Food habits of two species of tube-nosed bats, Murina hilgendorfi and Murina ussuriensis, in Hayakawa, central Japan

Knowledge of food habits is essential for understanding the life history of a species; however, such information about the enigmatic Murina genus of bats is little known. In this study, we examined the food habits of Murina hilgendorfi and Murina ussuriensis over four years in Hayakawa, central Japan, using traditional morphological fecal analysis. Fragments of arthropods of six orders (five identified families), and of five orders (five identified families), were found in the feces of M. hilgendorfi and M. ussuriensis, respectively. Both species consumed wingless arthropods (caterpillars and spiders), insects that rarely fly (ground beetles and bush crickets), or diurnal insects (dragonflies and hoverflies; i.e., that are resting at night) during the night, which is a clear indication of gleaning behavior in these bats. In spring, the large-bodied M. hilgendorfi more frequently consumed hard-bodied insects such as beetles and bush crickets, whereas the small-bodied M. ussuriensis more frequently consumed soft-bodied insects such as caterpillars, moths, spiders, and dipterans, suggesting that the body size difference influences their food habits, which may have contributed to food resource partitioning between these closely related bats. For M. hilgendorfi, beetles were the main prey in spring and autumn, while caterpillars and grasshoppers were more frequently consumed in spring and autumn, respectively, suggesting that they may have changed prey items according to seasonal fluctuations in food availability. To our knowledge, this study provides the first record of differences in the food habits of these two species.

Diet reflects opportunistic feeding habit of the Asian water monitor (Varanus salvator)

The Asian water monitor (Varanus salvator) is a large generalist predator and scavenger lizard. This species has a widespread distribution throughout South and Southeast Asia and is frequently encountered around the edges of urban settlements. Here, we present information on diet diversity and habitat utilisation of a population of Asian water monitors inhabiting the University of Malaysia Terengganu campus located on the east coast of mainland Malaysia. The stomach contents of 30 Asian water monitors were examined by stomach flushing, and 47.6% of stomach contents was mangrove crab, 26.2% was human waste and 26.2% was other natural foods consisting of fruits, fishes, leeches, snails, birds and insects. We then recorded the locations and habitats utilised by patrolling the campus area and found Asian water monitors preferred to use water and mangrove forest habitats that fringed and crisscrossed the campus. The broad diversity of stomach contents reflected food available at this location and indicates the opportunistic feeding habit of this species. Given that this species widely distributed in Southeast Asia, its broad diet diversity and habitat variations may promote the adaptation of Asian water monitor to different environments.

Effect of host plants on the oviposition preference of pink bollworm, Pectinophora gossypiella (Lepidoptera: Gelechiidae)

Pink bollworm (Pectinophora gossypiella (Saunders, 1843)) (Lepidoptera: Gelechiidae) is an important pest of cotton. We aimed to study the effect of different host plants on the oviposition preference of pink bollworm under laboratory conditions. Cotton (Bt and non-Bt), okra and hibiscus plants were used, which vary in morphological characteristics. Significant differences were observed in the density of trichomes and it is positively correlated with oviposition behaviour of pink bollworm. In a no-choice test, we recorded a higher number of eggs on Bt and non-Bt cotton plants. In two-, three- and four-choice experiments, pink bollworm preferred to deposit the maximum number of eggs on non-Bt cotton among other host plants. A substantially higher number of eggs were laid on Bt cotton in combinations with okra and hibiscus and a considerably lower number on non-Bt cotton. We recorded fewer numbers of eggs on hibiscus in all combinations. Overall, pink bollworm moths showed greater affinity towards non-Bt cotton plants and deposited the maximum number of eggs there. From the practical point of view, the development of cotton genotypes which are devoid or have a lesser density of trichomes may be a possible solution to reduce the pink bollworm egg load on cotton.

Sex and age differences in skull size in Myodes glareolus from Slovakia

The results of a craniometric analysis of the bank vole (Myodes glareolus) were evaluated in this study. Twenty cranial variables were measured and evaluated on 149 skulls (78 males, 71 females) with respect to sex and age. The main aim of this study was to test the sexual dimorphism in skull size. Overall, our results showed that on average, the values for adult and subadult females of M. glareolus were higher than for males. Results presented here thus reveal sexual differences in the measured cranial traits, most expressed for the length of the mandible and the height of the mandible. The effect size was very large for the length of the first upper molar. Comparison of our results with those from other countries confirmed that there are regional differences. These findings highlight the need for craniometric analysis of species also at the regional level.

Giant otter behaviour in a mega-hydroelectric reservoir, Central Amazon, Brazil

We tracked thirteen giant otters from three different groups in the Balbina Hydroelectric Reservoir. One of them was a transient animal, while the others were living in groups of five and seven individuals. Travelling was the most frequent behaviour, both for the transient otter (>40%) and group otters (46%). Diurnal resting was the longest-lasting behaviour. Most giant otter behaviour in the reservoir showed little difference when compared with the behaviour of giant otters living in nondammed areas, indicating a significant degree of resilience of this species. However, otters in the reservoir spent more time travelling, probably because their territory sizes were much greater than the territories of giant otters in nondammed areas. The frequency of fishing was similar to what has been recorded elsewhere, suggesting that current fish density and availability in the reservoir is similar to what is observed in nondammed areas. Nevertheless, otters in Balbina spent more time fishing than those in nondammed areas, which alternatively could suggest that fish density in the reservoir was low and could be compensated by increasing the time spent fishing. The high frequency of intraspecific kleptoparasitism observed in this study (62%) is noteworthy, although virtually undocumented for this species. This is the first study of giant otter behaviour in a hydroelectric reservoir that can be used for the conservation of this endangered species in man-made lakes.

