Šumarski list, Vol. 144 No. 3-4, 2020.
Izvorni znanstveni članak
https://doi.org/10.31298/sl.144.3-4.2
Research of golden jackal (Canis aureus) in the Nature park Lonjsko polje by acoustic and camera traps methods
Goran Gužvica
orcid.org/0000-0003-1504-0446
; OIKON d.o.o. – Institut za primijenjenu ekologiju, Zagreb
Monika Petković
; OIKON d.o.o. – Institut za primijenjenu ekologiju, Zagreb
Marko Augustinović
orcid.org/0000-0003-4128-9034
; OIKON d.o.o. – Institut za primijenjenu ekologiju, Zagreb
Lidija Šver
orcid.org/0000-0001-8418-4430
; Prehrambeno-biotehnološki fakultet Sveučilišta u Zagrebu
Sažetak
Golden jackal (Canis aureus Linné, 1758) belongs to the family Canidae, which is characterized by opportunism and life in a pack. The rapid dispersion of golden jackal, as well as the increase of population density, indicates a high degree of ability of this species to adjust to different habitat conditions. Only 15 years ago, the appearance of the golden jackal in the Lonjsko polje Nature Park (NP) was sporadic. Today, territorial packs in this area are widespread and confirmed.
Lonjsko Polje NP is located in the alluvial plain of the central Sava river basin, with mosaics of different habitats typical for flooded areas such as flooded forests, marshes, swamps, meadows and agricultural lands. Except insects, which make a significant proportion of fauna of this area, and mammal species related to aquatic and terrestrial habitats, more than 70% of all bird species recorded in Croatia inhabit NP Lonjsko polje. Small rodents, insects, birds and bird eggs, are highly represented in the diet of golden jackals.
During the research period from 2012 to 2015, the minimum number and minimum density of golden jackal territorial packs were estimated in the area of Lonjsko polje NP by acoustic and camera trap methods.
Using the acoustic (playback) method, we confirmed the existence of 14 territorial packs in Lonjsko polje NP (Figure 1). From each calling station a recorded group yip-howl was broadcasted, and the GPS locations where the jackal’s response was heard, were recorded. For the calculation of the packs territory, around each recorded GPS location, the circle of 1.8 and 2 km radius was created. Outside of this radius human ear is not able to hear the sound of golden jackals howling. For the pack number estimation Point Cluster and Heatmap analysis in Q GIS 3.4. were used. By the use of the Q GIS function “Dissolve” in the Geoprocessing tools the total effective area of the response of the packs was calculated and it ranged from 186.30 to 214.50 km2. The minimum density of territorial packs per 10 km2 was calculated as a ratio of the number of packs and the total area of response of jackals and ranged from 0.65 to 0.75 packs per 10 km2. If compared to other areas in Croatia, the territorial density of the jackal packs estimated by the acoustic method in the area of NP Lonjsko Polje was slightly smaller. This is probably due to land unavailability caused by floods which impacts the pattern of space use of animals.
As part of this research, in the period from 2012 to 2015, five camera traps had been set and were afterwards periodically relocated to the places where the occurrence of golden jackals was expected. The golden jackal was recorded on 437 (8.8% from all photos with recorded animal or humans; Figure 3) photos or video clips. After the removal of the triplicates, 336 events of golden jackal photos or video clips were confirmed (Table 1). Without distinguishing individuals from each other, altogether, 359 individuals were recorded. In 94.64% of all events, only one individual was recorded. The largest number of individuals, 5 individuals on the same photo/video clip, was recorded in 0.30% of events. To analyze daily/night/twilight activity and circadian rhythm, photos/videos were sorted by date and time in to 3 categories: day, night and twilight (Figure 4). Student’s T-test for two variables confirmed the highest activity of golden jackal during the night (73.51% from all events, p <0.01) and twilight (19.64%, p <0.05). Daily activity was recorded as well (6.82% from all events). The maximum number of events was recorded between 3 and 5 AM. During the day, in the four years of application of the camera trap method, a photo of the jackal was never taken between 2 and 4 PM and 5 and 6 PM. Golden jackal exploits the resources out coming from human activities, especially in the areas inhabited by humans. However, if mosaics of cultivated areas are a dominant habitat type, where prey is abundant but the possibility of daytime cover is limited, the jackal mostly move at night, reducing the risk of encountering humans. Hence, the high incidence of nocturnal photographs of golden jackal is probably the consequence of the prevailing human-dominated landscape, the presence of large areas of wet meadows in the Nature Park Lonjsko Polje and the increased risk of suffering due to human activities (traffic, hunting, direct persecution).
Ključne riječi
golden jackal; <i>Canis aureus</i>; number and packs density; camera traps; acoustic method; Lonjsko polje NP
Hrčak ID:
237627
URI
Datum izdavanja:
30.4.2020.
Posjeta: 2.717 *