Similar Body Size Research Articles

Low individual diet variation and high trophic niche overlap between the native polecat and invasive American mink

AbstractIntroductions of invasive species increase competitive interactions in a community proportionally to the similarity between the ecological niches of invasive and native species. Food represents one of the most important resources influencing competition, and differences in the trophic niche of native and invasive species can affect their ability to coexist. Moreover, in sympatric native and invasive species of similar body size and high sexual dimorphism, competition for food between individuals of the same sex may be higher than intraspecific competition between males and females, thus making the overall competitive interactions more complex. The aim of this study was to investigate the intraspecific and intrasexual competition for food resources between two sexually dimorphic mustelids, the native polecat Mustela putorius and invasive American mink Neovison vison, in riparian habitats of Białowieża Forest (Poland). Based on an analysis of 1215 scats, we studied the food habits of eight polecat and 24 mink individuals. The trophic niches of the polecat and mink were narrow and overlapped considerably. The diet of both predators was dominated by amphibians (mainly the common frog Rana temporaria), which comprised up to 94.1% and 89.7% of polecat and mink prey biomass, respectively. Individual diet variation was low within each sex group of both species. Interspecific similarities in body mass of the sexes and intraspecific differences in body mass between the sexes did not affect pairwise niche overlaps. However, we observed some mechanisms of food segregation between the sexes and species that reduced intra‐ and interspecies competition. Polecat males hunted more common toads Bufo bufo than polecat females, mink males and mink females. They also hunted larger frogs than polecat females, and the opposite pattern was recorded in mink. We conclude that two predator species exploiting abundant prey can coexist despite a very high overlap in their food niches.

Структурные адаптации копытец крупного рогатого скота в условиях современного агроценоза

The article presents the results of studies of anatomical, histological and morphometric characteristics of bovine ungulates aimed at identifying signs of structural adaptation of the distal part of the limb to anthropogenically modeled content conditions. The factors that the hoof experiences are the predominance of static load, the high weight of the animal, and the support on solid soil. As a morphological control, elk is considered as a parrotfish animal with similar body size and weight, located in the conditions of natural biotsenose and moving on forest soils. It is shown that constant presence of cattle in conditions of hypokinesia on hard floors leads to change of limb setting and change of hoof shape, which is reflected in change of hoof shape, increase of hoof angle, ratio of plantar and dorsal hoof surfaces length. At the same time, the biomechanical load is redistributed between parts of the hoof so that the load on the wall increases and on the ball decreases. This may be a factor predisposing the hoof to the appearance of microtraumas, later manifested by laminites.

Benefits of overwintering in the conservation breeding and translocation of a critically endangered amphibian

AbstractAt high altitudes, amphibians brumate (over winter) during the winter months, an adaptation that provides protection from harsh weather and minimizes metabolic demand when food resources are scarce. However, brumation in ex situ populations is often avoided due to concerns regarding slow growth rates, compromised immunity, and increased morbidity, and to accelerate growth and sexual maturation. Running counter to these ideas is the hypothesis that husbandry that mimics the environmental conditions under which a species evolved may benefit animal health and reproduction. This may be particularly critical for animals slated for release into the wild. Here, we evaluated the effects of brumation on juvenile southern mountain yellow‐legged frogs (Rana muscosa) in a conservation breeding and release program. Growth measurements, (weight and snout‐urostyle length [SUL]), were examined in three experimental groups: Nonbrumated, 1 or 3‐month brumation. Postrelease survival was also analyzed and compared between nonbrumated and 3‐month brumated frogs. This study indicates that brumated R. muscosa juveniles grow to sizes and weights similar to controls within 3 to 4 months following brumation. Mark‐recapture models suggested that short‐term postrelease survival was not lower and in fact, may be higher in brumated compared to nonbrumated frogs. Results of this study indicate that although brumation entails short‐term costs to growth, this species possesses compensatory growth mechanisms following brumation which allow them to attain similar body size to nonbrumated conspecifics in time for the next winter and that for frogs destined for translocation to the wild, brumation could improve survival outcomes.

