Maria José Madeira

One of the most fascinating mammalian range expansions in Europe involves an opportunistic mesocarnivore―the golden jackal (Canis aureus). However, key questions about the origins and dispersal strategies of pioneering individuals, likely the first to establish new populations, remain unanswered. We analyzed genetic data from three golden jackals found at the forefront of the expansion, reaching the Iberian Peninsula (Spain) and Fennoscandia (Finland and Norway, beyond the Arctic Circle). We genotyped two tissue samples and one fecal sample using 15 microsatellites and compared results with an extensive reference dataset. Additionally, we analyzed the mtDNA control region (HVR1) for two individuals. All individuals were males, identified as pure jackals and first-generation migrants. Our results suggested either western Pannonia (1650 km distance) or, less probably, the Adriatic region (1300 km) as the region of origin for the Spanish individual, also western Pannonia for the Finnish individual (2500 km), and the Baltics or the Caucasus for the Norwegian individual (1400 km to 3400 km). These sources represent abundant core populations or relatively recent and successfully colonized areas. Both the Spanish and Finnish individuals carried the prevalent H1 HVR1 haplotype in Europe, confirming matrilineal genetic uniformity on the continent. The recent expansion of C. aureus is fueled by several sources, showcasing the golden jackals’ remarkable ability for long-distance dispersal as they extend their range to northernmost and westernmost Europe. Our findings highlight the dynamic nature of wildlife distribution, providing insights into species movement across vast distances amidst climatic, environmental, and anthropogenic pressures.

Knowledge of feeding ecology of declining species, such as farmland birds, is essential to address their conservation requirements, especially when their habitats are suffering important reductions of trophic resources. In this study, we apply a metabarcoding approach to describe the diet composition of six of the most significant farmland birds inhabiting European cereal pseudo-steppes: little bustard, great bustard, pin-tailed sandgrouse, black-bellied sandgrouse, red-legged partridge, and common quail. We further studied seasonal diet variations (autumn to spring) in all species but the common quail, whose diet was studied during spring and summer. We show that study species´ diets mostly consisted of plants, although in the case of little bustard and great bustard arthropods are also highly relevant. Among arthropods, we found high proportions of thrips, arachnids, and springtails, which were previously unreported in their diet, and some taxa that could be used as antiparasitic food. Moreover, we report that little bustard’s diet is the least rich of that of all studied species, and that diet of all these species is less diverse in winter than in autumn and spring. Diet composition of these declining species supports the importance of natural and semi-natural vegetation and landscape mosaics that can provide a wide variety of arthropods, plants, and seeds all year-round.