Welfare Assessment of Brown Bears (Ursus arctos) in Bulgarian Zoos and Rehabilitation Centres

Abstract

Assessing the well-being of captive brown bears is essential for responsible species management and meeting European and national animal care standards outside their natural habitats. The present study aims to assess the welfare of captive brown bears in Bulgaria, considering environmental parameters, husbandry procedures, and the psychological and physical condition of the animals. The study was conducted on 28 brown bears in 11 zoos in Bulgaria and 19 bears in Bear Sanctuary Belitsa. A specific questionnaire and interviews were conducted with zoo managers and keepers. The welfare of the bears was evaluated based on their living conditions, husbandry, and physical and psychological well-being. The Nature and Animal Protection Center in Dobrich received the highest rating for the welfare of two brown bears among the zoos in the study. The study identified annual veterinary check-ups and enrichment programmes as areas needing improvement.

1. Introduction

Keeping large carnivores such as bears in artificially created conditions is a great challenge that arises from their complex species-specific needs [1,2], their cognitive abilities [3], the need for a large territory, and specific ecological requirements [4]. Bears also have relatively common health problems during their long captive lives [5,6]. Therefore, the welfare of many captive bears is not high [7]. The primary responsibility of zoos worldwide is to provide good animal welfare to captive animals [1,8].

Animal welfare assessments are part of the responsible management of species included in zoo collections, and a scientific welfare assessment should accompany any changes in husbandry and/or enclosure design [9]. Animal welfare provision and assessment are incorporated in the requirements of Council Directive 1999/22/EC of 29 March 1999 on keeping wild animals in zoos and EU Zoos Directive Good Practices Document [10] on its implementation. Furthermore, the World Association of Zoos and Aquariums [11] refers to the importance of animal welfare for modern zoo collections to maintain healthy, viable populations for conservation needs and to convey credible and effective conservation and educational messages to the public. According to EAZA (European Association of Zoos and Aquaria) Ursid husbandry guidelines [12], the welfare of captive animals is critical when changes are made in species management and when new enclosure design concepts are adopted. The assessment of zoo animals’ welfare involves measuring behavioural and physiological indicators, as well as evaluating enclosure conditions, environmental quality, and husbandry procedures [13,14,15]. Thus, stereotypic behaviour is among the most important criteria for evaluation [16,17]. According to Mason & Latham [16], the presence of stereotypic behaviour is among the most common behavioural symptoms of stress and reduced well-being. In addition, stereotypic behaviour, as a negative welfare indicator, often has clearer links to stress, making it relatively reliable to interpret than the positive ones [18]. Housing and management strategies influence brown bears’ abnormal repetitive behaviour that includes a set of stereotypic actions and social relationships and relevant changes may reduce them [19].

Maher et al. [20] developed a reliable tool for bear welfare assessment where keepers were asked to perform three assessments on the same bear. Their bear welfare assessment tool appears reliable, showing strong inter-observer consistency with multiple keepers independently evaluating the same bears and producing similar results, and could be chosen over others for its practical applicability in captive settings. Methods that could be used to evaluate animal welfare were also developed by Broom and Johnson [21] and Broom [22]. Particular attention is paid to the conditions and possibility of hibernation in captivity when assessing the welfare of bears living in zoos and sanctuaries. Hibernation is a physiological coping mechanism for adverse winter conditions in the wild [23,24]. In captivity, hibernation could help sustain natural rhythms and behaviors of brown bears, especially in temperate altitudes [25]. Previously, bears were not considered true hibernators because their body temperature does not drop as low during hibernation as other hibernating mammals, such as ground squirrels (Sciuridae) [26,27]. Compared to other hibernating small mammals, the bear can easily and quickly “wake up” and even leave its den. Based on physiological and biochemical data, it is considered that during hibernation, the organism has overall metabolic suppression [28,29]. Bears have a 20–50% metabolic slowdown during hibernation, and they are now considered true hibernators [26,30,31]. During this period, bears do not feed and rely on the accumulated subcutaneous fat reserves in the pre-hibernation period. The animal’s physiological functions decrease by 70% [32,33,34]. During hibernation, the body mass of the hibernating bear also decreases significantly [35]. In the wild, brown bears hibernate in natural dens, and their function is to provide a refuge that reduces energy loss and protects the bear from disturbance during winter [36,37,38,39]. The den also provides female bears with an opportunity and shelter to give birth to their cubs and spend the first months after birth with them undisturbed [40,41]. Therefore, the hibernation period is critical for bears’ reproduction and survival in the wild. We think that providing opportunities for hibernation, like bedding material, den sites, and seasonal changes in diet, could be an essential factor for promoting the welfare of captive bears [20,42].

