Intraspecific Behavior Research Articles

Recent Advances in the Behavioral Ecology of European Plethodontid Salamanders

There is a recent growing interest in the study of evolutionary and behavioral ecology of amphibians. Among salamanders, Plethodontidae is the most speciose family, with more than 500 species, while in Europe, there are only 8 species, all belonging to the genus Speleomantes. European plethodontids recently received increasing attention with regard to the study of their natural history, ecology and behavior; however, the lack of standardized data, especially for the latter, hampers comparative analysis with the species from the New World. We here synthetized the recent advances in Speleomantes behavioral ecology, considering as a starting point the comprehensive monography of Lanza and colleagues published in 2006. We identified the behavioral categories that were investigated the most, but we also highlighted knowledge gaps and provided directions for future studies. By reviewing the scientific literature published within the period 2006–2022, we observed a significant increase in the number of published articles on Speleomantes behavior, overall obtaining 36 articles. Behavioral studies on Speleomantes focused mainly on trophic behavior (42%), and on intraspecific behavior (33%), while studies on pheromonal communication and interspecific behavioral interactions were lacking. In addition, most of the studies were observational (83%), while the experimental method was rarely used. After providing a synthesis of the current knowledge, we suggest some relevant topics that need to be considered in future research on the behavioral ecology of European plethodontids, highlighting the importance of a more integrative approach in which both field observations and planned experiments are used.

Biting as an intraspecific behaviour of a male Common European Adder (Vipera berus, Linnaeus 1758) during courtship and mating competition

The article describes the first record of biting as an intraspecific behaviour of a male Common European Adder (Vipera berus) during courtship and mating. In venomous snakes this behaviour is rather rare and in Vipera berus this is the first time it has been observed in the wild. This behaviour is compared to similar observations in snakes and potential reasons are discussed.

Intraspecific behavior patterns of hoary fox (Lycalopex vetulus), a solitary canid endemic to Cerrado, Central Brazil

ABSTRACT The hoary fox, Lycalopex vetulus, is a small insectivorous canid endemic to grasslands of Central Brazil. Herein we characterize hoary fox social behavior, based on qualitative and quantitative differences in intraspecific communication among males, females, and subadults. A family group, two reproductive pairs and three other adult individuals of unidentified social status were directly observed from 1995 to 2001, for the continuous recording of all occurrences of behavioral events. Hoary fox exhibited behaviors related to communication and food consumption. A total of 4,240 behavioral events were recorded, most in the categories ‘Consumption’ (58%) and ‘Olfactory’ (23%). The frequencies of signaling types varied among individuals according to sex, age, and socioecological phase. Olfactory signalings were more frequent in adult males, and during the Mating and Dispersal phases. Acoustic signalings were more frequent in adult females and individuals rearing the young. ‘Consumption’ and ‘Tactile’ behaviors were more frequent in subadults. The hoary fox intraspecific communication is characteristic of solitary canids, but during mating season and rearing period, individuals become more ‘socialized.’ Data on courtship and mating, partnership dissolution phase, and the breakup of the family group until young dispersal, are necessary for a better understanding of intraspecific communication of the hoary fox.

Shelter Guarding Behavior of the Eastern Hellbender (Cryptobranchus alleganiensis alleganiensis) in North Carolina Streams

Cryptobranchus alleganiensis alleganiensis (Eastern Hellbender) is a fully aquatic salamander of conservation concern across the southeastern US. Characterization of shelter guarding by males and interspecific behavior during the breeding season in wild populations within the Blue Ridge ecoregion of North Carolina is lacking. To this end, we characterized diurnal video sequences of natural shelter-rock and nest-guarding behavior by male Eastern Hellbenders. We documented several intraspecific behaviors between resident males and nonresident conspecifics (males and females) during the breeding season (late summer to early fall) of 2018–2019 using modified action cameras with 4–6 hour battery life deployed in the French Broad River Basin of western North Carolina. Breeding behavior was documented (gravid females entering shelter) in 5 shelters, with 4 nests later confirmed by researchers. Across 21 unique shelters, we documented several examples of aggressive behaviors by resident Eastern Hellbender males toward conspecifics, including defensive posturing, territorial behavior, fights, biting, and bite-holds. All males occupying shelters (residents) spent the majority of time actively guarding the shelter entrance (81.7% of video) followed by maintenance behavior (e.g., modifying the shelter entrance; 5.3% of video), and short bouts (mean = 3.2 minutes) away from the shelter rock (2.5% of video). This study provides the first quantitative report of male breeding-season behavior across multiple natural shelters using non-invasive, affordable, waterproof cameras in North Carolina. We report on the utility of this method for observing behavior in stream systems and its potential application for monitoring of nests and behavior in other diurnal aquatic species.

