Showing papers in "Ethology Ecology & Evolution in 2018"
TL;DR: The survey revealed that bears used habitats ranging from dense forest to scrub lands, but preferred steep, high-altitude habitats with dense tree cover, and Anthropogenic activities were the main causes of conflict between humans and bears.
Abstract: Few studies have reported on the distribution, food choices, general behaviour, and interactions of the Asiatic black bear (Ursus thibetanus) with humans. We explored the conservation status of the...
47 citations
TL;DR: Female turtles that dig deeper nests may have more vigorous offspring, exhibiting faster locomotor abilities, and depth at which nests are re-buried should be considered a key factor for the success on nest relocation programmes.
Abstract: Nest-site selection and the depth at which turtle females deposit their eggs have a decisive influence on temperature in the nest chamber. Thus, female turtle nesting behaviour can influence the sex, fitness and emergence behaviour of their hatchlings. We studied nest-site selection and nest depth in 333 natural loggerhead (Caretta caretta) nests from a nesting population in Cabo Verde. Nest site and depth varied among females and among different nests from the same female. However, female body size only explained a very small part of the variability of nest depth. Nest incubation temperature also varied as a function of depth. To test the influence of nest depth on incubation and embryonic development, 90 loggerhead nests were incubated in standard conditions and at different depths (35, 40, 45, 50 and 55 cm) in a beach hatchery and monitored until hatching. Deeper nests had greater emergence success and lower temperature, and hatched later, affecting hatchling sex ratio. Incubation at 35 cm can lead to ...
25 citations
TL;DR: It is suggested that interactions among wild ungulates may increase with increasing global warming and range expansion of roe deer – a hypothesis that deserves further attention and field studies.
Abstract: The number of wildlife watchers and photographers sharing data on online platforms and social networks is increasing; images of interspecific relationships are among the most popular. Behavioural interference among wild ungulates is rare, but some occurrences of this behaviour may have been reported on wildlife-dedicated Facebook groups. We searched for information on the behaviour of roe deer, expanding towards high altitudes, in presence of Northern chamois. Our research was carried out on Facebook groups/pages of natural photography and wildlife watching. We analysed a total of 67 observations out of 73 collected: in over 67% of them, roe deer and chamois shared the same feeding site without interacting. In 28% of cases, female chamois chased and displaced female roe deer at feeding sites and only in the remaining 5% male roe deer displaced chamois (mainly at waterholes). Even if no data are available on distribution trends of these species, we suggest that these interactions may increase with increasi...
16 citations
TL;DR: Two species of Liolaemus used different postural and microhabitat path-selection strategies according to climate, allowing them to buffer changes in Tb, thus suggesting that the Bogert effect may be occurring in these two species.
Abstract: Fil: Stellatelli, Oscar Anibal. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina
14 citations
TL;DR: Biological sign surveys in forested components of a human-dominated landscape can be combined with human interviews in agricultural portions of a landscape to provide a full picture of seasonal use of different landscape components by wide-ranging animals and resulting human–wildlife conflict.
Abstract: Understanding how wide-ranging animals use landscapes in which human use is highly heterogeneous is important for determining patterns of human–wildlife conflict and designing mitigation strategies. Here, we show how biological sign surveys in forested components of a human-dominated landscape can be combined with human interviews in agricultural portions of a landscape to provide a full picture of seasonal use of different landscape components by wide-ranging animals and resulting human–wildlife conflict. We selected Asian elephants (Elephas maximus) in Nepal to illustrate this approach. Asian elephants are threatened throughout their geographic range, and there are large gaps in our understanding of their landscape-scale habitat use. We identified all potential elephant habitat in Nepal and divided the potential habitat into sampling units based on a 10 km by 10 km grid. Forested areas within grids were surveyed for signs of elephant use, and local villagers were interviewed regarding elephant use of ag...
14 citations
TL;DR: Evidence is provided that A. flavicollis exhibited distinct preferences in all seasons, highlighting a relevant affinity only for a strict array of plant species, and acting as seed specialist, and potential competitive interactions between these rodents in sub-Mediterranean deciduous forests are suggested.
