The age, size and morphology of trees, including crown dimensions, can influence crown defoliation. In Croatia, the selection management of silver fir (Abies alba Mill.) forests involves pure or ...mixed stands, either of which can be affected by various disturbances, resulting in unbalanced stand structures. The aim of this study was to estimate the probability of trees transitioning from one defoliation class to the next, examine the influence of tree attributes on that process and analyze the changes in survival over time. The study was conducted over a 18-year period (1990–2007) on two sites with contrasting stand structures: a uniform stand with a dominant share of silver fir (Site A) and an uneven-aged mixed beech–fir stand (Site B). Logistic regression was used to model tree transitions between defoliation classes. Uniform stand structure increased the likelihood of silver fir trees transitioning to a higher defoliation class, with limited dependence on the tree crown position. In contrast, suppressed and central trees in uneven-aged stands were more likely to transition to a higher defoliation due to greater competition between them. Diameter at breast height (DBH) was found to be a significant predictor of tree transition to higher defoliation classes, with a linear trend of increasing probability with increasing DBH. Crown position and crown length were also found to be significant predictors of changing defoliation class, with observed differences between sites occurring due to differences in stand structure. To ensure a balanced stand structure and enhance tree vitality, careful consideration of easily measurable tree elements such as DBH, crown length, and tree crown position is imperative when selecting trees for felling.
Gray wolf (
Canis lupus
) populations are expanding across Europe, which leads to an increase in their interactions with people and domestic animals, including dogs. Attacks on hunting dogs are ...becoming a major cause for conflicts between wolves and hunters in many countries, including Croatia, where this conflict has increased dramatically in recent years. To better understand the conflict and possible causes behind the attacks, we conducted a survey among Croatian hunters to investigate the trends and characteristics of the attacks. A total of 103 hunting dogs were reported as attacked by wolves in 2010–2018 with a significantly increasing trend. The attacks were fatal for 86% of the attacked dogs and among the dogs killed, 96% were at least partly consumed by the wolves. The most frequently attacked dogs were about 3 years old (47%), males (82%), and weighing 10–20 kg (62%) and belonged to scent hounds and related breeds. In respect to the breed, dogs were not attacked randomly, but we observed significant selection for tricolor hound, while Balkan hound, the Istrian hound, and the Posavina hound were avoided according to availability. Majority (64%) of dogs were killed during drive hunts on wild boar and highest frequency of attacks was recorded in the Split–Dalmatia County. More dogs were attacked in counties with more livestock and fewer wild prey, but correlations were not significant. Results suggest that wolves likely perceived dogs as potential prey and indicate some of the potential measures that could be used to mitigate the conflict.
The Mediterranean vegetation belt on the eastern Adriatic covers an area of nearly 15,000 km2. It is comprised of forest stands that can be divided into three vegetation zones based on the presence ...of certain plant species within each: sub-Mediterranean, eu-Mediterranean, and steno-Mediterranean. The dominant ecological factors result in the domination of specific tree species within the floral composition between these vegetation zones. The aim of this study was to collect climate data from 38 weather stations over a 30-year period to compare climate data and bioclimate properties in the area of these three vegetation zones. The results confirmed statistically significant differences between the main climatic elements and most bioclimatic indices between the vegetation zones. Cooler and more humid conditions were found in the sub-Mediterranean zone, warmer and somewhat drier conditions in the eu-Mediterranean zone, and particularly pronounced warm and dry conditions in the steno-Mediterranean zone. However, the analysis of the main components for researching climate parameters showed that the mean annual air temperature, average minimum air temperature of the coldest month of the year and continentality index, length of the dry season, and de Martonne aridity index contribute the most to the grouping of vegetation in forest stands in the Mediterranean vegetation belt of the eastern Adriatic.
The aim of this study is to examine the effect of sex and age on proximate chemical, fatty acid, amino acid and mineral content of axis deer (Axis axis Erx.) meat. Sixteen (n = 16) animals were ...hunt-harvested and assigned to groups according sex and age (sub-adult and adult). All analyses were made on m. longissimus thoracis sampled between the 9th and 13th ribs. Minor differences in nutritional composition of axis deer meat were found between analysed sex and age groups. Axis deer meat has a high protein (22.8%) and low fat (1.39%) content. Saturated fatty acids accounted for 44.97% and polyunsaturated for 29.66% of the total fatty acids. Ratios of fatty acids were within the recommended values. Glutamic and aspartic acid were the most abundant non-essential, and lysine and leucine the most common essential amino acids. The ratio of essential to non-essential amino acids was <1. Potassium and phosphorous were the dominant macro-minerals, while iron and zinc were the dominant micro-minerals. The results of this study show that regardless of sex or age, axis deer meat can be considered a good source of basic macro- and micro-nutrients, and can be recommended as a substitute for red meat from domestic animals.