There are 717 brown bears (350 males, 367 females) in 224 zoo institutions worldwide, according to the online zoo information management system (ZIMS, 12 March 2025). In zoo collections in Europe, the most kept bear species is the brown bear Ursus arctos (58% of bears in European zoos are of this species) [42]. The number of bears kept in zoos is likely much higher because many organizations do not record the composition of their zoo collections in ZIMS. Of the bears kept in Bulgaria, for example, only two individuals from Sofia Zoo are registered in it, due to the zoo being the only one in the country being part of ZIMS. There are also about 15 bear rehabilitation parks and sanctuaries in Europe, housing about 200 animals [42]. At the time of the study, about 50 brown bears were kept in Bulgaria, and the breeding of the species continues to be an annual practice. In Bulgaria, the species is traditionally kept in zoos, and until the early 2000’s, individual specimens were kept unregulated as dancing bears. In many zoos built before 1980, bears are kept in “pit cages” with no view outside the enclosure. The large number of individuals in captivity makes the issue of their welfare and quality of life even more significant because it relates to the conservation of the species and the maintenance of a viable and healthy “population” in captivity.

Currently, several national-level studies have been conducted in Europe to assess the welfare of captive brown bears in Georgia, Albania, Macedonia, and Poland [7,42]. Although much work has been done on the concept of animal welfare assessments, there are few publications where such studies have been conducted on bears, despite them being very important for improving the quality of life through practical application in zoo work. A good example is the extensive study by Maślak et al. [7], which covered all species of the family Ursidae kept in Polish zoos and bear sanctuaries, showing that the main problems are insufficient enclosure area, inadequate and hard surfaces and substrates in cages, inadequate nutrition, lack of swimming pools and fresh water, lack of stimulating environment and environmental enrichment, and lack of constant access to professional veterinary care. They also found different forms of stereotypic behaviour in all individuals included in the study. In Bulgaria, studies have been conducted on the manifestations of stereotypic behaviour [43,44,45] and activity and behaviour [46] in captive brown bears, but a welfare assessment has not been conducted. The present study aims to assess the welfare of all captive brown bears in Bulgaria, considering environmental parameters, husbandry procedures, and the psychological and physical condition of the animals. Although the IUCN Red List category of brown bear is Least Concern (LC), in Bulgaria, the species is strictly protected by national legislation (Biological Diversity Act). We hope the findings will provide a basis for recommendations to organizations that keep captive brown bears in Bulgaria.

2. Materials and Methods

Subjects of study. The study included the brown bears living in captivity as of 2021 (n = 47, 22 males and 25 females) in Bulgaria. In May–September 2021, all zoos where brown bears were living, as well as Bear sanctuary Belitsa, were visited. At the time of the research, 28 brown bears (14 females and 14 males) lived in 11 zoos, inhabiting 17 enclosures. Nineteen bears (eight males and eleven females) lived in seven enclosures, internally divided to ten, in Bear Sanctuary Belitsa. All the zoos are municipal. The bears kept in Bear Sanctuary Belitsa, which is managed and financed by Four Paws Foundation together with the Foundation Brigitte Bardot, are former dancing bears and confiscated individuals from private holders and zoos not only in Bulgaria but also from other Balkan countries (North Macedonia, Albania, Croatia, Serbia). The number and the area of enclosures, the number of bears in them, and their origin and kinship are presented in

Table 1. Information about the brown bears in captivity in Bulgaria and their enclosures. The number and age of individuals are presented at the time of the survey in 2021. It is indicated when several animals live in the same enclosure and are related. Explanation: ENC—enclosure, OE—outdoor enclosure, IE—indoor enclosure, M—male, F—female, CAPT—born in captivity, UNKN—origin unknown, WILD—from the wild, DB—dancing bear, SB—stereotypic behaviour.

