Use of behavioural observations and faecal progesterone sampling to monitor reproductive cyclicity and pregnancy in captive South China tigers, with regard to breeding and rewilding

Abstract

The objective of this study is to determine specific behaviours associated with different phases of the reproductive cycle in captive South China tigresses (P. t. amoyensis) and to measure progestagen concentrations in faeces of these females to determine the success of mating. This was aimed to assist a breeding and rewilding programme for South China tigers. Behavioural observations were performed twice daily over a period of 67 days and faecal samples were collected at least once weekly for 102 days. Data about behaviours such as general activity, spraying and social interaction, differed between individuals. Significant (p-value < 0.05) changes were associated with different phases of the reproductive cycle. Data from one tigress indicated an increase in activity during proestrus of almost 42%, but a decrease during estrus of almost 72%. Spraying frequency was higher during anestrus, 40.9 ± 7.9 times per active hour, but dropped by almost 59% during proestrus to 16.8 ± 3.3 times per active hour and was even lower during estrus, 6.2 ± 2.1 times per active hour. The positive social interaction frequency increased when the tigress entered proestrus and, simultaneously with the negative interaction frequency, increased further during estrus. Alterations in these specific behavioural patterns may therefore be useful parameters to determine estrous cycle stage in tigresses. Faecal samples were analysed for progesterone metabolites using a radioimmunoassay. Stress might have influenced the results slightly, but if measures are taken (double and fresh sampling) accurate data can be collected in future research. Progesterone concentrations were elevated up to parturition and were therefore useful for (pseudo)pregnancy determination.