Is the diet of vultures shaped by their culture?

Human eating habits are not born, they are made. Our food tastes and our diet are greatly influenced by where we are born and the social group in which we grow up or are educated.

However, this type of cultural transmission is not just a human characteristic: vultures display these types of cultural patterns as well. This is revealed by a new study. The results of this study indicate that vultures also have food preferences depending on the place or group to which they belong.

The study, led by Eneko Arrondo, a researcher at the University of Granada (UGR) in Spain, is the result of extensive collaboration between different centers and universities in Spain, including, in addition to the UGR, the Miguel Hernández University, the University of Alicante and the Doñana Biological Station, the latter dependent on the Higher Council for Scientific Research (CSIC).

Previous studies of vulture diets have focused more on the population as a whole than on individual individuals. However, in this work, the scientific team wanted to go further and for the first time has analyzed the diet of vultures on an individual scale. To do this, they carried out an exhaustive field campaign in the Iberian Peninsula and combined the monitoring by means of GPS devices of 30 griffon vultures captured in Las Bardenas Reales in Navarra and 35 in Sierra de Cazorla in Jaén.

Thanks to the accelerometer incorporated in the GPS, it was possible to know where each of the marked individuals had eaten. A team of ten people visited four thousand of these places analyzing what the vultures had eaten in each of them. With these data, they reconstructed their diet. “We observe, for example, that males prefer resources that are more closely linked to humans, such as intensive livestock farming and garbage, mainly, while females are more likely to feed on less predictable resources, such as hunting remains or extensive livestock farming,” explains the researcher Eneko Arrondo, from the University of Granada.

Griffon vulture in flight. (Photo: José Antonio Donázar)

The males, more daring

One of the hypotheses they use to explain this behavior is that males behave more confidently in humanized landscapes, close to human populations, with more infrastructure or highly altered environments, such as garbage dumps. “In other words, males would more often dare to eat in more dangerous places. On the contrary, the females would be less trusting and more prudent,” says Research Professor José Antonio Donázar, from the Doñana Biological Station. The team hopes to corroborate this hypothesis in the future with further studies.

These differences were also evident between the two populations of Navarra and Jaén. The individuals captured in Bardenas ate mainly the remains of intensive farms, which are very abundant in the area, while those captured in Cazorla preferred hunting remains and extensive livestock, which are the main resources of their range. “But what is most surprising is that, when we analyzed what the vultures of both populations ate when they shared space in the Extremadura meadows, we observed that the individuals continued to maintain their food preferences. The differences were maintained even though the availability of food was the same for all the individuals”, states Arrondo. “This shows that vultures acquire food “tastes” thanks to cultural transmission between individuals of the same population.”

These results are described by the team as “fascinating” since until now it was believed that vultures were opportunistic species that consumed any type of carrion without distinction. “We had no previous indications of this behavior, but advances in GPS technology are allowing us to closely monitor each individual and are helping us to better understand the ecology of these species, which are much more complex than expected. that was believed”, explains José Antonio Donázar. Thanks to this work, a new door is opened in the trophic ecology of these important scavengers, which provide essential ecosystem services in rural environments.

The study is titled “Vulture culture: dietary specialization of an obligate scavenger”. And it has been published in the academic journal Proceedings of the Royal Society B. (Source: UGR)