Spatial prey availability and pulsed reproductive tactics: Encounter risk in a canid-ungulate system.

Predation risk is a function of spatiotemporal overlap between predator and prey, as well as behavioural responses during encounters. Dynamic factors (e.g. group size, prey availability and animal movement or state) affect risk, but rarely are integrated in risk assessments. Our work targets a system where predation risk is fundamentally linked to temporal patterns in prey abundance and behaviour. For neonatal ungulate prey, risk is defined within a short temporal window during which the pulse in parturition, increasing movement capacity with age and antipredation tactics have the potential to mediate risk. In our coyote-mule deer (Canis latrans-Odocoileus hemionus) system, leveraging GPS data collected from both predator and prey, we tested expectations of shared enemy and reproductive risk hypotheses. We asked two questions regarding risk: (A) How does primary and alternative prey habitat, predator and prey activity, and reproductive tactics (e.g. birth synchrony and maternal defence) influence the vulnerability of a neonate encountering a predator? (B) How do the same factors affect behaviour by predators relative to the time before and after an encounter? Despite increased selection for mule deer and intensified search behaviour by coyotes during the peak in mule deer parturition, mule deer were afforded protection from predation via predator swamping, experiencing reduced per-capita encounter risk when most neonates were born. Mule deer occupying rabbit habitat (Sylvilagus spp.; coyote's primary prey) experienced the greatest risk of encounter but the availability of rabbit habitat did not affect predator behaviour during encounters. Encounter risk increased in areas with greater availability of mule deer habitat: coyotes shifted their behaviour relative to deer habitat, and the pulse in mule deer parturition and movement of neonatal deer during encounters elicited increased speed and tortuosity by coyotes. In addition to the spatial distribution of prey, temporal patterns in prey availability and animal behavioural state were fundamental in defining risk. Our work reveals the nuanced consequences of pulsed availability on predation risk for alternative prey, whereby responses by predators to sudden resource availability, the lasting effects of diversionary prey and inherent antipredation tactics ultimately dictate risk.

Brucine N-Oxide Reduces Ethanol Intake and Preference in Alcohol-Preferring Male Fawn-Hooded Rats.

BACKGROUND: Alcohol use disorder places a heavy burden on global public health systems and thus is in urgent need of improved pharmacotherapies. Previously, our group has demonstrated that 30 mg/kg of the indole alkaloid brucine significantly attenuates alcohol-drinking behavior; however, the high toxicity, poor water solubility, short half-life, and limited therapeutic window of brucine restrain its clinical application as an antialcoholism medication. We subsequently hypothesized that the oxide of brucine (brucine N-oxide) would produce a similar behavioral effect without the risk profile associated with brucine. METHODS: Male Fawn-Hooded rats with high innate alcohol preference underwent 2-bottle choice procedures (Experiments 1 to 3). Experiment 1 examined the effects of 7 daily BNO injections of 0, 30, 50, or 70 mg/kg (s.c.) on voluntary alcohol consumption (n = 9/group). Experiment 2 evaluated the impact of a single dose of 0 or 70 mg/kg BNO on the increased alcohol intake induced by a 4-day alcohol deprivation (n = 8/group). Experiment 3 tested the effect of 7 daily BNO injections of 0 or 70 mg/kg (s.c.) on sucrose preference (n = 6/group). Experiment 4 measured the median lethal dose (LD50) values of BNO and brucine to compare their acute toxicity in rats. Experiment 5 tested whether BNO (0, 30, 50, and 70 mg/kg, s.c.) affected locomotor activity using an open-field paradigm (n = 8/group). Finally, Experiment 6 evaluated the possible conditioned rewarding effects of 0, 30, 50, and 70 mg/kg BNO using the conditioned place preference paradigm (n = 6/group). RESULTS: BNO administration dose-dependently attenuated alcohol consumption without affecting food intake, total fluid consumption, or the natural preference for a sucrose solution, with 70 mg/kg BNO reducing consumption by 22.8%. A single dose of 70 mg/kg BNO significantly inhibited the alcohol deprivation effect. The LD50 values of BNO and brucine in rats were determined to be 1,103.5 ± 177.0 mg/kg and 264.6 ± 17.7 mg/kg, respectively. Finally, BNO administration did not affect spontaneous locomotor activity or induce a place preference. CONCLUSIONS: BNO may help to control excessive alcohol use and should be considered a treatment strategy for future study and development.

