terrapins and test the effects of 3 factors (a hurricane, water quality represented by nitrogen concentration, and injuries) on survival. The initial estimated annual survival was high (0.93) at RBH but declined to 0.89, while survival remained constant at JFK (0.92). Models examining the effect of Hurricane Sandy (2012) indicated a significant decline in survival in the 2 years following the hurricane in the RBH nesting aggregation but no change at JFK. Water quality did not influence trends in either aggregation, but the presence of major injuries (caused by boat collisions, predators, and the hurricane) significantly reduced annual survival at RBH. We propose increasing terrapin survivorship through mitigation of boat traffic, reducing populations of northern raccoons (Procyon lotor) to reduce injury to female terrapins and decrease egg and hatchling mortality, and increased law enforcement to reduce on‐going poaching and capture as illegal by‐catch.