Abstract: Having a thorough understanding of animal feeding behaviour is a basic aim in ecology. Food represents a crucial resource that can strongly rule animal populations, especially where food supplies are seasonal, such as in temperate areas. In Italy, sub-Mediterranean forests dominated by deciduous oaks are commonly inhabited by the yellow-necked mouse Apodemus flavicollis, the wood mouse A. sylvaticus and the bank vole Myodes glareolus. Despite the rich literature regarding their diet composition in northern Europe, to our knowledge no studies have been published on food preferences of these rodents in syntopy in sub-Mediterranean deciduous forests. Feeding preferences of 33 A. flavicollis, 10 A. sylvaticus and 18 M. glareolus on reproductive parts (flowers, unripe and ripe fruits) of 26 representative plant species in a deciduous oak forest of central Italy were investigated through seasonal cafeteria-style experiments. Our findings evidence that A. flavicollis exhibited distinct preferences in all seasons...
14 citations
TL;DR: Comparing the light intensities required to gather 50% of individuals to the panels revealed that the short wavelength region (λmax 470 nm) was more effective than longer wavelengths, which affected biological traits such as adult emergence and oviposition in the melon thrips.
Abstract: Phototactic behaviours and the toxic effects of certain light wavelengths have been used to control insect pests. However, in many species, little is known about this innate behaviour and the effects on physiological and biological traits related to the emission and/or reflection spectra of light. The present study investigated the phototactic behaviour and the effects on physiological and biological traits of a small insect, the melon thrips, Thrips palmi (Thysanoptera Thripidae). Using seven different light-emitting diode panels (355, 405, 470, 525, 590, 660 and 735 nm) under dark conditions, it was found that this species was attracted to a wide range of light from short to long wavelengths in all tested lights. Comparing the light intensities required to gather 50% of individuals to the panels revealed that the short wavelength region (λmax 470 nm) was more effective than longer wavelengths. None of the seven wavelengths examined affected biological traits such as adult emergence and oviposition in th...
12 citations
TL;DR: The data demonstrate that dingoes used a ‘bite and shake’ mode of killing that is dissimilar to those exhibited by large carnivores, but is consistent with behaviours shown by other medium-sized carnivores.
Abstract: Intraspecific conflict is an important process structuring carnivore populations However, few data are available describing the precise mode of killing used by carnivores, especially medium-sized carnivores that can exhibit behaviours typically associated with either smaller or larger species From records of free-ranging Australian dingoes killed during intraspecific fighting, we describe the types, location and frequency of injuries sustained, to assist in identifying killing behaviours common to medium-sized carnivores, or mesopredators Observed injuries included superficial minor cuts and other wounds, deep punctures (bite marks or holes), severe lacerations to internal organs, tissue bruising and crushing, mutilation of muscle tissue, perforation of the chest and abdominal cavities, and a variety of bone fractures The dingoes in this study predominately died from gross internal haemorrhaging caused by crushing bites coupled with vigorous shaking to the head, throat, neck and ventral chest areas O
11 citations
TL;DR: The correlation between the endangered D. suweonensis with a narrow ranges and depressed boldness, in comparison to the widespread and closely related D. japonicus is highlighted, making the later species more fit to its environment, allowing for faster escape and wider dispersal capabilities.
Abstract: Animal populations with narrow distribution ranges due to recent constrictions are predicted to be physiologically and evolutionarily less fit than their counterparts with wider distributions. In a...
10 citations
TL;DR: It is suggested that open areas may be dangerous to the predators of T. fosteri, making these habitats safer than the forests for this rodent, and that this tropical species adheres to global patterns, but only at microhabitat level.
Abstract: Rodent anti-predator behavior has been documented in many different habitats across the world. Most studies found that rodents seek shelter in bushes. However, there is little evidence for this fro...
10 citations
TL;DR: The aim was to assess if tadpoles of Phyllodytes luteolus are able to prey mosquito larvae, and if the predation rate differs according to the size of predator and prey, and to evaluate the importance of tadpole in the trophic structuring of aquatic environments.
Abstract: Mosquito-borne diseases have been spreading rapidly. Although Aedes sp. are believed to prefer man-made habitats for reproduction, its larvae can also be found in bromeliads in anthropic environmen...