Fine Sediment Removal Influences Biogeochemical Processes in a Gravel-bottomed Stream.

The transport and processing of nutrients and organic matter in streams are important functions that influence the condition of watersheds and downstream ecosystems. In this study, we investigated the effects of streambed sediment removal on biogeochemical cycling in Fawn River, a gravel-bottomed river in Indiana, U.S.A. We measured stream metabolism as well as nitrogen (N) and phosphorus (P) retention in both restored and unrestored reaches of Fawn River to examine how sediment removal affected multiple biogeochemical functions at the reach scale. We also assessed the properties of restored and unrestored streambed sediments to elucidate potential mechanisms driving observed reach-scale differences. We found that sediment removal led to lower rates of primary productivity and ecosystem respiration in the restored reach, likely due to macrophyte removal and potentially due to changes to sediment organic matter quality. We found minimal differences in N and P retention, suggesting that these processes are controlled at larger spatial or temporal scales than were examined in this study. Denitrification enzyme activity was lower in sediments from the restored reach compared to the unrestored reach, suggesting that restoration may have decreased N removal. Our results indicate that most near-term changes in biogeochemical function following restoration could be attributed to macrophyte removal, although effects from sediment removal may emerge over longer timescales.

Spatial processes decouple management from objectives in a heterogeneous landscape: predator control as a case study.

Predator control is often implemented with the intent of disrupting top-down regulation in sensitive prey populations. However, ambiguity surrounding the efficacy of predator management, as well as the strength of top-down effects of predators in general, is often exacerbated by the spatially implicit analytical approaches used in assessing data with explicit spatial structure. Here, we highlight the importance of considering spatial context in the case of a predator control study in south-central Utah. We assessed the spatial match between aerial removal risk in coyotes (Canis latrans) and mule deer (Odocoileus hemionus) resource selection during parturition using a spatially explicit, multi-level Bayesian model. With our model, we were able to evaluate spatial congruence between management action (i.e., coyote removal) and objective (i.e., parturient deer site selection) at two distinct scales: the level of the management unit and the individual coyote removal. In the case of the former, our results indicated substantial spatial heterogeneity in expected congruence between removal risk and parturient deer site selection across large areas, and is a reflection of logistical constraints acting on the management strategy and differences in space use between the two species. At the level of the individual removal, we demonstrated that the potential management benefits of a removed coyote were highly variable across all individuals removed and in many cases, spatially distinct from parturient deer resource selection. Our methods and results provide a means of evaluating where we might anticipate an impact of predator control, while emphasizing the need to weight individual removals based on spatial proximity to management objectives in any assessment of large-scale predator control. Although we highlight the importance of spatial context in assessments of predator control strategy, we believe our methods are readily generalizable in any management or large-scale experimental framework where spatial context is likely an important driver of outcomes.

Increases in residential and energy development are associated with reductions in recruitment for a large ungulate.