Ontogenetic plasticity in cranial morphology is associated with a change in the food processing behavior in Alpine newts

BackgroundThe feeding apparatus of salamanders consists mainly of the cranium, mandible, teeth, hyobranchial apparatus and the muscles of the cranial region. The morphology of the feeding apparatus in turn determines the boundary conditions for possible food processing (i.e., intraoral mechanical reduction) mechanisms. However, the morphology of the feeding apparatus changes substantially during metamorphosis, prompting the hypothesis that larvae might use a different food processing mechanism than post-metamorphic adults. Salamandrid newts with facultative metamorphosis are suitable for testing this hypothesis as adults with divergent feeding apparatus morphologies often coexist in the same population, share similar body sizes, and feed on overlapping prey spectra.MethodsWe use high-speed videography to quantify the in vivo movements of key anatomical elements during food processing in paedomorphic and metamorphic Alpine newts (Ichthyosaura alpestris). Additionally, we use micro-computed tomography (μCT) to analyze morphological differences in the feeding apparatus of paedomorphic and metamorphic Alpine newts and sort them into late-larval, mid-metamorphic and post-metamorphic morphotypes.ResultsLate-larval, mid-metamorphic and post-metamorphic individuals exhibited clear morphological differences in their feeding apparatus. Regardless of the paedomorphic state being externally evident, paedomorphic specimens can conceal different morphotypes (i.e., late-larval and mid-metamorphic morphotypes). Though feeding on the same prey under the same (aquatic) condition, food processing kinematics differed between late-larval, mid-metamorphic and post-metamorphic morphotypes.ConclusionsThe food processing mechanism in the Alpine newt changes along with morphology of the feeding apparatus during ontogeny, from a mandible-based to a tongue-based processing mechanism as the changing morphology of the mandible prevents chewing and the tongue allows enhanced protraction. These results could indicate that early tetrapods, in analogy to salamanders, may have developed new feeding mechanisms in their aquatic environment and that these functional innovations may have later paved the way for terrestrial feeding mechanisms.

Dietary bile acids supplementation improves the growth performance with regulation of serum biochemical parameters and intestinal microbiota of growth retarded European eels (Anguilla anguilla) cultured in cement tanks

The present trial was conducted to investigate the effects of bile acids on growth performance, digestive enzymes activities, serum biochemical parameters and intestinal microbiota on growth of retarded European eels (Anguilla anguilla) cultured in cement tanks. The trial fish with similar body size (about 140g per fish) cultured in nine cement tanks (fish weight, 681.7±22.7 kg per tank) were randomly divided into three groups and fed diets with bile acids supplementation at a level of 0, 500, and 1000 mg/kg, respectively. The trial period was 15 weeks. Dietary bile acids supplementation improved weight gain rate, feed intake, and activities of protease and lipase in intestine. There were also increases in levels of immunoglobulin and complements as well as activities of alkaline phosphatase (only in 1000 mg/kg bile acids group), acid phosphatase and lysozyme in serum. The levels of blood urea nitrogen, total cholesterol, triglyceride, low density lipoprotein cholesterol and activities of glutamic-oxalacetic transaminase and glutamic-pyruvic transaminase were decreased by dietary bile acids supplementation. There were no significant differences in growth performance or serum biochemical parameters except the lysozyme activity between two bile acids supplementation groups. Dietary bile acids supplementation could increase richness and decrease diversity of the intestinal microbiota with different enriched bacteria at genus level. In conclusion, this study demonstrated that 500 mg/kg bile acids supplementation in the diet of growth retarded European eels cultured in cement tanks could promote growth performance, improve some digestive enzymes activities, and beneficially regulate serum biochemical parameters and intestinal microbiota.

Social status and ejaculate composition in the house mouse.

