First record of allonursing in golden jackal (Canis aureus, L. 1758): a case of double breeding and communal denning within the same social unit

In the last decade, there has been a remarkable increase in the number of scientific publications on the ecology of the golden jackal Canis aureus, whereas information on its reproductive biology is still scanty, and the basic reproductive parameters of the species are not yet fully understood. In 2021, we began a research project in North-Eastern Italy, where the golden jackal is strictly protected under the National Law, to investigate the species behavioural ecology and reproductive biology at the den site, as a key element for defining conservation measures. Within this project, we documented allosuckling behaviour, possibly related to the breeding of two females within the same social unit, with den sharing and communal nursing of the cubs. Our observations open new scenarios and raise questions on the reproductive biology and social organisation of the golden jackal, stimulating further topics for research

A European Concern? Genetic Structure and Expansion of Golden Jackals (Canis aureus) in Europe and the Caucasus

In the first continent-wide study of the golden jackal (Canis aureus), we characterised its population genetic structure and attempted to identify the origin of European populations. This provided a unique insight into genetic characteristics of a native carnivore population with rapid large-scale expansion. We analysed 15 microsatellite markers and a 406 basepair fragment of the mitochondrial control region. Bayesian-based and principal components methods were applied to evaluate whether the geographical grouping of samples corresponded with genetic groups. Our analysis revealed low levels of genetic diversity, reflecting the unique history of the golden jackal among Europe’s native carnivores. The results suggest ongoing gene flow between south-eastern Europe and the Caucasus, with both contributing to the Baltic population, which appeared only recently. The population from the Peloponnese Peninsula in southern Greece forms a common genetic cluster with samples from south-eastern Europe (ΔK approach in STRUCTURE, Principal Components Analysis [PCA]), although the results based on BAPS and the estimated likelihood in STRUCTURE indicate that Peloponnesian jackals may represent a distinct population. Moreover, analyses of population structure also suggest either genetic distinctiveness of the island population from Samos near the coast of Asia Minor (BAPS, most STRUCTURE, PCA), or possibly its connection with the Caucasus population (one analysis in STRUCTURE). We speculate from our results that ancient Mediterranean jackal populations have persisted to the present day, and have merged with jackals colonising from Asia. These data also suggest that new populations of the golden jackal may be founded by long-distance dispersal, and thus should not be treated as an invasive alien species, i.e. an organism that is “non-native to an ecosystem, and which may cause economic or environmental harm or adversely affect human health”. These insights into the genetic structure and ancestry of Baltic jackals have important implications for management and conservation of jackals in Europe. The golden jackal is listed as an Annex V species in the EU Habitats Directive and as such, considering also the results presented here, should be legally protected in all EU member states

First record of multiple breeding and communal nursing within one social unit of European golden jackal (Canis aureus, L. 1758) in a low density area in NE Italy

Purpose/Objective: For species listed in Annex V of Habitats Directive, EU Member States shall, if deemed necessary, take measures only because of surveillance work, to ensure that their exploitation is compatible with maintaining them in a favorable conservation status. However, game management plans are elaborated without specific data on local density, at official rates overpassing 90–100 % (i.e. Romania), while the main reproductive parameters of the species are not yet understood. Our aim was to investigate reproductive biology at the den site as a key element in defining lethal control policies or conservation measures. In Italy the species legal status is strictly protected. Material/Methods: The study area is located in NE Italy on the lower Isonzo River catchment. First, we calculated the density performing a preliminary survey combining bioacoustics monitoring method (Giannatos 2004) and jackal litters opportunistic occurrence with camera trapping. Afterwards, we monitored 24 potentially suitable burrows during 2021 and 2022 breeding seasons with IR sensor cameras. Results: The local density was 0.53–0.65 groups / 10 km2. One of the monitored burrows has been occupied by three adult jackals (one male, two females). In this site, one camera trap was active from 20/02/2022 to 30/06/2022, with 112 days of recordings and 18 days (four interruptions) without recording. 1814 videos of jackals were collected. Significant observations: 04/04 – last record of the dominant female pregnant; 09/04 – the dominant female brought inside the burrow 8 new-born jackals; 10/04 – a second female (helper) was observed at den site from this date; 26/04 – first den exit of a cub; 29/04 – the helper female appeared pregnant; 02/05 – the helper female was recorded allo-suckling from this date; 20/05 – the dominant female brought away from the den 3 inept new-born cubs, whom 10 min later were brought back inside by the helper. Later in the day, the dominant female moved away 4 new-borns; 21/05 – the helper female brought at least one new-born back into the den; 28/05 – jackals leaved the den. Conclusion: We documented the first case of multiple breeding and communal nursing within one group of golden jackals. The dominant female gave birth to 8 cubs between the 4th and 9th of April and the period between gestation and independent den exit was 17–22 days. The two females cooperated in rearing the first litter throughout the denning period (49 days). A second litter of 4 cubs appeared related to the same den, as result of parturition by the helper female. The birth of this litter occurred between the 29th of April and 2nd of May. Based on observations of threatening / aggressive behaviors from the male toward the helper, polygyny might be excluded. Apparently the second litter did not survived. Our findings open new scenarios and questions about the reproductive biology and applied ecology of C. aureus in areas with low density and low mortality