Land-use change due to anthropogenic development is pervasive across the globe and commonly associated with negative consequences for biodiversity. While land-use change has been linked to shifts in the behavior and habitat-use patterns of wildlife species, little is known about its influence on animal population dynamics, despite the relevance of such information for conservation. We conducted the first broad-scale investigation correlating temporal patterns of land-use change with the demographic rates of mule deer, an iconic species in the western United States experiencing wide-scale population declines. We employed a unique combination of long-term (1980-2010) data on residential and energy development across western Colorado, in conjunction with congruent data on deer recruitment, to quantify annual changes in land-use and correlate those changes with annual indices of demographic performance. We also examined annual variation in weather conditions, which are well recognized to influence ungulate productivity, and provided a basis for comparing the relative strength of different covariates in their association with deer recruitment. Using linear mixed models, we found that increasing residential and energy development within deer habitat were correlated with declining recruitment rates, particularly within seasonal winter ranges. Residential housing had two times the magnitude of effect of any other factor we investigated, and energy development had an effect size similar to key weather variables known to be important to ungulate dynamics. This analysis is the first to correlate a demographic response in mule deer with residential and energy development at large spatial extents relevant to population performance, suggesting that further increases in these development types on deer ranges are not compatible with the goal of maintaining highly productive deer populations. Our results underscore the significance of expanding residential development on mule deer populations, a factor that has received little research attention in recent years, despite its rapidly increasing footprint across the landscape.

Progression of hypertension and kidney disease in aging fawn-hooded rats is mediated by enhanced influence of renin-angiotensin system and suppression of nitric oxide system and epoxyeicosanoids.

The fawn-hooded hypertensive (FHH) rat serves as a genetic model of spontaneous hypertension associated with glomerular hyperfiltration and proteinuria. However, the knowledge of the natural course of hypertension and kidney disease in FHH rats remains fragmentary and the underlying pathophysiological mechanisms are unclear. In this study, over the animals' lifetime, we followed the survival rate, blood pressure (telemetry), indices of kidney damage, the activity of renin-angiotensin (RAS) and nitric oxide (NO) systems, and CYP450-epoxygenase products (EETs). Compared to normotensive controls, no elevation of plasma and renal RAS was observed in prehypertensive and hypertensive FHH rats; however, RAS inhibition significantly reduced systolic blood pressure (137 ± 9 to 116 ± 8, and 159 ± 8 to 126 ± 4 mmHg, respectively) and proteinuria (62 ± 2 to 37 ± 3, and 132 ± 8 to 87 ± 5 mg/day, respectively). Moreover, pharmacological RAS inhibition reduced angiotensin (ANG) II and increased ANG 1-7 in the kidney and thereby may have delayed the progression of kidney disease. Furthermore, renal NO and EETs declined in the aging FHH rats but not in the control strain. The present results, especially the demonstration of exaggerated vascular responsiveness to ANG II, indicate that RAS may contribute to the development of hypertension and kidney disease in FHH rats. The activity of factors opposing the development of hypertension and protecting the kidney declined with age in this model. Therefore, therapeutic enhancement of this activity besides RAS inhibition could be attempted in the therapy of human hypertension associated with kidney disease.

EAR AND TAIL LESIONS ON CAPTIVE WHITE-TAILED DEER FAWNS (ODOCOILEUS VIRGINIANUS): A CASE STUDY.

During the 2008-2011 time period, undiagnosed lesions were observed in 21 of 150 white-tailed deer fawns (Odocoileus virginianus) that were part of a captive deer herd at Mississippi State University. Clinical findings in healthy and diseased fawns from 0 to 90 days of age included bite and scratch marks followed by moderate to severe ear and tail necrosis. Gross necropsy findings of necrotizing ulcerative dermatitis correlated with histopathologic findings that included focally severe multifocal vasculitis, vascular necrosis, and thrombosis. This article is a clinical description of these previously unreported lesions associated with tissue necrosis in young captive white-tailed deer.

R-Baclofen Treatment Corrects Autistic-like Behavioral Deficits in the RjIbm(m):FH Fawn-Hooded Rat Strain.

