Comparison of Eurasian Woodcock (Scolopax rusticola, L.) monitoring methods

Eurasian woodcock is a popular migrating game species in Hungary and in several European countries. For its wise management it is essential to collect reliable information of the breeding, wintering and also migrating populations. The aim of this study was to describe and analyze the differences among the monitoring methods used in different countries, and to give advices to improve the methods of data collection and evaluation of the monitoring system running in Hungary. Our study is based on the comparison of monitoring programs run in France, Russia, Belarus and in the Archipelago Azores. The key factor of all such surveys is the display behaviour of male birds, which is called roding. However there are some differences between them. We evaluated the different monitoring methods on the basis of scientific literature considering the place, time and duration of survey sessions, the collected data and the methods of their analysis. The main cause of differences is the different aim of the different studies. Hungary cannot obviously be taken as a breeding or wintering area, it rather plays an important role in migration. The aim of the monitoring in Hungary is to follow and characterize the flow of migration, and to estimate the minimal number of birds crossing our countries borders. The evaluation of data in Hungary is also different. However the methods of observations and the quantity of collected data allow us to evaluate our data in a similar way. It would be essential if we would like to compare our results to the results of other monitoring programs in Europe

Eurasian Woodcock monitoring in Hungary between 2009–2021

To preserve the traditional spring hunting of the Eurasian Woodcock (Scolopax rusticola) in Hungary while also assuring its sustainability, a monitoring program was maintained with the coordination of the Hungarian Hunters’ National Association. The program's primary goal was to estimate the size of the migrating population in the country based on synchronised census data and track its long-term changes. The program was maintained successfully with national coverage in the last 13 years, and it was based on synchronised roding surveys performed weekly, 12 times each spring. The observers used standardised paper forms to record the number of contacts (Woodcocks seen and/or heard). Hunting of Woodcock between 2010–2021 was only allowed for the monitoring program participants with strict regulation and obligatory sample collection from each bird. The primary purpose of sample collection was to assess the sex- and age structure of the population and to evaluate their trends. According to the results, no significant trend could be observed either in the population size or the sex- and age composition between 2009 and 2021. The proportion of males was above 75% each year, while the proportion of first-year birds and adults was almost identical in the annual hunting bags. The measure of harvesting was meagre compared to the size of the population, and it had no significant, detectable impact

Analysis of trophy parameters in Fallow deer (Dama dama) in Hungary, 1998-2016

The assessment of the trophy quality in Fallow deer (Dama dama) is often based on the measured values of the individuals with the largest antlers. However, there is little knowledge about the reliability and representativity of this approach. In our study, we analysed the trend of the annual number of evaluated trophies between 1998 and 2016, the age distribution of the harvested bucks, and the temporal variation in the values of trophy weight and antler length during the study period on the population level and in the case of the best quality antlers. The data were examined in 3 estimated age classes (young: up to 4 yrs, middle-aged: 5-9 yrs, old: from 10 yrs). The groups (year × age class) were characterized by the median, while the largest values were picked in each group by selecting the lowest value among the individuals belonging to the upper 1%, 5% and 10% of the sample size. The annual number of the presented trophies increased from 894 to 3,795 with an exponential trend. The proportion of the age classes changed significantly. The proportion of the young bucks increased by 10.2%, while the proportion of the middle-aged individuals decreased by 9.9%. The median of the weight showed no trend in the complete dataset. In the young age class, it increased until 2006, then decreased until 2016. In case of the middle-aged and old individuals, the median and the strongest values at each threshold also increased. The median of the complete dataset, as well as the middle-aged and old bucks, stagnated in the case of antler length. It showed an 8.5 cm decrease between 2007 and 2016 in the young age class. In general, the difference between the group median and the largest values showed the highest variability in case of the 1% threshold. We found a strong correlation between the group median and the strongest values only in two cases (Top 10% and 5% threshold, trophy weight of middle-aged bucks). Our results suggest that in Fallow deer, the assessment of the trophy quality based on only the largest antlers may be misleading in several cases, especially in the young age class or if the complete dataset is treated as one group. However, the trend of the largest trophy weight in the middle-aged and old age classes may refer to the trend of the median in the relevant groups

Habitat selection of Eurasian woodcock Scolopax rusticola during the spring migration period in Hungary

