Eating smart: Free-ranging dogs follow an optimal foraging strategy while scavenging in groups

Abstract

Foraging and acquiring of food is a delicate balance between managing the costs (both energy and social) and individual preferences. Previous research on solitarily foraging free-ranging dogs showed that they prioritise the nutritionally highest valued food, but do not ignore other less valuable food either, displaying typical scavenger behaviour. We conducted a similar experiment on 136 groups of dogs with the same set-up to see the change in foraging strategies, if any, under the influence of social cost like intra-group competition. We found multiple differences between the strategies of dogs foraging alone versus in groups with competition playing an implicit role in the dogs’ decision making when foraging in groups. Dogs continually assessed and evaluated the available resources in a “patch,” transitioning from random foraging to systematic foraging with time and more information. Dogs in groups used an, “eat first, sample afterwards” strategy whereas individual dogs sampled thoroughly before eating. Additionally, dogs in groups were quicker and more likely to respond to the experimental set-up and eat from it. The dogs adjusted their behaviour in terms of effort and time allocated according to the quality of the “patch.” Foraging in groups also provided benefits of reduced individual vigilance. The various decisions and choices made lend support to the optimal foraging theory wherein the dogs harvested the nutritionally richest patch possible with the least risk and cost involved but were willing to compromise if that was not possible. This underscores the cognitive, quick decision-making abilities and adaptable behaviour of these dogs, which is likely to have influenced the process of dog domestication.

Does novelty influence foraging decision of a scavenger?

“…Nonetheless, it can be assumed that object-neophobia does not constrain these dogs' foraging decision-making. In fact, freeranging dogs are known to engage with various kinds of human artefacts during scavengingrelated tasks, like baskets (Sarkar, Sau & Bhadra, 2019;Sarkar et al, 2023), bowls (Bhattacharjee et al, 2017c(Bhattacharjee et al, , 2019, containers and packaged food (Bhattacharjee et al, 2017b;Banerjee & Bhadra, 2019), etc. In future, it would also be interesting to test freeranging dogs' exploratory behaviour towards novel and familiar objects outside of the objectchoice paradigm.…”

“…This is attributed to dogs’ reliance on a complex multimodal sensory information system of vision and olfaction during foraging. Dogs are primarily known to rely on olfactory cues to make their foraging decisions (Bhadra et al, 2015; Banerjee & Bhadra, 2019; Sarkar et al, 2023), but they ‘seem to lose their nose’ in a communicative context with humans, where they rely more on visual than olfactory cues (Szetei et al, 2003). Although our study did not involve an active presence of human experimenters, particular interest towards human artefacts should be tolerated due to selection for neophilia (Kaulfuß & Mills, 2008).…”

“…However, it is unknown whether, in general, such behaviours are influenced by object-neophobia. Solitary foraging is prevalent in these dogs (Sen Majumder et al, 2014) to reduce intraspecific competition (Sarkar, Sau & Bhadra, 2019; Sarkar et al, 2023). At the same time, these dogs do not have any natural predators in human-dominated environments, where humans are the biggest cause of their mortality (Paul et al, 2016).…”

The unfulfilled potential of dogs in studying behavioural evolution during the Anthropocene

“…Dogs on the other hand, primarily scavenge on human food residues (26,29). These do not typically require any coordination with group members to procure and are also often distributed in quantities that are small enough to be monopolised by individuals (89). The looser social organisation of freeranging dogs, which may associate in transitional to stable packs but do not live in family groups (23,(95)(96)(97), thus allows for larger plasticity in foraging strategies.…”

Does novelty influence the foraging decisions of a scavenger?

“…All the objects contained equal-sized food items, except for the last condition ( i.e., two opaque balls), in which of one the balls was false-baited. Since free-ranging dogs benefit from reduced intraspecific competition during scavenging and experience little to no predation pressure in human-dominated environments ( Sarkar, Sau & Bhadra, 2019 ; Sarkar et al, 2023 ), we hypothesised that they would not exhibit object-neophobia. In particular, we expected dogs to inspect the novel objects first rather than the familiar ones in the test conditions but show comparable choices in the control and validation conditions.…”