The Fawn-hooded rat has long been used as a model for various peripheral and central disorders and the data available indicate that the social behavior of this strain may be compromised. However, a thorough description of the Fawn-hooded rat is unavailable in this regard. The objective of the present study was to investigate various aspects of the Fawn-hooded rat's social behavior in depth. Our results show that several facets of socio-communicational behavior are impaired in the RjIbm(m):FH strain, including defective ultrasonic vocalizations in pups upon maternal deprivation, reduced social play in adolescence and impaired social novelty discrimination in adulthood. In addition, Fawn-hooded rats exhibited heightened tactile sensitivity and hyperactivity. The defects observed were comparable to those induced by prenatal valproate exposure, a widely utilized model of autism spectrum disorder. Further on, the pro-social drug R-baclofen (0.25-1 mg/kg) reversed the autistic-like defects observed in Fawn-hooded rats, specifically the deficiency in ultrasonic vocalization, tactile sensitivity and social novelty discrimination endpoints. In conclusion, the asocial, hypersensitive and hyperactive phenotype as well as the responsivity to R-baclofen indicate this variant of the Fawn-hooded rat strain may serve as a model of autism spectrum disorder and could be useful in the identification of novel drug candidates.

Mule deer fawn recruitment dynamics in an energy disturbed landscape.

Wildlife population dynamics are modulated by abiotic and biotic factors, typically climate, resource availability, density-dependent effects, and predator-prey interactions. Understanding whether and how human-caused disturbances shape these ecological processes is helpful for the conservation and management of wildlife and their habitats within increasingly human-dominated landscapes. However, many jurisdictions lack either long-term longitudinal data on wildlife populations or measures of the interplay between human-mediated disturbance, climate, and predator density. Here, we use a 50-year time series (1962-2012) on mule deer (Odocoileus hemionus) demographics, seasonal weather, predator density, and oil and gas development patterns from the North Dakota Badlands, USA, to investigate long-term effects of landscape-level disturbance on mule deer fawn fall recruitment, which has declined precipitously over the last number of decades. Mule deer fawn fall recruitment in this study represents the number of fawns per female (fawn:female ratio) that survive through the summer to October. We used this fawn recruitment index to evaluate the composite effects of interannual extreme weather conditions, energy development, and predator density. We found that density-dependent effects and harsh seasonal weather were the main drivers of fawn fall recruitment in the North Dakota Badlands. These effects were further shaped by the interaction between harsh seasonal weather and predator density (i.e., lower fawn fall recruitment when harsh weather was combined with higher predator density). Additionally, we found that fawn fall recruitment was modulated by interactions between seasonal weather and energy development (i.e., lower fawn fall recruitment when harsh weather was combined with higher density of active oil and gas wells). Interestingly, we found that the combined effect of predator density and energy development was not interactive but rather additive. Our analysis demonstrates how energy development may modulate fluctuations in mule deer fawn fall recruitment concurrent with biotic (density-dependency, habitat, predation, woody vegetation encroachment) and abiotic (harsh seasonal weather) drivers. Density-dependent patterns emerge, presumably due to limited quality habitat, being the primary factor influencing fall fawn recruitment in mule deer. Secondarily, stochastic weather events periodically cause dramatic declines in recruitment. And finally, the additive effects of human disturbance and predation can induce fluctuations in fawn fall recruitment. Here we make the case for using long-term datasets for setting long-term wildlife management goals that decision makers and the public can understand and support.

History of the term 'appeasement': a response to Bailey et al. (2023).

This letter to the editor aims to address claims made by Bailey et al. [2023. Appeasement: Replacing Stockholm syndrome as a definition of a survival strategy. European Journal of Psychotraumatology, 14(1), 2161038] about the history of the concept of appeasement in relation to mammalian survival responses as well as the fawn response, by offering a brief overview and analysis of the literature.

Appeasement in political and foreign policy, social justice, ethology, psychology, and communication studies (multiple mammalian and avian species) feature elements of coregulation.The original conceptualisation of the fawn response may result in the misperception that it is unrelated to coregulation.Appeasement and coregulation can occur whether the vulnerable party initiating the appeasement is in a state that supports affiliative, distress, or shutdown behaviour.

