Decreased Body Condition Research Articles

Association between Outlying Values in Body Condition Indices in Small Mammals and Their Habitats

Habitat type and habitat change are very important factors in the body condition of small mammals that inhabit them. The response can be positive, increasing, or the opposite, decreasing body condition. We analyzed outliers of the body condition indices (BCIs) of 12 species trapped in nine different habitats during 1980–2023 in Lithuania, a mid-latitude country. Mixed and fragmented habitats, as well as commensal habitats, could be considered the least suitable for small mammals, based on the highest proportions of underfit and low proportions of best-fit individuals. On the contrary, meadows and disturbed habitats (landfills and cormorant colonies) had the highest proportions of best-fit individuals, while the proportion of under-fit individuals was much lower than expected. We found outliers in the BCI in all species, except for the under-fit harvest mice (Micromys minutus), and in all habitats, though not numerous. The presence of the highest BCI in yellow-necked mice (Apodemus flavicollis) and bank voles (Clethrionomys glareolus) in the disturbed habitats studied and in house mice (Mus musculus) in commensal habitats may be related to the resources provided by these habitats. Our results demonstrate the feasibility of using retrospective small mammal morphometric data to analyze their relationship with habitat.

Prevalence of paratuberculosis in Thuringian sheep and goat flocks

In Germany, only few data on the current distribution of paratuberculosis in sheep and goat flocks is available. The present study provides an overview of the distribution of Mycobacterium avium ssp. paratuberculosis (MAP) in 165 Thuringian sheep and goat flocks. Also, the study investigated the association between the MAP status of the flock and herd specific factors as well as the association between the individual measured value of ELISA and animal specific factors like age, body condition, sex, and animal species. To investigate the prevalence of MAP, serum samples from 2550 sheep and 1171 goats from 165 flocks (flock size 2 to 2879 animals) were serologically examined for MAP antibodies in 2021. Additionally, 1 to 6 environmental faecal samples were collected from every flock depending on the flock size. They were examined for the presence of MAP by using both bacteriological cultivation and a commercially available real-time-PCR. MAP antibodies were detected in 41 sheep (1.6%) and 29 goats (2.5%), which accounts to a detection of MAP antibodies in 20.6% of the 165 flocks (on herd level). The symptoms of paratuberculosis, weight loss with preserved appetite and altered fecal consistency, were observed in only four of the flocks. A positive association was identified between the detection of MAP or MAP-specific antibodies in a flock and flock size, as well as positive association between the measured value in the Elisa (s/p ratio) and the age of the animal. Furthermore, an association between an increasing s/p ratio of the ELISA and a decreasing body condition was found. Given what is known about the distribution of paratuberculosis in small ruminants, this disease should always be considered as a possible cause of weight loss and diarrhea. In case of high within-herd prevalence herd-specific control measures should be considered. In serological herd monitoring, animals with poor body condition should preferably be included in the sample, as the probability of being able to identify MAP positive animals is higher here.

PRIMARY HEPATIC NEOPLASIA IN THREE ADULT BAMBOO SHARKS (CHILOSCYLLIUM PLAGIOSUM AND CHILOSCYLLIUM PUNCTATUM) IN AN AQUARIUM POPULATION.

Neoplasia in elasmobranchs is uncommonly documented. This report describes primary hepatic neoplasia in three adult female bamboo sharks under managed care: biliary adenocarcinoma in a whitespotted bamboo shark (Case 1; Chiloscyllium plagiosum), biliary adenocarcinoma in a brownbanded bamboo shark (Case 2; Chiloscyllium punctatum), and hepatocellular carcinoma in a whitespotted bamboo shark (Case 3). Case 1 presented with extensive cutaneous papillomas and was electively euthanized. At necropsy, a 4-cm-diameter, pale-tan, firm hepatic mass was identified and diagnosed histologically as a biliary adenocarcinoma. Case 2 presented with decreasing body condition despite normal food intake. Coelomic ultrasound and exploratory surgery revealed several large masses in both hepatic lobes, and the patient was euthanized. At necropsy, nine, 1-6-cm-diameter, black to tan, firm hepatic masses were identified and diagnosed histologically as biliary adenocarcinoma with branchial intravascular neoplastic emboli. Case 3 presented for routine health examination and was euthanized for diagnostic purposes after coelomic ultrasound revealed multiple hepatic masses. At necropsy, two 1-3-cm-diameter, brown- and-black mottled, firm hepatic masses were identified and diagnosed histologically as hepatocellular carcinoma. Immunohistochemistry was performed in two of these cases and was noncontributory, likely because of a lack of cross reactivity between antibodies (antipancytokeratin) and elasmobranch tissues.

