Cottontail Research Articles

Recommended survey designs for occupancy modelling using motion-activated cameras: insights from empirical wildlife data.

Motion-activated cameras are a versatile tool that wildlife biologists can use for sampling wild animal populations to estimate species occurrence. Occupancy modelling provides a flexible framework for the analysis of these data; explicitly recognizing that given a species occupies an area the probability of detecting it is often less than one. Despite the number of studies using camera data in an occupancy framework, there is only limited guidance from the scientific literature about survey design trade-offs when using motion-activated cameras. A fuller understanding of these trade-offs will allow researchers to maximise available resources and determine whether the objectives of a monitoring program or research study are achievable. We use an empirical dataset collected from 40 cameras deployed across 160 km2 of the Western Slope of Colorado, USA to explore how survey effort (number of cameras deployed and the length of sampling period) affects the accuracy and precision (i.e., error) of the occupancy estimate for ten mammal and three virtual species. We do this using a simulation approach where species occupancy and detection parameters were informed by empirical data from motion-activated cameras. A total of 54 survey designs were considered by varying combinations of sites (10–120 cameras) and occasions (20–120 survey days). Our findings demonstrate that increasing total sampling effort generally decreases error associated with the occupancy estimate, but changing the number of sites or sampling duration can have very different results, depending on whether a species is spatially common or rare (occupancy = ψ) and easy or hard to detect when available (detection probability = p). For rare species with a low probability of detection (i.e., raccoon and spotted skunk) the required survey effort includes maximizing the number of sites and the number of survey days, often to a level that may be logistically unrealistic for many studies. For common species with low detection (i.e., bobcat and coyote) the most efficient sampling approach was to increase the number of occasions (survey days). However, for common species that are moderately detectable (i.e., cottontail rabbit and mule deer), occupancy could reliably be estimated with comparatively low numbers of cameras over a short sampling period. We provide general guidelines for reliably estimating occupancy across a range of terrestrial species (rare to common: ψ = 0.175–0.970, and low to moderate detectability: p = 0.003–0.200) using motion-activated cameras. Wildlife researchers/managers with limited knowledge of the relative abundance and likelihood of detection of a particular species can apply these guidelines regardless of location. We emphasize the importance of prior biological knowledge, defined objectives and detailed planning (e.g., simulating different study-design scenarios) for designing effective monitoring programs and research studies.

Shedding of a low pathogenic avian influenza virus in a common synanthropic mammal--the cottontail rabbit.

BackgroundCottontails (Sylvilagus spp.) are common mammals throughout much of the U.S. and are often found in peridomestic settings, potentially interacting with livestock and poultry operations. If these animals are susceptible to avian influenza virus (AIV) infections and shed the virus in sufficient quantities they may pose a risk for movement of avian influenza viruses between wildlife and domestic animals in certain situations.Methodology/Principal FindingsTo assess the viral shedding potential of AIV in cottontails, we nasally inoculated fourteen cottontails with a low pathogenic AIV (H4N6). All inoculated cottontails shed relatively large quantities of viral RNA both nasally (≤106.94 PCR EID50 equivalents/mL) and orally (≤105.09 PCR EID50 equivalents/mL). However, oral shedding tended to decline more quickly than did nasal shedding. No animals showed any obvious signs of disease throughout the study. Evidence of a serological response was found in all infected rabbits at 22 days post infection in convalescent sera.Conclusions/SignificanceTo our knowledge, cottontails have not been previously assessed for AIV shedding. However, it was obvious that they shed AIV RNA extensively via the nasal and oral routes. This is significant, as cottontails are widely distributed throughout the U.S. and elsewhere. These mammals are often found in highly peridomestic situations, such as farms, parks, and suburban neighborhoods, often becoming habituated to human activities. Thus, if infected these mammals could easily transport AIVs short distances.

