Body Condition Index Research Articles

Which processes are behind the relationship between species abundance and environmental suitability? Monte Albo cave salamander as model species

Species can show a strong variation of local abundance across their ranges. Recent analyses suggested that variation in abundance can be related to environmental suitability, as the highest abundances are often observed in populations living in the most suitable areas. However, there is limited information on the mechanisms through which variation in environmental suitability determines abundance. We analyzed populations of the microendemic Monte Albo cave salamander Hydromantes (Speleomantes) flavus Stefani, 1969 (Plethodontidae), and tested several hypotheses on potential relationships linking environmental suitability to population parameters. For multiple populations across the whole species range, we assessed suitability using species distribution models and measured density, activity level, food intake, and body condition index. In high-suitability sites, the density of salamanders was up to 30 times higher than in the least suitable ones. Variation in activity levels and population performance can explain such variation of abundance. In high-suitability sites, salamanders were active close to the surface and showed a low frequency of empty stomachs. Furthermore, when taking into account seasonal variation, body condition was better in the most suitable sites. Our results show that the strong relationship between environmental suitability and population abundance can be mediated by the variation of parameters strongly linked to individual performance and fitness. Furthermore, we highlighted the potential use of cave animals as model species to answer macroecological questions.

Ectoparasite communities of small-bodied Malagasy primates: seasonal and socioecological influences on tick, mite and lice infestation of Microcebus murinus and M. ravelobensis in northwestern Madagascar

BackgroundEctoparasitic infections are of particular interest for endangered wildlife, as ectoparasites are potential vectors for inter- and intraspecific pathogen transmission and may be indicators to assess the health status of endangered populations. Here, ectoparasite dynamics in sympatric populations of two Malagasy mouse lemur species, Microcebus murinus and M. ravelobensis, were investigated over an 11-month period. Furthermore, the animals’ body mass was determined as an indicator of body condition, reflecting seasonal and environmental challenges. Living in sympatry, the two study species experience the same environmental conditions, but show distinct differences in socioecology: Microcebus murinus sleeps in tree holes, either solitarily (males) or sometimes in groups (females only), whereas M. ravelobensis sleeps in mixed-sex groups in more open vegetation.ResultsBoth mouse lemur species hosted ticks (Haemaphysalis sp.), lice (Lemurpediculus sp.) and mites (Trombiculidae gen. sp. and Laelaptidae gen. sp.). Host species, as well as temporal variations (month and year), were identified as the main factors influencing infestation. Tick infestation peaked in the late dry season and was significantly more often observed in M. murinus (P = 0.011), while lice infestation was more likely in M. ravelobensis (P < 0.001) and showed a continuous increase over the course of the dry season. Genetic analyses identified Lemurpediculus sp. infesting both mouse lemur species. Ticks morphologically conform to H. lemuris, but genetic analysis showed a clear differentiation of the specimens collected in this study, suggesting a potentially new tick species. Host body mass decreased from the early to the late dry season, indicating nutritional stress during this period, which may render individuals more susceptible to parasitic infections.ConclusionsSeasonal differences and species-specific variations in sleeping site ecology in terms of sleeping site type and sociality were determined as key factors influencing ectoparasitism in M. murinus and M. ravelobensis. This needs to be taken into account when evaluating ectoparasite infestations at a given time point. The detection of the same parasite species on two closely related and sympatric host species furthermore indicates a potential pathway for disease transmission, not only within but also between lemur species.

Long-Term Changes in Age Structures of a Naturalized Population of Freshwater Turtle, Red-Eared Slider Trachemys scripta elegans

The red-eared slider turtle, Trachemys scripta elegans, is an invasive species, that may potentially induce negative impacts on native turtle communities and freshwater ecosystems. Effective control of invasive species requires knowledge of the process of invasion and the long-term dynamics of an introduced population. However, such studies are scarce. We investigated temporal changes in the species composition of a freshwater turtle assemblage including density and age structure of the red-eared slider turtle at the Kahokugata lagoon of Ishikawa Prefecture in central Japan over 15 years (2001–2003, 2013 and 2015). The number of red-eared sliders increased over time, whereas that of Reeves' pond turtle, Mauremys reevesii, remained flat for 15 years from 2001 to 2015. Data on morphological measurements in the red-eared slider population showed that the proportion of old individuals increased whereas juveniles decreased. Moreover, the body condition index decreased in all age classes. These results suggest that juvenile recruitment was limited in the recent years and thus breeding efficiency was lowered in the redeared slider population at this lagoon perhaps due to high population density.