Clinical features of chronic kidney disease in dogs with the serological presence of Leptospira spp., Ehrlichia canis, and Anaplasma phagocytophilum

Chronic kidney disease is commonly diagnosed in dogs, and clinical signs may be aggravated when infected agents are involved. In this case report, 33 dogs with chronic kidney disease were clinically evaluated and serologically tested for Leptospira spp., Ehrlichia canis, and Anaplasma phagocytophilum. The seroprevalence for Leptospira spp. was 39.4%. The most frequent serovars found were Pyrogenes, Canicola, Bratislava and Australis, with serological titers between 1:100 to 1:800. Clinical signs included fever, depression, decreased body condition, vomiting and hematuria. Significant laboratory findings were anemia, leukocytosis, thrombocytopenia, increased liver enzymes, urea and creatinine, hyperbilirubinemia and hyperphosphatemia. All leptospira seronegative dogs were positive for one or both monitored homoparasites (i.e., E. canis and A. phagocytophilum); only three leptospira seropositive dogs were positive for one or both hemoparasites. Findings also suggest that endemic hemoparasites of dogs should be monitored in dogs with a kidney condition for a better clinical picture of the patients and therapeutic approach.

A Post-Operative Follow-Up of an Endangered Saltwater Fish Lensectomy for Cataract Management in a Public Aquarium: A Case Series.

Mature cataracts can be a life-threatening condition in fish as it may result in anorexia. Lens extraction has been previously described in fish, but the long-term outcome of this procedure has not been evaluated. Eleven captive-bred adult fish housed in a public aquarium presented with unilateral (n = 3/11) or bilateral (n = 8/11) mature cataracts. All cases belonged to three endangered fish populations: striped bass (Morone saxatilis) originating from the Saint Lawrence River and Atlantic and spotted wolffish (Anarhichas lupus and Anarhichas minor). Pre-operatively, fish presented with anorexia, dark discoloration, abnormal position in the water column, skin abrasions, and/or decreased body condition scores. A lensectomy was performed in eleven fish, including a bilateral procedure in four fish, corresponding to fifteen eyes. Follow-up examinations were performed one to two weeks and one year post surgery. The main complication was self-resolving: corneal edema was present in 67% of eyes, persistent after a week in 47% of eyes, and resolved thereafter. Post-operatively, 73% of fish resumed feeding and regained a good body condition score. Persistent visual impairment post-surgery associated with anorexia required euthanasia in three out of eleven cases. The median time of death was 336 days post surgery (range: 27-1439 days) and three cases were still alive 1334 to 1425 days after the lensectomy. This was considered a favorable outcome for these older individuals with concurrent diseases.

Sublethal effects of kleptoparasitism on experimental social spider colonies

AbstractA defining feature of parasitism is the harm parasites cause to their host via a reduction in lifetime reproductive success. Harm, also referred to as “virulence,” may involve host mortality or sublethal effects, such as a decreased body condition or protracted development of immature individuals. We considered a system where colonies of the social spider Anelosimus eximius serve as hosts to confamilial kleptoparasitic spiders that steal food resources. In a laboratory experiment with parasitized and non‐parasitized colonies, we tested whether this host–parasite interaction meets the criterium of harm to host individuals and colonies. We assessed survival and measured scaled mass indices (SMI) before and after the experimental period. Linear mixed effects models demonstrated that colonies exposed to kleptoparasites had lower SMI values at the end of the experiment compared to controls, but found no effect of kleptoparasitism on mortality in treatment and control groups. We conclude that kleptoparasites meet the criterium of harm to their host to be considered parasitic and provide the first empirical measure of virulence for this study system.