Formulation of cidofovir improves the anti-papillomaviral activity of topical treatments in the CRPV/rabbit model

Current topical treatments for papillomas use ablative, cytotoxic and immunomodulating strategies and reagents. However, the effectiveness of topical treatments using different formulations has not been examined in preclinical models or clinical trials. The purpose of this study was to determine whether formulation of the small molecule acyclic nucleoside, cidofovir (CDV), could lead to improved therapeutic endpoints following topical treatment of papillomas using the cottontail rabbit papillomavirus (CRPV)/rabbit model. Different formulations with a set dose of 1% cidofovir were tested to establish comparative data.The results demonstrated that anti-papilloma treatments with topical CDV were greatly enhanced when formulated versus unformulated. Best results were obtained with CDV formulated in cremophor, then in Carbomer 940, and then in DMSO. Further studies indicated that effective formulations led to complete cures of papillomas at dilutions less than 0.3% CDV. These studies together with previous observations demonstrated that unformulated CDV under the same treatment regime required doses of 2% to achieve cures demonstrating that much less compound can be used when properly formulated.

Antibody detection in tear samples as a surrogate to monitor host immunity against papillomavirus infections in vaccinated and naturally infected hosts.

Monitoring serum antibodies against natural infections or after immunizations has been a standard clinical diagnostic procedure. However, collecting blood samples requires trained personnel, and may cause discomfort and increase the risk of complications. In this study, we investigated whether tear samples could serve as a surrogate for serum samples to measure specific antibodies. A widely used preclinical cottontail rabbit papillomavirus (CRPV)/rabbit model has been a surrogate model for high-risk human papillomavirus (HPV) infections. New Zealand white rabbits, either naturally infected with CRPV or immunized with two clinically available HPV vaccines (Gardasil and Cervarix), were examined for antibody generation in both tear and serum samples. We demonstrated that antibodies were detectable in tears from both naturally infected as well as vaccinated animals. Overall, the antibody levels in tears were ~10-fold lower than those from the corresponding serum samples, but background noise was lower in tear samples. The isotypes of antibodies in tears were predominantly IgA and IgG. These findings showed clearly that tears could be a surrogate for serum samples for monitoring antibody responses. As collecting tears causes no discomfort and poses no risk to patients, it represents a novel and promising method for monitoring future HPV epidemiological studies as well as for use in clinical practice.

Use of prey by sympatric bobcat (Lynx rufus) and coyote (Canis latrans) in the Izta-Popo National Park, Mexico

To investigate dietary differences in two coexisting competing predators, we determined prey consumed by bobcats (Lynx rufus) and coyotes (Canis latrans) from scats in the Izta-Popo National Park, central Mexico. Use of prey by bobcats and coyotes showed a Pianka's index of overlap of 0.94, much higher than in other studies of the diet of these two species. Diets of bobcats were comprised primarily of eastern cottontail (Sylvilagus floridanus, 33.7%), rodents (22.7%), Mexican cottontail (S. cunicularius, 13.1%), the endemic and endangered volcano rabbit (Romerolagus diazi, 12.5%), Merriam's pocket gopher (Pappogeomys merriani, 9.3%), and long-tailed partridge (Dendrortyx macroura, 1.4%). Prey used by coyotes included primarily eastern cottontail (43.8%), rodents (15.7%), Mexican cottontail (12.0%), Merriam's pocket gopher (6.4%), and volcano rabbit (5.5%).

Low doses of flagellin-L2 multimer vaccines protect against challenge with diverse papillomavirus genotypes

Genetically modified bacterial flagellin (Fla), a Toll-like receptor-5 (TLR5) ligand, was evaluated as a fusion partner for human papillomavirus (HPV) L2-based immunogens in two animal challenge models; either cutaneous inoculation of rabbits with HPV ‘quasivirions’ containing cottontail rabbit papillomavirus (CRPV) genomes that induce warts, or intra-vaginal inoculation of mice with HPV ‘pseudovirions’ encapsidating a luciferase reporter plasmid and measurement of bioluminescence to determine infectivity. An Escherichia coli production system was developed for flagellin-L2 (Fla-L2) fusions containing either monomeric HPV-16 L2 a.a. 11(×11–200) or oligomeric L2 comprising a fusion of the a.a. 11–88 peptides of five (Fla∼5×11–88) or eight (Fla∼8×11–88) genital HPV types. Immunogenicity and bioactivity of Fla-L2 constructs were assessed using an in vitro neutralization and cell-based TLR-5 binding assay, respectively. Efficacy was evaluated following active immunization of rabbits or mice administered 3 intramuscular doses of Fla-L2 recombinants without exogenous adjuvant, followed by challenge. In addition, passive immunization studies of naïve rabbits with serial dilutions of pooled immune sera were used to determine End-Point Protection Titers (EPPT) for each formulation against a broader spectrum of HPV quasivirions. Efficacy was assessed for up to 10 weeks on the basis of wart volume induced following challenge and results compared to licensed L1-VLP vaccines (Gardasil and Cervarix). Following active immunization at doses as low as 1μg, Fla-L2 fusions afforded complete protection against infection (mice) and disease (rabbits) following either homologous or heterologous HPV challenge. Passive immunization with anti-L2 immune sera discriminated between the different vaccine candidates under evaluation, demonstrated the protective role of antibody and suggested the superiority of this oligomeric L2-TLR5 agonist fusion approach compared to L1-based vaccines in its ability to cross-protect against non-vaccine HPV types.

