Seasonal migrations (i.e. seasonal round‐trips between disjunct areas) have been rarely documented for large carnivores. The Dinaric‐Pindos brown bear (Ursus arctos) population is the third largest ...in Europe, but little information is currently available on individual movement patterns. We studied movement patterns by 12 GPS‐collared adult and subadult bears in Croatia and Bosnia Herzegovina during 2004–2017, including migratory movements by some instrumented bears. To investigate environmental correlates of migrations, we first used the canonical Outlying Mean Index analysis, identifying habitat descriptors of summer and fall ranges, and then applied mixed‐effects logistic regression to quantify variation in habitat use between them. Thirty‐seven per cent 37% of the bears (7 bear‐years) migrated during hyperphagia (i.e. partial migration), and seasonal migration was also facultative, as it occurred only during mast (i.e. beechnut) poor years. Migrating bears entered migration during early fall (median = 25 Sept) and returned to their pre‐migratory ranges after about 7 weeks (median = 18 Nov). Net distances between pre‐migratory (summer) and post‐migratory (fall) averaged (±sd) 26.5 ± 9.7 km, with a maximum distance of 38.8 km, corresponding to actual distances travelled of 61.1 ± 21.5 km. Summer ranges from which bears migrated were best described by proximity to supplemental feeding sites and mixed forests, whereas fall ranges reached by migrants were differentiated by lower elevations, and a higher share of deciduous forest, grasslands, forest edges and shrublands. Relative to pre‐migratory ranges, bears in post‐migratory ones increased their distance to anthropogenic features and showed higher use of cover types expectedly richer in berries and other fleshy fruits. Although we lack any causative evidence, we speculate migration in this bear population is triggered during poor beechnut years by increased social despotic interference at supplemental feeding sites that elicits redistribution of subordinate bears.
Seasonal migrations have been rarely documented for large carnivores. We studied movement patterns in Dinaric‐Pindos brown bears, a large European population exposed to anthropogenic supplemental food. In 2004 – 2017, thirty‐seven per cent of the GPS‐collared bears showed a complex, flexible behavioural trait such as partial and facultative migration, involving seasonal movements between areas where they are likely to increase their foraging opportunities in years of poor beechnuts production. Migrating bears entered migration during early fall and returned to their pre‐migratory ranges after about 7 weeks. Relative to pre‐migratory ranges, bears in post‐migratory ones increased their distance to anthropogenic features and showed higher use of cover types expectedly richer in berries and other fleshy fruits. We speculate migration in this bear population is triggered during poor beechnut years by increased social despotic interference at supplemental feeding sites that elicits redistribution of subordinate bears.
The conservation of gray wolf (Canis lupus) and its coexistence with humans presents a challenge and requires continuous monitoring and management efforts. One of the non-invasive methods that ...produces high-quality wolf monitoring datasets is camera trapping. We present a novel monitoring approach where camera traps are positioned on wildlife crossing structures that channel the animals, thereby increasing trapping success and increasing the cost-efficiency of the method. In this way we have followed abundance trends of five wolf packs whose home ranges are intersected by a motorway which spans throughout the wolf distribution range in Croatia. During the five-year monitoring of six green bridges we have recorded 28 250 camera-events, 132 with wolves. Four viaducts were monitored for two years, recording 4914 camera-events, 185 with wolves. We have detected a negative abundance trend of the monitored Croatian wolf packs since 2011, especially severe in the northern part of the study area. Further, we have pinpointed the legal cull as probable major negative influence on the wolf pack abundance trends (linear regression, r2 > 0.75, P < 0.05). Using the same approach we did not find evidence for a negative impact of wolves on the prey populations, both wild ungulates and livestock. We encourage strict protection of wolf in Croatia until there is more data proving population stability. In conclusion, quantitative methods, such as the one presented here, should be used as much as possible when assessing wolf abundance trends.
Naglo širenje područja obitavanja čaglja, ali i povećanje gustoće populacije, govori o visokom stupnju prilagodljivosti te vrste različitim stanišnim uvjetima. Prije 15-tak godina, pojava čaglja na ...području Parka prirode (PP) Lonjsko polje bila je sporadična, dok danas na tom području nedvojbeno egzistiraju teritorijalni čopori. U razdoblju od 2012. do 2015. godine provedeno je istraživanje s ciljem utvrđivanja broja i minimalne prosječne teritorijalne gustoće čopora čagljeva na području PP Lonjsko polje primjenom akustične metode i metode fotozamki.