Population transcriptogenomics highlights impaired metabolism and small population sizes in tree frogs living in the Chernobyl Exclusion Zone

BackgroundIndividual functional modifications shape the ability of wildlife populations to cope with anthropogenic environmental changes. But instead of adaptive response, human-altered environments can generate a succession of deleterious functional changes leading to the extinction of the population. To study how persistent anthropogenic changes impacted local species’ population status, we characterised population structure, genetic diversity and individual response of gene expression in the tree frog Hyla orientalis along a gradient of radioactive contamination around the Chernobyl nuclear power plant.ResultsWe detected lower effective population size in populations most exposed to ionizing radiation in the Chernobyl Exclusion Zone that is not compensated by migrations from surrounding areas. We also highlighted a decreased body condition of frogs living in the most contaminated area, a distinctive transcriptomics signature and stop-gained mutations in genes involved in energy metabolism. While the association with dose will remain correlational until further experiments, a body of evidence suggests the direct or indirect involvement of radiation exposure in these changes.ConclusionsDespite ongoing migration and lower total dose rates absorbed than at the time of the accident, our results demonstrate that Hyla orientalis specimens living in the Chernobyl Exclusion Zone are still undergoing deleterious changes, emphasizing the long-term impacts of the nuclear disaster.

Epidemiology of skin changes in endangered Southern Resident killer whales (Orcinus orca).

Photographic identification catalogs of individual killer whales (Orcinus orca) over time provide a tool for remote health assessment. We retrospectively examined digital photographs of Southern Resident killer whales in the Salish Sea to characterize skin changes and to determine if they could be an indicator of individual, pod, or population health. Using photographs collected from 2004 through 2016 from 18,697 individual whale sightings, we identified six lesions (cephalopod, erosions, gray patches, gray targets, orange on gray, and pinpoint black discoloration). Of 141 whales that were alive at some point during the study, 99% had photographic evidence of skin lesions. Using a multivariate model including age, sex, pod, and matriline across time, the point prevalence of the two most prevalent lesions, gray patches and gray targets, varied between pods and between years and showed small differences between stage classes. Despite minor differences, we document a strong increase in point prevalence of both lesion types in all three pods from 2004 through 2016. The health significance of this is not clear, but the possible relationship between these lesions and decreasing body condition and immunocompetence in an endangered, non-recovering population is a concern. Understanding the etiology and pathogenesis of these lesions is important to better understand the health significance of these skin changes that are increasing in prevalence.

Computed tomographic features of double aortic arch in six dogs.

Double aortic arch (DAA) is a rare, congenital anomaly in small animals, resulting in a complete vascular ring encircling the esophagus and trachea, and subsequent compression of these organs. Few studies have reported utilizing CT angiography (CTA) for diagnosing DAA in dogs; thus, the imaging features are currently lacking in the literature. The objectives of this retrospective, multicenter, descriptive case series were to report the clinical and CTA characteristics of DAA in surgically treated cases. Medical records and CTA images were reviewed. Six juvenile dogs met the inclusion criteria (median age: 4.2 months; range: 2-5 months). The most common clinical signs included chronic regurgitation (100%), decreased body condition (67%), and coughing (50%). Common CTA features of DAA included a dominant left aortic arch (median diameter: 8.1mm) and minor right aortic arch (median diameter: 4.3mm; 83%), an aberrant right subclavian artery arising directly from the right aortic arch (83%), segmental esophageal constriction (100%), and variable degrees of dilation cranial to the heart base, and marked tracheal luminal compression (median percent change: -55%; 100%) and leftward curvature of the trachea at the level of the bifurcation of the aortic arches (100%). All dogs underwent successful surgical correction with only minor postoperative complications. Due to the similarity of clinical and imaging characteristics described to that of other forms of vascular ring anomalies (VRA), CTA is vital for the specific diagnosis of DAA in dogs.

