The Hunger Games: Canine Edition
Dogs are highly intelligent creatures, a fact that scientists and affectionate pet parents can both agree on. They are a fascinating model system for the effects of socialisation on cognitive abilities. Stray dogs are an excellent source of information over pets for the same, as their learning is strongly influenced by their innate cognitive abilities rather than induced conditioning. This article talks about one such study.
From 'puppy love' and 'underdog' to 'a dog-eat-dog world', our daily repertoire of expressions is rife with references to man's best friend. Yet, surprisingly little is understood by most people about the strays that are so ubiquitous on any Indian street. Ignorance and fear often feed into the belief that they are a nuisance, actively eradicated by citizens and municipal bodies alike, across the country. While many NGOs are working towards humanely reducing stray dog populations by spaying and neutering, others in the scientific community study these wonderful creatures and their tremendous ability to survive and adapt to the hostile world they live in.
The Dog Lab at IISER Kolkata champions one such effort. Headed by Dr Anindita Bhadra, Associate Professor, Department of Biological Sciences, the lab studies the behaviour, ecology and cognitive abilities of stray dogs, also termed as free-ranging dogs (Canis lupus familiaris). This lab has recently published a paper titled, 'Free-Ranging Dogs Are Capable of Utilising Complex Human Pointing Cues' in Frontiers of Psychology . This study, conducted on 160 stray dogs in three different semi-urban and rural locations in West Bengal, examines the responsiveness of the strays to shorter and extended pointing cues to food placed at a distance.
Stray dogs often rely on humans to feed them and resort to begging. Hence, a dog must understand human pointing cues to obtain food. These dogs receive a range of positive and negative experiences from the humans they coexist with. As a result, there are differences between individual dogs that arise from their distinct life experiences. This study hypothesises that these differences govern a dog's readiness to approach food provided by an unfamiliar human (in this case, the experimenter of the study).
The methodology of the study itself is intuitive. The original sample of 160 was divided into three groups of 60, 60, and 40 used for testing shorter or momentary pointing cues, extended or dynamic pointing cues, and a control setting where no pointing was performed, respectively. The test was carried out using two opaque and covered plastic bowls that were placed at an equal distance from the dog and the experimenter. One of the bowls contained small pieces of chicken used as a reward while the other was rubbed with chicken pieces (see Figure 1) to ensure that a dog is not drawn to either bowl due to its smell alone. The study utilised a double-blind experimental approach. One experimenter set up the system and placed the reward in a bowl known to neither the second experimenter (who performed the act of pointing) nor the dog.
A still from the performed experiment where a stray dog chooses between two bowls after acquiring a pointing cue. As this setup was unfamiliar to a stray dog, it necessitated an initial trial of familiarisation - wherein the dog was simply provided a piece of chicken in one of the experiment bowls. Following this, only successfully familiarised dogs were included in the final experiment. In a trial, the experimenter established eye contact with the dog and randomly provided either a momentary (short duration) or extended (dynamic, long duration) cue to any one of the bowls. If the dog approached any one of the bowls, irrespective of which bowl it was, it was considered an approach. If the dog chose the bowl with the chicken pieces, it would eat the reward. This setup was replicated in the control except for the experimenter's cue. Three consecutive trials were carried out with each dog in all three groups.
Dr Debottam Bhattacharjee, the lead author of the paper, explains the difference between a momentary and a dynamic cue as, "Cognitively speaking, dynamic cues contain more information of intent than momentary cues. Thus, when a cue is given for a comparatively longer period, it requires less attention from an individual."
The study noted the subjects' behavioural states and categorised them into three primary states viz., affiliative (friendly), anxious, and neutral. These behavioural states were used as markers of a subject's experiences with an unfamiliar human.
The study found that nearly 80% of the subjects approached the pointed bowl in both test setups. The difference between the dogs that approached the reward and false-baited bowls was not statistically significant in the control setup. It also discovered a higher frequency of gaze alternation between the experimenter and the bowls in the dynamic cue condition compared to the momentary cue condition. This could be attributed to a greater number of movements in a dynamic cue that required the dog to adjust their gaze.
In the test conditions, the study found that 61% of the dogs that did not approach the setup were anxious, while 23% were affiliative, and 16% were neutral. Anxious dogs were more reluctant to approach the bowls. While this reluctance could be attributed to a lack of motivation or an inability to follow the cue, this is unlikely. This is because stray dogs, as scavengers, are unlikely to be well-fed, and thus should not leave any chance to get some food. Additionally, these dogs have been successfully familiarised to follow a cue.
Further analysis revealed no effect of the sex of the subject or the type of pointing cue provided. Dr Bhattacharjee explained that repeating the experiment during the mating season is unlikely to affect the results, since the willingness to approach seems to be a function of an individual's experiences and not the ecology of the species. Interestingly, the study also found that individuals are more likely to follow the experimenter's cue in a repeat trial if they had obtained a reward in the previous trial by following the cue, implying that positive reinforcement was effective. However, if the dog followed the cue and did not obtain a reward in the first trial, the trend continued in subsequent trials.
Surprisingly, testing the ability of stray dogs to dynamic cues to food placed nearby revealed a lesser ability to respond to such cues than cues at a distance. While it may seem counterintuitive, examining a dog's typical feeding habits holds the answer to the reason. Dogs are typically fed by throwing food at a distance and are hence likely to understand distal cues better.
Therefore, it is evident that dogs possess a great deal of “behavioural plasticity”, meaning that they can adapt their behaviours according to the stimulus they are exposed to. It is also likely that human interactions are indirectly responsible for shaping the personality of stray dogs. As a result, an increased understanding of canine abilities is crucial towards understanding evolutionary processes that occur on much shorter timescales than typically thought.
Ankita is a final year student in the integrated BS-MS program at IISER Kolkata. She is currently pursuing her thesis in the Copper Trafficking Lab, investigating the different pathways of trafficking of copper exporting proteins in cells. Her research interests are ever-evolving, and her short attention span is often engaged in pursuing arcane bits of knowledge. She is an avid reader and an amateur history enthusiast.
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