Variations of body mass and thermogenesis properties in Eothenomys olitor during cold acclimatization

The set-point hypothesis states that there is a biological control method in mammals that actively regulates weight toward a predetermined set weight for each individual, which may occur by regulation of energy intake or energy expenditure. In order to investigate the effects of low temperature on body mass regulation in Eothenomys olitor, body mass, body fat mass, food intake, resting metabolic rate (RMR), non-shivering thermogenesis (NST), serum leptin levels, morphology, biochemical indexes of liver and brown adipose tissue (BAT) and hypothalamic neuropeptide genes expression were measured during cold acclimatization. The results showed that there was no significant difference in body mass, but food intake, RMR and NST increased during cold acclimatization. Cytochrome c oxidase (COX) and α-glycerophosphate oxidase (α-GPO) activities in liver and BAT were significantly enhanced during cold acclimatization, and triiodothyronine (T3) and thyroxine (T4) levels in serum were significantly higher than those in the control group. Serum leptin levels decreased after cold acclimatization. Low temperature significantly increased the expression of neuropeptide Y (NPY) and agouti-related peptide (AgRP), while it decreased cocaine- and amphetamine-regulated transcript peptide (CART) and pro-opiomelanocortin (POMC) expressions. All of the above results suggested that body mass in E. olitor can remain relatively stable at low temperature, which conforms to the ‘set-point hypothesis’. However, the species showed differences with sympatric species, such as E. miletus, Apodemus chevrieri and Tupaia belangeri. Moreover, E. olitor can cope with low temperature by increasing its metabolic rate and thermogenesis properties.

Conservation biology of the critically endangered salamander, Paradactylodon persicus gorganensis (Clergue-Gazeau & Thorn, 1979) (Amphibia: Hynobiidae) in northeastern Iran

Paradactylodon persicus gorganensis is a critically endangered salamander found in northeastern Iran which faces increasing major anthropogenic threats such as agriculture, industry and mining. The aim of the current study is to identify key environmental variables associated with the species’ presence. Also, measuring and comparing the water quality parameters in habitats where P. p. gorganensis is present and absent are the other aims of the study. The results indicate that high pH and dissolved oxygen values have a negative effect on the species’ presence, while its presence was strongly correlated with low mean water temperatures. The species’ range in response to the climate change will shift to the south and east, where areas of high elevation occur, because the species favors cold habitats. This study indicates that it will be particularly important to evaluate the whole range where P. p. gorganensis exists when preparing conservation action plans. It is recommended that ex-situ conservation programs are incorporated into conservation planning for the species, because the number of individuals in the wild is so low and their future viability is fragile.

Does gut microbiota regulate brooding in geese?

Domestic geese can reduce the amount of food intake when brooding. Because of the reduction in food intake, the total number of microorganisms in the gut is also reduced. Will this affect the goose’s thinking and make the goose stop brooding and eat food? We hypothesize that gut microbiota affects the brain through a brain–gut peptide and further regulates the breeding behavior of geese. In this study, we evaluated the microbiome related to the goose and transcription groups of brooding and egg production periods. The changes and differences in gut microbiota and gene expression of female geese in different reproduction periods were analyzed, and the possible interaction between them was explored. The results showed that the relative abundance of Faecalibacterium with a growth-promoting effect in the cecum was higher in the egg production group than in the brooding group. Microbial metabolic pathways with significant differences between the two groups were also enriched in the secondary functional groups with different gut microbiota metabolism. The downregulated genes in the egg production group were mainly related to energy metabolism, such as ATP synthesis-related genes. These results suggest that the brooding group’s gut microbiota can make relevant changes according to the reproduction stage of the goose. Since the amount of food taken in is reduced, it can promote the decomposition of the host’s fat. Simultaneously, insulin is also used to deliver messages to the brain; it is necessary to end the brooding behavior at an appropriate time and for eating to start.

Effects of biotic and abiotic stressors on asymmetries and head size in two sympatric lizard species

Organisms face numerous environmental stressors, which can affect developmental precision, including symmetry of various physical characteristics. Fluctuating asymmetry (FA) has therefore been suggested as a simple and efficient tool for assessing sub-lethal stress levels. We analyzed FA in two sympatric lizard species (Iberolacerta horvathi and Podarcis muralis) to determine potential effects of interspecific competition and urbanization, as proxies of stress, taking into account sexual dimorphism and environmental conditions. We sampled 16 syntopic and allotopic populations and used geometric morphometrics of head morphology. We detected significant but mixed effects on the head asymmetry from the environment and the syntopic occurrence that differed between species. P. muralis lizards had more asymmetric heads at higher altitudes, while I. horvathi lizards did at mid altitudes, which may be explained by P. muralis experiencing environmental stress of colder conditions at higher altitudes. The mid-altitude effect on asymmetries in I. horvathi might be explained by a lower availability of stony walls and higher abundance of P. muralis, thus higher competition. The asymmetry of supraciliary granules was affected by the presence of other species. However, lizards from allotopic populations attained larger asymmetries compared to lizards from syntopic populations, which was the opposite from what was expected. There was no effect of urbanization in P. muralis, which could be due to relatively low pollution and habitat degradation in study locations. Overall, we highlighted the possibility of using lizards and FA for bioindication of environmental stressors and especially improved the knowledge gap in the research of biotic stressors.