TL;DR: The results suggest the occurrence of high levels of maternal cares in a gregarious herbivore, with frequent allosuckling and apparent willingness of females to nurse offspring throughout summer-autumn, and suggest that the mother's role does not terminate with weaning.
Abstract: Maternal cares and, in particular, suckling behaviour, are fundamental for early growth and survival of offspring ungulates. In turn, factors influencing maternal cares can have important effects a...
TL;DR: A behavioural and social polymorphism comprising monogyny with and without internest aggression is revealed in Tetramorium alpestre sampled in Tyrol, Austria, and it is speculated that the non-aggressive and partly aggressive encounters observed represent different options in the social structure of T. al pestre.
Abstract: Social structure influences animal societies on various levels (e.g., relatedness, behaviour). In ants, both the number of matings per queen and the number of queens per colony can vary strongly. While workers from both monogynous and polygynous colonies often fight fiercely, in supercolonies (an extreme form of polygyny comprising thousands of queens in spatially separated but interconnected nests), non-nestmates interact peacefully. Studies on social and behavioural polymorphism within ant species can help elucidate their influence on genetic diversity and behaviour and the factors triggering variation in social structure and behaviour. Here, we reveal a behavioural and social polymorphism comprising monogyny with and without internest aggression in Tetramorium alpestre sampled in Tyrol, Austria. The social polymorphism is based on genetic and behavioural evidence and contrasts with the supercolonial organisation known from another location in Austria (Carinthia), 150 km away. Microsatellite genotyping ...
TL;DR: It was found that males which originated from populations in which eugregarine parasites were present had smaller wing spots than individuals from parasite-free populations, and parasitism is an important additional factor to interspecific aggression in determining variation in the sizes of the wing spots of C. splendens males.
Abstract: Sexually selected ornaments in animals are costly, with parasitism often affecting the degree to which they are expressed. Male Calopteryx splendens damselflies exhibit melanised ‘wing spots’. Those possessing large spots are favoured by females but also have an increased likelihood of being attacked by Calopteryx virgo, a common sympatric competitor. Melanin is used to produce the wing spots, but it is also used in immune defence against parasites that commonly infect damselflies. A total of 261 C. splendens males were collected from 26 Finnish and Latvian populations, of which half were found to be sympatric with C. virgo. It was found that males which originated from populations in which eugregarine parasites were present had smaller wing spots than individuals from parasite-free populations. Contrary to previous studies, the wing spots of C. splendens males in populations sympatric with C. virgo were not found to be smaller than those in allopatric populations. Parasite presence in C. splendens was fo...
TL;DR: This study identifies specific ways in which trade-offs between predation risk and energetic costs could affect anti-predator behaviour.
Abstract: Predation is a strong selective force that affects prey population and ecosystem dynamics. Detecting predators and associated levels of threat is crucial to prey responses. Once a predator is detected, anti-predatory responses improve the chances of survival of prey. We used Aedes aegypti larvae to study behavioural responses to predation threat from guppies (Poecilia reticulata). Specifically, we tested the relative importance of chemical cues, both in isolation and in combination with physical cues, in eliciting anti-predatory behaviours. Larvae responded more strongly, by reducing the lengths of their wriggle bursts, when presented with a combination of chemical and physical cues than with chemical cues alone. Anti-predatory responses often come with an associated cost, and we expect that the ability to pay these costs should influence responses to predation risk. To test this, we compared wriggling patterns of satiated vs starved larvae in the same experiment. We found that, under predation risk, star...
TL;DR: It is concluded that between-group encounters in Nicobar long-tailed macaques serve to defend food resources and mates rather than that they are examples of territoriality.