Altered thyroid hormone levels affect body condition at metamorphosis in larvae of Xenopus laevis.

Chemical, physical and biological environmental stressors may affect the endocrine system, such as the thyroid hormone (TH) axis in larval amphibians with consequences for energy partitioning among development, growth and metabolism. We studied the effects of two TH level affecting compounds, exogenous l-thyroxine (T4 ) and sodium perchlorate (SP), on various measures of development and body condition in larvae of the African clawed frog (Xenopus laevis). We calculated the scaled mass index, hepatosomatic index and relative tail muscle mass as body condition indices to estimate fitness. Altered TH levels significantly altered the growth, development, survival and body condition in metamorphic larvae in different directions. While exogeno us T4 reduced growth and accelerated development, SP treatment increased growth but slowed down development. Altered TH levels improved body conditions in both treatments and particularly in larvae of the SP treatment but to the detriment of lower survival rates in both TH level altering treatments. The hepatosomatic index was negatively affected by exogenous T4 , but not by SP treatment indicating a lower lipid reserve in the liver in larvae of T4 treatment. These altered TH levels as caused by several environmental stressors may have an influence on individual fitness across life, as body condition at the onset of metamorphosis determines metamorphic and juvenile survival. Further research is needed to determine synergetic effects of environmental stressors on TH levels and its effects on physiological traits such as metabolic rate.

Blood biochemistry of olive ridley (Lepidochelys olivacea) sea turtles foraging in northern Sinaloa, Mexico

Blood parameters provide an excellent tool to evaluate the health status of wildlife. However, there are few studies about health parameters of sea turtles in Mexico. For olive ridley turtles (Lepidochelys olivacea), no information was available to establish the health baseline for the species. The objective of this study was to establish reference blood biochemistry values for olive ridley turtles in the northern Sinaloa foraging area. Between 2013 and 2015, 82 olive ridley turtles were captured. Body condition index (BCI) presented a mean of 1.46 ± 0.14 (1.17–2.02) that categorized the population with excellent body condition; in addition, 99% of the turtles captured had a good physical appearance. Blood was collected for biochemistry analysis from 60 turtles. Significantly higher values of total protein, albumin, A/G ratio (albumin/globulin) and PCV (packed cell volume or hematocrit) were observed in adult when compared to subadult turtles. On the other hand, no significant differences were found when females and males were compared. Based on the BCI, physical assessment, and blood parameters, and compared to other sea turtle species, olive ridley turtles in northern Sinaloa were considered in excellent health. To the best of our knowledge, this is the first study to establish normal blood biochemistry values of foraging olive ridley turtles in northern Sinaloa.

Supplementation stocking of Lake Trout (Salvelinus namaycush) in small boreal lakes: Ecotypes influence on growth and condition.

Supplementation stocking is a commonly used management tool to sustain exploited fish populations. Possible negative consequences of supplementation on local stocks are a concern for the conservation of wild fish populations. However, the direct impacts of supplementation on life history traits of local populations have rarely been investigated. In addition, intraspecific hybridization between contrasting ecotypes (planktivorous and piscivorous) has been seldom considered in supplementation plans. Here, we combined genetic (genotype-by-sequencing analysis) and life history traits to document the effects of supplementation on maximum length, growth rates, body condition and genetic admixture in stocked populations of two Lake Trout ecotypes from small boreal lakes in Quebec and Ontario, Canada. In both ecotypes, the length of stocked individuals was greater than local individuals and, in planktivorous-stocked populations, most stocked fish exhibited a planktivorous-like growth while 20% of fish exhibited piscivorous-like growth. The body condition index was positively related to the proportion of local genetic background, but this pattern was only observed in stocked planktivorous populations. We conclude that interactions and hybridization between contrasting ecotypes is a risk that could result in deleterious impacts and possible outbreeding depression. We discuss the implications of these findings for supplementation stocking.