Enclosure	Enclosure Size (m2)	Number, Sex and Age	Accommodation and Kinship	Origin	SB
Aytos Zoo
ENC01	OE—110	1 F, 23	alone, mother	CAPT	Yes
ENC02	OE—110	1 F, 14	alone, daughter	CAPT	Yes
Blagoevgrad Zoo
ENC03	OE—3500, IE—35	1 F, 18	group, mother	CAPT	No
		1 M, 9	group, son	CAPT	Yes
Dimitrovgrad Zoo
ENC04	OE—200, IE—6	1 F, 27	group, sister	WILD	Yes
		1 M, 27	group, brother	WILD	Yes
Dobrich Zoo
ENC05	OE—3000, IE—33	1 F, 9	group, not related	CAPT	No
		1 M, 8	group, not related	CAPT	No
Kyustendil Zoo
ENC06	OE—335, IE—12	1 F, >30	alone	UNKN	Yes
Lovech Zoo
ENC07	OE—77, IE—22	1 M, unknown	alone	CAPT	Yes
ENC08	OE—124, IE—30	1 F, 16	group, mother	CAPT	Yes
		1 F, 8	group, daughter	CAPT	Yes
		1 M, 19	group, father	CAPT	No
ENC09	OE—395, IE—15	1 F, 13	group, mother	WILD	Yes
		1 M, 1.6	group, son	CAPT	No
Pavlikeni Zoo
ENC10	OE—200, IE—6	1 M, 14	alone	WILD	No
Pleven Zoo
ENC11	OE—510, IE—50	1 F, 10	group, not related	WILD	Yes
		1 M, 10	group, not related	CAPT	Yes
Sofia Zoo
ENC12	OE—500, IE—50	1 F, 32	alone	WILD	No
ENC13	OE—2200, IE—75	1 M, 16	alone	CAPT	Yes
Stara Zagora Zoo
ENC14	OE—500, IE—8	1 F, 24	group, mother	CAPT	No
		1 M, 8	group, son	CAPT	Yes
ENC15	OE—500, IE—8	1 F, 12	group, sister	CAPT	No
		1 M, 12 *	group, brother	CAPT	Yes
ENC16	OE—120, IE—15	1M, 9	group, brother	CAPT	Yes
		1 M, 9	group, brother	CAPT	Yes
		1 M, 9	group, brother	CAPT	Yes
Varna Zoo
ENC17	OE—160, IE—10	1 F, 33	alone	CAPT	No
Bear sanctuary Belitsa
Sector 1	OE—27,000	1 F, 21	group, not related	UNKN (DB)	Yes
		1 M, 6	group, not related	WILD	Yes
		1 M, 5	group, not related	WILD	Yes
Sector 2	OE—16,000	1 F, 28	group, not related	UNKN (DB)	No
		1 F, 33	group, not related	UNKN (DB)	No
		1 M, 25	group, not related	UNKN (DB)	No
		1 M, 30	group, not related	UNKN (DB)	No
Sector 3	OE—4000	1 F, 29	group, not related	UNKN (DB)	Yes
		1 M, 11	group, not related	WILD	No
Sector 4	OE—7000	1 F, 24	group, not related	UNKN (DB)	No
		1 M, 12	group, not related	WILD	No
Sector 5	OE—6500	1 F, 14	group, sister	CAPT	Yes
		1 M, 14	group, brother	CAPT	Yes
Sector 6	OE—21,000	1 F, 31	group, not related	UNKN (DB)	Yes
		1 F, 26	group, not related	UNKN (DB)	Yes
Sector 7	OE—3000	1 F, 17	alone	CAPT	Yes
Sector 8	OE—3000	1 F, 20	alone	UNKN (DB)	Yes
Sector 9	OE—3000	1 M, 34	alone	UNKN (DB)	Yes
Sector 10	OE—3000	1 F, 34	alone	UNKN (DB)	Yes

* Died in the year 2022.

Data collection. The study consists of two parts: housing conditions and hibernation. We developed a case-specific questionnaire that comprises five parts, each containing questions based on the Five Freedoms concept [47]. They are related to the following:

1. Feeding and access to fresh water (diet, feeding methods, access to fresh water, control over feeding by visitors, etc.).

2. Environment (area of the enclosures, area per individual, access to the external and internal enclosure during the day, substrate, vegetation, topographic features, enclosure furnishing, temperature conditions, etc.).

3. Veterinary medical services (availability of a veterinarian, number of preventive examinations per year, availability of a preventive program, staff qualification, etc.).

4. Biological and behavioural needs (environmental enrichment, social environment, hibernation conditions, seasonal diet, etc.).

5. Risk of stress (noise level, number of visitors, possibility of withdrawal into an internal enclosure, possibility of separation of individuals living together in one enclosure, etc.).

The questionnaire contains 30 questions, and the answers and collected data for each bear were evaluated on a pre-defined scale with a certain number of points. The maximum score in the questionnaire was 54 points. The questionnaire was completed on-site, with some information collected through face-to-face interviews with zoo staff and others through personal observations to validate some of the information received. A separate questionnaire was completed for each bear, and the data were then summarised for each zoo enclosure. The questionnaire was based on that used by Maślak et al. [7] for bears in captivity in Poland to make the results compatible. The data recorded on each of the five components were scored as follows:

Part 1—Nutrition and access to fresh water: diet composition (poor composition-0, balanced and nutritious-1); feeding method (one portion per day-0, scattered feeding two times a day-1, feeding with scattered and hidden food items two or three times a day-2); providing daily access to fresh water (no access to fresh water-0, fresh water provided daily-1); control over feeding by visitors (no control-0, there is control of feeding-1).

Part 2—Environment in which the bears are kept: enclosure size (m²) including inner and outdoor enclosure and area per individual bear (under 150 m² per individual-0; 150 m² per individual-1; 1000 m² per individual-10); access outdoors during day and night (access every other day-0, access only during the day within 1/3 of the day-1, daily access while being closed indoors at night-2, unlimited access throughout the day and night-3); access to swimming pools and their sizes (no swimming pool-0, small swimming pool of a size allowing the bear to sit inside of it, bigger swimming pool allowing the bear to lie down in-2, large pool of a size allowing the bear to swim in it-3); thermal conditions (no shaded area in the outdoor enclosure-0, shaded area in the outdoor enclosure-1); type of substrate in enclosures (concrete, without vegetation-0; concrete covered with sand or tree bark-1; natural substrate of soil with grass-2); vegetation in the enclosures (no vegetation at all-0; grass only-1; grass, single trees or shrubs-2; full vegetation coverage with groups of trees or shrubs-3); topographical features of enclosures (flat-0, diversified-1); enclosure furnishing (empty enclosure-0, fixed objects preventing manipulation-1, platform or climbing structure or both-2, seminatural arrangement and objects that can be manipulated-3); presence of an indoor enclosure or den (absent-0; present-1); possibility for the animal to view outside the outdoor enclosure (no possibility-0; there is a possibility-1); maintaining hygiene in the enclosure (cleaning is carried out once a week -0; cleaning is carried out daily-1).