Akustičnom metodom je procijenjeno da je na području PP Lonjsko polje u istraživanom razdoblju obitavalo 14 teritorijalnih čopora čagljeva, područje odaziva čagljeva bilo je od 186,30 do 214,50 km2 te se minimalna procijenjena gustoća čopora čagljeva kretala u rasponu od 0,65 do 0,75 na 10 km2. U usporedbi s drugim istraživanim područjima u Hrvatskoj teritorijalna gustoća čopora čagljeva procijenjena akustičnom metodom na području PP Lonjsko polje je nešto manja, a jedan od mogućih razloga je činjenica da su određeni dijelovi PP Lonjsko polje u nekim razdobljima nedostupni čagljevima zbog poplava, što bi moglo imati utjecaj na njihovo korištenje prostora.
U razdoblju od 2012. do 2015. godine metodom fotozamki je prikupljeno 437 (8,8 %) fotografija/video isječaka na kojim su zabilježeni čagljevi. Nakon uklanjanja triplikata preostalo je 336 događaja čaglja odnosno fotografija/video isječaka na kojima je ukupno zabilježeno 359 jedinki čaglja, bez mogućnosti determinacije na razini jedinke. Od ukupnog broja događaja, jedna jedinka je zabilježena u 94,64 % događaja, a u 0,30 % događaja zabilježen je najveći broj jedinki, odnosno 5 jedinki na istoj fotografiji/video isječku. Uporabom metode fotozamki je utvrđeno da je najveći stupanj aktivnosti čagljeva noću (73,51 % od ukupnog broja događaja) i u sumrak (19,64 %), ali su zabilježene i dnevne aktivnosti (6,85 %). Najveći broj događaja, zabilježen je između 3 i 5 sati. Tijekom dana, u četiri godine primjene metode fotozamki, nikada nije snimljena fotografija čaglja između 14 i 16 sati te 17 i 18 sati. Čagalj iskorištava resurse koje mu omogućavaju ljudske aktivnosti i naseljena područja. Međutim, ako na području obitavanja čaglja prevladavaju mozaici poljoprivrednih površina, gdje plijena ima u izobilju, ali je ograničena mogućnost dnevnog zaklona, čagljevi se pretežito kreću noću, što smanjuje rizik od susreta s ljudima.
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).
Green bridges are used to decrease highly negative impact of roads/highways on wildlife populations and their effectiveness is evaluated by various monitoring methods. Based on the 3-year monitoring ...of four Croatian green bridges, we compared the effectiveness of three indirect monitoring methods: track-pads, camera traps and active infrared (IR) trail monitoring system. The ability of the methods to detect different species and to give good estimation of number of animal crossings was analyzed. The accuracy of species detection by track-pad method was influenced by granulometric composition of track-pad material, with the best results obtained with higher percentage of silt and clay. We compared the species composition determined by track-pad and camera trap methods and found that monitoring by tracks underestimated the ratio of small canids, while camera traps underestimated the ratio of roe deer. Regarding total number of recorder events, active IR detectors recorded from 11 to 19 times more events then camera traps and app. 80% of them were not caused by animal crossings. Camera trap method underestimated the real number of total events. Therefore, an algorithm for filtration of the IR dataset was developed for approximation of the real number of crossings. Presented results are valuable for future monitoring of wildlife crossings in Croatia and elsewhere, since advantages and disadvantages of used monitoring methods are shown. In conclusion, different methods should be chosen/combined depending on the aims of the particular monitoring study.
The highway from Zagreb to Rijeka stretches 68.5 km through a wildlife core area in Gorski kotar (Croatia). It has 43 viaducts and tunnels, and one specifically constructed (100 m wide) green bridge ...(Dedin). One quarter of the total highway length consists of possible crossing structures. At Dedin green bridge, a total of 12,519 crossings have been recorded during 793 different days of active infrared monitors being in operation, or 15.8 crossings per day. Two monitored tunnel overpasses had 11.2 and 37.0 crossings per day, respectively, whilst 4.3 crossings occurred per day under one monitored viaduct. Of those crossings, 83.2% were by ungulates and 14.6% by large carnivores. Radio-tracked large carnivores, brown bear (
Ursus arctos
), grey wolf (
Canis lupus
) and Eurasian lynx (
Lynx lynx
), expressed strong positive selection for tunnels and viaducts, whilst avoiding small underpasses or bridges. Selection for the use of Dedin green bridge was equal to its availability. We conclude that this green bridge, constructed as a measure to mitigate the negative effects of the studied highway, served its purpose acceptably. Territorial and dispersing radio-tracked large carnivores crossed the highway 41 times, using both sides of the highway as parts of their home ranges. Overall, the highway in Gorski kotar does not seem to be a barrier. This demonstrates that it is possible to maintain habitat connectivity during the process of planning the highway route.