Empagliflozin Is Not Renoprotective in Non-Diabetic Rat Models of Chronic Kidney Disease.

Gliflozins (sodium-glucose transporter-2 inhibitors) exhibited renoprotective effects not only in diabetic but also in non-diabetic patients with chronic kidney disease (CKD). Controversial results were reported in experimental non-diabetic models of CKD. Therefore, we examined empagliflozin effects in three CKD models, namely, in fawn-hooded hypertensive (FHH) rats, uninephrectomized salt-loaded (UNX + HS) rats, and in rats with Goldblatt hypertension (two-kidney, one-clip 2K1C) that were either untreated or treated with empagliflozin (10 mg/kg/day) for eight weeks. Plethysmography blood pressure (BP) was recorded weekly, and renal parameters (proteinuria, plasma urea, creatinine clearance, and sodium excretion) were analyzed three times during the experiment. At the end of the study, blood pressure was also measured directly. Markers of oxidative stress (TBARS) and inflammation (MCP-1) were analyzed in kidney and plasma, respectively. Body weight and visceral adiposity were reduced by empagliflozin in FHH rats, without a significant effect on BP. Experimentally induced CKD (UNX + HS and 2K1C) was associated with a substantial increase in BP and relative heart and kidney weights. Empagliflozin influenced neither visceral adiposity nor BP in these two models. Although empagliflozin increased sodium excretion, suggesting effective SGLT-2 inhibition, it did not affect diuresis in any experimental model. Unexpectedly, empagliflozin did not provide renoprotection because proteinuria, plasma urea, and plasma creatinine were not lowered by empagliflozin treatment in all three CKD models. In line with these results, empagliflozin treatment did not decrease TBARS or MCP-1 levels in either model. In conclusion, empagliflozin did not provide the expected beneficial effects on kidney function in experimental models of CKD.

A Comparison of Oxidative Stress Biomarkers in the Serum of Healthy Polish Dairy Goats with Those Naturally Infected with Small Ruminant Lentivirus in the Course of Lactation.

The present study examines the effects of natural infection by small ruminant lentivirus (SRLV) in the two most common goat breeds in Poland, i.e., Polish white improved and polish fawn improved. It focuses on biomarkers of oxidative stress, oxidatively modified proteins and antioxidant defenses, ceruloplasmin level as an acute phase protein, and the activities of antioxidant enzymes in the goat serum. It was conducted on 24 goats divided into two equal groups: one SRLV-seropositive (SRLV-SP) and another SRLV-seronegative (SRLV-SN). Both groups were identical in terms of breed and parity. Despite infection, the SRLV-SP goats demonstrated no symptoms of caprine arthritis-encephalitis. In addition, the SRLV-SP goats did not reveal pronounced dysfunctions in oxidative stress biomarkers in the serum compared to the SRLV-SN animals. However, both groups demonstrated elevated levels of the aldehydic and ketonic derivatives of oxidatively modified proteins during the lactation period. In addition, both groups retained a high total antioxidant capacity in serum despite the decrease of enzyme antioxidant defenses throughout the 200-day lactation period.

Does Small Ruminant Lentivirus Infection in Goats Predispose to Bacterial Infection of the Mammary Gland? A Preliminary Study.

The aim of this study was to determine whether asymptomatic small ruminant lentivirus seropositive (SRLV-SP) goats were more susceptible to bacterial infection of the udder when lactating by comparing the presence and species of pathogenic bacteria in their milk with the values for seronegative goats (SRLV-SN). Milk samples were collected during morning milking on days 20, 40, 60, 150, and 210 of lactation for three consecutive years and subjected to bacteriological examination. Staphylococcus caprae and S. xylosus were the most frequent strains identified in both SRLV-SP and SRLV-SN goats. The prevalence of pathogenic bacteria was the highest in the 1st lactation, regardless of SRLV status. Moreover, the prevalence of pathogenic bacteria was significantly higher in SRLV-SP goats, but only those in the 5th or further lactation (p = 0.010). This suggests a relationship between long-lasting SRLV infection and susceptibility to bacterial infections of the udder.