Floodplain forests with regular flooding regimes are the largest natural retentions areas in Croatia and are important as natural habitats for ungulates. The aim of this study was to determine the ...scale of mortality caused by flooding within these forests. Over a 10-year period, data on ungulate mortality (red deer, roe deer and wild boar), flood duration and flooded surface area were recorded. The study was conducted in primary (Posavske Šume—RET I) and secondary (Opeke II—RET II) retention areas within Lonjsko Polje Nature Park (Sava River region, Croatia). The longest flood period and the largest flooded surface area were recorded in RET I. Total ungulate mortality was 749 individuals, with 482 individuals in RET I and 267 individuals in RET II, predominantly wild boar. Flood mortality did not differ by gender. The highest mortality of wild boar was recorded for the juvenile and yearling age classes. Low mortality of red and roe deer can be attributed to their body size and ecological niches. Differences in mortality between the primary and secondary retention areas corresponded to differences in flood regimes, flood column heights and micro relief structures. In both retention areas, wild boar mortality and flood duration, i.e. flooded surface area, were positively correlated. Because the growth rate of the analysed ungulate populations was higher than the recorded mortality, no long-term effect of floods is expected on species abundance in these areas.
Although game meat quality has been under the spotlight in numerous studies, the quality of brown bear (
) meat is still unknown. The aim of this study was to determine the effects of sex and age on ...the proximate chemical composition, fatty acid profile, and lipid indices of brown bear meat. Nine (
= 9) females and nine (
= 9) males were hunted during the Croatian spring hunting period in 2018. Based on age, bears were divided into two groups: <3 years (
= 9; five females and four males) and 4-6 years (
= 9; four females and five males). For analysis purposes, samples of
were collected. Age was shown to have an effect on the traits analyzed, while sex-related differences were not found. Brown bear meat has a high fat content (average 6.12%), especially in older bears (~9%). The contents of protein, dry matter, and ash were similar to those of other game species. Monounsaturated fatty acids made up approximately 50% of all fatty acids, with the most abundant being C18:1n-9. More favorable profiles of essential polyunsaturated fatty acids were found in younger bears. The ratio of polyunsaturated and saturated fatty acids was closer to the recommended ratio than the ratio of n-6 and n-3 polyunsaturated fatty acids, and lipid indices were favorable. Further research is needed to determine seasonal changes in brown bear meat quality.
In recent decades, the golden jackal
Canis aureus
has experienced a population increase in many European countries, including Croatia. As a result, human-jackal conflicts (e.g., damage to livestock ...and wildlife, general nuisance in (sub)urban areas) have increased dramatically, and there is an urgent need to develop and use a range of mitigation tools that also aim to control population growth. Hunting is one of the well-known tools for population control; therefore, the aim of this study was to determine the effects of habitat type and weather conditions on jackal hunting success. From 2019 to 2023, a total of 217 jackals were culled during 106 hunting events in an approximately 10,500 ha lowland habitat along the Sava River in central Croatia. All jackals (56% males and 44% females) were culled using small calibre rifle (222 Remington) with night vision scope. Based on age structure, 16% juveniles and 84% adults were shot, and the average catch per unit effort (CPUE) was 2.0 animals/day. The best hunting success was obtained by attracting jackals with a calling method, i.e., by playing the sound of a wounded hare. Regarding the type of habitat, 56% of the culls were in cultivated, non-forested areas. It was confirmed that weather conditions, i.e., daily temperature and precipitation, influence hunting success, especially for males. Hunting success of adult males was lower on days with higher temperatures and on days with more precipitation. We can state that individual hunting with using calling method is an effective tool for successful golden jackals harvesting; moreover, jackal hunting can minimize the conflict with gamekeepers and farmers and would help to improve public perception of jackals.