A Camera-Trap Home-Range Analysis of the Indian Leopard (Panthera pardus fusca) in Jaipur, India.

Simple SummaryJhalana Reserve Forest (JRF) is engulfed by the city of Jaipur, India, with a human population of 3.9 million. Due to a continuum between human habitation and forests, frequent interactions with wildlife are inevitable. The leopard is the apex predator in JRF, sharing a habitat and resources with the human population. It is imperative to understand and study the leopard ecology to design and implement conservation strategies. We used a simple but effective and non-invasive technique—camera trapping—to identify leopards individually. The data analyzed using the minimum convex polygon (MCP) 100% method helped us estimate their home ranges. The use of camera traps was preferred over radio collaring, considering the permits of the Forest Department. We observed that males have larger home ranges than females. The females established their home ranges in the core area and on the fringes of the reserve. We discovered familial (mother and daughter) establishment of overlapping home ranges adjacent to one another. Three females who established themselves on the fringes were successful mothers raising cubs during the study period. The human population in the villages on the fringe areas share resources with the leopards, demonstrating that coexistence with predators is possible in a human-dominated landscape.The suitability of the camera trap–retrap method was explored for identifying territories and studying the spatial distribution of leopards (Panthera pardus fusca) in the Jhalana Reserve Forest, Jaipur, India. Data from two years (November 2017 to November 2019, N = 23,208 trap-hours) were used to provide estimates of minimum home-range size and overlap. We conducted home-range analysis and estimation, using the minimum convex polygon (MCP) method with geographic information system (GIS) tools. We are aware of the limitations and advantages of camera trapping for long-term monitoring. However, the limitations of the research permit allowed only the use of camera traps to estimate the home ranges. A total of 25 leopards were identified (male = 8, female = 17). No territorial exclusivity was observed in either of the sexes. However, for seven females, we observed familial home-range overlaps wherein daughters established home ranges adjacent to or overlapping their natal areas. The median home range, as calculated from the MCP, was 305.9 ha for males and 170.3 ha for females. The median percentage overlap between males was 10.33%, while that between females was 3.97%. We concluded that camera trapping is an effective technique to map the territories of leopards, to document inter- and intraspecific behaviors, and to elucidate how familial relationships affect dispersal.

Scaring Nemo: Contrasting effects of observer presence on two anemonefish species.

Behaviours of Clark's anemonefish Amphiprion clarkii and the dusky anemonefish Amphiprion melanopus were studied in Vanuatu. Six anemones and their resident fish were observed for typical behaviours (hiding, watching, roaming, inter-, and intraspecific behaviour) with and without the presence of a snorkelling observer. Observer presence had significant but contrasting effects on hiding behaviour in A. clarkii and A. melanopus. Bolder anemonefish species may be able to outcompete other species in areas with high human presence.

Synergistic Degradation of Pyrethroids by the Quorum Sensing-Regulated Carboxylesterase of Bacillus subtilis BSF01.