Sperm competition theory predicts that males should tailor ejaculates according to their social status. Here, we test this in a model vertebrate, the house mouse (Mus musculus domesticus), combining experimental data with a quantitative proteomics analysis of seminal fluid composition. Our analyses reveal that both sperm production and the composition of proteins found in seminal vesicle secretions differ according to social status. Dominant males invested more in ejaculate production overall. Their epididymides contained more sperm than those of subordinate or control males, despite similar testes size between the groups. Dominant males also had larger seminal vesicle glands than subordinate or control males, despite similar body size. However, the seminal vesicle secretions of subordinate males had a significantly higher protein concentration than those of dominant males. Moreover, detailed proteomic analysis revealed subtle but consistent differences in the composition of secreted seminal vesicle proteins according to social status, involving multiple proteins of potential functional significance in sperm competition. These findings have significant implications for understanding the dynamics and outcome of sperm competition, and highlight the importance of social status as a factor influencing both sperm and seminal fluid investment strategies.This article is part of the theme issue ‘Fifty years of sperm competition’.

Transgenerational plasticity mediates temperature effects on fitness in the water fleaDaphnia magna

Phenotypic plasticity is an important way by which organisms respond to changes in their local environment, but it is not clear whether parents can buffer the negative impacts of high temperature on offspring fitness. To investigate this question, we exposed the water flea Daphnia magna Straus, 1820 and their offspring to either low (15 °C) or high (25 °C) temperature in a crossed factorial design. High parental temperature reduced the age and size at reproductive maturation and resulted in smaller mean clutch size, regardless of offspring temperature. This suggests that parents did not buffer the effects of high temperature on their offspring. However, offspring raised at high temperature that came from parents also raised at high temperature had similar adult body size and longer lifespan than offspring produced by parents exposed to low temperature. As a consequence of these apparent trade-offs, there was no detectable effect of parental temperature on offspring lifetime reproductive success. These results suggest that although transgenerational plasticity could help organisms to cope with stressful changes in their local environment, such effects might be difficult to detect in natural populations due to associated life-history trade-offs.

Computed tomographic comparison of esophageal hiatal size in brachycephalic and non-brachycephalic breed dogs.

To determine whether an anatomical difference in esophageal hiatus (EH) size exists between brachycephalic and nonbrachycephalic dogs. Retrospective clinical study. Client-owned dogs (n = 87). Clinical records and images of dogs that underwent computed tomography between June 2015 and September 2018 were reviewed. For the first part of the study, EH and aortic (Ao) cross-sectional surface areas were measured in brachycephalic (group 1) and nonbrachycephalic dogs of similar body size (<15 kg) without respiratory or gastroesophageal (GE) signs (group 2) by using multiplanar reconstruction. Esophageal hiatus:aortic ratio was calculated. In the second part of the study, absolute EH measurements were also compared in weight-matched (WM) dogs (8-10 kg) from groups 1 and 2. Mean (±SD) of EH:Ao values for group 1 (8.1 ± 2.8) were higher (P < .0001) than those for group 2 (3.7 ± 1.1). In addition, EH measurements of 20 WM dogs in group 1 were higher than those of 20 dogs in group 2 (P < .05). Esophageal hiatus cross-sectional surface area (directly and indirectly measured) in brachycephalic dogs was considerably larger than that in nonbrachycephalic dogs of generally similar body size. Results of this study provide evidence to support the existence of a specific anatomical factor that could likely correlate to functional GE alterations (eg, regurgitation, gastroesophageal reflux, and sliding hiatal hernia) commonly seen in brachycephalic dogs.

Egg-laying site, fecundity and degree of sexual size dimorphism in frogs

AbstractFemale fecundity is an important selective force leading to female-biased sexual size dimorphism (SSD) in frogs. Because anurans exhibit diverse reproductive modes, we investigated whether variation in SSD and fecundity are related with oviposition site. We asked whether arboreal breeding species show pronounced female-biased SSD and if, paradoxically, females have lower fecundity because of the costs of carrying oocytes and amplectant males. Conversely, we tested whether species that deposit eggs in concealed sites show less pronounced SSD, because females do not carry males and space limitation may reduce female size and fecundity. Our results showed that, in general, males were approximately 20% smaller than females. However, for species with hidden oviposition sites, males and females exhibited more similar body sizes and arboreal hylids showed more pronounced female-biased SSD. Overall, fecundity was higher in aquatic breeders, as expected, but in hylids, fecundity was smaller in arboreal breeders, which suggests that arboreality may impose restrictions on fecundity. By analysing SSD in a broader and more specific lineage (Hylidae), we found that reproductive microhabitat may also influence female size and fecundity, playing an important role in the evolution of SSD in frogs at different evolutionary scales.