In this paper we present techno-typological and raw material analysis of the Mousterian lithic assemblage from Vinica cave (Hrvatsko zagorje, Croatia) excavated during late 1990s and early 2000s. ...Lithic artefacts are found in two Mouste- rian layers, c and d, whose age is determined by 14C AMS dating. Sample from layer d brought indefinite age older than 50,300 years BP while calibrated age for the sample from layer c is 36–34.5 ka BP. Quartz is predominant raw material in both layers followed by different cherts. Quartz cobbles were knapped on-site while at least some chert artefacts were not flaked in the cave but brought from elsewhere as blanks and tools. Among small number of tools, scrapers are the most frequent. Small lithic assemblages from both layers suggest that cave was used as short term Neandertal camp during Middle Paleolithic.
In this paper we present techno-typological and raw material analysis of the Mousterian lithic assemblage from Vinica cave (Hrvatsko zagorje, Croatia) excavated during late 1990s and early 2000s. ...Lithic artefacts are found in two Mouste- rian layers, c and d, whose age is determined by 14C AMS dating. Sample from layer d brought indefinite age older than 50,300 years BP while calibrated age for the sample from layer c is 36–34.5 ka BP. Quartz is predominant raw material in both layers followed by different cherts. Quartz cobbles were knapped on-site while at least some chert artefacts were not flaked in the cave but brought from elsewhere as blanks and tools. Among small number of tools, scrapers are the most frequent. Small lithic assemblages from both layers suggest that cave was used as short term Neandertal camp during Middle Paleolithic.
The comparative analysis of the cave lion teeth (M1 and P4) from North-western Croatian Pleistocene sites (Veternica, Velika pecina and Vindija caves) indicated the presence of Middle and Upper ...Pleistocene forms of this species. Some common characteristics of stratigraphically younger populations of the cave lion from North-western Croatia and the Repolusthöhle population, suggest that Croatian populations belong to the Westeuropean lineage with special characteristics.
Here we present the methodology used for terrestrial biodiversity analysis and site selection in Phase B of the UNDP/GEF COAST project. The analysis was focused on the problem of biodiversity ...evaluation in four Croatian counties stretching from sea level to the highest mountain in Croatia. Data on habitats, vascular flora, and fauna (mammals, birds, reptiles, amphibians, butterflies, ground beetles, and underground invertebrates) were collected and analyzed for each of the four counties. Emphasis was given to the richness of endangered species and the rarity of endemic species. Based on the spatial analyses of habitat, fauna, and flora data, four to six areas were selected from each county and ranked according to their biodiversity importance. Overlap between areas important for richness and those important for rarity was highest for data on flora (65.5%) and lowest for data on fauna (16.7%). When different data sets were compared, the lowest overlap was between flora and fauna (17.1%) and largest between fauna and habitats (23.9%). Simultaneous overlap among all three data sets was found in just 6.5% of the overall selected areas. These results suggest that less specific data, with respect to taxa threat status, could better serve as surrogate data in estimating overall biodiversity. In summary, this analysis has demonstrated that Dalmatia is a region with a high overall biodiversity that is important in a broader European context.
The last specimens of indigenous Eurasian lynx (Lynx lynx) in Croatia were exterminated around year 1903. Lynx dispersed back to Croatia after six animals were reintroduced to Slovenia from Slovakia ...in 1973. Considering the consequences of founder effect, genetic drift and expected high level of homozygosity, the goal of this paper was to determine variation in teeth number, teeth and skull disorders in Croatian lynx. It should also determine whether there has been a change in frequency of occurrence of developmental anomalies in relation to the population it originates from and in relation to other lynx populations. We studied 58 lynx skulls originating from the reintroduced lynx population. Changes on teeth and skull were found on 23 skulls (39.7%): supernumerary maxillary second premolar P2 (9 skulls, 15.5%), supernumerary mandibular second molar M2 (3 skulls, 5.2%), congenitally absent maxillary incisor (3 skulls, 6.9%), extra tooth between maxillary third incisor I3 and canine (1 skull, 1.7%) and acquired disorders of teeth and skull (9, 15.5%). PUBLICATION ABSTRACT
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