Abstract: Group living primates often participate in between-group encounters to defend monopolizable resources. Participation in an encounter is influenced by the density and abundance of resources and the relative fighting ability of groups. We studied between- 15 group encounters in three groups of Nicobar long-tailed macaques (Macaca fascicularis umbrosus) in the Great Nicobar Island, with one group, TR, being the focal study group to measure the influence of these factors on between-group encounters. Encounters varied rom mutual tolerance to aggressive fights, with females participating less aggressively than males. Sleeping site and vegetation cover were the primary influences on the nature of 20 interaction in the areas where home range overlapped. The initiation and intensity of an encounter were influenced by relative group size. The focal group (TR) was the smallest of the three groups in the area and it actively avoided confrontation with the other two groups (MG and PI), resulting in a lower observed encounter rate than expected. Both the frequency and aggressiveness of encounters was influenced by the number of females 25 cycling and the number of males present in the study group. Inasmuch as encounters were influenced by the number of females and the distribution of food, rather than geography, we conclude that encounters serve to defend food resources and mates rather than that they are examples of territoriality.
TL;DR: The results suggest that sexual selection plays an important role in maintaining paternal care not only in species of the genus Appasus, but also in the genus Diplonychus.
Abstract: Paternal care can be maintained under sexual selection in case that it helps caring males to attract more mates. Females of two back-brooding water bug species, the belostomatids Appasus major and ...
TL;DR: This first description of barn swallow CM in Italy, together with two previous studies from Europe, suggests that CMs of geographically different barn swallow populations are dominated by bacteria belonging to the same phyla but different genera.
Abstract: Bird gut microbiota shows large variation among geographical populations of the same species – probably because, differently from mammals, gut microbiota of birds is largely affected by extrinsic f...
TL;DR: Bees and stinging wasps (Hymenoptera Aculeata) are well known for the great variety of their nesting resources, which include cavities such as empty reed galls, but P. fabricii uses a different type of late progressive provisioning, described here.
Abstract: Bees and stinging wasps (Hymenoptera Aculeata) are well known for the great variety of their nesting resources, which include cavities such as empty reed galls. The majority of the species are mass provisioners, and they do not take any care of their brood after provisioning of the nest. Pemphredon fabricii (Crabronidae) nests in abandoned reed galls of Lipara (Diptera Chloropidae) frit flies. However, P. fabricii uses a different type of late progressive provisioning, described here. Nesting females do not make separate chambers for larvae, but instead fill the interior space of the gall with paralysed aphids and lay a single egg at the body surface of one to eight aphids out of the total number of aphids provisioned. Larvae are polyphagous, and are provisioned with at least 21 aphid species. Hyalopterus pruni is the most common prey, since it feeds on common reed in summer. Before pupation, the larvae sort in the cavity from the biggest (turning to females) at the base to the smallest (turning to males)...
TL;DR: Although the results likely underestimate the range of variation in behavior across groups of juveniles, they suggest that variation in the experience of signaling environments during juvenile development has the potential to contribute to social plasticity in the mating signals and mate preferences.
Abstract: Social plasticity may be an important originator of divergence in mating signals and other sexual traits. Understanding the evolutionary causes and consequences of social plasticity requires analyzing how different features of the social environment influence the expression of signals and preferences. Here we focus on experience of signaling environments. We adopt the vantage point of a hypothetical focal juvenile individual, and ask whether its experience of the interactions between other individuals in the group would vary across groups of different size and species composition. We worked with Enchenopa treehoppers, group-living herbivorous insects that communicate with plant-borne vibrational signals as juveniles and adults. We manipulated group composition and size experimentally and monitored the behavior of the juvenile treehoppers. We found that the treehoppers’ signaling rates varied with group type, size, and disturbance. Although our results likely underestimate the range of variation in behavio...
TL;DR: Investigation of the relationship between the forest structure and the occurrence of common chaffinch Fringilla coelebs, wood warbler Phylloscopus sibilatrix, common chiffchaff Phylloscopeopus collybita and Eurasian blackcap Sylvia atricapilla indicates need to restore the diversified structure of beech forests by ensuring the heterogeneity of forest stands, to increase avian diversity in managed forests.
