Do pigs communicate with us as dogs do?
Just like dogs, pigs are social, group-living animals. Due to the fact that they are also very trainable, the miniature variant is becoming more and more popular as a companion animal. “We launched the Family Pig Project in 2017 at the Department of Ethology, Budapest. The animals are raised in a similar environment as family dogs from as early as 6-8 weeks of age, which provides the basis for unique comparative investigations between these two species” – says Attila Andics, principal investigator of the MTA-ELTE ‘Lendület’ Neuroethology of Communication Research Group.
The researchers examined the behaviour of young family dogs and miniature pigs in two experiments. “Dogs, already as puppies, are known to be uniquely skilful in communicating with us, even without any specific training” – says Linda Gerencsér, lead researcher of the study, fellow researcher at the Research Group. “We were curious whether family pigs also exhibit similar communicative signals as dogs, and whether they spontaneously rely on human cues.”
In the first experiment the researchers observed how the animals behaved with the experimenter without the presence of food, and also after they had been fed by her. “In the presence of food, both pigs and dogs oriented more towards the experimenter, they touched her more often and looked at her face more frequently. As an interesting difference, though, only dogs and not pigs looked up at the human face when they did not expect to receive any food” – points out PhD student Paula Pérez Fraga. In another experiment the animals were allowed to choose between two hiding locations several times. The experimenter always pointed at the one that contained the hidden piece of food. “Without having been trained for this, only dogs followed the pointing, pigs did not. Pigs did not choose randomly either, but they rather followed a side-preference strategy, going to the same hiding location over and over again” – says Pérez Fraga.
The study is the first one presenting similarities and differences in juvenile family dogs’ and miniature family pigs’ behaviour during interspecific communicative interactions with humans. “To what extent the found similarities are the result of environmental effects, that is learning by experience or rather due to similar species-specific predispositions needs further investigations” – adds Gerencsér. “We think that the primary difference between pigs and dogs lies in the fact that the natural salience of the human as a social stimulus for dogs can facilitate learning about communicative cues even without specific training. Furthermore, our results are also informative with regard to the potentials of involving miniature pigs in comparative ethological research.”
This research, that was founded by the National Research, Development and Innovation Office, the Hungarian Academy of Sciences (’Lendület’ Program) and the Eötvös Loránd University (ELTE), was published in Animal Cognition titled Comparing interspecific socio-communicative skills of socialized juvenile dogs and miniature pigs.
Photos illustrating the research (photographer’s name in the filename): https://bit.ly/2RLYK4f