 Reference Base  A visit to the Nimule National Park in the Southern Sudan |
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Kock, D., 1961. A visit to the Nimule National Park in the Southern Sudan. African Wildlife 15 (4): 323-329, figs. 1-6
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| Location: |
Africa - Southern Africa - Zimbabwe |
| Subject: |
Morphology - Size |
| Species: |
White Rhino |
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Regrowth of horn after dehorning in Zimbabwe. Horn Regrowth: rates and form. Linear rates of horn re-growth were measured for white rhino adults immobilised in 1992, ca one year after horn removal (see Table 2 for measurements after dehorning, Table 3 for regrowth measurements). Average regrowth rates for adults did not differ significantly between the sexes for either anterior (males: n = 7, x = 6,8 cm/yr; females: n = 7, x = 7,0 cm/yr) or posterior horns (males: x = 3,4 cm/yr, females: x = 2,5 cm/yr). Rates of regrowth for all adults (n = 14) differed significantly between anterior (x = 6,7 cm/yr) and posterior (x = 2,9 cm/yr) horns. Thus, total horn regrown by white rhino adults averaged 9,6 cm/yr. Berger reported mean rates of regrowth (summed for both horns) for desert black rhinos in Namibia as 8,7 cm/yr and 13,3 cm/yr for adults and juveniles, respectively; no significant differences were detected between the sexes. Although we observed some evidence of rubbing of horn bases one year after horn removal in white rhinos, most horn wear was restricted to the lateral surfaces. Therefore, measured changes in horn length closely reflect rates of horn regrowth. Data are presented for black rhinos (Table 4).
Table 3. White rhino horn regrowth, measured ca 1 year after dehorning, Hwange NP, 1992
Age/Sex number Front horn (cm/yr) number rear horn (cm/yr)
Adults 14 6.7 14 2.9
male 7 6.8 7 3.4
female 7 7.0 7 2.5
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