Do female frogs have higher resting metabolic rates than males? A case study with Xenopus allofraseri

AbstractThe energetic costs of body maintenance can have a profound influence on the energy that an individual can allocate to other functions such as growth, locomotion, or reproduction. Therefore, resting metabolism can ultimately affect an individual's survival or reproductive success, especially when food is limited. Although males and females often differ in their body composition (e.g. sex organs and fat accumulation) and body size, the occurrence and direction of sexual dimorphism in resting metabolism remains poorly understood in anurans. In the present study, we investigated whether males and females of the false Fraser's clawed frog Xenopus allofraseri differ in their resting metabolic rates. We used an open‐flow push‐through respirometry system to measure the volume of carbon dioxide (VCO2) produced by animals at rest. Variation inwas explained by ambient temperature, body size, and sex. For a similar body size, our results revealed that females had about a 50% higher resting metabolic rate (RMR) than males. We suggest that the enhanced investment in gamete production in females compared to males may explain this difference. We further suggest that a lower RMR in males compared to females at similar body size could be selectively advantageous as unallocated energy may be devoted to costly mating, in support of the ‘compensation’ hypothesis.

Timing of Resource Availability Drives Divergent Social Systems and Home Range Dynamics in Ecologically Similar Tree Squirrels

Intraspecific variation in home range size has important implications for the distribution of animals across landscapes and the spatial structuring of population, community and ecosystem processes. Among species of similar trophic guild and body mass, differences in home range size can reflect extrinsic variables that exert divergent selective forces upon spacing behavior and social organization. We tested predictions about how resource availability and timing influence social system, home range size and territoriality in two tree squirrel species of similar size and ecological niches but that differ in foraging strategy and social organization. We estimated home range size and intraspecific home range core overlap in the Mt. Graham red squirrel (Tamiasciurus fremonti grahamensis; Arizona USA; MGRS) and the Eurasian red squirrel (Sciurus vulgaris; Alps, Italy; ERS) as functions of species, sex, season, and individual’s body mass. However, body mass did not explain differences found between the two species. We found MGRS home ranges being 3 times smaller with higher core area exclusivity compared to ERS in all seasons. In fact, territorial MGRS evolved in a system of brief resource pulses and are larder hoarders, whereas ERS experience prolonged resource availability and are non-territorial. Only male MGRSs increased their home range during the breeding season, reflecting interspecific differences in social organization and mating behavior. Male ERS home ranges always overlap with several females to enhance mating success, while male and female MGRS maintain nearly exclusive territories throughout the year. Only during spring and summer males temporarily leave their food-based territory to increase mating opportunities with neighboring estrus females. Home range comparisons between ecologically similar species emphasized the importance of divergent extrinsic factors in shaping variability in body size – home range size scaling relationships. Timing in resource availability influenced the social structure and space use in tree squirrels of similar body size, highlighting how the coevolution of arboreal squirrels with conifer tree species has shaped their natural history.

A new species of South Asian Cnemaspis (Squamata: Gekkonidae) from the Eastern Ghats, India.

We describe a new species from within the South Asian clade of the polyphyletic gekkonid genus Cnemaspis from the Velikonda Range, in the Eastern Ghats, Andhra Pradesh, India. The new species is the smallest known Indian gekkonid and can be diagnosed from all Indian congeners by its small body size (SVL <29 mm), the absence of spine-like scales on flank, heterogeneous dorsal pholidosis, presence of precloacal pores and no femoral pores in males, tail with enlarged, strongly keeled, conical tubercles forming whorls, median row of sub-caudals smooth and slightly enlarged, and a distinct colour pattern. This is the 12th species of Cnemaspis to be described from outside the Western Ghats and is the first endemic from the Velikonda region of the Eastern Ghats. The new species is only known from its type locality, a lowland riparian habitat (<200 m asl.) in dry evergreen forest at the base of a ~1200 m asl. peak. This discovery extends the range of the genus in peninsular India by ~130-150 kilometres to the northeast and suggests the genus is likely to be even more widely distributed than understood. The new species is clearly allied to C. mysoriensis, C. otai and C. yercaudensis with which it shares superficial colour pattern and similar body size, but is the first species from outside the Western Ghats in which males lack femoral pores.