Chronic debilitation in stranded loggerhead sea turtles (Caretta caretta) in the southeastern United States: Morphometrics and clinicopathological findings.

Chronically debilitated loggerhead sea turtles (Caretta caretta) (DT) are characterized by emaciation, lethargy, and heavy barnacle coverage. Although histopathological findings associated with this condition have been reported, only limited data is available on health variables with clinical application. The objectives of this study were to 1) to compare morphometrics, clinicopathological variables, and immune functions of DTs to a group of apparently healthy loggerhead turtles to better understand the pathophysiology of the condition and 2) to assess health parameters in live debilitated turtles as they recovered during rehabilitation in order to identify potential prognostic indicators. We examined and sampled 43 DTs stranded from North Carolina to Florida for 47 health variables using standardized protocols to further characterize the condition. DTs were grouped into categories of severity of the condition, and those that survived were sampled at four time points through rehabilitation. All groups and time points were compared among DTs and to clinically healthy loggerhead turtles. Compared to healthy turtles, DTs had significantly lower body condition index, packed cell volume (PCV), total white blood cell (WBC) count, lymphocytes, glucose (Glc), total protein, all protein fractions as determined by electrophoresis, calcium (Ca), phosphorus (P), Ca:P ratio, potassium (K), lymphocyte proliferation, and greater heterophil toxicity and left-shifting, uric acid (UA), aspartate aminotransferase, creatine kinase, lysozyme, and respiratory burst. From admission to recovery, hematology and plasma chemistry data improved as expected. The most informative prognostic indicators, as determined by correlations with a novel severity indicator (based on survival times), were plastron concavity, P, albumin, total solids, UA, lymphocyte proliferation, WBC, K, Glc, Ca:P, and PCV. The results of this study document the wide range and extent of morphometric and metabolic derangements in chronically debilitated turtles. Monitoring morphometrics and clinicopathological variables of these animals is essential for diagnosis, treatment, and prognosis during rehabilitation.

Fatty acid profiles of migrating female silver eel from Mediterranean coastal lagoons as integrative descriptors of spawners biological quality

The present study analyzed the lipid content and fatty acid profiles of European silver eels from Mediterranean lagoons, to interrogate the ecology and biology of eel, a panmictic species well represented in the region, with particular reference to breeder quality. Lagoons are coastal waterbodies included in transitional waters, sharing with these ecosystems, that include also brackish wetlands and river mouths, the characteristic of being influenced both by sea and continental waters. In the Mediterranean area these highly productive ecosystems, that also support a rich specific biodiversity, have a great relevance in relation to their great extent and the human and historical dimension, since they have long been exploited for their natural resources, especially for fishing. Eel collection was carried out in nine Italian lagoons typically representing these habitats, and two inland water habitats (a river and a lake) were added for comparison. Female silver eel muscle tissue revealed a mean lipid content significantly above the threshold considered necessary to provide the cue to trigger physiological reproductive changes for this species, in all the sampling sites irrespective of their typology. This emphasises the importance of Mediterranean coastal lagoons as habitats contributing to the eel oceanic migration, providing a significant share of spawning-stock biomass, both in terms of quality of the breeders and of their fitness to perform migration. Whereas the overall lipid content was similar among sites, the nine local populations differed in their fatty acid signatures. Thus, FA signatures might be proposed as integrative descriptors of eel spawner biological quality since they easily are able to differentiate among silver eel local stocks. Growth rates and body condition indices were strongly positively correlated to n-3:n-6 and DHA:EPA ratios in silver eels ready-to-migrate from the studied locations. This demonstrates that distinct PUFA, exclusively obtained through diet, are correlated with crucial biological features such as growth and condition of the silver eels that are going to undertake their journey to their oceanic reproduction sites. Overall, our results show the importance of additional tools for evaluating eel breeder quality that could also be integrated in the overall assessment of local stocks, a crucial step for ongoing and further management strategies of this endangered species.