The well-studied quorum sensing (QS) mechanism has established a complex knowledge system of how microorganisms behave collectively in natural ecosystems, which contributes to bridging the gap between the ecological functions of microbial communities and the molecular mechanisms of cell-to-cell communication. In particular, the ability of agrochemical degradation has been one most attractive potential of functional bacteria, but the interaction and mutual effects of intracellular degradation and intraspecific behavior remained unclear. In this study, we establish a connection between QS regulation and biodegradation by harnessing the previously isolated Bacillus subtilis BSF01 as a template which degrades various pyrethroids. First, we characterize the genetic and transcriptional basis of comA-involved QS system in B. subtilis BSF01 since the ComQXPA circuit coordinates group behaviors in B. subtilis isolates. Second, the genetic and transcriptional details of pyrethroid-degrading carboxylesterase CesB are defined, and its catalytic capacity is evaluated under different conditions. More importantly, we adopt DNA pull-down and yeast one-hybrid techniques to reveal that the enzymatic degradation of pyrethroids is initiated through QS signal regulator ComA binding to carboxylesterase gene cesB, highlighting the synergistic effect of QS regulation and pyrethroid degradation in B. subtilis BSF01. Taken together, the elucidated mechanism provides novel details on the intercellular response of functional bacteria against xenobiotic exposure, which opens up possibilities to facilitate the in-situ contaminant bioremediation via combining the QS-mediated strategies.

Kleptoparasitic strategies of Mallards towards conspecifics and Eurasian Coots

We describe interspecific and intraspecific kleptoparasitic behaviour in Mallards Anas platyrhynchos, attempting to steal Zebra Mussels Dreissena polymorpha from other Mallards and Eurasian Coots Fulica atra. Both Coots and Mallards were most often attacked by Mallards perpetrating kleptoparasitic attacks when they handled large or intermediate-sized prey items. The probability of attack was nearly halved when the foraging birds had small versus large prey items in their bills. The overall probability of success of a kleptoparasitic attack was lowest when the attacked birds had small prey items, but higher if they had intermediate or large prey items. Kleptoparasitic attacks carried out on Coots were more often successful than those on Mallards. The results suggest that the optimal foraging theory, where animals tend to maximize net benefits, may be applicable to kleptoparasitic behaviour.

Could land surface phenology be used to discriminate Mediterranean pine species?

Land surface phenology (LSP) can improve the monitoring of forest areas and their change processes. The aim of this study was to characterize the temporal dynamics in Mediterranean pines and evaluate the potential of LSP for species discrimination. We used 661 mono-specific plots for five different Pinus species (Pinus halepensis, P. pinea, P. pinaster; P. sylvestris, P. nigra) and the MOD13Q1-NDVI time series (2000–2016) to perform the analyses. The time series were smoothed to extract the phenological parameters and calculate multi-temporal metrics, to synthesize the inter-annual variability. The potential of LSP for discriminating between Pinus species was evaluated by the application of the Random Forest (RF) classifier from different subsets of explanatory variables: i) the smooth time series; ii) the multi-temporal metrics; and iii) the multi-temporal metrics plus the auxiliary physical variables. This latter subset was also used as input to a Classification and Regression Tree (CART) algorithm to better explain the differences between Pinus species regarding LSP parameters and other environmental drivers. The analysis showed two different patterns: an important NDVI decrease during the summer for P. halepensis, P. pinea, and P. pinaster; and lower NDVI variation along the year for P. sylvestris. P. nigra showed a heterogeneous intra-specific behavior, having locations with different patterns. We distinguished Pinus species plots with a global accuracy of 0.82, when we used multi-temporal metrics of LSP and auxiliary physical variables. More generally, the Mediterranean Pinus species could be differentiated considering the 23rd of July as the start of season and 179 km and 1100 m as distance to the coastline and elevation, respectively.

First experimental evidence that proteins from femoral glands convey identity-related information in a lizard

Transferring identity-related information (IRI) to conspecifics may give advantage in effectively tuning intraspecific behaviour. Some lizard species use the secretions of specialized epidermal glands (femoral or cloacal) to convey IRI. Those secretions are made of lipids and proteins, the former been suggested to inform about signaller quality, the latter suspected to communicate IRI to conspecifics. Here, we tested the hypothesis that proteins broadcast IRI by analysing the movement patterns of 28 male common wall lizards (Podarcis muralis) under strictly controlled experimental conditions. Lizards were videotaped in plastic terraria where the substrate scent was manipulated by filling it with a solution bearing (i) the proteins extracted from the secretions of the tested lizard (SELF); (ii) the proteins from a never-met donor from other nearby populations (NON-SELF); and (iii) the solvent alone. Lizards showed higher behavioural response to the NON-SELF treatment with respect to both CTRL and SELF ones. Further, protein concentration did not affect behavioural response, suggesting an all-or-nothing effect. Both results agree with the hypothesis that proteins may be used in chemical communication and convey IRI, demonstrating for the first time that they can be used as intraspecific signal.