Food availability limits avian reproduction in the city: An experimental study on great tits Parus major.

The altered ecological and environmental conditions in towns and cities strongly affect demographic traits of urban animal populations, for example avian reproductive success is often reduced. Previous work suggests that this is partly driven by low insect availability during the breeding season, but robust experimental evidence that supports this food limitation hypothesis is not yet available. We tested core predictions of the food limitation hypothesis using a controlled experiment that provided supplementary insect food (nutritionally enhanced mealworms supplied daily to meet 40%-50% of each supplemented brood's food requirements) to great tit nestlings in urban and forest habitats. We measured parental provisioning rates and estimated the amount of supplementary food consumed by control and experimental nestlings, and assessed their body size and survival rates. Provisioning rates were similar across habitats and control and supplemented broods, but supplemented (and not control) broods consumed large quantities of supplementary food. As predicted by the food limitation hypothesis we found that nestlings in (a) urban control broods had smaller body size and nestling survival rates than those in forest control broods; (b) forest supplemented and control broods had similar body size and survival rates; (c) urban supplemented nestlings had larger body size and survival rates than those in urban control broods; and crucially (d) urban supplemented broods had similar body size and survival rates to nestlings in forest control broods. Our results provide rare experimental support for the strong negative effects of food limitation during the nestling rearing period on urban birds' breeding success. Furthermore, the fact that supplementary food almost completely eliminated habitat differences in survival rate and nestling body size suggest that urban stressors other than food shortage contributed relatively little to the reduced avian breeding success. Finally, given the impacts of the amount of supplementary food that we provided and taking clutch size differences into account, our results suggest that urban insect populations in our study system would need to be increased by a factor of at least 2.5 for urban and forest great tits to have similar reproductive success.

Does Competition Shape Cheetah Prey Use Following African Wild Dog Reintroductions?

Both interference and exploitative competition for prey occurs between carnivore species, which can be exacerbated if the carnivore species are of similar body size, meaning that they select for similar prey species. Studies on competition within the large carnivore guild in Africa have mainly focused on the interactions between the larger dominant (lions, Panthera leo, and spotted hyaenas, Crocuta crocuta) and smaller, submissive (cheetahs, Acinonyx jubatus, and African wild dogs, Lycoan pictus) species. However, given that cheetahs and African wild dogs are similar-sized and diurnal, they have a high overlap in dietary preference and hence scope for competition. Here, we investigate whether competition with African wild dogs shapes cheetah prey preference by comparing cheetah prey selection before and after reintroductions of African wild dogs. We show that cheetahs experienced high dietary overlap with African wild dogs but become more generalized hunters in the presence of African wild dogs. Moreover, cheetahs used three key prey species (impala, Aepyceros melampus, nyala, Tragelaphus angasii, and common duiker, Sylvicapra grimmia) differently following African wild dog reintroductions. We suggest that this reflects predominantly exploitative competition between these predators, particularly for impala. Such diet shifts may be useful indicators of resource limitations for managers conserving these two threatened small predators.

How and when melanic coloration is an advantage for lizards: the case of three closely-related species of Liolaemus

Body temperature affects various aspects of ectotherm biology. Reptiles, as ectotherms, gain and control their temperature mainly through behavioural adjustments, although some body traits may also be advantageous. According to the thermal melanism hypothesis (TMH) dark colour may be thermally advantageous in cold environments. Additionally, differences in thermoregulatory capacity may also affect performance. We analysed the role of melanism in the thermoregulation and sprint speed performance of three species of Liolaemus lizards from Argentinean Patagonia. Liolaemus shitan, L. elongatus and L. gununakuna are phylogenetically close, with similar body sizes and life history traits, but differ in their melanic colouration, L. shitan being the darkest and L. gununakuna the lightest species. We estimated sprint speed performance curves and heating rates, and recorded final body temperature and sprint speed achieved after a fixed heating time, from two different initial body temperatures, and with and without movement restriction. Performance curves were similar for all the species, but for L. gununakuna the curve was more flattened. Darker species showed faster heating rates, ran faster after fixed heating trials at the lowest temperature, and reached higher body temperatures than L. gununakuna, but this was compensated for by behavioural adjustments of the lighter lizards. Similarity of sprint speed performance may be due to the conservative nature of this character in these species, while variation in heating ability, particularly when starting from low temperatures, may reflect plasticity in this trait. The latter provides support for the TMH in these lizards, as melanism helps them increase their body temperature. This may be especially advantageous at the beginning of the day or on cloudy days, when temperatures are lower.