Long‐term increase in female body condition and its effect on reproduction in two European red‐listed species, Common Pochard (Aythya ferina) and Tufted Duck (Aythya fuligula)

Body condition of breeding females is an important driver of an individual's fitness and the consequent dynamics of populations. Long‐term changes in female body condition are likely to be affected by recent shifts in climatic and environmental conditions that can result in changes to population demography. To help explain the drivers shaping body condition during the incubation period and its consequences for reproductive success, we examined the long‐term pattern in the body condition of breeding females of two declining sympatric diving duck species: Common Pochard Aythya ferina and Tufted Duck Aythya fuligula. We analysed the data obtained from 139 females of Common Pochard and 251 females of Tufted Duck breeding on fishponds in South Bohemia, Czechia, between 2004 and 2020. We calculated the body condition index of females during late incubation based on the residuals from the relationship between body mass and tarsus length and used the incubation stage as an additional predictor of body mass. Body condition of both species did not decline over the 17 years of the study. The effect of winter weather conditions (winter temperature), water transparency (a proxy for food availability) and reproductive investment on body condition was not confirmed. Female body condition positively affected mean egg mass and hatchability in both studied species, i.e. females in better body condition laid larger eggs and hatched eggs with a higher hatching probability. We conclude that the population declines of the studied species are probably not connected to decreasing body condition of breeding females, but other reasons such as change in breeding propensity or offspring survival and recruitment should be considered in future studies.

FACTORS IMPACTING SUCCESSFUL REHABILITATION OF BIG BROWN BATS (EPTESICUS FUSCUS) IN A WISCONSIN WILDLIFE REHABILITATION CENTER: A 5-YEAR RETROSPECTIVE.

The big brown bat (Eptesicus fuscus; EPFU) is widely distributed throughout the Americas and plays critical roles in sustaining cave ecosystems and abating agricultural pests. In Wisconsin, EPFU is a threatened species with declining populations due to hibernacula disturbances, wind turbines, and habitat destruction. Due to their ecological and economic value, it is important to be able to release EPFU that enter wildlife rehabilitation centers back to the wild. This study evaluated the medical records of 454 EPFU (275 male, 179 female) admitted to a wildlife rehabilitation center in Wisconsin from 2015 to 2020. For each bat, the season at intake, examination findings, length of time in rehabilitation, and final outcome (released or not released) were recorded. Using a multiple variable logistic regression model, there was a statistically significant positive association between length of time in the rehabilitation center and likelihood of release (odds ratio [OR] 1.08; 95% CI 1.06-1.12); this association can be explained by the need to overwinter some otherwise healthy bats in rehabilitation during hibernation. The following examination findings were associated with a significantly lower likelihood of release: wing injury (OR 0.32; 95% CI 0.10-0.89) and decreased body condition (OR 0.29; 95% CI 0.12-0.64). When corrected for time spent in rehabilitation (potentially artificially lengthened due to hibernation), patients admitted in the summer and fall were less likely to be released than those admitted in the winter (OR 0.93; 95% CI 0.90-0.96 and OR 0.95; 95% CI 0.92-0.97, respectively). The results of this study can be used to help veterinarians and licensed rehabilitators better triage EPFU during admission to wildlife rehabilitation centers in order to improve management and promote successful release back to the wild.

Body size and body condition in the nose-horned viper (Vipera ammodytes): effects of sex and populations

Snakes are ecologically and morphologically plastic organisms that exhibit extensive variations in body size and body condition in response to environmental factors. Documenting inter-population variations is important to describe species comprehensively across their distribution range and to monitor trends over time (e.g. decreasing body condition due to alteration of habitat). Thus, we analyzed the influence of population and sex on body size and body condition in three populations of nose-horned vipers (Vipera ammodytes) in Serbia. In one population, males were larger than females (F1, 39=4.802, p=0.034), but not in the two other populations (F1, 36=0.075, p=0.786; F1, 21=0.018, p=0.893). Females exhibited higher body condition (residual values from the regression of log-body mass against log-body size) than males (F1, 90=10.444, p=0.002); this sex difference was not found in one population when analyzed separately (F1, 35=1.834, p=0.184). Moreover, we found strong inter-population differences in mean body size and mean body condition (F2, 96=8.822, p<0.001 and F2, 90=10.319, p=0.001, respectively). While inter-population difference in body size was driven by males, inter-population difference in body condition was driven by females. These results suggest that, in this species, body size might be an important determinant of mating success in males, while body condition may play a major role in female fecundity.

Unique Presentations of Burkholderia gladioli Infections in Several Strains of Immunocompromised Mice.

