Bulgarian Society for the Protection of Birds

Moult, breeding, and migration are the three major life‐history events in the annual cycle of birds. All are energetically demanding processes that rarely overlap. In large raptors such as the Egyptian vulture Neophron percnopterus , completing a full moult may take more than one year, requiring birds to balance this process with other life‐cycle events. We analysed 740 moult cards from across the species' distribution, including migratory, sedentary and mixed subpopulations, to test predictions about trade‐offs between the physiological demands of migration and moult. Juveniles began moulting in January–February of their second calendar year and continued ‘year‐round' until their fifth calendar year. Adults, however, suspended moult from the months preceding spring migration until the late breeding phase. Subadults from the Canary Islands started moulting earlier and completed it faster than those from western Europe, while adults from western Europe initiated moult later than adults from the Canary Islands, India, and Oman. Sedentary subpopulations, particularly that from the Canary Islands, showed a greater moult extent and replaced more primaries annually than migratory and mixed subpopulations, whereas the wintering subpopulation of southwestern Spain (Extremadura) exhibited the smallest moult extent. Moult symmetry decreased from the second plumage onwards and differed between the Canary Islands and Oman subpopulations. Geographic differences in moulting patterns likely arise from population‐specific life‐history trade‐offs, reflecting local adaptations or responses to environmental constraints. These patterns highlight the influence of migratory strategy on moult progression and suggest that sedentary lifestyles may allow more extensive feather renewal in long‐lived raptors.

Breeding performance encompasses offspring production, their survival rate, fertility, overall reproductive outcome, timing of reproduction, and breeding frequency. It varies in raptor species, being affected by different biotic, abiotic, and anthropogenic factors. The Lesser Spotted Eagle is a monogamous, long-lived, slowly reproducing raptor, characterized by site-fidelity and strongly territorial behavior. In this study, we examined data collected over a 10-year period, highlighting the eagles’ main breeding parameters, analyzing whether any of them demonstrated significant trends or spatial or temporal differences over the study period. We also searched for a strict correlation between species breeding density and breeding performance. We found out that the mean occupancy rate of the territories marginally decreased β2 = −0.64 ± 0.27, p = 0.047, as this process was clearly visible in Sakar Mnt. (β2 = −0.66 ± 0.27, p = 0.038), where in 2022, only 67% of the monitored territories were occupied. The overall mean productivity, breeding success, and breeding frequency did not indicate any trend over the years (p > 0.05). Of all tested breeding parameters, occupancy rate (β2 = 0.29 ± 0.14, p = 0.04) and breeding success (β2 = −0.12 ± 0.06, p = 0.04) varied yearly, while productivity (β2 = 0.25 ± 0.12, p = 0.03) and breeding frequency (β2 = 0.27 ± 0.12, p = 0.03) were influenced by density. None of the tested indicators demonstrated significant regional differences, which indicated a temporally determinate, but spatially consistent pattern of breeding performance of the species in this part of its distribution. Recently, the landscape pattern in the south-eastern part of the country was marked by spectacular habitat loss, driven by human activities and natural phenomena, with entire biodiversity facing an uncertain future. Prompt action and urgent decisions are needed to prevent the negative consequences of these imminent threats to the species. Conservation efforts should be focused on the restoration of breeding and foraging habitats. Further research on the response of eagles to the effect of natural (fires) and anthropogenic (habitat transformation) factors, as well as the relationship between breeding performance and different drivers of reproduction, such as diet, weather, habitat features, and presence of intra- and interspecific competitors, would be of crucial significance.

The current publication gives a detailed assessment of the results from a population reinforcement of a European ground squirrel's (Spermophiluscitellus) colony in south-eastern Bulgaria. The reinforcement was planned and implemented along with multidisciplinary research of the adaptation process (including radiotelemetry, parasitological study and assessment of the stress in the animals) and regular monitoring (yearly burrow counting). Although the donor and recipient populations were genetically similar, morphometrical data indicated variations in the body size probably due to the difference in population densities in the two sites. The monitoring revealed that the burrows were aggregated and there was a positive correlation in the spatial distribution of the ground squirrels’ burrow holes and the colonies of Harting's vole (Microtushartingi) - another social ground-digging rodent that co-inhabits the study area. The first results showed successful reinforcement according to the three classical evaluation criteria: the individuals survived the translocation process, they successfully reproduced and an initial population growth was observed, based on the burrow entrances’ count - from 36 in 2017 to 280 in 2020. In 2021, however, a considerable decline in the abundance of the population was recorded - 58.5% decline in the burrow number and 36% decline in the colony area. A decrease was also observed in the abundance of the Harting's voles' colonies. A review of all the collected information suggests it is unlikely that the decrease is due to helminth parasites, translocation stress or other behaviour issues. The most probable explanation is the bad weather conditions - unusually high rainfalls combined with relatively high temperatures in January 2021. In conclusion, we strongly emphasise the need for detailed and long-term monitoring after conservation translocation and careful evaluation of all the influencing factors before, during and after such actions.