Seasonal variation in the strength of interference competition among headwater stream predators

Abstract Vertebrate communities in headwater streams are assumed to be regulated through competitive and predatory interactions. Although documented predation is rare, studies regularly report competitive dominance by fish that, as larger competitors reliant on aquatic habitat, exclude semi‐aquatic salamanders to marginal stream habitat. However, it is unclear whether fish interact with stream‐breeding salamanders through indirect effects such as competition for resources (e.g. food or cover) or fear (i.e. threat of predation) nor is it known whether these interactions are consistent through time. This study used a novel caging approach to determine if competitive outcomes between a headwater fish and salamanders were regulated primarily through resource depletion (exploitative competition) or behavioural avoidance (interference competition). We paired banded sculpin (Cottus carolinae) and larval red salamanders (Pseudotriton ruber) of similar body size in independent flow through mesocosms with intra‐ and inter‐specific pairs allowed to interact physically or non‐physically. The experiment was repeated in the autumn and in the spring when stream salamander larvae begin to transform into terrestrial juveniles. Banded sculpin negatively influenced growth of red salamanders regardless of whether they were allowed to physically interact, suggesting interference competition and behavioural avoidance. This asymmetrical effect was strongest in the spring when salamanders underwent metamorphosis at higher rates in the presence of fish. However, in the autumn, the effects were more balanced between the two species with salamanders impacting fish through exploitative competition. By studying the temporal relationships between two competitors and using a caging method novel to competition studies, we established that the outcomes of competition are dependent on season and may vary in type relative to the timing of life‐history events. For this community, these results suggest that outcomes of competition are highly dependent on season and could indicate a biotic mechanism maintaining headwater salamander distributions through source–sink dynamics. Our results also suggest that, in this species interaction, it may be unwarranted to assume that the outcomes of competition at one time represent the complex relationships regulating community interactions.

Species-specific schooling behaviour of fish in the freshwater pelagic habitat: an observational study.

Social living of animals is a broadly occurring phenomenon, although poorly studied in freshwater systems, fish schooling behaviour is an excellent example. The composition of fish schools, species-specific schooling tendencies and preferences of adult fish were studied in the pelagic habitat of the Římov Reservoir, Czech Republic. Video recordings captured over a total of 34 days (16 h per day) in the clear water period of three seasons were analysed. From four species identified as school-forming species - bream, bleak, roach and perch, 40% of the individuals observed formed schools of 3-36 individuals. Although conspecific schools prevailed, 20% of individuals formed heterospecific schools, except bleak that schooled strictly with conspecifics. Schools were composed of individuals of similar body size and life strategy. Heterospecific schools were significantly larger than conspecific schools and showed uneven proportion among species, that is, one species being more abundant when the school dimension increased. Probability of encounter in bleak was lowest and proved highest inclination for schooling. Gregarianism levels depended on species morphology and body size, with larger and morphologically advanced fish tending less to sociability. This indicates that the antipredator function of schooling behaviour is intensified with increasing vulnerability of the species.