Four strains of experimentally naïve mice (NOD. Cg-Prkdc scid Il2rg tm1Wjl /SzJ [NSG], NOD. Cg- Rag1 tm1Mom Il2rg tm1Wjl /SzJ [NRG], B6.129S(Cg)-Stat1 tm1Dlv/J [STAT1 -/-], and B6.129S7- Ifngr1 tm1Agt/J[IFNγR -/-] housed in a barrier facility developed unusual and seemingly unrelated clinical signs. Young NSG/NRG mice (n = 49, mean age = 4 ± 0.4 mo) exhibited nonspecific clinical signs of moderate-to-severe lethargy, hunched posture, decreased body condition, and pallor. In contrast to the NSG/NRG mice, the STAT1-/- and IFNγ R-/- mice (n = 5) developed large subcutaneous abscesses on the head and neck. These mice were euthanized, and samples were collected for culture. NSG/NRG mice had moderate-markedly enlarged livers (20 of 49, 40%) and spleens (17 of 49, 35%). The livers contained multiple, variably-sized, tan regions throughout all lobes. Histology revealed necrotizing hepatitis (13 of 17, 77%), splenic and hepatic extramedullary hematopoiesis (17 of 17, 100%), glomerular histiocytosis (6 of 17, 35%), and metritis (6 of 11, 55%) with perivascular inflammation, suggesting hematogenous spread Differentials for these lesions included mouse hepatitis virus, ectromelia virus, Pseudomonas aeruginosa, Salmonella spp., and Clostridium piliforme. Burkholderia gladioli was cultured from liver lesions and subcutaneous abscesses and confirmed with 16S ribosomal RNA sequencing. After completing systematic testing of the environment, failure of the water autoclave cycle was suspected as the cause of the outbreak. To address the situation, individually ventilated racks were sanitized and new breeders were purchased; these actions dramatically reduced B. gladioli infections. The current literature contains few reports of B. gladioli infections in immunocompromised mice, and its typical presentation is torticollis and rolling. B. gladioli infection is a potential differential for subcutaneous abscesses, hepatitis, and splenomegaly in immunocompromised mice. Careful monitoring of sterilization techniques is essential to prevent such infections in a barrier facility.

Trace metal elements and organic contaminants are differently related to the growth and body condition of wild European sea bass juveniles.

Chemical contaminants are one of the causes of the ongoing degradation of coastal and estuarine nurseries, key functional habitats in which the juveniles of many marine species grow. As chemical contaminants can cause a decrease in the energy available and induce defence mechanisms reducing the amount of energy allocated to life history traits, quantifying their effect on the fitness of juvenile fish is key to understand their population-level consequences. However, these effects are primarily estimated experimentally or in the wild but on a limited number of contaminants or congeners that do not reflect the wide variety of chemical contaminants to which juvenile fish are exposed. To address this issue, we measured concentrations of 14 trace metal elements (TMEs) and bioaccumulative organic contaminants (OCs) in European sea bass juveniles (1-year-old) from three major French nurseries (Seine, Loire and Gironde estuaries). We tested the hypotheses that (i) levels and profiles of contaminants differed among studied nurseries, and ii) fish growth and body condition (based on morphometric measurements and muscle C:N ratio) were lower in individuals with higher contaminant concentrations. Multivariate analyses showed that each nursery had distinct contaminant profiles for both TMEs and OCs, confirming the specific contamination of each estuary, and the large array of contaminants accumulated by sea bass juveniles. Increasing concentrations in some TMEs were associated to decreased growth, and TMEs were consistently related to lower fish body condition. The effect of OCs was more difficult to pinpoint possibly due to operational constraints (i.e., analyses on pooled fish) with contrasting results (i.e., higher growth and decreased body condition). Overall, this study shows that chemical contaminants are related to lower fish growth and body condition at an early life stage in the wild, an effect that can have major consequences if sustained in subsequent ages and associated with a decline in survival and/or reproductive success.