Part 3—Veterinary medical services: full preventive examination once a year or periodically (no-0; yes-1); availability and implementation of a preventive program for deworming and vaccination (no-0; yes-1); access to specialized veterinary medical care (availability of a veterinary specialist in the organization or on call)-(no-0; yes-1).

Part 4—Biological and behavioural needs: existence and implementation of an environmental enrichment program (no-0; yes-1); availability of objects for manipulation in the enclosure (no objects-0; special toys for the bear-logs, balls, etc., which are constantly in the enclosure-1; fresh branches and new, suitable and safe objects that are changed every day-3); conditions for entering hibernation (none-0; there is an indoor room-1; there is a natural den where the bear hibernates-2); provision of seasonal nutrition in accordance with the bear’s physiological needs (no-0; yes-1); suitable social environment (two or more bears in an area under 300 m²-0; single bear in an area of 1000 m²-1; two bears in an area over 2000 m²-2);

Part 5—Risk of stress: noise (noisy area-0; quiet area-1), we defined a noisy area as one where the enclosure was located close to a public road or entertainment place with a decibel level more than 75 dB measured with Sound meter app; number of visitors per day (over 500-0; from 500 to 100-1; under 100-2; no visitors-3); possibility of retreating out of sight of visitors to a shady spot in the outdoor enclosure (no-0; yes-1); proximity of bear exhibit to a constant irritant like zoo entrance, parking lot, food stall, noisy entertainment facilities, construction, etc. (yes-0; no-1); possibility of separating males from females, which are kept in the same enclosure (no-0; yes-1); possibility of separating young bears from their mothers after 4 years of age (there is no possibility and they live together-0; there is a possibility of separation-1). Additionally, detailed information on each individual was collected regarding age and origin, years spent in the enclosure, reproduction, health status, hibernation, and stereotypic behaviour (Supplementary Materials File S1).

To assess whether animals exhibit stereotyped behaviour, the team’s other studies on the behaviour of individuals were taken into account [43,44,45]. When completing the questionnaires, additional focal observations of each individual were made for 4 h per day for a minimum of one day, to record that no change had occurred from the previous observations. The focus of the observations, which were conducted by an observer and recorded with a video camera for more precise and complete registration of the behaviour, was the presence or absence of stereotypic behaviour.

Data on hibernation were collected during the winter periods of 2021–2022 and 2022–2023 for all bears living in captivity in Bulgaria at that time (n = 46). Data were collected for each bear, which included information on the bears’ pre-hibernation diet (composition and amount of food provided), hibernation conditions (availability of dens and indoor facilities and provision of den bedding, access by visitors and staff), and about the hibernation of the bears during the indicated periods (whether they hibernate, whether they fell into a temporary torpor or were just inactive when they went to hibernate, and when they woke up).

Statistical analysis. The Phi coefficient was used to study the correlation between the two dichotomous variables “sex” and “manifestation of stereotypic behaviour” of the bears kept in the zoos and Bear Sanctuary Belitsa. Correlation dependences between a continuous variable and a dichotomous variable were investigated by point biserial correlation for the variables: 1. “ manifestation of stereotypic behaviour” and “score from the questionnaire”; 2. “manifestation of stereotypic behaviour” and “age of bear”, 3. “ manifestation of stereotypic behaviour” and “enclosure size”, and only in bears kept in zoos between the variables “manifestation of stereotypic behaviour” and “ duration of life in the enclosure”. Based on the collected data on bear hibernation for the winter period 2021–2022, the correlation between “sex” and “hibernation”, as well as “manifestation of stereotypic behaviour” and “hibernation”, was researched by using the Phi coefficient. The relationship between the age of the bears and hibernation was also analysed by point biserial correlation. Additionally, a linear regression was conducted to examine whether hibernation status predicts animal welfare scores. In all tests performed, p < 0.05 was accepted for statistically significant differences.

3. Results

3.1. Housing Conditions

Bears in Zoos in Bulgaria. Twenty-one zoo bears were born in captivity, six were born in the wild, and one was with unknown origin. The average age of brown bears in zoos at the time of the study was 17 years, with the youngest being 1.7 years old and the oldest being 33 years old. Due to the completed questionnaires, the average welfare score of bears in Bulgarian zoos was 21.28 points, with the lowest score being 12 points and the highest being 45 points. The zoo with the highest score was Dobrich Zoo (

Table 2. Assessments of brown bear enclosures in the zoos and the Bear Sanctuary Belitsa and recommendations for improving the welfare of bears in individual enclosures.

