Visual Cues Given by Humans Are Not Sufficient for Asian Elephants (Elephas maximus) to Find Hidden Food

Abstract

Recent research suggests that domesticated species – due to artificial selection by humans for specific, preferred behavioral traits – are better than wild animals at responding to visual cues given by humans about the location of hidden food. \Although this seems to be supported by studies on a range of domesticated (including dogs, goats and horses) and wild (including wolves and chimpanzees) animals, there is also evidence that exposure to humans positively influences the ability of both wild and domesticated animals to follow these same cues. Here, we test the performance of Asian elephants (Elephas maximus) on an object choice task that provides them with visual-only cues given by humans about the location of hidden food. Captive elephants are interesting candidates for investigating how both domestication and human exposure may impact cue-following as they represent a non-domesticated species with almost constant human interaction. As a group, the elephants (n = 7) in our study were unable to follow pointing, body orientation or a combination of both as honest signals of food location. They were, however, able to follow vocal commands with which they were already familiar in a novel context, suggesting the elephants are able to follow cues if they are sufficiently salient. Although the elephants’ inability to follow the visual cues provides partial support for the domestication hypothesis, an alternative explanation is that elephants may rely more heavily on other sensory modalities, specifically olfaction and audition. Further research will be needed to rule out this alternative explanation.

Elephants have a nose for quantity

“…Next, the elephants were given a "solid-lid" control condition to rule out the potential effect of the elephants perceiving nonolfactory information about the quantities of food presented (one set of 12 trials with solid lids only, 24 g of seeds vs. none). They were then trained on a small ratio (1:8, i.e., 4 vs. 32 g of seeds) to ensure that they understood that both buckets could contain food [these elephants had extensive previous experience with object-choice tasks in which only one bucket had food (34,43)]. The elephants all reached criterion (80% correct within a set of 12 trials) in eight or fewer sets (mean = 2.67 sets).…”

“…This time frame commenced as soon as the subject used his/her trunk to contact a bucket. The table was then pulled back, the cable ties were cut, and the perforated lids were replaced with solid lids positioned upside down on top of the buckets [subjects were previously trained in earlier experiments to remove the lids from the buckets when the lids were placed upside-down on top of the openings (34,43)]. The table was again extended, allowing the subject to remove the lid from one bucket to potentially retrieve the reward (the "choice phase").…”

Asian Elephants (Elephas maximus) Discriminate Between Familiar and Unfamiliar Human Visual and Olfactory Cues

“…Past research on the African elephants' visual system states that they can detect important conspecific behavioral cues, such as ear and trunk movements (Byrne et al, 2009;Kahl & Armstrong, 2000) as well as important heterospecific behavioral cues, such as human pointing, face and body orientation (Smet & Byrne, 2013; however, research by Plotnik et al (2013) found that Asian elephants could not follow human pointing cues. The results of the current study suggest that Asian elephants are able to detect more subtle visual cues, which may be important for establishing and maintaining social bonds.…”

Zoo elephant research: contributions to conservation of captive and free‐ranging species

“…Further work on problem-solving (e.g. Foerder et al, 2011;Plotnik et al, 2011Plotnik et al, , 2013Plotnik et al, , 2014Mizuno et al, 2015) coupled with multi-modal input and reward/non-reward designs could be helpful in deciphering what deterrents would be best to test in wild settings as one tool for reducing crop raiding and ameliorating human-elephant conflict.…”