Female sex pheromone emission is affected by body condition, but not immune system function, in the orb‐web spider Argiope bruennichi

AbstractSex pheromones function as species and sex recognition signals but can be equally important for mate assessment and choice. Adaptive mate choice requires the covariation of signal characteristics with fitness‐relevant traits, which can be achieved by condition‐dependent costs of signalling. Given a physiological link between signal production and other vital processes, such as immune system function, the expression of the sexual signal may result in decreased body condition or increased pathogen susceptibility. According to honest signalling theory, only high‐quality individuals should be able to produce high‐quality sexual signals. We tested this prediction in the sexual signal of female wasp spiders, Argiope bruennichi. Female A. bruennichi produce the volatile pheromone trimethyl methylcitrate, which not only attracts males from a distance but also is the main foundation for short‐distance male mate choice. Recent experiments showed that females use pheromones prudently and tailor the amount of pheromone produced to their needs, suggesting costs of pheromone production. Here we manipulated female physiological condition using both immune challenge and feeding treatments in a fully factorial design. Fed or starved females were injured with a needle that was sterile or coated with bacterial lipopolysaccharides. We found no effect of immune system stimulation on pheromone production, but food stress significantly reduced the amount of pheromone produced. Importantly, this response was apparent in terms of both absolute pheromone amounts and body mass‐normalized relative pheromone amounts indicating that this effect was due to reduced pheromone production rather than reduced body surface or volume. Given the close association of the female pheromone and the citric acid cycle, the main catabolism pathway for energy production in the cell, we argue that the female pheromone of A. bruennichi may signal a female's general capacity of energy production according to the “shared pathway hypothesis” for signal honesty.

Prevalence of iatrogenic heart murmurs in a population of apparently healthy cats.

To determine the prevalence of iatrogenic heart murmurs in a population of apparently healthy cats and to investigate factors that may predispose cats to iatrogenic murmurs. Apparently healthy cats presenting for routine examinations were prospectively enrolled. Following a physical examination to confirm there were no abnormalities, a cardiac examination was performed before and during a provocative manoeuvre performed independently by two clinicians. The provocative manoeuvre was performed on the right side of the chest wall by applying gentle pressure with a stethoscope to ascertain whether a murmur became audible, graded using a modified descriptive scale (soft/moderate). The cat's heart rate before and during the provocative manoeuvre and their age, sex, body condition score and bodyweight were recorded. One hundred and six cats were prospectively enrolled. The average prevalence of iatrogenic murmurs was 28.2% with good interobserver agreement recorded on both the presence (kappa 0.67 and 0.62) and grade of the murmur (kappa 0.6 and 0.53). A significant association was noted between age and body condition score, with iatrogenic murmurs more likely in cats with increasing age and decreasing body condition score. There was no association between heart rate and the presence of an iatrogenic murmur. Iatrogenic murmurs are a common finding in cats with increasing prevalence noted in older and lean cats. Iatrogenic murmurs should therefore be considered as a differential diagnosis in a cat when an audible soft systolic right-sided murmur occurs with gentle pressure application to the chest wall during auscultation.

Investigating the effect of habitat modification on chronic stress in deer mice: a preliminary study

Anthropogenic habitat modification can lead to chronic stress in wildlife. This can result in immunosuppression and higher disease prevalence. Chronically stressed individuals typically have elevated baseline GCs and decreased body condition. GCs are called FGMs when excreted in feces and can be used to noninvasively evaluate stress in free-ranging wildlife. In the deer mouse (Peromyscus maniculatus)–SNV system, SNV prevalence is higher in deer mice at peridomestic settings, which are human-modified habitats. This is problematic because SNV causes a fatal disease in humans, and thus the higher SNV prevalence may lead to higher risk of infection for humans. In our study, we hypothesized that SNV prevalence would be higher in deer mice at human-modified habitats due to chronic stress. To test our hypothesis, we compared two stress measures (i.e., baseline FGMs and body condition scores) in deer mice from one peridomestic and one sylvan grid over 2 months. Captured deer mice were tagged, weighed, sexed and sampled for feces and blood and were evaluated for reproductive status and body condition before release. Blood samples were analysed for SNV antibodies, and fecal samples were evaluated for FGMs. We found higher deer mouse numbers at the sylvan grid. There were no differences in baseline FGM levels between peridomestic and sylvan populations. However, peridomestic deer mice had overall lower body condition. Given the low SNV prevalence across both grids, we were unable to examine potential correlations between SNV prevalence and chronic stress. Regardless, we conclude that deer mice at human-modified habitats may not be chronically stressed, which may suggest that higher SNV prevalence at peridomestic settings may not be the result of chronic stress. Although we did find that peridomestic deer mice had lower body condition, this may not have been related to chronic stress because there were no differences in baseline FGMs. Longer studies with more site replication are needed to validate and expand on our findings. Our preliminary study adds to the existing body of knowledge that examines relationships between stress physiology and disease prevalence in human-modified environments.