Are wintering Common Redpolls <i>Carduelis flammea</i> more exposed to avian predators than other small passerines?

The Common Redpoll Carduelis flammea is a highly social flocking bird which forms cohesive groups outside the breeding season. Being small birds (12-15g), they need to forage almost continuously during a few hours of daylight in winter to meet their energy demands. Although predation risk is reduced as a result of improved surveillance of many eyes, increased flock size may also increase the agonistic interactions among individuals within the flock and as a consequence lower the probability of detection of a predator’s approach. To examine whether Common Redpolls, living in relatively large winter flocks, are more exposed to avian predators than small passerines living in groups of only a few individuals, I recorded the responses of Common Redpolls, Willow Tits Poecile montanus and Great Tits Parus major to a life-like stuffed specimen of two different predators, the Siberian Jay Perisoreus infaustus (body length 30 cm) and the Hooded Crow Corvus cornix (50 cm). After the presentation of a predator model, Redpolls returned to the seed sites on the average earlier than the tits, and significantly so versus both tit species after exposure to the Siberian Jay, and for Great Tits after exposure to the Hooded Crow. Whereas Willow and Great Tits seemed to pick up sunflower seeds in the snow without much competition, Common Redpolls displayed a more conspicuous, aggressive, intraspecific behaviour. Thus, the individual vigilance of Common Redpolls was most likely reduced and exposure time to predation increased. The seed-eating Common Redpolls may be more food-stressed than the year-round resident Willow Tits that have stored food within their territories. If so, Common Redpolls may be forced to take greater predation risks because of a higher hunger level. If the differences in return times after exposure to a predator model reflected an adaptation to perceived predation risk, the Common Redpolls apparently evaluated the Siberian Jay as less dangerous than did the tits.

Effect of astressin, a corticoliberin antagonist, on aggression and anxiety-fobic states in male rats reared in social isolation

Aim. Intraspecific behavior, emotional and explorative activity were investigated after intranasal administration of astressin, a non-selective antagonist of CRF receptors, in the male rats reared in social isolation from 21 to 93 days.
 Results. In the “resident-intruder” test there was an increased level of aggression and communications in isolated rats compared to grouped animals. After intranasal administration of astressin (20 μg in 20 μl), rats grown in isolation demonstrated an increase in aggression and decreased in communicability compared to intact animals reared in isolation. In the “open field” test a level of motor activity was increased in rats grown in isolation compared to grouped animals. The anxiety-phobic state, as well as behavior in an elevated plus maze, revealed enhance of anxiety and fear in rats reared in isolation. After astressin administration to isolated animals the levels of anxiety and fear significantly decreased.
 Conclusion. The results of the work revealed that the antagonist of the CRF receptor astressin disinhibited aggression, removing anxious and phobic state in male rats reared in social isolation. The results prove the necessity of taking into account CRF mechanisms in the formation of the social isolation syndrome and the possibility of using CRF receptor antagonists to control the central mechanisms of stress and dependence in ontogenesis.

Basic elements of behavior of the cricket Phaeophilacris bredoides Kaltenbach (Orthoptera, Gryllidae)

The intraspecific behavior of the non-singing cricket Phaeophilacris bredoides Kaltenbach, 1986, which has no tympanal system, stridulatory apparatus, and classical acoustic communication, was studied. Even though this cricket has no song, its intraspecific behavior can be differentiated into reproductive and agonistic (defensive and aggressive), as this was done before for singing crickets. The main elements and the sequence of the phases were described for reproductive behavior. The active role during copulation belongs to the male. Wingflicks and rocking movements of the male can function as a “song.” Wing-flicks apparently generate air movements that function as short-range signals during reproductive and aggressive behavior. Substrate-borne vibrations produced by rocking also seem to be associated with aggressive behavior. Antennal contacts form an important part of interaction between crickets of both sexes. Thus, intraspecific signaling is at least partly mediated by mechanosensory channels. The assumption about the possible direction of evolution in the singing and non-singing groups of crickets was made.

