Joshua Plotnik

Dr. Joshua Plotnik

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Research Focus & Metrics

Academic Career Length

16Years (2011-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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7 March 2011 in Proceedings of the National Academy of Sciences
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Journal Article
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JPJoshua Plotnik
Joshua Plotnik
RLRichard Lair
Richard Lair
WSWirot Suphachoksahakun
Wirot Suphachoksahakun
FWFrans B. M. de Waal
Frans B. M. de Waal
Elephants are widely assumed to be among the most cognitively advanced animals, even though systematic evidence is lacking. This void in knowledge is mainly due to the danger and difficulty of submitting the largest land animal to behavioral experiments. In an attempt to change this situation, a classical 1930s cooperation paradigm commonly tested on monkeys and apes was modified by using a procedure originally designed for chimpanzees (Pan troglodytes) to measure the reactions of Asian elephants (Elephas maximus). This paradigm explores the cognition underlying coordination toward a shared goal. What do animals know or learn about the benefits of cooperation? Can they learn critical elements of a partner's role in cooperation? Whereas observations in nature suggest such understanding in nonhuman primates, experimental results have been mixed, and little evidence exists with regards to nonprimates. Here, we show that elephants can learn to coordinate with a partner in a task requiring two individuals to simultaneously pull two ends of the same rope to obtain a reward. Not only did the elephants act together, they inhibited the pulling response for up to 45 s if the arrival of a partner was delayed. They also grasped that there was no point to pulling if the partner lacked access to the rope. Such results have been interpreted as demonstrating an understanding of cooperation. Through convergent evolution, elephants may have reached a cooperative skill level on a par with that of chimpanzees.

18 February 2014 in PeerJ
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JPJoshua Plotnik
Joshua Plotnik
FWFrans B.M. de Waal
Frans B.M. de Waal
Contact directed by uninvolved bystanders toward others in distress, often termed consolation, is uncommon in the animal kingdom, thus far only demonstrated in the great apes, canines, and corvids. Whereas the typical agonistic context of such contact is relatively rare within natural elephant families, other causes of distress may trigger similar, other-regarding responses. In a study carried out at an elephant camp in Thailand, we found that elephants affiliated significantly more with other individuals through directed, physical contact and vocal communication following a distress event than in control periods. In addition, bystanders affiliated with each other, and matched the behavior and emotional state of the first distressed individual, suggesting emotional contagion. The initial distress responses were overwhelmingly directed toward ambiguous stimuli, thus making it difficult to determine if bystanders reacted to the distressed individual or showed a delayed response to the same stimulus. Nonetheless, the directionality of the contacts and their nature strongly suggest attention toward the emotional states of conspecifics. The elephants’ behavior is therefore best classified with similar consolation responses by apes, possibly based on convergent evolution of empathic capacities.

20 August 2018 in Frontiers in Ecology and Evolution
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HMHannah Mumby
Hannah Mumby
JPJoshua Plotnik
Joshua Plotnik
Conflict between humans and wildlife is an increasing problem worldwide due to human population growth and habitat fragmentation, with growing interest amongst scientists and conservationists in developing novel solutions toward sustainable coexistence. Current efforts to mitigate human–wildlife conflict, however, are often unbalanced; they consider immediate human-centric concerns and offer deterrents against wildlife, rather than offering solutions to the underlying problems. Recently, there has been an increase in the number of calls to action for the integration of animal behavior, cognition and knowledge of individual variation into conservation practice. However, as elephant researchers, we have seen that most human–elephant conflict mitigation strategies employed in Asia and Africa are based on conditioning fear in elephants, or general monitoring of individual or group activities aimed at altering elephant movements, rather than understanding and providing for elephant and human needs. We see an opportunity to do more by investigating elephant behavior, cognition and ecology at the level of the individual to prevent conflict from occurring in the first place. Here, we review studies on elephants to illustrate this concept and to outline avenues for the application of research on elephant ecology, life history, behavior and personality to the development of new, comprehensive conservation strategies that take both human and elephant behavior into account.

3 June 2019 in Proceedings of the National Academy of Sciences
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Journal Article
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JPJoshua Plotnik
Joshua Plotnik
DBDaniel L. Brubaker
Daniel L. Brubaker
RDRachel Dale
Rachel Dale
LTLydia N. Tiller
Lydia N. Tiller
HMHannah Mumby
Hannah Mumby
NCNicola S. Clayton
Nicola S. Clayton
Significance: Although many animal species have demonstrated an ability to differentiate between more and less when presented with different amounts of food, they have done so primarily using vision. In this study, by contrast, elephants showed that they can detect differences between various quantities of food using only their sense of smell. Thus, elephants may be unique in their use of olfaction in cognitive tasks. This research suggests that it is important for psychologists to incorporate into experimental designs the ways in which different animals interact with their environment using all of their senses. Such species-specific paradigms would ensure comparisons about cognition across taxa are fair and relevant.

12 April 2017 in Scientific Reports
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Journal Article
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RDRachel Dale
Rachel Dale
JPJoshua Plotnik
Joshua Plotnik
The capacity to recognise oneself as separate from other individuals and objects is difficult to investigate in non-human animals. The hallmark empirical assessment, the mirror self-recognition test, focuses on an animal’s ability to recognise itself in a mirror and success has thus far been demonstrated in only a small number of species with a keen interest in their own visual reflection. Adapting a recent study done with children, we designed a new body-awareness paradigm for testing an animal’s understanding of its place in its environment. In this task, Asian elephants (Elephas maximus) were required to step onto a mat and pick up a stick attached to it by rope, and then pass the stick forward to an experimenter. In order to do the latter, the elephants had to see their body as an obstacle to success and first remove their weight from the mat before attempting to transfer the stick. The elephants got off the mat in the test significantly more often than in controls, where getting off the mat was unnecessary. This task helps level the playing field for non-visual species tested on cognition tasks and may help better define the continuum on which body- and self-awareness lie.

17 April 2013 in PLOS ONE
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Journal Article
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JPJoshua Plotnik
Joshua Plotnik
JPJennifer J Pokorny
Jennifer J Pokorny
TKTitiporn Keratimanochaya
Titiporn Keratimanochaya
CWChristine Webb
Christine Webb
HBHana F Beronja
Hana F Beronja
DGDavid Getz
David Getz
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.