Sheep are one of the most important livestock species in Croatia, found mainly in the Mediterranean coastal and mountainous regions along the East Adriatic coast, well adapted to the environment and ...mostly kept extensively. Our main objective was therefore to map the positive selection of the X-chromosome (18,983 SNPs that passed quality control), since nothing is known about the adaptation genes on this chromosome for any of the breeds from the Balkan cluster. Analyses were performed on a sample of eight native Croatian breeds (101 females and 100 males) representing the East Adriatic metapopulation and on 10 mouflons (five females and males), all sampled in Croatia. Three classical within-population approaches (extreme Runs of Homozygosity islands, integrated Haplotype Score, and number of Segregating Sites by Length) were applied along with our new approach called Haplotype Richness Drop (HRiD), which uses only the information contained in male haplotypes. We have also shown that phylogenetic analyses, such as the Median-joining network, can provide additional information when performed with the selection signals identified by HRiD. Our new approach identifies positive selection signals by searching for genomic regions that exhibit a sudden decline in haplotype richness. In total, we identified 14 positive selection signals, 11 using the classical approach and three using the HRiD approach, all together containing 34 annotated genes. The most reliable selection signal was mapped by all four approaches in the same region, overlapping between 13.17 and 13.60 Mb, and assigned to the CA5B, ZRSR2, AP1S2, and GRPR genes. High repeatability (86%) of results was observed, as 12 identified selection signals were also confirmed in other studies with sheep. HRiD offers an interesting possibility to be used complementary to other approaches or when only males are genotyped, which is often the case in genomic breeding value estimations. These results highlight the importance of the X-chromosome in the adaptive architecture of domestic ruminants, while our novel HRiD approach opens new possibilities for research.
The purpose of this study was to determine the frequency of wildlife-vehicle collisions (WVC) based on the animal species, and to deepen the knowledge of temporal patterns of vehicle collisions with ...roe deer and wild boar. The study analyses the data from police reports on vehicle collisions with animals on state roads, by date and time, section of road, and animal species over a 5-year period (2012–2016). These data were analysed to determine the temporal dynamics of vehicle collisions with roe deer and wild boar by month, time of day, and moon phase. On the state roads in the Dinaric area, roe deer are most commonly involved in vehicle collisions (70.1% of all collisions), followed by wild boar (11.0%). Other large species involved in collisions were fallow deer (4.8%), brown bear (1.8%), red deer (0.9%), grey wolf (0.7%), and European mouflon (0.5%), respectively. Most collisions with roe deer occurred in the period April–August, with reduced frequency during autumn and winter. For wild boar, there was no association between month and frequency of collisions. At the annual level, collisions with roe deer were significantly higher during night (37%) and twilight (41%) than during the day (22%). For wild boar, most collisions occurred during twilight (26%) and night (72%), although the difference between these two periods was not statistically significant. For roe deer, collisions had no association with lunar phase, though wild boar collisions during twilight (dawn or dusk) were more common during twilight periods on days with less moonlight. Since vehicle collisions with wildlife showed certain temporal patterns, these should be taken into consideration in developing statistical models of spatial WVC patterns, and also in planning strategies and countermeasures to mitigate WVC issues.
European beech (
L.) is an important component of forests in the alpine and continental biogeographical regions of Croatia. This study aimed to (1) analyze the long-term response of beech to climate, ...(2) identify potentially critical climatic conditions that could negatively affect the radial increment (RI) and vitality of beech, and (3) evaluate differences in the response of beech between the two biogeographical regions in Croatia. We used the 16 × 16 km Croatian ICP Forests Level 1 network. On a total of 25 plots, we cored between 5 and 24 trees for dendrochronological analysis. Tree-ring widths (TRW) were measured and standardized using cubic spline. TRW chronologies for the two regions were calculated and correlated to the temperature and precipitation data and Standardized Precipitation and Evapotranspiration Index (SPEI) using bootstrapped correlations. Continental region precipitation from April to August and alpine region precipitation from June to August were significantly important for RI. Temperature was less important for RI than precipitation in both regions, but the importance of the negative impact of above-average temperatures in the continental region and the positive impact of above-average precipitation in the alpine region has increased over the last two decades. A comparison with the 3-month SPEI confirmed the significant influence of high temperatures and the lack of precipitation in August on the RI of beech trees in both regions.
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