A night of devastation: Natural and life history observations of an en-masse single night collection of Fallicambarus devastator.

Due to their fossorial tendencies, primary burrowing crayfish are the most difficult behavioral group of crayfish to study in-situ. In this study we elucidated both natural and life history aspects and intraspecific behaviors from a collection of 111 individual Fallicambarus devastator collected in Angelina County, Texas, on the night of May 15th, 2015. We also intend to emphasize the importance of environmental cues on collection success. Significant amounts of precipitation occurred during the days prior to 15 May 2015, resulting in the majority of burrows to be flooded on the day of collection. All animals were collected either traversing the landscape or captured at the portal of their burrow. Behaviors observed included excavation, respiration, feeding, and interspecific interactions. The majority of animals observed were adults, with juveniles noticeably absent on the surface. Life history observations included evidence of synchronous alteration to reproductive form in males, as well as sexually-dependent chelae morphometric ratios. Fallicambarus devastator meristically displayed sexual dimorphism between form I male and female chelae, with form I chelae having longer propodus length and greater palm widths, compared to the squamous and shorter chelae of females. Understanding the significance of studying these animals in favorable conditions is of paramount importance to the quality of future primary burrowing crayfish research.

Trace fossils of possible parasites inside the gut contents of a hadrosaurid dinosaur, Upper Cretaceous Judith River Formation, Montana

AbstractTiny sinuous trace fossils have been found within probable gut contents of an exceptionally preserved specimen of a hadrosaurid dinosaur,Brachylophosaurus canadensis, from the Judith River Formation of Montana. Approximately 280 examples of the trace fossils were observed in 19 samples of gut region material. The tubular structures typically are about 0.3 mm across. Many have thin calcareous linings or layers, and some exhibit fine surficial striae. At least two dozen of these trace fossils share walls with adjacent tubular traces, and this association can extend for several millimeters. While the trace fossils share some characteristics with fine rhizoliths, these features are most consistent with tiny burrows, or possibly body impressions, of worms (vermiform organisms) of uncertain biologic affinity. Such trace fossils have not been reported previously, and herein described asParvitubulites striatusn. gen. n. sp. Either autochthonous (parasites) or allochthonous (scavengers) worms may have created the trace fossils, but taphonomic factors suggest that autochthonous burrowers are more likely. Several lines of evidence, such as constant diameters and matching directional changes, suggest that the paired trace fossils were made by two individuals moving at the same time, which implies sustained intraspecific contact.Parvitubulites striatusprovides a rare record of interactions between terrestrial, meiofaunal-sized, soft-bodied invertebrates and a dinosaur carcass. The evidence that the worms may have parasitized a living hadrosaur and subsequently left traces of intraspecific behavior between individual worms adds unique information to our understanding of Mesozoic trophic interactions.

Pair formation, home range, and spatial variation in density, size and social status in blotched foxface Siganus unimaculatus on an Okinawan coral reef.

The present study examined pair formation, spatial pattern of home range and spatial variation in density, size and social status of blotched foxface Siganus unimaculatus (family Siganidae) on an Okinawan coral reef. Of 32 pairs sampled for sexing, 31 (96.9%) were heterosexual and showed size-assortative pairing. Developed ovaries were found in April and July, whereas oocytes were immature in August, September and February. Heterosexual pairing was found in both reproductive and non-reproductive periods. Home range size tended to be positively related to fork length (FL). The degree of home range overlap for same size class pairs was smaller than that for different size class pairs. The intraspecific behavior when two pairs approached each other was categorized as ‘attack,’ ‘agonistic display’ and ‘no interactions,’ and the frequency of agonistic behaviors (“attack” or “agonistic display”) was significantly greater than “no interactions.” Underwater observations at a seagrass bed, a rocky reef flat and a sheltered reef slope revealed that the mean FL was significantly smaller at the sheltered reef slope (4–13 cm) than at the rocky reef flat (>13 cm). No individuals were found in the seagrass bed. Most individuals less than 6 cm FL were solitary, whereas most individuals over 7 cm FL were paired. Density was significantly greater on the sheltered reef slope than on the rocky reef flat.