Invasive species and their parasites: eastern cottontail rabbit Sylvilagus floridanus and Trichostrongylus affinis (Graybill, 1924) from Northwestern Italy

The eastern cottontail Sylvilagus floridanus is a native American lagomorph. Within the genus Sylvilagus, the eastern cottontail is the species with the widest distribution. From 1950s, the species was introduced to several European countries. A rapid territorial expansion of the introduced eastern cottontails has been observed in many areas of Italy. The eastern cottontail has been demonstrated to play a main role as carrier of exotic parasites. To date, three nematode species, exotic in Italian ecosystems, have been reported from introduced S. floridanus. However, its parasite fauna biodiversity is richer in native populations of the American continent. The aim of this work was to further investigate the gastrointestinal parasites of S. floridanus, to evaluate the potential presence of other exotic species. During 2010, 101 hosts were examined, and three nematodes were collected from their digestive tract. Two parasite species (Obeliscoides cuniculi, Trichostrongylus calcaratus) were already reported in Italy; the isolation of Trichostrongylus affinis is instead the first report of this nematode in Italy and in Europe as a whole. This study wants to highlight the great risks related to the introduction of allochthonous species. The impact of the invasion by alien animal species may be particularly severe for public and animal health, due to the potential introduction of new pathogens. The good number of exotic parasites found in introduced eastern cottontails, together with the few sanitary surveys carried out, suggests that an epidemiological survey, with specimens from multiple localities on a wider geographic range, could lead to interesting findings on parasites of native and alien lagomorphs in Europe.

Prickly Pear Conversation

Some love it as a plant they know in its proper habitat-a native plant in deserts of North and South America, or as a crop for the cultivation of cochineal insects for their red dye, or simply as an exotic potted plant that is carefully tended in climates unsuitable for its growth. In many countries around the world it is hated as a weed- a plant that can grow uncontrollably fast in places where it has been imported.Prickly pear plants are made up of pads joined together, which are actually flattened stems. The only leaves are small, short-lived fingers that cover the new, expanding pads in spring. Scattered over the mature pads are areoles from which long spines, and fine brown bristles, or glochids, grow. Each areole is also a growing point from which a new pad, flower, or root can develop. Any pad broken off and allowed to lie on the ground will put down roots when it rains and soon become a new plant. In this way prickly pear can spread fast.I sat one November day in Montrose Canyon near Tucson. It had been hot and dry for months. The pads of prickly pear were thin and wrinkly; diamond shapes between spines, rows of ridges like ripples on a sand bar. They looked old, for surely wrinkled means old. But they were mostly not old. With winter rain they would swell and fatten, swell out and become smooth with no sign of wrinkles. Not many living things rejuvenate themselves like cactus pads, though they cannot regain the tiny little pinky-green fat fingers that were leaves. I thought how, inside those wrinkled pads, there was still moisture, waiting, storing life inside those wrinkled green skins, and marveled at the adaptation to drought conditions that occur in southern Arizona before and after the short-lived summer rains.Although there are hundreds of species of prickly pear, varying from miniature plants to trees one hundred feet tall, the common ones are wide, spreading shrubs about four feet high, with their pale, gray-green rounded pads about nine inches long. The Englemann's prickly pear (Opuntia englemannii) is one of the commonest, with its long white spines and rusty colored glochids. Looking across the sun-bright desert of Arizona, patches of round, clumped pads in their faded watercolor-green, between giant saguaros and Palo Verde trees, is the classic Sonoran desert scene. Or, looking at a steep rocky slope from a distance, one sees, between the giant saguaros, the regular patches of rounded pads, their smooth hard surfaces reflecting sunlight at different angles, those in shade enhancing the green of their sunlit neighbors by their contrast. No other place in the world resembles the deserts of southwest North America.It rains. The muted greens of cactus plants seem brighter without sun and drops roll off the prickly pear pads to darken the desert pan. Moisture causes the strange fragrance of creosote bushes to pervade the atmosphere. Cottontail rabbits have taken cover and no birds sing. Rain is such an event in the desert, and through the melancholy air I watch the gentle fall of contentment. This winter rain will make a colorful spring. The pads of prickly pear are swelling, the wrinkles of drought ironing out as the masses of fine roots absorb water. Those fine roots take up the merest suggestion of water, roots that hold together the thin layer of desert soil.From every window of my house here in the Sonoran desert I see Englemann's prickly pear. As far as I can see this is the most common plant, though patches of different cacti, bur-sage, and creosote bush are intermingled, along with a wide variety of less common desert plants. The diversity is remarkable to me after having known the Sahara, where the few plants species are scattered and rare. And with this rain, the seed bank in the soil will sprout dozens more species that wait for a little more warmth to grow up and flower.How much the prickly pear will grow in the spring and how many flowers develop depends on how much rain we get this winter, and I think of April when the young soft pads swell out-the soft, bright green nopales that provide a vegetable for many, especially Native Americans. …