To establish a decent regulation of the hunting of woodcock in Hungary, a monitoring programme started in 2009 at a national scale. More than 900 participating observers collect data of woodcock during synchronized censuses each spring and in autumn to have basic knowledge of woodcock presence and abundance in the country. Data collecting locations were selected by the observers themselves based on their former experiences, which was primarily influenced by the former knowledge about habitat use of woodcock. Their selection of sites could primarily be influenced by the former knowledge about habitat use of woodcock. This situation offers an opportunity to evaluate this choice of habitats. In this study we investigated the habitat selection of woodcock during spring migration and we tested whether the preceding designation of observation points reflects enough knowledge about their habitat preferences. We used four year spring observation data of the Hungarian woodcock monitoring programme based on synchronized censuses. In order to evaluate the choice of the observers, observation points were buffered with a radius of 874 meters - 2* radius of a 60 ha circle which is known to be used by woodcock individuals in the evening roding period. We intersected the buffers with the Corine Landcover map, and we compared their composition with the composition of buffers of randomly generated points.To evaluate the choice of the birds, correlation between landcover types preferred or avoided by the observers and the detections of woodcock was tested using the nonparametric Spearman correlation. In the case of forests we performed an additional analysis: We classified the buffers using 3 categories of their forest cover rates (0-45% OPEN, 45-77% MID, 77-100% FORESTED). We took 50 random samples of each forest cover rate class per year and we tested the differences among them in the number of woodcock detections and the frequencies of positive sites (where woodcock observation happened).According to our results, the locations of the observation points might not be resulted by random choice. Most landcover types preferred or avoided are also correlated with woodcock abundance. However the correlations we have found were weak. The key element of choice is the presence of forests. The higher rate of broad-leaved forests near the points can raise, the higher rate of discontinuous urban fabric or non-irrigated arable land can lower detection probability

Analysis of game damage estimation methods in winter wheat (Triticum aestivum) thruogh GIS simulations

Wildlife damage to agriculture causes significant economic loss worldwide annually. Game managers or hunters are responsible for the financial compensation of the crop damage caused by game species in several countries, including Hungary. Accredited experts estimate the level of the damage; however, currently, there are no standardised methods that would be obligatory to apply. In order to obtain information on the accuracy and bias of the different sampling methods, we designed GIS simulations in winter wheat (Triticum aestivum), which covers a significant proportion of the arable land not only in Hungary, but also globally. We tested two sampling methods with three sampling plot arrangements in a GIS environment. Our questions were the following: (1) How accurate and biased are the examined samplings? (2) Does the rate or the spatial distribution of the damage (or the interaction of these factors) affect the results of the investigated methods? We created 15 wheat field models with 1:2 side ratio, 12 cm row width and the area of 3 ha. We simulated 5 damage rates (10%, 30%, 50%, 70%, 90%) and 3 spatial damage patterns [random, aggregated in 1 and 2 field edges], of which the latter two follow the actual pattern of crop damage caused by big game species. V, W and X sampling tracks were allocated on each field model, and then they were sampled with square shaped, 1 m2 quadrats and 1 m long row sections (with 5 repetitions). The sample size was 20 and 25 plots, respectively (determined by the original description of the methods). At the sample plots, the total number of plants and the number of damaged plants were counted. According to our results, the statistical parameters of the different samplings were similar; the difference between the best and the poorest values was low. The rate and spatial distribution of the damage, as well as their interaction,  had a significant effect on the estimation of each quadrat sampling, while the row sections were significantly affected only by the damage distribution (V and W tracks) or the damage rate (X track). According to our findings however, the difference between the labour-intensity of the two approaches can be decisive. With the sample sizes in our study, remarkably lower number of plants had to be examined along the row sections, than in the quadrats. This suggests that the experts can obtain similar quality results with less effort, if they choose the row section sampling over the quadrats

Habitat use of roe deer in a floodplain forest and the neighbouring agricultural area

The purposes of this study were 1) to determine the annual and seasonal home range sizes of roe deer captured and radio-tagged in a floodplain forest, and 2) to evaluate the habitat-use in light of the differences in vegetation between the floodplain forest and the neighbouring agricultural lands. We used one year localization data of six roe deer equipped with GPS-GSM collars in January 2007. Their home ranges were estimated with minimum convex polygon and kernel home range (with 60% and 90% probability contours) methods. To evaluate the habitat-use we also utilized the land cover map of the study area. The size of the MCP home ranges varied between 500-1000 hectares. The size of the KHRs (90% probability contours) varied between 30-120 hectares, while the core areas (60% probability contours) were between only 5-35 hectares. The core area of each roe deer contained at least 10% forested habitat; while the agricultural habitat type played a significant role only in four of the cases (the proportion of agricultural land was higher than 50% only in three of them). Significant differences were found between home range sizes and also between the proportions of the used habitat types. The results of yearly vegetation-preference calculations showed that each studied roe deer avoided the agricultural lands. Based on these results we suppose that different spaceuse strategies can exist among roe deer living in our study area