The welfare and behavior of animals kept under human care has generated growing interest and concern for zoos and wildlife conservation research. Animals have been kept in zoos and ex-situ environments for the purposes of education, breeding, research and public awareness. However, the challenge of ensuring that these animals thrive in non-natural environments raises important questions related to their welfare and behavior (Garcia, 2021).
To assess animal welfare, it is essential to consider the "Five Domains" model (Mellor et al, 1994). This framework encompasses four physical domains (nutrition, environment, physical health and behavior) plus a fifth domain dealing with the mental state of animals. This approach allows systematic assessments of animal welfare to be carried out in a comprehensive manner. The "Five Domains" assume that both negative and positive experiences, when balanced, are part of a healthy routine in the lives of animals. However, when this balance is disrupted, animal welfare is compromised, which can result in consequences such as the emergence of stereotypical behaviors (Mellor, 2015).
Stereotyped behavior is commonly associated with the occurrence of inadequate enclosures with reduced size or no environment, as well as a lack of stimuli, isolation, improper feeding and management, and stress. In addition, these behaviors can have a long-term impact on the animal's reproductive capacity, diet and health (Daniel, 2018). It is known that animals in unsuitable captivity conditions tend to show more intense behavioral changes, which can include stereotyped movements, self-injurious behaviors, immunosuppression and impaired reproduction (Morgan, 2007).
In this sense, Boere (2002) presents stress as an adaptation tool that organisms use to face everyday challenges. Thus, stress can be understood as a natural state of animals, both ex situ and in situ, but in animals kept under human care, confinement intensifies the responses generated by this event. This is because, according to Fowler (2008, p. 33-49), in captivity, animals are deprived of the opportunity to make choices, so they are unable to move away from the stressful phenomenon and end up in constant need of adaptation (apud Cubas, 2014, p. 35).
In this way, zoos have used tools such as environmental enrichment protocols to improve animal welfare and, as a consequence, provide better reproduction rates, reduce stress-related behavioral changes and establish better physical and mental conditions for the animals; as well as assist in animal management, with the aim of reducing stress levels during transport, clinical assessments and human-animal interaction (Hashimoto, 2008). As exemplified by Young (2003), increasing the quality of life of animals through environmental enrichment strategies is of paramount importance, especially considering that zoos are institutions based on the dissemination of environmental education, which should be based on the natural behavioral patterns of each species.
In this way, making a commitment to the welfare of animals under human care not only promotes the individual well-being of these organisms, but also contributes significantly to society's complex learning network. Environmental enrichment can vary according to the purpose of the interaction, and can be of the food, physical, social, sensory and cognitive type. Thus, this strategy tries to reduce the occurrence of altered behaviors by using the environment in a positive way (Garcia, 2021).
Environmental enrichment, widely recognized as a fundamental strategy in the management of animals in captivity, has been shown to be equally effective in improving the well-being of reptiles. Although not as obvious as in other animals, reptiles also suffer from stressful situations, which can result in serious consequences. Among the most obvious signs are changes in skin color, open-mouthed behavior, inflating the body, flattening against the ground and lashing the tail for no apparent reason. Introducing stimuli that replicate elements of their natural habitats and promote instinctive behaviors helps to reduce this stress, as well as improving physical and mental health and increasing the adaptive capacity of these animals. In the case of reptiles, practices such as the control of thermal variations, the inclusion of hiding places, climbing structures and specific food challenges are essential to minimize stereotyped behaviors and promote greater activity and interaction with the environment, essential aspects for improving their quality of life in captivity (Mader, 2019).
A notable example of the use of these techniques occurred at the Butantan Institute, where an anaconda exhibited defensive behaviors and avoided any approach by the keepers, making veterinary procedures extremely difficult. Lucas Simões Lima, a biologist and animal welfare specialist, implemented an innovative approach of environmental enrichment and operant conditioning, exploiting the snake's taste for water. By associating human presence with this positive stimulus, the anaconda was gradually desensitized and began to accept interaction with the veterinary team. After a period of consistent training, the animal allowed the approach, significantly facilitating handling and making veterinary examinations possible without the previous stress, demonstrating the positive impact of enrichment and conditioning techniques on animal welfare (Tavares, 2024).
Source: Instituto Butantan
Author: Victória Brienze - Member of GEAS Brazil Regional Representatives
Comments