Reproductive Dynamics of the Nectarivorous Geoffroy's Tailless BatAnoura geoffroyi(Glossophaginae) in a Highland Neotropical Area of Brazil, with Evidence of a Mating Period

This study investigated the reproductive dynamics of a colony of Geoffroy's tailless bat (Anoura geoffroyi), an important pollinating bat, in a highland area of Southeastern Brazil. The colony was monitored each month from November 2014 to December 2015 with 154 males and 117 females captured. Testicular and ovarian histological data from 31 adult males and 22 adult females were obtained. Body condition index of male and female, and gonadosomatic index, epididymis-somatic index and Sertoli cell efficiency were analyzed. Females with spermatozoa in uterine crypts, embryos in oviducts, gravid uteri, and pregnant females were registered during the rainy season (November-March) and into the beginning of the following dry season (April), indicating asynchrony of births. The ovaries showed all types of ovarian follicles, and a polarized ovary cortex was found, differing from the organization pattern of most mammals. The testes showed continuous spermatic activity, but testicular parameters analyzed showed significantly higher values during the rainy season. A shorter mating period during the beginning of this season was detected, when values of the gonadosomatic and epididymis-somatic indexes, and Sertoli cell efficiency showed more pronounced differences in relation to the remaining period of study. Unlike polyestry known for some Neotropical phyllostomids, the reproductive cycle of A. geoffroyi was characterized as seasonal monoestrous, with the main reproductive events occurring during the rainy season, as the best time for females to reproduce, but with offspring recruitment occurring predominantly during the dry season, a period with fewer food resources.

Environmental suitability models predict population density, performance and body condition for microendemic salamanders

Species can show strong variation of local abundance across their ranges. Recent analyses suggested that variation in abundance can be related to environmental suitability, as the highest abundances are often observed in populations living in the most suitable areas. However, there is limited information on the mechanisms through which variation in environmental suitability determines abundance. We analysed populations of the microendemic salamander Hydromantes flavus, and tested several hypotheses on potential relationships linking environmental suitability to population parameters. For multiple populations across the whole species range, we assessed suitability using species distribution models, and measured density, activity level, food intake and body condition index. In high-suitability sites, the density of salamanders was up to 30-times higher than in the least suitable ones. Variation in activity levels and population performance can explain such variation of abundance. In high-suitability sites, salamanders were active close to the surface, and showed a low frequency of empty stomachs. Furthermore, when taking into account seasonal variation, body condition was better in the most suitable sites. Our results show that the strong relationship between environmental suitability and population abundance can be mediated by the variation of parameters strongly linked to individual performance and fitness.

Response to capture stress involves multiple corticosteroids and is associated with serum thyroid hormone concentrations in Guadalupe fur seals (Arctocephalus philippii townsendi)

AbstractGuadalupe fur seals are a threatened species with few breeding locations, which potentially makes them sensitive to environmental or anthropogenic stressors. We present the first study to quantify adrenal and thyroid function in this species in an effort to measure their stress response to capture. We analyzed a suite of corticosteroid hormones released over time during capture in both adult females (n = 10) and weanling pups (n = 26) during March 2016. Multiple corticosteroids were released during capture, and aldosterone was associated with the response to stress in adults only. These results suggest the regulation of aldosterone secretion in association with the HPA axis in otariids as reported in other marine mammals. Individuals varied markedly in the magnitude of their endocrine response to capture. A lower total integrated stress response to capture for both cortisol and corticosterone was associated with decreased concentrations of thyroid hormone T3 and elevated concentrations of reverse T3 (rT3), suggesting parallel downregulation of adrenal and thyroid endocrine axes in some individuals. A scaled body condition index was negatively associated with T3 and positively associated with rT3 in adults. Together these findings suggest utility in using endocrine responses to capture stress to evaluate individual and population health.

Differential effects on life history traits and body size of two anuran species inhabiting an environment related to fluorite mine

