2.2 | Location and life history data
Location data are collected during annual systematic surveys conducted between the months of July–September. Each day (weather permitting) one of seven sections is surveyed on foot by one or multiple observers, and adjacent sections are not surveyed on consecutive days. Consequently, each section is typically surveyed once per week over a 6 to 8 weeks period. When horses are encountered, identifying photos are taken alongside location to the nearest 5 m using a handheld GPS device. Every year, each horse is sighted 5 ± 2 times (\(\overset{\overline{}}{x}\) ± SD; Rozen-Rechels et al., 2015). Annual surveys across years allow us to track the birth, age, change in reproductive status, death, and social parentage of every individual.