Evaluation of Positron Emission Tomographic Tracers for Imaging of Papillomavirus-Induced Tumors in Rabbits

In this study, simultaneous positron emission tomography (PET)/magnetic resonance (MR) imaging was employed to evaluate the feasibility of the PET tracers 2-deoxy-2-18F-fluoro-d-glucose (18F-FDG), 11C-choline, and 18F-fluorothymidine (18F-FLT) to detect papillomavirus-induced tumors in an established rabbit model system. The combined PET/MR allowed the analysis of tracer uptake of the tumors using the morphologic information acquired by MR. New Zealand White rabbits were infected with cottontail rabbit papillomavirus genomes and were imaged for up to 10 months with a simultaneous PET/MR system during the course of infection. The uptake characteristics of the PET tracers 11C-choline and 18F-FLT of tumors and reference tissues were examined relative to the clinical standard, 18F-FDG. Tracer biodistribution of various organs was measured by gamma-counting after the last PET scan and compared to the in vivo PET/MR 18F-FDG uptake. Increased tracer uptake was found 2 months postinfection in primary tumors with 18F-FDG and 11C-choline, whereas 18F-FLT failed to detect the tumors at all measured time points. Our data show that the PET tracer 18F-FDG is superior for imaging papillomavirus-induced tumors in rabbits compared to 11C-choline and 18F-FLT. However, 11C-choline imaging, which has previously been applied to detect various tumor entities in patients, appears to be an alternative to 18F-FDG.

Long-peptide therapeutic vaccination against CRPV-induced papillomas in HLA-A2.1 transgenic rabbits

Long peptide immunization is a promising strategy to clear established tumors. In the current study, we investigated the therapeutic effect of a naturally existing long peptide that contained two HLA-A2.1 restricted epitopes (CRPVE1/149–157 and CRPVE1/161–169) from cottontail rabbit papillomavirus (CRPV) E1 using our CRPV/HLA-A2.1 transgenic rabbit model. A universal Tetanus Toxin helper motif (TT helper) was tagged at either the N-terminus or the carboxyl-terminus of this long peptide and designated as TT-E1 peptide and E1 peptide-TT, respectively. Four groups of HLA-A2.1 transgenic rabbits were infected with wild type CRPV DNA. Three weeks post-infection, the rabbits were immunized four times with TT-E1 peptide, E1 peptide only, E1 peptide-TT or TT-control peptide with two-week intervals between immunizations. Tumor outgrowth was monitored and recorded weekly. After the third booster immunization, tumors on two of the four E1 peptide-TT immunized rabbits began to shrink. One animal from this group was free of tumors at the termination of the study. The mean papilloma size of E1 peptide-TT immunized rabbits was significantly smaller when compared with that of the three other groups (P<0.05, one way ANOVA analysis). It is interesting that E1 peptide-TT vaccination not only stimulated stronger T cell mediated immune responses but also stronger antibody generations. We conclude that the location of a TT helper motif tagged at the long peptide vaccine is critical for the outcome of therapeutic responses to persistent tumors in our HLA-A2.1 transgenic rabbit model.