Mining activity is an important cause of physicochemical, biological, and landscape alterations. Several studies involving disturbed environments confirmed the modification of demographic traits in anuran populations. The current study aimed to assess the effects of natural and artificial surface waters associated with a fluorite mine on the body size and life history traits of Rhinella arenarum and Boana cordobae. Sampling was done in three areas: stream running on granitic rock, with medium natural fluoride content (CN); stream running on metamorphic rock, with low natural fluoride content (LV); and artificial decantation pond (DP) with large variation in physicochemical parameters. Adult individuals of the two anuran species were measured and weighed, and their body condition (BC) was calculated. Life history traits were assessed using the skeletochronology method. Individuals from DP weighed significantly heavier than individuals from streams. The BC index in R. arenarum was higher at LV, whereas in B. cordobae, a higher index was obtained at both LV and DP. The average age differs between sites in B. cordobae but not in R. arenarum. Growth coefficient was higher for altered environment in both species (CN; DP), whereas the estimated SVLmax was slightly higher in populations from less disturbed sites (LV). The most affected species was B. cordobae. Therefore, for future studies, it is important to know the biology of sentinel species because not all amphibian species may respond in the same way to similar disturbances. Differences obtained in life history traits may be explained by the lack of survival of larger/older individuals or compensatory growth, required to balance fast growth with the costs on survival at more disturbed sites.

Seasonal and Sexual Variation of the Intermediate Metabolism and Body Condition Indexes in the LizardTropidurus catalanensis(Gudynas and Skuk, 1983) (Squamata: Tropiduridae)

Throughout the life cycle of organisms, nutrient intake is necessary for the maintenance of the functions of daily life and in preparation for a variety of biological events, such as molting, migration, hibernation, and reproduction. One of the most energetically costly events is reproduction. Present study sought to elucidate the seasonal variations in the markers of intermediate metabolism (total proteins, uric acid, glucose, total lipids, triglycerides, total cholesterol, VLDL cholesterol, and glycogen) and body condition indices (gonadossomatic, hepatosomatic, and abdominal fat index) in Tropidurus catalanensis, in order to know the physiological costs of reproduction in this species, also allowing these parameters to be used as markers in studies of environmental alterations. During the study period, 38 males and 35 females were collected. Tropidurus catalanensis is a lizard that inhabits the Pampa grasslands, a biome that stretches across Argentina, Brazil, and Uruguay. Results obtained reveal that this lizard exhibits a clear pattern of seasonal variation in its metabolism, as reflected mainly in levels of plasma total protein, liver glycogen, total lipids, and triglycerides in males and females; and in blood glucose and lipid, and liver protein levels in females. It bears stressing that all body condition indices analyzed varied over the course of the year. The parameters studied can be used to evaluate the impact of changes in environmental conditions on these animals. Winter months appear to trigger a reduction in overall metabolism, most intensely in males. Reproductive period seems to be the biological event that demands greater energy demand, leading to the mobilization of energy stocks mainly in females, where the search for food may be reduced in the months of reproductive peak (spring). The response pattern observed during the reproductive period suggests that this time represents a critical point in terms of the animal's adaptation to its life cycle.

Possible unintended effects of management at an invasion front: Reduced prevalence corresponds with high condition of invasive bigheaded carps

Limiting the prevalence of invasive species is a global conservation priority. Invasive species can have varying ecosystem effects and responses to control throughout an invaded range, and removal near invasion fronts may inadvertently alter these characteristics. Bigheaded carp (bighead carp (Hypophthalmichthys nobilis Richardson) and silver carp (H. molitrix Valenciennes)) are invasive fishes from Asia invading North American freshwater ecosystems. We used mobile hydroacoustic surveys to examine bigheaded carp population characteristics from 2012 to 2015 across an invasion gradient in the Illinois River (USA), one of the most likely pathways to the Laurentian Great Lakes. These bigheaded carp species comprised 23–46% of fish community abundance and 45–78% of fish biomass across reaches, with lower contribution near the invasion front where intensive management by harvest occurs. Bigheaded carp prevalence in the community did not differ by habitat and comprised >50% of community abundance and biomass throughout the river for most size classes. We identified negative relationships between density and relative weight (an index of body condition) of bigheaded carp, suggesting evidence of potential density-dependent intraspecific competition. Efforts to reduce invasive species abundances near invasion fronts may reduce prevalence. However, this could inadvertently release individuals from density-dependent competition and could enhance reproductive potential, growth or movements. By employing a suite of control efforts, including continuous removal efforts (including novel approaches) and by limiting movements (e.g., utilizing roads, fences, dams), it may be possible to offset undesired consequences of increased condition.

