Fission-fusion social societies allow animals to respond in a flexible manner to environmental changes by adapting the size and composition of a group. Although group members change frequently in these systems, associations with preferred partners may be found. In this study, we examined the grouping patterns of a population of 80 individual giraffes in a fenced South African game reserve over a 12-month period. Using social network analyses as a tool to evaluate observed associations, we subsequently analysed both sex- and season-related grouping patterns within the study population. Mixed sex groups represented 49% of all groups observed, and although overall group composition distribution did not differ significantly between seasons, the number of encountered single females decreased by 50%, whereas the number of multi-male groups increased by over 50% in winter. Overall average group size did not differ significantly between seasons, but significantly larger multi-female and multi-male groups were seen in winter. Within the social network, two distinct clusters were found in summer, with the population more divided in winter, with five distinct clusters emerging. The strongest ties (highest HWIGs) were found between adult females. Our study revealed that giraffes not only live in a highly flexible social fission-fusion system, but also show seasonal patterns of grouping.

Measuring energetic condition of wild animals is of major importance in ecological research, as it is profoundly linked to fitness. However, noninvasive monitoring of energetic condition in wild-living animals is methodologically challenging. Measuring urinary C-peptide levels is a suitable method to noninvasively assess energy balance in wild-living animals. As collecting urine is not always feasible in the wild, it is essential to establish alternative biomarkers for other sample types to assess energy balance. Thyroid hormones (TH) are potential candidates as they are involved in the regulation of metabolic processes. During periods of low energy intake, serum TH levels are reduced, leading to a decrease in metabolic activity. To investigate whether fecal TH can serve as a biomarker for energy balance, we validated a total T₃ ELISA to measure immunoreactive T₃ (iT₃) in fecal samples of yellow-breasted capuchins. We restricted caloric intake of seven males, assessed daily group caloric intake and determined daily individual fecal iT₃ levels. Analytical validation of the assay showed that fecal iT₃ levels can be reliably measured; however, proper storage conditions must be implemented and possible degradation to be accounted for. IT₃ levels were significantly higher on days with high group caloric intake. However, individual iT₃ levels varied substantially, resulting in an overlap across individuals between conditions. Our results indicate that fecal iT₃ levels can serve as a useful biomarker to detect changes in energy intake of yellow-breasted capuchins. Overall, measuring fecal iT₃ levels may present a suitable method for monitoring energy balance when urine collection is impossible.

Intensive pig management involves in a commercial setting the housing and implementation of certain procedures, such as castration and tail docking, which may be stressful for the animal. Good farming practices include the reduction of stress due to management processes, but assessing the level of stress perceived entirely through behavioural observations can be challenging. The monitoring stress-related physiological markers, like glucocorticoids (GC), can be an accurate alternative that would presumably be more objective. In order to avoid an additional stressor by taking blood, a non-invasive approach is advisable. We used an adrenocorticotropic hormone (ACTH) stimulation test and the effect of transport to examine the suitability of different enzyme immunoassays (EIAs) for monitoring adrenocortical function in domestic pigs using saliva and faeces as sample matrices. An assay measuring faecal glucocorticoid metabolites (fGCMs) with a 3ß,11ß-diol group has proven suited to determine adrenocortical activity, showing an overall increase of 180% in fGCM concentrations related to ACTH administration and of 70% related to transport, respectively. A cortisol EIA was used to detect salivary glucocorticoid (sGC) concentrations, revealing a 1100% increase in sGC concentrations after ACTH administration. The stability of fGCM concentrations post-defecation was determined to assess possible changes in measured fGCM concentrations in unpreserved faecal material over time, with fGCM concentrations being relatively stable (maximal 12% change) under natural conditions for approximately two days after defecation. This implicates that untreated faecal material from pigs can be analysed for up to two days after collection without appreciable level of depreciation in fGCM concentrations. Being able to assess the physiological stress response of domestic pigs non-invasively can help to improve the well-being of commercially reared pigs.