Dietary flexibility promotes range expansion: The case of golden jackals in Eurasia.
Above: Golden jackal in carcass cleaning role (with raven Corvus corax). According to the literature, the consumption of wild ungulates and domestic animals are mainly due to scavenging. Photo: Zoltán Horváth.
Global changes can lead to the expansion of a species geographical range. Exploring the causes and potential effects of predatory mammalian expansion is also relevant from a scientific, wildlife management, animal husbandry and conservation perspective
The golden jackal (Canis aureus) is a 10-15 kg canid that is one of the most successful carnivore species in Europe. Its original range included Central and Southeast Asia, the Arabian Peninsula, the Middle East and Eastern Central Europe. Isolated populations lived along the Mediterranean and Black Sea coastal regions until the middle of the 20th century. The species range then rapidly expanded to encompass the entire Balkans in the 1970s-1980s, and further to the north and west such that it is now found across Europe. Within this wide geographic range, the golden jackal also occurs in temperate, sub-Mediterranean, Mediterranean and subtropical climates. It occurs in habitats from grasslands to wetlands to deciduous forests to near-natural and highly artificial anthropogenic habitats, and even in the vicinity of large cities.
Cover image article: (open access)
Lanszki, J., Hayward, M. W., Ranc, N. & Zalewski, A. (2022). Dietary flexibility promotes range expansion: The case of golden jackals in Eurasia. Journal of Biogeography, 49, 993– 1005. https://doi.org/10.1111/jbi.14372
The limiting and facilitating factors driving this range increase are of particular interest given the present rapid population expansion in Europe. The occupation of the jackal, previously considered to prefer a warm climate and it has recently been observed beyond the Arctic Circle. The species expansion may have been triggered by various factors, such as changes in land use or climate change, the abundance of anthropogenic food sources or a historic decline of the grey wolf (Canis lupus) as apex predator and competitor. The jackal’s population growth and range expansion are likely facilitated by the species’ dispersal potential, its ability to live in human-dominated environments and flexible social behaviours.
During range expansion, wildlife must adapt their foraging and trophic niche to the new biotic and abiotic conditions. In this study, based on 40 published datasets, we analysed which climatic and environmental factors affected/shaped the dietary composition of golden jackals. Furthermore, we compared these drivers in the species’ historic and recently colonized distribution ranges.
Golden jackal dietary study sites have occurred across Eurasia. White circles – Reviewed studies, black circles – studies of sufficient quality to be included in our analyses. Orange colour indicates the current geographical range with established, reproducing jackal populations. A blue dashed line separates the study sites of the recently colonized and historic ranges. Golden jackal photo by Zoltán Horváth.
Our analyses revealed that three main food groups dominate the golden jackal’s diet – small mammals, domestic animals and plants – but the proportions of each vary greatly. Other food types (for example birds, wild ungulates, reptiles, waste) may only be significant locally. We found that the jackal diet composition is shaped by climate, habitat productivity and habitat composition in similar way in both historic and recently colonized range. The proportion of small mammals in the golden jackal diet decreased with annual mean temperature, whereas the consumption of wild ungulates increased with environmental productivity (NDVI).
The jackal diet composition and trophic niche are shaped by climate and habitat productivity
The recently colonized distribution range of golden jackals in Europe had a lower mean temperature but higher environmental productivity compared to the species’ historic range in Eurasia. In the recently colonized range, jackals consumed small mammals and/or wild ungulates (mostly from scavenging or viscera eating) more frequently, and fewer plants and/or domestic animals (again, mostly from scavenging or feeding on the remnants of domestic animal slaughter).
That is, climatic and environmental factors shape the golden jackals’ diet composition and trophic niche breadth, which, in a changing environment, greatly enhances the opportunities for jackals to colonize new areas successfully.
József Lanszki (1), Matt W. Hayward (2), Nathan Ranc (3) & Andrzej Zalewski (4)
(1) Full professor, Department of Nature Conservation, Hungarian University of Agriculture and Life Sciences, Kaposvár Campus, Hungary
(2) Professor of Conservation Science, School of Environmental and Life Sciences, The University of Newcastle, Callaghan, Australia
(3) Research Engineer, Université de Toulouse, INRAE, CEFS, Castanet‑Tolosan, France
(4) Full professor, Mammal Research Institute, Polish Academy of Sciences, Białowieża, Poland