When we talk about the negative effects humans have had on the environment throughout history, particularly in the last century, it’s more about what we’ve torn down (habitats, ecosystems) and polluted and hunted to extinction, NOT about what we’ve taught. Many species have faced a greater threat from what they have learned from and about humans than from what we have done to them directly. From spoiling these animals with an easier food source to mitigating their fear of us, we have created a problem that might be easily overlooked without a deeper understanding of the natural behaviors of the species within these taxa. Many of these habits are believed to be passed on through social learning, meaning the animals can share them by watching each other and seeing what the results are of certain actions for other members of their population; in the Animal Conservation journal, Rebecca Donaldson, H. Finn, L. Bejder, D. Lusseau, and M. Calver, from Murdoch University in Perth, Australia, reported the results of their study that investigated to what degree social learning can impact a population’s ability and predilection to use anthropogenic food sources, AKA food provided (directly and indirectly) by humans. Using data spanning 10 years, the researchers concluded that social learning can in fact be an important reason for the spread of behaviors that ultimately threaten wildlife and the biodiversity of a given area.
This question is not one that is frequently asked, so this study of social learning is an important first step in identifying another threat that humans pose to different species and which species in particular could be most susceptible to these observationally-learned, maladaptive behaviors. Using a population of 74 bottlenose dolphins (excluding youth) that resided year-round in Cockburn Sound, Donaldson et al. controlled for four variables (age, sex, human density in the area, and patterns of associations of the animals prior to human contact) to analyze which, if any, had the largest impact on the conditioning of a dolphin to use the anthropogenic food source. Conditioned dolphins were identified by two criteria: if they exhibited behaviors often displayed by animals that have been food conditioned by humans (think: your family dog) and if this was a change from past behavior. What exactly does that mean? If the animal approaches a boat or pier directly, remains close, and takes food when offered and in the past has not exhibited these behaviors, then the animal is considered to be ‘conditioned’.
The aims of this study were two-fold: to investigate whether social learning influences how an individual learns to use a human-based food source and also whether data from specific individuals is sufficient to predict if that animal is susceptible to this phenomenon. Age and sex proved to be an insignificant indicator of whether or not the organism would become conditioned, but the researchers do note that you shouldn’t immediately dispose of that information, because of the fact that their small, gender-unequal sample size could bias the data. In fact they even reference several other studies in which age and sex do contribute to an individual’s tendency to interact with humans (Mann & Smuts, 1999; Constantine, 2001; amongst others). Donaldson et al. concluded that individual acquisition of these human-friendly behaviors is unlikely, considering a large number exhibited them, and because no calves were included in the study, horizontal transfer seems to be a logical conclusion. The data supported this, because the proportion of ‘conditioned’ individuals in areas of high human density was larger than those in areas low density and higher in those who spend larger amounts of time with ‘conditioned’ individuals.
The impact of this research is slightly alarming, in the sense that many humans probably believe that they are helping out the species by throwing them a little extra food here and there. In reality, however, they might be training that animal to become dependent, who in turn illustrates for another individual that this strategy can be effective to an extent, and like dominos, the species collapses. Perhaps the data collected in this study and the broader implications of social learning can be used to help wildlife managers make better decisions and focus their efforts in the most efficient way. I, for one, will not be feeding any wildlife anytime soon.
The photo above is of Beggar the dolphin, who was known as a local tourist attraction around Sarasota County, FL, where he approached every boat “begging for food,” and who the locals say spent more time begging than foraging for himself. (http://baynews9.com/content/news/baynews9/news/article.html/content/news/articles/bn9/2012/9/25/often_fed_by_humans_.html)
Donaldson, R., Finn, H., Bejder, L., Lusseau, D., Calver, M. (2012), The social side of human–wildlife interaction: wildlife can learn harmful behaviours from each other. Animal Conservation, 15: 427–435. doi: 10.1111/j.1469-1795.2012.00548.x