Small airway function in obese individuals with self-reported asthma

Diagnosis of asthma in obese individuals frequently relies on clinical history, as airflow by spirometry may remain normal. This study hypothesised that obese subjects with self-reported asthma and normal spirometry will demonstrate distinct clinical characteristics, metabolic comorbidities and enhanced small airway dysfunction as compared with healthy obese subjects.Spirometry, plethysmography and oscillometry data pre/post-bronchodilator were obtained in 357 obese subjects in three groups as follows: no asthma group (n=180), self-reported asthma normal spirometry group (n=126), and asthma obstructed spirometry group (n=51). To assess the effects of obesity related to reduced lung volume, oscillometry measurements were repeated during a voluntary inflation to predicted functional residual capacity (FRC).Dyspnoea was equally prevalent in all groups. In contrast, cough, wheeze and metabolic comorbidities were more frequent in the asthma normal spirometry and asthma obstructed spirometry groups versus the no asthma group (p<0.05). Despite similar body size, oscillometry measurements demonstrated elevated R5–20 (difference between resistance at 5 and 20 Hz) in the no asthma and asthma normal spirometry groups (0.19±0.12; 0.23±0.13 kPa/(L·s−1), p<0.05) but to a lesser degree than the asthma obstructed spirometry group (0.34±0.20 kPa/(L·s−1), p<0.05). Differences between groups persisted post-bronchodilator (p<0.05). Following voluntary inflation to predicted FRC, R5–20 in the no asthma and asthma normal spirometry groups fell to similar values, indicating a reversible process (0.11±0.07; 0.12±0.08 kPa/(L·s−1), p=NS). Persistently elevated R5–20 was seen in the asthma obstructed spirometry group, suggesting chronic inflammation and/or remodelling (0.17±0.11 kPa/(L·s−1), p<0.05).Thus, small airway abnormalities of greater magnitude than observations in healthy obese people may be an early marker of asthma in obese subjects with self-reported disease despite normal airflow. Increased metabolic comorbidities in these subjects may have provided a milieu that impacted airway function.

Morphology of the Semicircular Canals and Locomotion of Zionodon satanus

Zionodon satanus is a relatively large “insectivore” from the Uinta Formation of Utah, known from associated fragmentary dental, cranial, and postcranial elements. Features of the postcrania, particularly the knee and ankle joints, suggest that this species primarily engaged in swift terrestrial locomotion, but with some climbing and digging capability. Among the cranial fragments of Z. satanus are two petrosal bones preserving portions of the bony labyrinth, particularly the semicircular canals, which are known to vary among extant mammals according to locomotor agility, with more agile animals having semicircular canals with a larger radius of curvature than slower ones. Thus, semicircular canal dimensions can provide insight into locomotion independent of postcranial morphology. Here we compare measurements of the semicircular canals of Z. satanus to other extant and extinct mammals to assess the degree of locomotor agility of this species and compare those results to those obtained by functional analysis of the postcrania.The petrosal bones of the type specimen of Z. satanus were microCT scanned and virtual models of the semicircular canals were extracted with AMIRA 6.5.0 software. One petrosal includes a complete posterior and partial lateral semicircular canal, whereas the other preserves a complete lateral, damaged but complete posterior, and most of the anterior semicircular canal. The height and width of each semicircular canal was measured from the extracted surface models and the radius of curvature was calculated from height and width measurements. The average radius of curvature of the semicircular canals of Z. satanus overlaps with extant mammals of similar body size of “fast” or “medium” agility and lies well outside the range of slow‐moving small mammals. Compared to other fossil “insectivores”, Z. satanus has relatively smaller semicircular canals than Leptictidium from the middle Eocene of Messel, Germany, which has been reconstructed as a bipedal runner and saltator, but larger ones than the North American leptictids Paleictops and Leptictis. These results corroborate observations from the postcranial skeleton, suggesting that Z. satanus likely engaged in frequent, rapid locomotion.

Effects of body size and prior residence on dominance hierarchies in female Asian particolored bats

Abstract Social animals may cooperate to gain resources such as food and territory. However, unavoidable conflicts over limited resources frequently occur between group members. Social rank may effectively decrease conflicts within animal social groups, thereby reducing energy consumption and maintaining group stability. In this study, we tested the two factors most often proposed to influence winning a conflict: body size and prior residence. Our results showed that female Asian particolored bats (Vespertilio sinensis) formed near-linear dominance hierarchies. Forearm length was significantly positively correlated with dominance rank in three replicate experiments. In addition, prior residents had significantly higher dominance ranks than intruders of similar body size. These results suggested that both body size and prior residence might affect dominance ranks in female Asian particolored bats.