Enclosure/ SECTOR	Rating	Recommendations
ENC01	18	Increase enclosure size, introduce environmental enrichment programme and regular full veterinary checks. Improve control of visitors feeding the bears. Relocate the brown bear exhibit from its current location at the entrance of the zoo, where the bears are exposed to disturbance throughout the year. In the current cage, the bears live on a concrete floor with small pools and are viewed by visitors from above; the cage is a pit. There is a project for a new, large enclosure at this zoo, which will be set in a natural forest.
ENC02	18	The same as for ENC01.
ENC03	29	Implement a habitat enrichment programme, improve control of visitors feeding the bears. Carry out regular full preventative veterinary checks and take steps to prevent unwanted inbreeding.
ENC04	20	Increase the enclosure’s area, introduce a habitat enrichment program, and improve the control of visitors who feed the bears. Conduct regular full preventative veterinary checks and diversify the bears’ diet.
ENC05	45	Conduct periodic, complete, preventive veterinary examinations and diversify the diet.
ENC06	25	Conduct environmental enrichment, introduce more than one feeding per day, and conduct periodic complete preventive veterinary examinations.
ENC07	14	Increase the size of the fence, improve the environment for growing, implement a programme for soil enrichment, introduce natural substrate and suitable planting. Diversify the diet, introduce more than one feeding per day, and ensure access to fresh water for drinking. Conduct periodic full preventive veterinary examinations. Improve visitor control and hygiene standards in the zoo.
ENC08	15	The same as for ENC07.
ENC09	18	The same as for ENC07.
ENC10	16	The environment must be improved to enhance the overall well-being of the animals. This includes ensuring there are shady areas outside the fence, implementing a programme for soil enrichment, placing natural substrates, and arranging the environment appropriately. Periodic full preventive veterinary examinations must also be conducted, and visitor control must be improved.
ENC11	17	The environment needs to be improved. There should be sunnier areas outside the fence, renewal of the soil, natural substrate, and an appropriate layout. It is essential to ensure that the male and female bears, who currently live together, are provided with the opportunity to be separated. Periodic complete preventive veterinary examinations must be conducted, and visitor control must be improved.
ENC12	22	It is of great importance for the bear’s welfare that it has constant access to the outdoor enclosure and that the environment is improved. This will be achieved by placing natural substrate and implementing an appropriate arrangement. Periodic complete preventive veterinary examinations must be conducted, and visitor control must be improved.
ENC13	38	The bears must have uninterrupted access to the outdoor enclosure. Comprehensive veterinary examinations must be conducted on a regular basis, and visitor control must be enhanced.
ENC14	18	Improve the overall environment in which bears live. This will require an enrichment programme, using natural substrates and appropriate planting, and improving hygiene. Diversifying the diet and ensuring access to clean drinking water are essential. Periodic, complete preventive veterinary examinations must be conducted. It is necessary to improve control over visitors. Ensure that the male and female bears currently living together can be separated.
ENC15	17	The same as for ENC14
ENC16	12	Same as for ENC14, and also increase the area of the enclosure and separate the three mature male bears.
ENC17	17	Introduce a programme of environmental enrichment and improve hygiene. Periodic full preventive veterinary examinations must be conducted, and visitor control must be improved.
Sector 1	49	Measures should be taken to avoid overcrowding in the summer season.
Sector 2	45	-
Sector 3	49	The same as for Sector 1
Sector 4	45	-
Sector 5	47	-
Sector 6	46	-
Sector 7	48	-
Sector 8	44	-
Sector 9	47	-
Sector10	45	-

). The considerable variation in zoo scores was mainly due to the difference in enclosure area, which scores the most in the questionnaire. Thus, five of the bear enclosures (29% of the total) in the zoos were found to have an area of 150 m², the minimum area for keeping one individual according to the Bulgarian legal basis (Regulation No. 6 of 23 October 2003 on the minimum requirements and conditions for growing animals in zoos and centres for breeding, and for the breeding of protected animal species), with some of them housing more than one individual, i.e., even the minimum standards for the species are not covered. These enclosures receive zero points when evaluating the area indicator. In contrast, other enclosures, such as those in Dobrich Zoo and Blagoevgrad Zoo, have an area of over 3000 m², for which they receive 10 points each.

All bears are vaccinated and dewormed annually according to an established veterinary preventive plan and have access to veterinary care, usually given when needed. However, periodic, complete preventive examinations are not carried out in zoos. For 44% of zoo bears, hibernation conditions have been created, and they hibernated during the winter period of 2020–2021. Manifestations of stereotypic behaviour were observed in 18 individuals (10 males and 8 females), representing 64% of all zoo bears. No correlation was found between the manifestations of stereotypic behaviour and the time spent in the enclosure of bears in zoos (r = 0.079; p = 0.690).