Bold Behavior Is Associated with Genes That Regulate Energy Use but Does Not Covary with Body Condition in Food-Restricted Snails.

AbstractTheoretical models about the relationship between food restriction and individual differences in risk-taking behavior (i.e., boldness) have led to conflicting predictions: some models predict that food restriction increases boldness, while other models predict that food restriction decreases boldness. This discrepancy may be partially attributable to an underappreciation for animals' complex physiological responses to food restriction. To understand the proximate mechanisms mediating state-dependent boldness, we used freshwater snails (Helisoma trivolvis) to examine the relationships among food availability, body condition, boldness (latency to reemerge from shell and exploration), and mRNA expression of three genes (adenosine monophosphate-activated protein kinase [AMPK], molluscan insulin-like peptide [MIP], and serotonin receptor [5-HT]) involved in maintaining energy homeostasis during periods of moderate food restriction. Latency to reemerge and exploratory behavior decreased over time, but fed snails were bolder than fasted snails, suggesting that food restriction reduces bold behavior. Although food restriction decreased body condition, there was not a relationship between body condition and latency to reemerge from shell. However, expression of MIP was positively correlated with latency to reemerge from shell. Furthermore, AMPK was positively correlated with MIP and negatively correlated with body condition and 5-HT. Therefore, individual differences in physiological responses to food restriction, not overall body condition per se, appear to be more closely associated with state-dependent bold behavior. Finally, snails that experienced a novel assay environment returned to their initial "shy" behavior, suggesting that habituation to the assay environment may contribute to snails expressing bolder behavior over time.

Does Wealth Predict Health Among Dogs in a Protected Area?

As the world's most ubiquitous carnivore, domestic dogs maintain unique proximity to human populations. Partly because dogs potentially serve as hosts of zoonotic diseases, determinants of canine health are increasingly the focus of interdisciplinary research. Emerging perspectives suggest that dogs' health may vary as a function of their owners' wealth and financial resources, a correlation that could potentially inform public health programs and conservation efforts. The objective of this study was to evaluate associations between household wealth and the health of domestic dogs (n = 208) among indigenous Mayangna communities in the Bosawás Biosphere Reserve, Nicaragua. The dogs were evaluated using serum biochemistry, complete blood count, and physical exam findings. Using these data, a principal components analysis (PCA) determined the presence of four "syndromes": 1) decreased body condition score (BCS) & hypoalbuminemia; 2) lymphocytosis & eosinophilia; 3) segmented neutrophilia; and 4) lymphadenopathy, tick infestation, & hyperglobulinemia. An inventory of possessions indexed household wealth. For all four syndromes, household wealth was a weak and uninformative predictor of the dogs' health. The few differences seen among dogs from households with different degrees of wealth likely reflect that nearly all dogs had marginal health and all households were relatively poor. Results from this study imply that owners' wealth may have diverse effects on canine health in rural settings.

Does urbanization ameliorate the effect of endoparasite infection in kangaroo rats?

Urban development can fragment and degrade remnant habitat. Such habitat alterations can have profound impacts on wildlife, including effects on population density, parasite infection status, parasite prevalence, and body condition. We investigated the influence of urbanization on populations of Merriam's kangaroo rat (Dipodomys merriami) and their parasites. We predicted that urban development would lead to reduced abundance, increased parasite prevalence in urban populations, increased probability of parasite infection for individual animals, and decreased body condition of kangaroo rats in urban versus wildland areas. We live trapped kangaroo rats at 5 urban and 5 wildland sites in and around Las Cruces, NM, USA from 2013 to 2015, collected fecal samples from 209 kangaroo rats, and detected endoparasites using fecal flotation and molecular barcoding. Seven parasite species were detected, although only two parasitic worms, Mastophorus dipodomis and Pterygodermatites dipodomis, occurred frequently enough to allow for statistical analysis. We found no effects of urbanization on population density or probability of parasite infection. However, wildland animals infected with P. dipodomis had lower body condition scores than infected animals in urban areas or uninfected animals in either habitat. Our results suggest that urban environments may buffer Merriam's kangaroo rats from the detrimental impacts to body condition that P. dipodomis infections can cause.