Zoo-housed mammals do not avoid giving birth on weekends.

There is evidence that zoo visitor presence can influence the behaviour and, in some cases, adrenal response of zoo animals, and can sometimes compromise animal welfare. In some laboratory studies, significantly more primate births have been reported on weekends, when fewer people are working there, compared with weekdays when staffing levels are at their highest. Here, we investigate whether there is evidence of a "weekend effect" on births in zoo animals as a result of visitor numbers.

Is wounding aggression in zoo-housed chimpanzees and ring-tailed lemurs related to zoo visitor numbers?

Chimpanzees in laboratory colonies experience more wounds on weekdays than on weekends, which has been attributed to the increased number of people present during the week; thus, the presence of more people was interpreted as stressful. If this were also true for primates in zoos, where high human presence is a regular feature, this would clearly be of concern. Here we examine wounding rates in two primate species (chimpanzees Pan troglodytes and ring-tailed lemurs Lemur catta) at three different zoos, to determine whether they correlate with mean number of visitors to the zoo.

Can zoo records help answer behavioral research questions? The case of the left-handed lemurs (Lemur catta).

Most zoos keep comprehensive records, which potentially form a database for use in answering some research questions, such as in veterinary and population management research. They have not, however, been widely used to answer questions about animal behavior and welfare. Here we try to assess the usefulness to behavioral research of two sorts of zoo records (ARKS, the Animal Records Keeping System, and student dissertations held on file) to test the hypothesis that ring-tailed lemurs with a left limb preference experience more negative social lives.

Measuring zoo animal welfare: theory and practice.

The assessment of animal welfare relates to investigations of how animals try to cope with their environment, and how easy or how difficult it is for them to do so. The use of rigorous scientific methods to assess this has grown over the past few decades, and so our understanding of the needs of animals has improved during this time. Much of the work in the field of animal welfare has been conducted on farm animals, but it is important to consider how the methods and approaches used in assessing farm animal welfare have been, and can be, adapted and applied to the measurement of welfare in animals in other domains, such as in zoos.