Bear Sanctuary Belitsa. Of the 19 bears living in Bear Sanctuary Belitsa, the youngest was 5 years old, and the oldest was 34 (average age 19.5). They lived in 10 enclosures (in the 7 Sectors of the Sanctuary). The average score of the welfare level of the bears in the sectors calculated from the questions in the questionnaire was 46.5 points, with the lowest score being 44 points and the highest being 49 points. All bears in the park undergo a complete preventive veterinary check-up every three years and are regularly vaccinated and dewormed according to an approved preventive program. Animals have access to highly specialized veterinary medical care, including dental treatment. For all bears, conditions for hibernation have been created using natural or artificial dens. During the winter of 2020/2021, almost all bears in the park (95%) hibernated. This was also helpful because the park is closed to visitors yearly from the beginning of November to the end of March. The bears’ enclosures are in their natural habitat and have a total area of 93,500 m². The smallest has an area of 3000 m², and the largest has an area of 27,000 m², with an average of 4921 m² of natural forest per individual. Each enclosure has at least one pool. Every facility has an environmental enrichment program, including staff training plans. The sanctuary’s policy is not to breed bears, so all males are castrated. Visitors are allowed in one-third of the park area, entering only with a guided tour. This eliminates the possibility of unregulated feeding and annoying the bears and regulates the number of visitors entering the park at a specific time.

From here on, the results are divided between zoos and sanctuary. Based on the results of the completed questionnaires, we have summarised the following problems related to the welfare of bears in zoos:

• Housing in limited living space: The study found that the living space per individual was less than 150 m² in 5 out of 17 enclosures, and 11 bears lived in these conditions;
• Most zoos lack plans for environmental enrichment: Some enclosures are provided with various stimuli on an irregular basis, but no measures are in place to properly and regularly enrich the environment, increase natural behaviour, and reduce the manifestations of stereotypic behaviour;
• Use of an unsuitable surface: A concrete surface was recorded in 8 of 17 enclosures;
• It is not standard practice for any zoo to regularly carry out complete health examinations of bears;
• 56% of the brown bears in Bulgarian zoos were not provided with suitable conditions for hibernation (e.g., lack of natural substrate for digging a den, lack of bedding material, disturbance during the winter period, lack of seasonal feeding);
• There is a lack of effective control over visitors’ unregulated feeding of bears;
• Most bear caretakers in zoos lack specialized education and training;

The study observed that the animals at Bear Sanctuary Belitsa are kept in optimal conditions. However, the increased flow of visitors in summer led to a rise in disturbance, noise, and pollution from parking near some of the bear enclosures. Measures are taken to reduce the disturbance; however, despite the staff’s efforts to prevent it, we have observed stereotypic behaviour in 12 bears (63% of all bears in the sanctuary). This was probably the result of the bears being separated from the mother too early and being kept in deplorable conditions before coming to the sanctuary [19]. Once it becomes part of the behavioural repertoire of carnivores for one reason or another, persistent stereotypic behaviour is challenging to eradicate. The sanctuary staff have found that its manifestations decrease in some cases when the bears were socialized and moved to another enclosure.

Table 2 presents ratings for all enclosures in the zoos and the Bear Sanctuary Belitsa, obtained after processing the information from the questionnaires, as well as recommendations for improving bear welfare and good husbandry practices.

The combined sample of all bears in captivity was analysed and no correlation was found between the manifestations of stereotypic behaviour and the sex of the bears (phi = 0.036; p = 0.805), their age (r = 0.077; p = 0.616), the size of the enclosure they live in (r = 0.285; p = 0.142), and the score of the enclosure, according to the questionnaire (r = 0.107; p = 0.475).

3.2. Hibernation

For all bears in captivity (n = 46) during the winter period of 2021–2022, it was found that 9 individuals (2 males and 7 females) out of 27 bears in zoos (13 males and 14 females) were hibernating, or 33% of zoo bears. Of those in Bear Sanctuary Belitsa (19 bears, 8 males and 11 females) hibernated, a total of 17 animals (6 males and 11 females), or 89% of the bears in the park, hibernated. It was also found that 69% of all females and 31% of all male bears in captivity were hibernating.

A positive correlation was proved between bears’ age and hibernation (r = 0.53161; p = 0.00014). Although the correlation between the variables was weak, bears under ten years of age were less likely to hibernate. Additionally, individuals up to twenty years old hibernated half as often as older bears. No correlation was found between the manifestations of stereotypic behaviour and whether bears hibernate (phi = 0.085; p = 0.440).

The diet of captive bears was adjusted to meet their increased food and nutrient requirements in the fall and their decreased needs in the winter and during hibernation. However, human disturbance significantly affects successful hibernation. This was evidenced by the fact that the bears hibernate for over two months in Bear Sanctuary Belitsa and Dobrich Zoo, where visitors do not have access to the bear exhibits in winter. In some zoos, bears do not hibernate but become more lethargic during the winter period. The majority of bears in zoos (45%) hibernate indoors. Some bears (33%) hibernate in semi-natural dens, which are dug and reinforced by humans in the soil or at the base of trees in the bears’ outdoor enclosures. Keepers in Bear Sanctuary Belitsa prepare such dens for elderly and less mobile bears that are unable to dig them themselves. During the winter period of 2020/2021, almost all bears in the park (95%) hibernated. The results indicated that hibernation significantly predicted welfare scores (β = 0.652, t(46) = 5.77, p < 0.001) with hibernating animals scoring 18.82 points higher on average (B = 18.82, SE = 3.26) than non-hibernating animals.

