Laboratory soundscapes: optimising acoustic environments for avian welfare

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Music has profound effects on our mood, increasing happiness and decreasing anxiety. It is commonly believed that music has similar effects in other animals, and music is often played to captive animals to improve their welfare. However, we actually know very little about the long-term effects of music on animals. In fact, music may not be the most appropriate form of acoustic enrichment. The idea that the sounds animals hear when in captivity, in scientific studies or on a farm, can enhance quality of life is an important one. Over four million animals are used in scientific experiments each year in the UK alone, with a further 100 million estimated worldwide. Maximising the welfare of these animals is an important focus of many policy-making bodies, including the UK Government and European Parliament. The central aim of many of these policy makers is to develop best practices based on scientific data to improve the health and wellbeing of animals used in scientific procedures. One way that we could create better environments for captive animals is to enrich the acoustic surroundings (soundscapes) within their enclosures. However, there are no data on the types of sounds that animals would prefer to hear. This is the obvious first step in informing our idea of what an enriched soundscape sounds like. Listening to preferred soundscapes could reduce stress, limit the impact of anthropogenic noises associated with captivity (e.g. machinery) and reduce anxiety. This could lead to an overall increase in physiological welfare indicators and mean healthier and happier animals. We intend to test this hypothesis using several innovative experiments. We will do this using the zebra finch, which are arguably the most extensively studied songbirds in the world. They account for the majority of the 300,000 songbirds used annually for studies on social behaviour, cognition, neurobiology, physiology, auditory perception, and welfare in research laboratories worldwide. Yet despite being an important model species, almost nothing is known about how acoustic environments in captivity impact their health and wellbeing. Firstly we will discover what sounds zebra finches prefer to hear by giving them the choice between a range of man-made, natural and music-like sounds. Once we have this information we will use it to construct two experimental soundscapes that represent enrichment, one based on natural sounds the other on music-like stimuli. We can compare birds living in these environments to those in 'normal' soundscapes and a group that has anthropogenic sounds removed by soundproofing. We will then look at adult bird health, stress levels and behaviour over an eight month period to establish how long-term exposure to enriched sounds impacts on welfare. After this we will determine the effects of our soundscapes on breeding performance and the effects of hearing these sounds during development of the offspring. In all birds we will focus on measuring traits that we know relate to health and wellbeing, including stress levels, anxiety behaviour, immunocompetence, social cohesion and damage to cells by oxidative molecules. The final part of the study will investigate whether enriched soundscapes can increase the likelihood of birds to participate in behavioural experiments (to learn about a new object or food source). This type of experiment often requires training the birds and in most studies 10-20% of animals do not engage with the task. This may be due to high stress levels during tests, which soundscapes may be able to ameliorate. Overall our work aims to enhance avian welfare in a laboratory setting, and we are confident that it will have repercussions beyond this into other environments, such as farmed birds. In addition we will be able to produce a significant refinement of current welfare protocols. We also suggest that the work will lead to significant reductions in the numbers of animals used in behavioural experiments.