New publication reports that dolphins learn maladaptive behaviours from each other

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Bottlenose dolphin. Image by PhD candidate Kate Sprogis.

Recently members of MUCRU published a paper in the journal Animal Conservation:

The social side of human-wildlife interaction: wildlife can learn harmful behaviours from each other. 2012. Donaldson, R., Finn, H., Bejder, L., Lusseau, D. and Calver, M. Animal Conservation. doi: 10.1111/j.1469-1795.2012. 00548.x.

This paper found that social learning – ie learning from other individuals – can influence whether dolphins learn maladpative behaviours. In this case, dolphins learned how to acquire food from recreational fishers.

Here we examine the findings from the paper and describe the history of the research which contributed to it. The Abstract for the paper and other relevant papers are also provided.

History of Research

The findings in this paper arose from a long-term study of dolphins in Cockburn Sound, Western Australia. Cockburn Sound is a large (80km2) semi-enclosed bay south of Fremantle and includes Perth’s main industrial area, a naval base, and important recreational and commercial fishery. It is also home to a resident community of about 75 Indo-Pacific bottlenose dolphins (Tursiops aduncus).

Bec Donaldson from Murdoch’s Conservation Medicine Program, one of the authors of the paper, initiated research into the Cockburn Sound dolphins in 1993, focused on the social ecology of dolphins in the Sound. The completion of intensive research in 1997 was followed by two years of low-intensity monitoring of the population (1998-1999). Hugh Finn, another of the paper’s authors, resumed research in 2000 and continued study until mid-2003.

The dolphins in Cockburn Sound are resident year-round and exhibit long-term fidelity (e.g. many of Bec’s study animals are still present in Cockburn Sound). This allowed Bec and Hugh to monitor the behaviour of known individuals across an eleven-year period (i.e. 1993 – 2003).

Learning a harmful behaviour

During the course of their research, Bec and Hugh collected information on the feeding of dolphins by recreational fishers in Cockburn Sound, a practice that is illegal under state and federal law in all Australia jurisdictions.

The managed feeding of wild dolphins occurs in a few places, including Monkey Mia, Western Australia. The feeding interactions are licenced and are subject to stringent regulations to protect dolphins (e.g. to prevent dolphins from becoming dependent on food from humans).

When Bec began her research in 1993, only one dolphin (an adult male named Touch) approached humans for food-handouts. However, by 2000, 13 dolphins had been observed to exhibit behaviours indicating that they had become conditioned to human interaction by food reinforcement.

Bec noticed that all of the dolphins that learned to ‘beg’ from humans were associates of dolphins that had previously learned to beg. For example, some of the first ‘beggars’ in Cockburn Sound were close associates of Touch. Many of the later dolphins which learned to beg were male associates of each other.

This pattern of behaviour acquisition raised the question of whether social learning might facilitate the learning of begging behaviours, e.g. by providing opportunities for naïve dolphins to learn associations between human stimuli (boats and fish) and a set of behaviours (approach boats and stick your head out of the water). Of particular interest, Bec had observed several adolescent male associates of Touch remaining within 5 to 10 meters of Touch and orientated towards him while he begged for food from a boat, in the months prior to becoming beggars themselves.

Analyses of the long-term data indicated that dolphins were more likely to become beggars if they spent more time in areas with high densities of recreational boats and with other conditioned dolphins. This suggested that repeated exposure to human provisioners is critical for dolphins to learn how to beg, but that observing other dolphins – particularly associates – also supported the learning process.

Implications

Mom and calf bottlenose dolphins. Image by PhD candidate Kate Sprogis

These findings are important for two reasons. First, they support previous studies indicating that ‘social’ animals like elephants, canids, and dolphins may acquire maladaptive behaviours at least in part through social learning. Novel behaviours anthropogenic food sources – whether these foods be fish, crops, or garbage – can lead to harmful consequences for humans and wildlife.

Second, these findings suggest that efforts to manage harmful human-wildlife interactions should consider the potential for animals to learn harmful or undesirable behaviours socially. Social learning may influence which animals acquire these behaviours and how fast they spread through the population. Thus, managers may benefit from investing in long-term wildlife studies that monitor known individuals and their ranging and association patterns.

Other Relevant Papers (Please contact Hugh Finn for further information or copies of the papers)

Finn, H.C., Donaldson, R., and Calver, M.C. (2008) Feeding Flipper: a case study of a human-dolphin interaction. Pacific Conservation Biology 14: 215-225.

Donaldson, R., Finn, H., and Calver, M. (2010) Illegal feeding increases risk of boat-strike and entanglement in Bottlenose Dolphins in Perth, Western Australia. Pacific Conservation Biology 16: 157-161.

 

Abstract (The social side of human-wildlife interaction: wildlife can learn harmful behaviours from each other. 2012)

Although harmful human–wildlife interactions involving anthropogenic food sources are a significant issue for wildlife conservation, few studies have addressed whether social learning may influence how animals learn to use anthropogenic foods. We examined a long-term (1993–2003) human–wildlife interaction involving the illegal feeding of bottlenose dolphins (Tursiops aduncus) by recreational fishers in south-western Australia. We developed predictor variables for whether dolphins learned to accept food handouts from human provisioners, based on biological (age-class, sex) and behavioural (ranging and association patterns) data for a population of 74 dolphins. Two variables provided clear predictors for whether dolphins became conditioned to food handouts: the use of areas with high densities of recreational boats (BOAT) and the average coefficient of association with previously conditioned dolphins (ASSOC). An individual was more likely to become conditioned when it spent more time in high boat density areas and when it spent more time with other conditioned dolphins. When considering all the models available, there was strong weight of evidence for the effects of ASSOC and BOAT on the response variable. We were unable to detect any effects of age-class and sex with the available statistical power. These findings suggest that social learning can facilitate the acquisition of undesirable and maladaptive behaviours in wildlife, and indicate the value of long-term individual-specific data for the conservation management of wildlife engaging in undesirable interactions with humans.

You can download the PDF through the Animal conservation journal website:

http://onlinelibrary.wiley.com/doi/10.1111/j.1469-1795.2012.00548.x/abstract

 

Alternatively, you can contact the following co-authors:

Bec Donaldson, Conservation Medicine Program, Murdoch University

Hugh Finn, Cetacean Research Unit, Murdoch University

Lars Bejder, Cetacean Research Unit, Murdoch University

Mike Calver, School of Biological Sciences and Biotechnology, Murdoch University

 

 

Lars Bejder PhD
Lars Bejder PhD
Professor Lars Bejder PhD is the Research Leader of the Murdoch University Cetacean Research Unit.
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