Biology subjects

Bhattacharjee, D.

Publications and source records attributed to Bhattacharjee, D..

22 records · Page 2Linked to original sources

bioRxiv2019

\"Bolder\" together - response to human social cues in free-ranging dogs

Interspecific interactions within an ecosystem have different direct and indirect effects on the two interacting species. In the urban environment, humans are a part of an interaction network of several species. While indirect human influence on different urban species has been measured extensively, experimental studies concerning direct human influence are lacking. In this study, we tested interactions between groups of urban free-ranging dogs (Canis lupus familiaris) and solitary unfamiliar humans in ecologically relevant contexts. We provided different sets of dogs with four commonly used human social cues (neutral, friendly, low and high impact threatening) to understand their responses at the group-level and identify potential inter-individual differences. Finally, we compared data from a previous study to investigate the differences in behavioural outcomes between solitary and groups of dogs while interacting with humans. The study not only strengthens the idea of situation-relevant responsiveness in free-ranging dogs but also highlights the minute differences between solitary and group-level reactions in the form of higher approach and less anxious behaviour of groups towards the unfamiliar human. Additionally, we report inter-individual differences and the effect of sex while responding to the threatening cues. Our study suggests a direct benefit of group-living over a solitary lifestyle in free-ranging dogs while interacting with humans in the streets.\n\nSummary statementFree-ranging dogs can benefit by living in groups over a solitary lifestyle while interacting with unfamiliar humans in urban habitats irrespective of having significant inter-individual differences.

animal behavior and cognition↗

bioRxiv2019

Free-ranging dogs are capable of comprehending complex human pointing cues.

Dogs are the most common species to be found as pets and have been subjects of human curiosity leading to extensive research on their socialization with humans. One of the dominant themes in dog cognition pertains to their capacity of understanding and responding to human referential gestures. The remarkable socio-cognitive skills of pet dogs, while interacting with humans, is quite well established. However, studies regarding the free-ranging subpopulations are greatly lacking. Free-ranging dogs represent an ideal system to investigate interspecific communication with unfamiliar humans, nullifying any contribution of indirect conditioning. The interactions of these dogs with humans are quite complex and multidimensional. For the first time, we tested free-ranging dogs ability to understand relatively complex human referential gestures using dynamic and momentary distal pointing cues. We found that these dogs are capable of apprehending distal pointing cues from humans. However, approximately half of the population tested showed a lack of tendency to participate even after successful familiarization with the experimental set-up. A closer inspection revealed anxious behavioural states of the individuals were responsible for such an outcome. We assume that life experiences with humans probably shape personalities of free-ranging dogs, which in turn influence their responsiveness to human communicative gestures.

animal behavior and cognition↗

bioRxiv2019

Cooperation only for high rewards - a solvable task-based study on free-ranging dogs

The benefits of group living mostly surpass the disadvantages like sharing of resources and competition over food, space and mates, driving the evolution of social organization. Group living can be facilitated by social tolerance and cooperation among the group members. Social canids (e.g. wolves) display cooperative breeding, hunting, and prosocial activities in different contexts. Unlike cooperative pack-living wolves (Canis lupus lupus), their descendants, domesticated dogs (Canis lupus familiaris), show varying levels of associations from solitary to stable social groups. Free-ranging dogs are group-living but prefer to forage solitarily, hence providing an excellent opportunity for investigating social tolerance and coordinated task performance among the members in various situations. We tested 113 adult-only groups of free-ranging dogs in three different tasks to investigate group responses and performance in problem-solving situations in the presence of an unfamiliar human. Task 1 (unfamiliar, single food reward) and 2 (familiar, single food reward) examined group responses and cooperation from the perspective of familiarity, while Task 3 (familiar, multiple food rewards) enabled us to test whether increased food rewards promote social tolerance and food sharing among the group members. Regardless of significantly higher performance in Task 2 compared to Task 1, cooperation and food sharing were significantly lower in both. Task 3 revealed a strong positive correlation between food sharing and social tolerance, but not between success and social tolerance, suggesting a tendency for cooperation. We conclude that context-dependent cooperation and tolerance among group members facilitate group-living in free-ranging dogs.\n\nSignificance statementGroup living is a common phenomenon in the animal world where the members of a group show social tolerance and co-operative behaviours towards each other. This need for cooperative intents increases manifolds while groups face different problem-solving situations in their day to day lives. Here, we tested a large number of free-ranging dog groups to understand general cooperative intents such as social tolerance and food sharing in different problem-solving conditions. We found shreds of evidence of context-dependent cooperation and social tolerance among group members with minimal display of aggression. It is not adaptive for the dogs to fight or display aggression over resources. Alternatively, use of subtle cues such as display of dominance and subordination seem to be more plausible mechanisms for the development of efficient scavenging strategies and maintaining hierarchy.

animal behavior and cognition↗

bioRxiv2018

Free-ranging dogs understand human intentions and adjust their behavioral responses accordingly

Domestic dogs (Canis lupus familiaris) are remarkably sensitive and responsive while interacting with humans. Pet dogs are known to have social skills and abilities to display situation-specific responses, but there is lack of information regarding free-ranging dogs which constitute majority of the worlds dog population. Free-ranging dogs found in most of the developing countries interact constantly with familiar and unfamiliar humans receiving both positive and negative behavior. Thus, understanding human intentions and subsequent behavioral adjustments are crucial for dogs that share habitats with humans. Here we subjected free-ranging dogs to different human social communicative cues (friendly and threatening - low and high), followed by a food provisioning phase and tested their responsiveness. Dogs exhibited higher proximity seeking behavior as a reaction to friendly gesture whereas, they were prompted to maintain distance depending on the impact of the threatening cues. Interestingly, only the high-impact threatening showed to have a persistent effect which also remained during the subsequent food provisioning phase. An elevated approach in the food provisioning phase elicited the dependency of free-ranging dogs on humans for sustenance. Our findings suggest that free-ranging dogs demonstrate behavioral plasticity on interacting with humans; which provides significant insights into the establishment of the dog-human relationship on streets.

animal behavior and cognition↗