Abstract: Despite the fact that the structure of a forest, its vegetation composition and the species diversity in its tree stands are among the key factors shaping avian communities in forests in general, there are few studies on this topic relating to the deciduous forests of Central and East-Central Europe. The aim of the present study was therefore to investigate the relationship between the forest structure and the occurrence of common chaffinch Fringilla coelebs, wood warbler Phylloscopus sibilatrix, common chiffchaff Phylloscopus collybita and Eurasian blackcap Sylvia atricapilla, and also investigate habitat occupancy as expressed by territory size, in certain areas of NW Poland. The hypothesis tested was that if a habitat is rich, then the territory should be smaller. The mean territory size was 0.704 ha in the case of F. coelebs, 0.307 ha for P. sibilatrix, 0.148 ha for P. collybita and 0.312 ha for S. atricapilla. The use of a generalised linear mixed model demonstrated statistically significant relation...
TL;DR: The results suggest that Icterine warbler males largely reflect the surrounding acoustic environment in their song, but simultaneously selectively include vocalisations that are similar to their own song as a result of physiological constraints.
Abstract: Vocal mimicry in birds is a well-known phenomenon, but in the majority of bird mimic species, its function, variability and accuracy still remain undiscovered. We analysed the song of 23 Icterine w...
TL;DR: The nocturnal activity of C. laticeps occurs in spite of predation risk in this period; thus, it is suggested that timing of above-ground activity is probably a strategy to avoid thermal stress, and the benefits of being active in thisperiod compensate the costs ofpredation.
Abstract: Choosing a period to perform basic survival and breeding activities follows a trade-off between the costs and benefits associated to environmental and biotic demands, in which individuals try to maximize their fitness. Once the rodents have small tolerance to high temperatures, their activity patterns are usually thermally constrained. No information is registered about the activity patterns of semi-fossorial spiny rat Clyomys laticeps, which inhabits open physiognomies in savannah formations, hence dealing with large daily variations in temperature and humidity. In this way, the aim of this study was to describe the above-ground activity of free-living C. laticeps individuals, and test the hypothesis that their activity patterns are thermally restricted. By using camera traps set along one year, we demonstrated that individuals were more frequently active during night and dawn, which corresponded to the periods with lower temperatures. Hence, C. laticeps proved out to be nocturnal, with some degree of cr...
TL;DR: It is hypothesize that feather microbiomes reflect, at least partly, airborne bacterial communities of the environments where individuals spent non-breeding periods, or of those that they crossed during migration, rather than breeding environment.
Abstract: We provide the first-ever investigation of feather microbiota by high throughput DNA sequencing for any bird species by describing bacteria found on the innermost tertial feather of 22 adult common...
TL;DR: The role of agonistic behavior in determining differences in habitat utilization between life stages in an ecologically damaging invasive lizard, Trioceros jacksonii xantholophus, in the Hawaiian Islands is examined and the hypothesis that intraspecific aggression by adults drives observed niche separation and juvenile dispersal is tested.
Abstract: Various aspects of social structure can be important drivers of basic behavioral patterns, including dispersal, intraspecific niche partitioning, and resource utilization. Juvenile–adult interactio...
TL;DR: The results of this study have demonstrated that switching a host plant by aphids activates both oxidoreductases (PPO, POD) in the tissues of C. tujafilina and confirmed that these enzymes act in a complementary fashion in the aphid body.
Abstract: Interactions occurring between the insect and its host plant are an important aspect of understanding the process of species dispersal and the colonisation of new host plants. Aphid adaptive proces...
TL;DR: It is found that females with a concomitant increase in body size produce larger eggs and more offspring in warm environments than females in cold environments do, and it is suggested that temperature plays an important role in shaping maternal investment variation in R. kukunoris across geographical gradients.
Abstract: Environmental pressures vary by geographic location and will lead to differentiation in life history traits according to which maximize fitness. Life history theory predicts that harsh environments are likely to select for larger egg or offspring size, and for a stronger trade-off between offspring size and number. To test this prediction, we compared life history traits among 11 plateau brown frog (Rana kukunoris) populations at different altitudes. We found that females with a concomitant increase in body size produce larger eggs and more offspring in warm environments than females in cold environments do. Moreover, females from two natural populations produced offspring of different sizes between years. The decreasing resource allocation to current offspring size and number may increase survival and future fecundity in harsh environments. Thus, there may be a trade-off between mortality and fecundity in different environments. In addition to body size, we suggest that temperature plays an important rol...