Leukocyte profiles and body condition of free-living Burrowing Owls (Athene cunicularia) from rural and urban areas in the Argentinean Pampas

Animals living in urban areas are exposed to novel and potentially stressful human disturbances. In response to the increased number of stressors in these habitats, they may manifest changes in their immune system, body condition and physiology. Many bird species are negatively impacted by urbanization, whilst other species thrive in urban areas. The capacity to adjust the physiological responses to the stressors associated with urban areas may play a key role in explaining the success of some bird species in these environments. In this study, we compared indicators of physiological stress response and body condition in freeliving Burrowing Owls (Athene cunicularia) inhabiting urban and rural areas. We calculated a scaled index of body condition, and assessed leukocyte profiles and the heterophil/lymphocyte ratios of chicks and adults. We found no significant differences in these parameters between individuals from rural and urban areas. Chicks showed higher relative leukocyte counts than adults, which may be associated with ontogenetic development and immune system activation processes.

Persistent organic pollutants and organophosphate esters in feathers and blood plasma of adult kittiwakes (Rissa tridactyla) from Svalbard – associations with body condition and thyroid hormones

Polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), organochlorine pesticides (OCPs) and organophosphate esters (OPEs) were assessed in blood plasma and feathers of 19 adult black-legged kittiwakes (Rissa tridactyla) breeding in two colonies (Blomstrandhalvøya and Krykkjefjellet) at the Arctic archipelago, Svalbard. Potential associations with body condition index (BCI) and thyroid hormones were investigated. All compound classes were detected in both blood plasma and feathers, but due to low sample size and volumes, OPEs could only be quantified in four individuals, warranting larger follow-up studies. Kittiwakes breeding at Blomstrandhalvøya had significantly higher concentrations of organic pollutants in blood plasma than kittiwakes breeding at Krykkjefjellet (p < 0.001). Concentrations in blood plasma and feathers did not significantly correlate for any of the investigated compounds, and feather concentrations did not differ significantly between the colonies. This suggests that pollutant levels in adult kittiwake feathers do not reflect local contamination at breeding sites and are as such not useful to monitor local contamination at Svalbard. Significant negative associations between BCI and most pollutants were found in both populations, whereas significant correlations between the BCI, the ratio of total triiodothyronine to free triiodothyronine (TT3:fT3), and several pollutants were only found for kittiwakes from Blomstrandhalvøya (all r ≥ −0.60 and p ≤ 0.05). This indicates that higher levels of circulating pollutants during the breeding period covary with the TT3: fT3 ratio, and may act as an additional stressor during this period.

Effect of fish length and nutritional condition on the fecundity of distressed Atlantic cod Gadus morhua from the Baltic Sea

The disappearance of larger individuals and the decrease in individual body condition suffered by Atlantic cod Gadus morhua in the eastern Baltic during the past two decades can be expected to affect the stock reproductive output. To investigate this, female G. morhua were collected during the spawning and pre-spawning period in 2015-2016. The current individual potential fecundity (FP ) of eastern Baltic G. morhua was estimated and analysed in relation to total length (LT ) and indices of nutritional status such as body condition (K) and hepato-somatic index (IH ) using generalized linear models. In addition, the current prevalence of atresia and its potential relation to K were investigated. Moreover, a calibration curve to estimate FP from oocyte diameter, based on the autodiametric oocyte counting method, was established for the first time for eastern Baltic G. morhua and can be used for future fecundity studies on this stock. The results showed that FP was mainly positively related to fish length, but K and IH also contributed significantly to the variation in FP . The model predicted that fish with K = 1·2 have a FP 51% higher than fish of the same LT with K = 0·8. The prevalence of fecundity regulation by atresia was 5·8%, but it was found only in fish in the pre-spawning maturity stage and with low K. Temporal changes in biological features such as the length composition and individual body condition of eastern Baltic G. morhua, should be accounted for when estimating stock reproductive potential.

