Field Notes

January - April 2020

It was hot and humid with heavy rains between January and April in the bull area. Many plants typically produce leaves during the rains and shed their leaves a month after the rains have stopped. But when the rains started last October and continued through April many plants including Commiphora, Bauhinia and Delonix produced leaves and shed them three times in seven months. In the bull area, most waterholes were small lakes. When the waterholes are full, tortoises are often on the bank basking in the sun. With the rains, butterflies, termites and dragonflies seemed to be everywhere. Migratory birds left the bull area in mid-April: Barn Swallows, Steppe Eagles and Eurasian Rollers.


Most bulls were with family groups or alone: Swift, Moonlight, Quark, Oort and Pemba. Breeze and Kilo were with their natal group; not yet ready to be on their own or join a bull group. When I found Pemba, id-2015, during the rains in mid-April he was in musth, alone feeding. Over the next two hours he joined a family of six, split from this family, joined another family, then he headed west alone where Oort and a 15 year old bull joined him. Pemba has been in musth at the same time during the rains in the past four year. In late April, Saturn (photo right, id-2010), was not in musth, but had similar behavioral patterns to Pemba. During four hours, he joined and split from five different families: Heloise, Lya, Vanilla, Summer and Savanna.


During the past four months, almost all of the known families (mother & offspring) were with their bond group or aggregated with other families: Summer and Savanna, Bermuda, Crescent, Heloise and Teak. Most of the aggregations had two or more bulls, 30-40 years old, with them. In most of the family groups, there were two to three newborns. In one aggregation of 68 individuals, I counted eight calves between one and two months old. It was a challenge to concentrate on id’s when the calves were busy chasing butterflies or birds and attacking bushes. This was one of those times, data had to wait so I could just watch. Summer, C.T., and Teak had a calf one-two months old; black hair on their forehead, trunk and back. In late April, Lya (photo left, id-2009) with her male calf were with Vanilla and her calves (male and female) resting in the shade of a Delonix and a 45-year-old unknown bull.