4. Discussion

The welfare assessment of brown bears in Bulgarian zoos and rehabilitation centres defined the main problems significantly lowering their welfare and quality of life. Insufficient space in most of the zoo enclosures was one of the identified significant welfare problems for brown bears in captivity in Bulgaria. The study found that the housing area per individual in five zoo enclosures was less than 150 m², and eleven brown bears lived under these conditions. The Bulgarian legislation stipulates a minimum area of 150 m² per individual, and there must be a minimum of 20 m² more for each subsequent individual. This means that according to the regulation, if two bears coexist in one enclosure for each of them, the minimum permissible space will be 85 m², which is highly insufficient. This was a main welfare issue in the study of Maślak et al. [7], where the space for one bear in Poland was smaller than 100 m² in 12 of the 30 enclosures. In some countries, regulations specify a larger minimum space for brown bears in captivity. For example, in Austria, a minimum of 300 m² is required for two individuals and in Sweden, the minimum space for two individuals is 1500 m² [42]. According to experts, it is recommended to keep brown bears in enclosures with an area of 4000 m² to 10,000 m², depending on the number of bears [42,48]. The European Association of Zoos and Aquaria (EAZA) requires a minimum area of 300 m² per individual for captive brown bears. The small area of the enclosure would lead to the unsatisfied need to travel large distances in bears, which creates a basis for developing behavioural disorders, especially stereotypic behaviour [49]. We believe that in Bulgaria, the regulations regarding the minimum area of 150 m² for keeping brown bears should be changed, and the area should be increased to 500 m² per individual, with an additional 500 m² for each subsequent individual in the enclosure. Bears are solitary animals and gather in groups during the breeding season or when abundant food resources are available. If they live together, this is usually a mother and her cubs, who are together until they are 2–3 years old. The long-term coexistence of a female with her cubs in captivity can lead to abnormal behaviour [44]. We found that only in Dobrich Zoo and in Blagoevgrad Zoo the bears, kept together, can be separated into two different sectors of the enclosure. Permanent cohabitation of a male and a female bear without the possibility of separating the two animals in different parts of the enclosure can lead to distress, especially in females, and to unwanted reproduction and infanticide. This would be inconsistent with the breeding standards of the species and with maintaining a high level of welfare. Also, this leads to problems in handling the animals and in their hygienic and veterinary care. In four of these cases, it led to unwanted inbreeding, and in two cases, to the killing of the young by the father soon after their birth. Unplanned breeding of bears should be avoided since there are a limited number of facilities for bears not only in Bulgaria but also throughout Europe. Also, rearing the animals is expensive and complicated, and they are long-lived; their life expectancy in captivity can reach up to 50 years [50]. In the Bulgarian zoos, only one male bear has been castrated, while two other males have been vasectomized at the time of the study. This increases the risks of unplanned breeding and inbreeding. Three bears were born in 2022 and 2023, although there are no conditions for raising more brown bears in their native zoos. The system of interconnected sectors and isolators in Bear Sanctuary Belitsa allows the relocation and separation of the animals kept in groups of up to four bears. The sanctuary’s policy is to prevent the breeding of bears. This is achieved by castrating all the males, which also reduces the levels of aggression and makes it easier for them to live with other animals. The staff are confident that redeployment and socialisation with suitable individuals is a practical approach for overcoming the stereotypical behaviour of animals. The study identified that most zoos do not have this option. Accordingly, bears should live in an environment close to their natural habitat and a space adapted to their natural needs. A spacious enclosure will offer a variety of stimuli that are biologically relevant to different bear species and allow the animals to display their species-specific behaviour in other seasons. Therefore, the design of new bear enclosures in zoos should follow the Large Bear Enclosures concept in Europe standards, presented in the EAZA Ursid husbandry guidelines [48]. Thus, keeping bears in small, concrete cages or bear pits should be a thing of the past.

The possibility for animals in zoos to choose whether to stay in an indoor room or an outdoor enclosure (or in a specific part of it) is another essential condition for their calmness and well-being that was established. In only one of the zoos, the bears are confined for 2/3 of the day in cramped indoor spaces for security reasons and have access to the outside space for 8 h a day during the keepers’ working hours. This practice limits the animals’ ability to be most active in the morning and at night, which is their natural behaviour. In a study on giant pandas, Owen et al. [51] found decreased urinary cortisol levels and abnormal behaviour after bears were given the choice of staying indoors or outdoors.

The lack of regular and appropriate environmental enrichment was a common issue in the husbandry of brown bears in Bulgarian zoos. In Polish zoos, the lack of stimulation was defined also as one of the main welfare issues [7]. In Bulgaria, enrichment programs are created and implemented only in Sofia Zoo, a member of EAZA since April 2023, and in Bear Sanctuary Belitsa. In the other zoos, some forms of environmental enrichment, such as providing logs, branches, and car tyres and dispersing food, are offered periodically. Bear Sanctuary Belitsa staff have developed individual programmes for the bears, offering appropriate enrichment, socialisation, and training. This approach is crucial for older individuals, especially blind bears and those with limited mobility.