Riqueza y la abundancia de mamíferos medianos de la reserva biológica Tirimbina, Costa Rica

Resumen The Mexican cottontail rabbit, Sylvilagus cunicularius, is the endemic rabbit with the widest distribution and the largest size (485-515 mm) of all rabbits in Mexico. This cottontail is abundant throughout its range but some populations are declining due to habitat destruction and poaching. In La Malinche National Park (LMNP), Tlaxcala, fires and excessive logging have reduced the habitat (grassland and pine forest) of the Mexican cottontail rabbit. To determine the Mexican cottontail rabbit home range will reveal their spatial ecology, social behavior and infer useful information in the development of programs for conservation. In this work, we investigated the home range size of the Mexican cottontail rabbit and the differences among sexes. The study was developed from May 2006 throughout February 2008 at LMNP, with a sample size of 12 individuals (seven females and five males). The home range size of S. cunicularius averaged 3.62 ± 0.62 hectares and was not different between males and females (U = 12.0, P = 0.43). Furthermore, home ranges of individuals of S. cunicularius overlapped between individuals of the same sex and of the opposite sex. This is the first formal report of home range size for the Mexican cottontail, which contributes to understand how S. cunicularius uses a grassland habitat (dominated by Muhlenbergia macroura) in a pine forest (Pinus spp.) on the central plateau of Mexico.

Diet of Mexican Spotted Owls in Utah and Arizona

Mexican Spotted Owls (Strix occidentalis lucida) occupy forest-dominated environments but also inhabit rocky canyonlands. I studied the owls' diet in canyon habitats in southern Utah and northern Arizona (1991–2007), and in mixed-conifer forest in the Rincon Mountains of southeast Arizona (1996–1997). I identified 3,315 prey items in regurgitated pellets from 38 pairs of owls in canyon habitat, and 383 prey items from 5 pairs in the Rincon Mountains. In canyons and forests, vertebrates dominated owl diets (97–99% of total prey biomass) with mammals accounting for 91–92% of prey biomass. In canyons, mammalian prey was primarily woodrats (Neotoma spp., 79% biomass), followed by white-footed mice (Peromyscus spp., 11%), and cottontail rabbits (Sylvilagus spp., 5%). In forest habitat, woodrats comprised 54% of biomass, followed by Botta's pocket gophers (Thomomys bottae, 13%), and cottontail rabbits (11%). For nine owl territories in three canyon regions in Utah, diets varied among the owl pairs with contribution to total prey biomass by woodrats ranging from 65–91%, typically followed by white-footed mice ranging from 13–19%. In both canyon and forest study areas, a variety of prey were consumed in addition to murids, including rabbits, pocket gophers, sciurids (Tamias spp.), heteromyids (e.g., Perognathus spp.), various bats (Vespertilionidae), shrews (Sorex spp.), small passerine birds, and numerous arthropods.

Survival, abundance, and capture rate of eastern cottontail rabbits in an urban park

Eastern cottontail rabbits (Sylvilagus floridanus) are common, conspicuous denizens of urban environments. They are associated with human-wildlife conflict due to vegetation damage. Prior to this study, population dynamics of this species in urban environments remained largely uncharacterized. For three consecutive winters, we used classic field ecology methods (mark-recapture and mark–resight surveys) to estimate demographic parameters of rabbits in a city park in Chicago, Illinois. Rabbits occurred in densities as high as 16.3 rabbits/ha, which is comparatively high for the Midwestern United States. An annual survivorship of 30.4 ± 12.9 % SE was similar to that observed in natural environments in similar climates. This result refuted our hypothesis that urban rabbits would have higher annual survival rates than rabbits in natural settings due to food subsidies supplied by landscaping in parks. Mean distance between trap locations for rabbits trapped three or more times was 43.14 ± 30.01 m SD, suggesting that rabbits in the urban study area had smaller home ranges than rabbits in non-human-dominated habitats. This study contributes to our understanding of population dynamics of a human-wildlife conflict species in urban environments and provides useful information for managers dealing with damage caused by rabbits. The mark-resight method employed here could be used by managers to estimate pre- and post-management population sizes of other conflict species, for example Canada geese (Branta Canadensis), in parks and green spaces, provided that the species is trappable, visible, and individuals have relatively small home ranges.