TL;DR: This study provides further support for the role of short-toed snake eagles as sentinel species for Mediterranean habitats, and highlights the link between the location of nesting sites and the occurrence of human-modified landscapes characterised by high prey richness.
Abstract: Birds of prey, as top predators, play a key role in ecosystem functioning by regulating prey populations and, by means of cascade effects, promoting biodiversity. This makes them adequate sentinels of ecosystem health. Here we analyse the relationship between the occurrence of breeding short-toed snake eagle (Circaetus gallicus) and both the richness of potential prey species and landscape characteristics by taking into account two different spatial scales (i.e. nest-site scale and landscape scale). The short-toed snake eagle offers an interesting case study for investigating the relationships between top predators, prey diversity, and habitats, because it is an extremely specialised raptor that feeds on mesopredators, mostly snakes. Additionally, short-toed snake eagles are mainly threatened by changes in agriculture and land use in Europe, which have reduced the extent of suitable hunting habitats, and by the decrease in snake populations. Our study was conducted in the Latium Region (central Italy) in ...
TL;DR: The role of tail conspicuousness in the diversion of predatory attacks from the vital parts of the body in the juveniles of Bosk’s fringe-toed lizard is highlighted and agonistic interactions between adults and juveniles play important roles in shaping their antipredatory behaviour.
Abstract: Many lizard species show ontogenetic changes in tail colour that are coupled with changes in the antipredatory strategy. However, the ecological factors that influence the relationships between age...
TL;DR: The Eastern hellbender is a large, fully aquatic salamander found throughout the eastern United States, and little is known regarding hellbender reproductive behaviors, especially parentage, which leads us to hypothesize that cannibalism might be a factor in the lack of recruitment in this low-density population.
Abstract: For aquatic species with mating systems characterized by parental care, cannibalism is increasingly recognized as an evolutionary strategy (Manica 2002). Brooding parents may eat some (partial filial cannibalism) or all (total filial cannibalism) of their own offspring to forgo current breeding efforts in order to invest in future reproductive efforts (Rohwer 1978). The incidence of filial cannibalism can be influenced by several factors, such as presence of predators or conspecifics (Chin-Baarstad et al. 2009), reduced food intake (Walls 1998), or poor somatic condition of parental males (Gomagano & Kohda 2008). Experimental data on fish have shown that parents in poor body condition are more likely to cannibalize their brood to replenish energy reserves (Neff 2003; Manica 2004; Takeyama et al. 2013). Among species that cannibalize their offspring, one common theme involves guarding of large clutches of eggs, often with multiple dams (DeWoody et al. 2001). This can be problematic if these evolutionary behaviors remain intact despite changes in recent population demography (e.g., low population densities), which is the case for many amphibians experiencing declines (Wheeler et al. 2003). The Eastern hellbender (Cryptobranchus alleganiensis alleganiensis) is a large, fully aquatic salamander found throughout the eastern United States. Due to their cryptic nature, little is known regarding hellbender reproductive behaviors, especially parentage. During the breeding season, males move to breeding sites (large rocks) and excavate a nesting cavity that females visit to deposit eggs; only males actively guard these eggs, for prolonged periods of 5–6 months (Nickerson & Mays 1973). Typically, multiple females may visit denmasters (Floyd&Unger 2016), so thatmalesmay end up guarding numerous clutches with eggs numbering in the thousands in areas with high population densities. In low-density populations, however, males may only encounter a single dam and guard a few hundred eggs. One well-studied population (Blue River, Indiana) has experienced a dramatic decline over the past few decades (Burgmeier et al. 2011b). Moreover, we have observed eight clutches of eggs within the last decade, yet we have not documented recruitment since 1983 (Kern 1984). This leads us to hypothesize that cannibalism might be a factor in the lack of recruitment in this low-density population. Cannibalism of eggs and larvae has been documented in hellbenders (Smith 1907; Humphries et al. 2005), but it is not clear whether males are consuming the eggs of conspecifics in nest takeovers or consuming their own genetic offspring. In the closely related Andrias, hygienic filial cannibalism occurs whereby guardian males selectively Ethology Ecology & Evolution, 2018 Vol. 30, No. 2, 187–193, https://doi.org/10.1080/03949370.2017.1342696