Kunene, Namibia - Diceros bicornis. In 1992, drought set in, up to 1993: 1 subadult died from starvation
In July 1993, Berger and Cunningham (1993) concluded in an unpublished progress report to the Namibian Ministry of Environment and Tourism (MET) that three black rhinoceros (Diceros bicornis) calves had died in the only part of their study area in the Kunene region of Namibia where rhinos were dehorned and where large predators occurred. They claimed that two black rhino calves born in 1992 could not be found in 1993, nor could they find a third calf, never seen, but which was assumed to have been born to a dehorned female which had a swollen udder. All three alleged calf deaths were attributed to predation by spotted hyaenas and lions. Berger & Cunningham (1994a) contrasted calf survival in three areas (known as SR, DC and NVF) of hyperarid broken terrain in the Kunene region of Namibia, previously known as Damaraland. Two areas larger than 1000 km? (SR and DC) each contained fewer than 10 rhinos which had all been dehorned once since 1989 (See Table). Large predators allegedly occurred only in area SR and in the third region where no rhinos were dehorned (NVF).
Horn growth in females dehorned in Kunene, Namibia - average horn lengths in cm 1989 0 cm 1990 6.4 cm 1991 12.8 cm 1992 19.2 cm 1993 25.6 cm 1994 32.0 cm
The fact that black rhino cows hide their small calves has been reported interalia by Joubert & Eloff (1971), Hall-Martin & Penzhorn (1977) and Owen-Smith (1988), and not for the first time as claimed by Berger (1993b). Berger & Cunningham (1994a) alleged that all three calves disappeared within one year after birth, during the interval that calves are most often hidden (Berger, 1993b). Berger & Cunningham (in press) also recorded spatial displacement by females of several kilometers in one day in response to human presence. No more extreme than their predation theory is the speculation that Berger and Cunningham's activities and presence might have also affected the period of separation between cow and calf, especially in situations compounded by drought, poor body condition and displacement from watering points. No data have been published comparing the vulnerability of hidden calves versus those accompanied by their mothers, or the proportion of time spent in hiding at various age intervals. If calves are preyed on whilst in hiding, maternal horn length is of no consequence. This possibility should have been discussed in any paper dealing with predation on rhino calves.
Kunene, Namibia - Diceros bicornis. In 1994, 1 adult died from infection of Staphylococcus sp.