Cottontail Rabbit Papillomavirus Infection in a Desert Cottontail (Sylvilagus audubonii) from Colorado, USA

A wild-caught desert cottontail rabbit (Sylvilagus audubonii) from Colorado was observed to have large, pedunculated, dark cutaneous lesions on its abdomen and cylindrical masses on its mouth. Morphologically, the masses were consistent with previous reports of virally induced papillomas. Subsequent DNA analysis indicated widespread infection with cottontail rabbit papillomavirus.

Apparent effect of rabbit endogenous lentivirus type K acquisition on retrovirus restriction by lagomorph Trim5αs.

To test the hypothesis that rabbit endogenous lentivirus type K (RELIK) could play a role in shaping the evolution of TRIM5α, the susceptibility of viruses containing the RELIK capsid (CA) to TRIM5 restriction was evaluated. RELIK CA-containing viruses were susceptible to the TRIM5αs from Old World monkeys but were unaffected by most ape or New World monkey factors. TRIM5αs from various lagomorph species were also isolated and tested for anti-retroviral activity. The TRIM5αs from both cottontail rabbit and pika restrict a range of retroviruses, including HIV-1, HIV-2, FIV, EIAV and N-MLV. TRIM5αs from the European and cottontail rabbit, which have previously been found to contain RELIK, also restricted RELIK CA-containing viruses, whereas a weaker restriction was observed with chimeric TRIM5α containing the B30.2 domain from the pika, which lacks RELIK. Taken together, these results could suggest that the pika had not been exposed to exogenous RELIK and that endogenized RELIK might exert a selective pressure on lagomorph TRIM5α.

Comparison of live-trapping and noninvasive genetic sampling to assess patch occupancy by New England cottontail (Sylvilagus transitionalis) rabbits

The New England cottontail (Sylvilagus transitionalis) is a species of high conservation priority in the northeastern United States and a candidate for federal listing under the Endangered Species Act. Eastern cottontails are abundantly distributed and similar in appearance to New England cottontails. Our objective was to compare cost, effort, and effectiveness of live-trapping and noninvasive genetic monitoring for assessing patch occupancy by New England cottontail. We collected 113 tissue samples and 240 fecal pellets samples for diagnostic genetic testing to detect species presence and assess the proportion of samples consisted of New England and eastern cottontail on 5 study sites in Connecticut in 2008 and 2009. Both methods detected presence of New England cottontail at 4 of 5 sites. Overall proportion of DNA samples consisted of New England cottontail was similar between sampling methods (χ2 = 0.189, P = 0.664). However, species composition on individual sites was inconsistent between methods and no clear pattern of bias was discernible. Mean cost per DNA sample to collect and analyze was US$433 for tissue samples and US$33 for fecal pellets. Samples collected per person-day of effort were 40 for fecal samples and 0.7 for tissue samples. Genetic monitoring via noninvasive fecal sampling was a low-cost, time-efficient method for assessing species occupancy, but development of an optimal sampling strategy is needed to evaluate composition and distributions of species on sympatrically occupied sites. © 2013 The Wildlife Society.

Environmental Investigation Following the First Human Case of Babesiosis in Tennessee

Babesiosis is an emerging tick-borne zoonotic disease in the United States caused by Babesia parasites. In 2009, the first case of babesiosis was documented in Tennessee. Environmental investigation at the reported site of tick exposure included collection of ticks and specimens from eastern cottontail rabbits (Sylvilagus floridanus) and white-tailed deer ( Odocoileus virginianus ) that were tested for piroplasms by molecular and serologic methods. One hundred and sixty-six Ixodes scapularis ticks and biological samples from 8 rabbits and 5 deer were collected. Ixodes scapularis were PCR positive for Babesia odocoilei (n = 7, 4%) and Theileria cervi (n = 24, 14%). Deer were seropositive for B. odocoilei and PCR positive for T. cervi. Rabbits were seropositive for B. odocoilei and Babesia sp. MO1, and 1 rabbit was PCR positive for Babesia sp. MO1. In summary, zoonotic Babesia sp. MO1 infection in rabbits is reported here for the first time in Tennessee as well as infection of deer and I. scapularis ticks with 2 other piroplasms of veterinary importance.