The study discovered that in several zoos, the bears had a diet that lacked or contained minimal animal-origin food. There bears were primarily consuming bread and other carbohydrate-rich foods that are not natural for them, as also practiced in zoos in Poland [7] and Albania [52]. This is partly due to the still widespread prejudice in Bulgaria that providing meat will “enrage” the bear and make it aggressive. Bear Sanctuary Belitsa does not abide by this practice, as about 15% of the diet is meat. Although the brown bear is omnivorous, it is a carnivore and undoubtedly needs food of animal origin. In bear husbandry guidelines, food charts for providing a balanced diet to brown bears are established, defining the composition, amount of food, forms, and feeding frequency. In the research questionnaire, the highest score was given to feeding three times daily, offered in the Bear Sanctuary Belitsa. Bears travel long distances in the wild and spend much time foraging [49]. Therefore, hiding, scattering, and offering food more often in the enclosure allows the animal to follow its natural behaviour. Feeding once or twice a day at the same time (usually in the morning and at the end of the staff’s working day) and in a particular place is a prerequisite for developing stereotypic behaviour. Adjusting the bears’ feeding in captivity to their seasonal needs is essential for their welfare. In August and September, bears enter a period of hyperphagia, increasing their food intake to accumulate subcutaneous fat as an energy source during hibernation [53]. After that, food gradually decreases, and the bears do not eat during hibernation. One of the critical conditions for successful hibernation in zoos is following these nutritional principles.

Many zoo enclosures still have a hard concrete surface, which is a highly unsuitable environment for bears. It can lead to dermatitis on the underside of the paws and skin, and arthritic problems. Natural substrate and vegetation are also imperative for maintaining the bears’ natural foraging habits [54]. Not to be overlooked is that many of the evaluated enclosures lacked fresh drinking water, and the bears drank water from their pools. A similar problem was found in zoos in Poland [7].

All the zoos in Bulgaria have an annual prophylactic programme for deworming and vaccinating bears. However, a medical examination is only conducted when necessary and when pathological symptoms appear. Periodic complete veterinary preventive examinations of the bears are performed exclusively at the Bear Sanctuary Belitsa. The procedure involves full anaesthesia, blood sampling, and X-ray and ultrasound scans, as well as eye and dental treatments. Health check intervals are typically every 2–3 years to minimize the need for frequent sedation, which can pose health risks for older individuals. Monitoring physical health parameters is considered when assessing animals’ welfare [55]. Common in captive bears are dental problems, injuries from conspecifics in co-housing, and degenerative joint problems in old bears [5].

Bears are particularly prone to developing stereotypic behaviour, often expressed in locomotion, such as walking along a specific trajectory. One reason for its occurrence is the attempt to adapt to the unsuitable conditions in which the animal is placed [56]. In the present study, as well as in previous studies, we observed various forms of stereotypic behaviour in 30 bears at zoos and Bear Sanctuary Belitsa, including pacing, head tossing, walking in the figure of eight, oral stereotypy, circling, and others [43]. Despite the large enclosures in the Sanctuary, the bears were visible most of the time. They were often near the fence, likely due to many being former dancing bears, seeking contact with humans. In their study on the welfare of bears in Poland, Maślak et al. [7] stated that they found stereotyping in all the bears they observed. They describe the same forms of stereotypic behaviours plus one particularly severe case of self-mutilation in which the bear bites parts of its body. The behavioural assessment in this study was primarily focused on the manifestation of stereotypic behaviours. Further investigation of positive behaviours would contribute to a better assessment of welfare.

Our study found that bears in zoos in winter often only enter a less active state and do not go into prolonged hibernation. Bears at the zoo experience daily anxiety due to husbandry routines and the presence of visitors. Therefore, hibernation may often not be possible under these conditions, even when bears demonstrate a significant decrease in activity and are lethargic. In confirmation of what we said, Itoh et al. [57] also concluded that the ability of bears in zoos to hibernate requires the provision of a secluded and undisturbed environment, as well as the introduction of appropriate husbandry procedures. Bears up to 20 years of age hibernate less than older ones and this may necessitate the introduction of different husbandry procedures for young bears during the autumn-winter period. We believe, like Dori et al. [41], that creating conditions for brown bears, especially in zoos in temperate climates, to exhibit their natural behaviours associated with preparation for hibernation and hibernation itself in captivity would benefit their welfare, but further research is needed in this regard.

5. Conclusions

The main welfare problems of brown bears in zoos in Bulgaria identified during the research were insufficient space, unsuitable enclosure surfaces, insufficient environmental enrichment, inappropriate social structure, absence of hibernation conditions, poor visitor control, incomplete diet and absence of fresh drinking water, and inadequate comprehensive and preventive veterinary care. Presumably, the places with high assessment scores provide better long-term care for the bears in captivity, resulting in improved welfare. The study-based recommendations would enable state policy and zoo management to significantly improve the welfare of bears in captivity by providing a more natural environment and meeting their behavioural and biological needs. This will also help convey the right message to zoo visitors, increasing their awareness and empathy for animal conservation. Ultimately, these developments will bring zoo institutions in Bulgaria closer to the best practices for keeping wild animals and to the educational and conservation standards found in modern zoos worldwide.