Use of aerial thermography to reduce mortality of roe deer fawns before harvest.

In agricultural landscape, there are thousands of young wild animals killed every year. Their deaths are caused mostly by agricultural fieldworks during spring harvest. Among the affected animals there are also fawns of roe deer (Capreolus capreolus), which react to danger by pressing themselves against the ground in order to be protected from predators. There were various methods tested in the past aimed at decreasing roe deer mortality caused by agriculture machinery with varied levels of success. This contribution presents technology that documents the possibility of searching for fawns with a thermal imaging device carried by an unmanned aerial vehicles (UAV). The results are based on field research that estimated the ideal height of flight being ±40 meters above ground. If the climatic conditions are favourable, it is possible to monitor and mark fawn locations using GPS coordinates in an area of about 14 ha in 25 minutes, which is the average flight time of UAV on one battery charge. The thermo-camera is very reliable in finding fawns in early morning hours (4 to 6 a.m.) when there is the highest temperature contrast between the searched object and its surroundings. The main limiting factors are climatic conditions and the short time span in which the thermo-camera can be used. If the basic requirements are met, the rate of successful fawn detection can be even up to 100%. An undisputed advantage of this method is the possibility of involvement of local gamekeepers. Thus the agricultural fieldworks are not interrupted.

A new inbred strain of Fawn-Hooded rats demonstrates mania-like behavioural and monoaminergic abnormalities.

The Fawn-Hooded (FH) rat carries a gene mutation that results in a dysfunctional serotoninergic system. However, previous studies have reported differing features between the FH/Wjd and FH/Har strains. We aimed to compare the behavioural and neurobiological features of FH/HamSlc rats with those of Fischer 344 rats. We performed the open field, elevated minus-maze, Y-maze spontaneous alternation, and forced swim tests to investigate behavioural alterations. We also assessed neurobiological characteristics by quantifying monoamines and their related compounds in the prefrontal cortex, hippocampus, and striatum using high-performance liquid chromatography with an electrochemical detection system. FH/HamSlc rats showed hyperactivity and a high impulsivity tendency in the open field and the elevated minus maze test, but no cognitive dysfunction. In addition, the hyperactivity was suppressed immediately after the forced swim test. FH/HamSlc rats showed low dopamine levels, but high dopamine turnover in the striatum. Serotonin and noradrenaline levels were low in the prefrontal cortex and the hippocampus of FH/HamSlc rats, but high serotonin turnover was observed in the prefrontal cortex, hippocampus, and striatum. FH/HamSlc rats show (1) mania-like behavioural characteristics that are different from those of other strains of FH rats; (2) stimulus dependent suppression of hyperactivity similar to the clinical findings that exercise alleviates the symptoms of bipolar disorder; and (3) monoaminergic dysregulation such as monoamine imbalance and hyperturnover that may be associated with mania-related behavioural characteristics. Thus, the FH/HamSlc rat is a new animal model for mania including bipolar disorder.

Bleeding Diathesis in Fawn Hooded Rats-Possible Implications for Invasive Procedures and Refinement Strategies.

The Fawn hooded (FH) rat is commonly used in biomedical research. It is widely acknowledged that the FH rat has a bleeding disorder; leading to abundant bleedings. Although this bleeding disorder is investigated to model the storage pool defect; its impact on commonly performed invasive laboratory procedures has not yet been described. Our research group experienced clinically significant consequences of this bleeding disorder following invasive procedures (including intraperitoneal injections and neurocranial surgery) in the Rjlbm: FH stock. The clinical consequences of the surgical and anesthetic protocols applied; are described including the subsequent procedural refinements applied to minimize the impact of this disorder. It is strongly recommended to take the bleeding diathesis into account when performing invasive procedures in FH rats and to apply the suggested refinement of procedures.