Nest Failure Owing to Intraspecific Agonistic Behaviour in Dupont's LarkChersophilus duponti

Abstract Intraspecific nest aggression in a diverse array of passerine species is usually explained in the context of competition for nesting sites among cavity nesters, or as parental investment among polygynous species, but has been reported only rarely in monogamous, open ground-nesting species such as larks. We video-monitored ten Dupont's Lark nests. This declining species has a patchy and restricted distribution in Iberia and northern Africa. We detected aggression toward one nest, during which a female deserted her clutch after being attacked by another Dupont's Lark. This is the first record of nest abandonment resulting from intraspecific agonistic behaviour in the Alaudidae family. The high density and proximity of territories of Dupont’s Lark in the study area seems a likely explanation for such agonistic behaviour, which may be a neglected cause of nest failure in shrinking Dupont’s Lark populations living in small habitat patches.

Forebrain neuropeptide regulation of pair association and behavior in cooperating cleaner fish

Animals establish privileged relationships with specific partners, which are treated differently from other conspecifics, and contribute to behavioral variation. However, there is limited information on the underlying physiological mechanisms involved in the establishment of these privileged ties and their relationship to individual cooperation levels. The Indo-Pacific bluestreak cleaner wrasse Labroides dimidiatus often forages in mixed-sex pairs when cleaning fish clients. Intra-couple conflicts often arise during a joint client inspection, which may alter the overall quality of cleaning service provided. Here we tested two hypotheses: a) whether intra-pair association (i.e. association index), measured with joint interspecific cleaning and intraspecific behavior, is correlated with neuroendocrine mechanisms involving forebrain neuropeptides arginine vasotocin (AVT) and isotocin (IT) and b) whether these neuropeptide level shifts relate to an individual's interspecific service quality. We found that partner support (number of cleaning interactions and tactile stimulation) received by male cleaners increased with association index. When cleaners inspected clients alone, cleaners' cheating decreased with association index for females but not males. AVT levels did not differ according to sex or association level. Forebrain IT levels increased with association index for males, whereas no relationship was found for females. Finally, cleaner cheating varied between sex and forebrain IT levels. Findings indicate that variation in pairs' relationships influences male and female cleaner fish differently and contributes to the variation of brain neuropeptide levels, which is linked to distinct cooperative outcomes.

Intraspecific larval aggression in two species of Hyperini (Coleoptera: Curculionidae)

Two unusual types of behaviour (wandering and intraspecific aggressive behaviour) have been observed when rearing larvae of two species of the tribe Hyperini. Wandering of Hypera postica in search for food was observed in L1, L2 and L3 larvae, as well as in young L4 larvae. L1 larvae also disperse in response to crowding. Wandering of L2 to young L4 instars was a response to food shortage. Wandering of late L4 larva (‘prepupa’) occurs because of searching for a place to spin the cocoon and pupate. Encounters between the larvae may result in agonistic behaviour, and some larvae may die as a consequence of fighting. This aggression increases with food limitation. Agonistic intraspecific behaviour has not been described to date in weevil’s larvae and it probably may not occur under natural conditions when there is a plenty of food and larval densities are decreased by pathogens or parasitoids.

On monogyny of the four-eyed fir bark beetle Polygraphus proximus Blandf. (Coleoptera, Curculionidae: Scolytinae) and its reproductive behavior

The reproductive behavior of the four-eyed fir bark beetle Polygraphus proximus Blandf., an invasive pest of the Siberian fir, was studied. Monogyny of this species was demonstrated in an experiment with colonization of fir logs by groups of adults with a given sex ratio. The female of P. proximus can build several egg galleries and has a mean fecundity of 45 ± 15 eggs. The main elements of intraspecific (reproductive and agonistic) behavior of P. proximus inside the galleries are described in detail. The four-eyed fir bark beetle has some behavioral patterns which are typical of more advanced species of the same genus, such as male entry hole initiation. Comparative analysis of the reproductive behavior and phylogenetic studies of the representatives of the genus Polygraphus Erichson may clarify the functional role of evolutionary transition from monogyny to polygyny in bark beetles.