Landscape structure and composition define the body condition of dung beetles (Coleoptera: Scarabaeinae) in a fragmented tropical rainforest

Environmental disturbance generates changes in local abiotic and biotic conditions, which affect the physiological condition of the organisms. However, most of the studies dealing with environmental disturbance have focused only on species diversity, and often ignore the species’ health to evaluate habitat quality. Recently, through tools that evaluate the body condition of individuals, some studies have demonstrated that it is possible to know how species respond to environmental changes. In this study, we evaluated the effect of local and landscape parameters on different indicators of body condition and abundance of three dung beetle species in a fragmented Tropical rainforest in Mexico. We measured beetle’s body size and three indicators of physiological condition (body dry mass, lipid and muscle mass) in 15 sites with different vegetation configuration. In general, abundance, body size and physiological condition of all species were sensitive to different landscape features. Onthophagus rhinolophus, a species typically found in conserved forest, unexpectedly showed a positive relation of body condition with landscape diversity and amount of edge, and the presence of altered sites remnants favored its body dry mass, muscle mass and body size. Nevertheless, Onthophagus batesi and Canthon cyanellus, mostly found in disturbed areas, exhibited better body condition when there were conserved habitats nearby. Therefore, we showed that O. rhinolophus is a sensitive species supporting reduced levels of habitat disturbance, while O. batesi and C. cyanellus are tolerant species that need conserved forests nearby. We highlight the importance of understanding the effect of environmental disturbance on the species’ body condition in order to maintain not only abundant, but also healthy populations of wild animals in fragmented forests.

Anthropogenic food provisioning and immune phenotype: Association among supplemental food, body condition, and immunological parameters in urban environments.

Direct or indirect supplemental feeding of free‐ranging animals occurs worldwide, resulting in significant impacts on population density or altered demographic processes. Another potential impact of increased energy intake from supplemental feeding is altered immunocompetence. As immune system maintenance is energetically costly, there may be trade‐offs between immune responses and other energy‐demanding physiological processes in individual animals. Although increased availability of food sources through supplemental feeding is expected to increase the overall immunocompetence of animals, empirical data verifying the association between supplemental feeding and different immune parameters are lacking. Understanding the potential influence of supplemental feeding on immune phenotypes is critical, as it may also impact host–pathogen dynamics in free‐ranging animals. Using urban stray cats as a study model, we tested for associations between the intensity of supplemental feeding due to cat caretaker activity (CCA); body condition; and immune phenotype (bacterial killing assay (BKA), immunoglobulin G (IgG) concentration, and leukocyte counts). Significantly higher bacterial killing ability was observed in cats from high CCA districts, whereas higher IgG concentration and eosinophil counts were observed in cats from low CCA districts. Other leukocyte counts and body condition indices showed no significant association with CCA. We observed varying patterns of different immune components in relation to supplemental feeding. Out data suggest that supplemental feeding influences immune phenotype, not only by means of energy provisioning, but also by potentially reducing exposure rates to parasite infections through stray cat behavioral changes.

Avian predator buffers against variability in marine habitats with flexible foraging behavior

How well seabirds compensate for variability in prey abundance and composition near their breeding colonies influences their distribution and reproductive success. We used tufted puffins (Fratercula cirrhata) as forage fish samplers to study marine food webs from the western Aleutian Islands (53°N, 173°E) to Kodiak Island (57°N, 153°W), Alaska, during August 2012–2014. Around each colony we obtained data on: environmental characteristics (sea surface temperature and salinity, seafloor depth and slope, tidal range, and chlorophyll-a), relative forage fish biomass (hydroacoustic backscatter), and seabird community composition and density at-sea. On colonies, we collected puffin chick-meals to characterize forage communities and determine meal energy density, and measured chicks to obtain a body condition index. There were distinct environmental gradients from west to east, and environmental variables differed by ecoregions: the (1) Western-Central Aleutians, (2) Eastern Aleutians, and, (3) Alaska Peninsula. Forage fish biomass, species richness, and community composition all differed markedly between ecoregions. Forage biomass was strongly correlated with environmental gradients, and environmental gradients and forage biomass accounted for ~ 50% of the variability in at-sea density of tufted puffins and all seabird taxa combined. Despite the local and regional variability in marine environments and forage, the mean biomass of prey delivered to puffin chicks did not differ significantly between ecoregions, nor did chick condition or puffin density at-sea. We conclude that puffins can adjust their foraging behavior to produce healthy chicks across a wide range of environmental conditions. This extraordinary flexibility enables their overall success and wide distribution across the North Pacific Ocean.