The stable and radio-isotope chemistry of southeastern Utah Basketmaker II burials: dietary analysis using the linear mixing model SISUS, age and sex patterning, geolocation and temporal patterning

The Bayesian linear mixing model SISUS is used to reconstruct reliance on maize and intake of animal protein from the stable carbon (δ13C) and nitrogen (δ15N) isotope values of 149 directly dated Basketmaker II burials. Maize is the primary dietary staple. δ13C values are also enriched by intake of yucca and wild C4 plant foods but these resources are of minor importance in sampled diets. Animal protein intake is low and cottontail rabbits make the greatest contribution to female diets. Adolescent diets are indistinguishable from the diets of adult females and both groups are less reliant on artiodactyls than males. The δ13C and δ18O values of bone hydroxyapatite distinguish nursing infants and oxygen isotope values identify outsider adults relative to those local to the region where their deaths occurred. Most Utah Basketmaker II burials are contemporary with Black Mesa Lolomai phase occupations, postdating the Marsh Pass, AZ, White Dog phase. All burials in both studies were recovered from sheltered rather than open sites and reliance on maize does not increase over the temporal span of the Utah study, covering the two sigma range 415 BC–AD 322.

The safety of ONRAB® in select non-target wildlife

ONRAB® is a recombinant human adenovirus type 5 (HAd5) with the rabies glycoprotein gene incorporated into its genome. ONRAB® has been used in Canada as an oral rabies vaccine in target wildlife species such as: red fox (Vulpes vulpes), raccoon (Procyon lotor), and striped skunk (Mepthis mephitis). We evaluated the safety of ONRAB® in non-target wildlife species likely to contact the vaccine baits during oral rabies vaccine campaigns in the United States. We investigated the effects of oral inoculation of high titer ONRAB®, approximately ten times the dose given to target species, in wood rats (Neotoma spp.), eastern cottontail rabbits (Sylvilagus floridanus), Virginia opossums (Didelphis virginiana), eastern wild turkeys (Meleagris gallopavo silvestri), and fox squirrels (Sciurus niger). We performed real-time polymerase chain reaction (PCR) on fecal swabs, oral swabs, and tissues, including lung, liver, kidney, small intestine, large intestine, and when appropriate nasal turbinates, to detect ONRAB® DNA from inoculated animals. By seven days post-inoculation, turkeys, opossums, and cottontails had all stopped shedding ONRAB® DNA. One wood rat and one fox squirrel still had detectable levels of ONRAB® DNA in fecal swabs 14 days post-inoculation. Real-time PCR analysis of the tissues revealed some ONRAB® DNA persisting in certain tissues; however, there were no significant gross or histologic lesions associated with ONRAB® in any of the species studied. Our results suggest that many non-target species are not likely to be impacted by the distribution of ONRAB® as part of oral rabies vaccination programs in the United States.

Encephalitozoon cuniculi, Toxoplasma gondii and Neospora caninum infection in invasive Eastern Cottontail Rabbits Sylvilagus floridanus in Northwestern Italy

Sylvilagus floridanus is a lagomorph introduced for hunting purposes from North America to Europe where, in certain areas like Northern Italy, its population reached high densities. Brain, kidney and skeletal muscle of 144 Eastern Cottontail Rabbits S. floridanus were examined by PCR for Encephalitozoon cuniculi, Toxoplasma gondii and Neospora caninum. DNA of E. cuniculi was found with a prevalence of 9.72% (CI 95% 0.058–0.156). T. gondii and N. caninum DNA was detected in 2.08% (CI 95% 0.0071–0.0595) and 2.78% (CI 95% 0.0109–0.0692) of the samples examined, respectively. This is the first report of E. cuniculi infection in a lagomorph species other than in its natural host Oryctolagus cuniculus, and this is also the first time N. caninum is found to naturally infect S. floridanus. E. cuniculi, T. gondii and N. caninum infect S. floridanus at low but relevant prevalences, considered the important role that these pathogens could play in both animal and human health.