We developed an algorithm to classify brown hares into two age classes, juveniles (up to 1 year old) and adults (over 1 year old), based on body weight, which can be determined by both the examination of live animals and postmortem analysis. Considering the strong correlation between lens weight and carcass weight, we assumed that hares could be classified into one of the two age groups based only on carcass weight, using a logistic regression model. Using logistic regression, a model was constructed to assess the age of hares based on their body weight. For comparison with the current age-assessment method based on the dry lens weight, a logistic regression classifying the hares based on the dry lens weight was performed as well. The results of the study facilitated the development of a method to classify hares into age groups based on body weight. The proposed approach is innovative, as it allows for the determination of the age of not only culled (postmortem) but also live hares. The method is easy and does not require laboratory tests; hence, the results can be used immediately following evaluation. This method allows hares to be categorized into two age groups (juveniles and adults). With an accuracy of 97.52% and 95.45% in the case of juvenile and adult hares, respectively, the proposed approach can be widely used both in population management and scientific research.

This study presents the hematological and serum biochemical values of physically captured roe deer (Capreolus capreolus). The study material was blood sampled from roe deer captured with the use of a specialist trap mesh and no anesthesia. Blood samples were collected from 122 roe deer from January to April in 2016, 2017, and 2018 in the Lublin region of Poland. The hematological and biochemical variables were determined with results showing statistically significant differences between the mean values of RBC, HCT, and HB according to sex. Reference intervals should be more specific to the broad physical versus chemical capture categories.

The study aimed to determine the exact duration of individual stages of the territorial vocalisation ritual of Phasianus colchicus cocks living in an urban area. Thorough knowledge of the courtship behavior can be the basis for understanding the mechanisms that influence female's preferences when choosing a cock for mating. The work was performed based on the analysis of film recordings of 7 male pheasants recorded in the Bystrzyca Valley in Lublin (Poland). Several-minute recordings were made from April 19 to June 27, 2018 in the morning (around 6:00-8:00). The characteristic of the species ritual vocalization were divided into four phases. The study concluded that the average duration of individual phases of ritual vocalization within individual birds varies and is an individual value.

The aim of the study was to assess the impact of the duration of the mating season and the time of day on the parameters of the vocalization pheasants (duration of vocalization, frequency of the sound wave, intervals between vocalizations). In the study, pheasant vocalization recorded in the morning (6⁰⁰–8⁰⁰) and in the afternoon (16⁰⁰–18⁰⁰) between April and June 2020 was analyzed. In total, the research material consisted of 258 separate vocalizations. After recognition of the individual songs of each bird, frequency-time indicators were collected from the samples to perform statistical analysis of the recorded sounds. The duration of the first syllable [s], the duration of the second syllable [s], the duration of the pause between the syllables [s], the intervals between successive vocalizations [min], and the peak frequency of the syllables I and II [Hz] were specified for each song. The duration of the syllables and the pauses between the syllables and vocalizations were determined through evaluation of spectrograms. The peak amplitude frequencies of the syllables were determined via time-frequency STFT analysis. Statistically significant differences in the distributions of the values of all variables between the analyzed months were demonstrated. The longest duration of total vocalization and the shortest time between vocalizations were recorded in May. Therefore, this month is characterized by the highest frequency and longest duration of vocalization, which is related to the peak of the reproductive period. The time of day was found to exert a significant effect on all variables except the duration of syllable II. The duration of vocalization was significantly shorter in the morning, which indicates that the cooks are more active at this time of day in the study area. The highest peak amplitude frequencies of both syllables were recorded in April, but they decreased in the subsequent months of observation. The time of day was also shown to have an impact on the peak amplitude frequencies, which had the highest values in the morning.

W pracy zaprezentowano wykorzystanie zdjęć wykonanych przez drony do oceny wpływu działalności bobra europejskiego Castor fiber na ekosystemy Poleskiego Parku Narodowego (PPN). Badania potwierdzają ścisły związek obecności bobrów na tym terenie z wielkością powierzchni lustra wody, co oznacza pozytywny wpływ działalności bobrów na retencję zlewni. Dzięki obecności i działalności tych zwierząt drastyczny spadek poziomu wód powierzchniowych, spowodowany suszą meteorologiczną, nie spowodował suszy glebowej. Może o tym świadczyć wzrost powierzchni roślin zielnych w okresie jesiennym na terenach, na których wykazano całkowity spadek lustra wody. Wraz ze wzrostem powierzchni i liczby żeremi spadała powierzchnia zajmowana przez roślinność suchą. Może to potwierdzać pozytywny wpływ obecności bobrów na retencję wody i roślinność na badanych powierzchniach, szczególnie w warunkach występowania skutków suszy atmosferycznej.

The study tested the suitability of consumer drones for monitoring the abundance of the European pond turtle Emys orbicularis, an endangered species whose reliable monitoring is crucial for active species conservation. The widely available semi-professional DJI Mavic Air2 model was used, as it can be used to obtain 48 Mpix images or 4K videos. Until now, the species has been monitored visually with binoculars, but this method only works well in specific habitats, such as ponds and drainage ditches. It has been shown that the best method in inaccessible habitats, such as tall rushes, sedges, etc., is to plan a drone flight along a specific trajectory and take a series of photos. In addition, the size of the area can be accurately assessed, and animal density can be calculated. The research is essential for retardation of negative changes in the state of biodiversity in Poland.