SummaryThe Eurasian Griffon Vulture Gyps fulvus is a large Palearctic, Indohimalayan and Afrotropical Old-World vulture. The species’ range is vast, encompassing territories from the Pyrenees to the Himalayas. We reviewed and analysed a long-term data set for Griffon Vulture in the Balkans to estimate the change in its population size and range between 1980 and 2019. After a large historical decline, the Griffon Vulture population slightly increased in the last 39 years (λ = 1.02) and reached 445–565 pairs in 2019. We recorded a gradual increase of Griffon Vulture subpopulations in Serbia (λ = 1.08 ± 0.003), Bulgaria (λ = 1.08 ± 0.003) and Croatia (λ = 1.05 ± 0.005) and steep to a moderate decline of the species subpopulations in Greece (λ = 0.88 ± 0.005) and North Macedonia (λ = 0.94 ± 0.01). However, species range contracted to half of its former range in the same period. It occurred in 42 UTM squares in the 1980–1990 period and only 20 UTM squares between 2011 and 2019 and concentrated into three source subpopulations in Bulgaria, Serbia, and Croatia. Following reintroductions of the Griffon Vulture in Bulgaria, new colonies were formed at three novel localities after 2010. Regular movements of individuals between the different subpopulations exist nowadays. Therefore, preservation of both current and former core areas used for breeding and roosting is essential for species conservation in the region. However, the Griffon Vulture still faces severe threats and risk of local extinction. Various hazards such as poisoning, collision with energy infrastructure, disturbance and habitat alteration are depleting the status of the Balkan population and its full recovery. Further studies should analyse age-specific survival and mortality, recruitment, genetic relatedness, spatial use to inform the viability of this population in the future.

IntroductionHistorically, the incidence rate of cervical cancer (CC) in Eastern Europe and particularly in Bulgaria has constantly been higher than that in the other European countries. Adenosquamous carcinoma (ASC) is a rare histological subtype of CC with incidence rate of less than 6 per 100,000. We aimed to analyze the epidemiology and prognosis of all Bulgarian patients with ASC, registered at the Bulgarian National Cancer Registry (BNCR), and to compare patients’ characteristics and outcomes with those of patients, treated at a large specialized institution – the Department of Gynecologic Oncology, University Hospital in Pleven, Bulgaria.Materials and MethodsThis is a retrospective study of all cases of ASC, registered at the BNCR for a 10-year period of time. The Kaplan–Meier analysis with Log rank test was used to estimate the significant differences.ResultsThe incidence rate of ASC was calculated as 3.2% of all CC registered in BNCR and 4.97% of all stage I patients, treated in our department. The 5-year overall survival (OS) rate of all patients with ASC tumors from the registry was 50.5%. A total of 171 (48.4%) of the patients had T1 tumors and a 5-year OS of 67.1%. Lymph node status was a significant prognostic factor for OS (p=0.001). Thirty-one patients with T1 tumors and ASC histology were treated in our department for the same period of time. Lymph node metastases were found in 10 of them (32.2%). The 5-year observed OS in ASC group was 74.19%.ConclusionThe histological subtype of cancer of the uterine cervix has an impact on prognosis and should not be simply considered as a descriptive characteristic but a poor prognostic feature and should be an integral part of the decision-making in clinical management of patients.

ABSTRACT Capsule The Eurasian Griffon Vulture Gyps fulvus is an obligate scavenger relying on spatially and temporally unpredictable food resources. We demonstrate how high-frequency telemetry data can be efficiently used to identify vultures’ feeding locations in the wild and study their diet. Aims To study the Griffon Vulture diet composition, seasonal variations, and bathing frequency in an area with high natural food availability. Methods We used a remote-sensing technique based on GPS and accelerometry data to identify the feeding locations, and ground-truthing to identify the carcass species and investigate the causes of mortality. Results We identified 13 taxa in the diet of Griffon Vultures. Cattle comprised 48.5% of the diet, followed by sheep (24.3%), while wild animals were 13.1%. We observed seasonal variation in the proportion of small stock and game species in the diet. Predation was reported as the main cause of mortality (60.2%) for prey species, while natural causes accounted for 37.6%. Vultures were mainly feeding in areas south of their breeding colonies in Bulgaria and Greece. Natural springs and fountains were regularly used by the Griffon Vultures for bathing and drinking, especially in the summer. Conclusions Free-ranging livestock creates favourable feeding conditions for vultures, especially in areas with rugged terrain and a high density of predators. An increase in the number of wild ungulates can potentially buffer the fluctuations in livestock numbers and be beneficial for vultures, especially in the autumn and winter months. Lead ammunition must be substituted with non-toxic alternatives to reduce the exposure of vultures and other scavengers to lead poisoning.

Social isolation is an important determinant of elderly people's health and well-being. Modern technologies could be a powerful ally in combating social isolation. However, instead of replacing human relationships they should help build them within a person's most natural social circles. This paper presents a framework for development of a technological coaching solution that can safeguard or even boost the everyday social life of the elderly. The modus operandi of this system spans from unobtrusive data collection through data processing and situation assessment of social behaviour, to selection and rendering of the most appropriate coaching actions to the elderly person including through members of their social circles. The assessment and decision-making process also integrates three important groups of external factors which influence the solution. These are: (i) personal profiles of the elderly and those members of the social circles who participate in the coaching process; (ii) objective external environment and (iii) the quality of the coaching actions. The latter is a crucial element of the system's learning abilities.

SummaryWith the combination of worldwide landscape changes and the uncertainty about the impact on species abundance and distribution, the value of spatio-temporal modelling tools is increasingly obvious. The Little Bustard Tetrax tetrax breeds on low-intensity arable cultivation and pastoral land and is currently threatened by diverse landscape modifications. The aim of this research was to predict Little Bustard population trends in the face of realistic scenarios of land use and infrastructure changes, applying a recently developed spatially explicit framework, based on the stochastic dynamic methodology (StDM). The application of this approach provided some basis to analyse the responses of breeding populations’ spatial distribution and abundance to the scenarios implemented. Since some of these scenarios represent local and/or regional risks to the viability of Little Bustard breeding populations, the results obtained demonstrate the potential of the proposed framework for landscape planning in the scope of the conservation of this threatened species. This approach also provides a promising baseline to support ecological risk assessments for other species, derived from ecological models with increased predictive power and intuitiveness to decision makers and environmental managers.