Digital photogrammetry and laser rangefinder techniques to ... - CERU

6 South African Journal of Wildlife Research Vol. 36, No. 1, April 2006
Table 2.Comparison of actual heights with estimates of shoulder height (mean ± SE, n = 5 measurements) derived for
12 elephants of different ages from various distances using (a) a laser rangefinder and (b) digital photogrammetry.
Values in brackets represent the mean distance from an individual elephant during the five repeat measures within the
distance class.
Elephant Sex Age Height
(years) (cm)
Distance classes
~25 m ~30 m ~75 m ~115 m ~50 m ~65 m
(a) Rangefinder
Themba 8 2.2 137.00 137 ± 2.1 – 144 ± 1.5 – 139 ± 2.1 –
(26.5 ± 0.2) (49.8 ± 0.1) (75.4 ± 0.1)
Tumelo 9 5.5 155.00 158 ± 1.3 – 162 ± 2.9 – 165 ± 3.0 –
(27.6 ± 0.1) (48.9 ± 0.1) (73.5 ± 0.5)
Thandi 9 10.5 200.00 199 ± 0.8 – 207 ± 2.6 – 208 ± 3.5 –
(24.9 ± 0.1) (49.3 ± 0.1) (75.7 ± 0.1)
Jabu 9 12 201.00 201 ± 1.0 – 209 ± 2.1 – 198 ± 3.7 –
(25.6 ± 0.1) (49.0 ± 0.1) (74.67 ± 0.1)
Maroela 9 10.5 202.00 206 ± 1.4 – 214 ± 1.5 – 209 ± 3.5 –
(26.0 ± 0.1) (49.6 ± 0.1) (75.0 ± 0.1)
Khumba 9 11.5 211.00 210 ± 0.5 – 212 ± 1.9 – 214 ± 4.4 –
(26.5 ± 0.4) (50.8 ± 0.1) (73.6 ± 0.1)
Mosadi 9 12 211.00 215 ± 0.7 – 217 ± 2.8 – 211 ± 2.7 –
(26.1 ± 0.3) (49.8 ± 0.1) (76.3 ± 0.1)
Sappi 8 18 255.60 – 255 ± 2.0 – 257 ± 4.5 – 251 ± 3.8
(29.2 ± 0.1) (62.6 ± 0.1) (115.7 ± 0.1)
Sharu 8 19 257.00 – 260 ± 1.3 – 256 ± 3.4 – 257 ± 4.4
(37.3 ± 0.1) (68.4 ± 0.1) (120.1 ± 0.1)
Chikwenya 9 19 259.00 – 259 ± 2.1 – 253 ± 2.0 – 249 ± 6.4
(30.8 ± 0.1) (66.6 ± 0.3) (119.1 ± 0.1)
Mana 8 19.5 262.00 – 260 ± 2.9 – 262 ± 3.9 – 259 ± 9.0
(32.4 ± 0.1) (66.1 ± 0.1) (119.1 ± 0.1)
Michael 8 19.5 266.00 – 262 ± 1.2 – 257 ± 4.5 – 269 ± 6.0
(30.3 ± 0.2) (62.4 ± 0.1) (115.2 ± 0.1)
(b) Digital photogrammetry
Elephant
Sex Age Height
(years) (cm)
Distance classes
∼25 m ~30 m ~75 m ∼115 m ∼50 m ∼65 m
Themba 8 2.2 137 142 ± 0.9 – 142 ± 0.4 – 141 ± 0.2 –
(26.5 ± 0.2) (49.8 ± 0.1) (75.4 ± 0.1)
Tumelo 9 5.5 155 157 ± 0.2 – 159 ± 0.5 – 157 ± 0.7 –
(27.6 ± 0.1) (48.9 ± 0.1) (73.5 ± 0.5)
Thandi 9 10.5 200 198 ± 0.1 – 205 ± 0.8 – 203 ± 0.4 –
(24.9 ± 0.1) (49.3 ± 0.1) (75.7 ± 0.1)
Jabu 9 12 201 199 ± 1.2 – 202 ± 0.5 – 201 ± 0.5 –
(25.6 ± 0.1) (49.0 ± 0.1) (74.7 ± 0.1)
Maroela 9 10.5 202 205 ± 0.6 – 205 ± 0.2 – 203 ± 0.7 –
(26.1 ± 0.1) (49.6 ± 0.1) (75.1 ± 0.1)
Khumba 9 11.5 211 211 ± 0.7 – 215 ± 0.4 – 211 ± 1.9 –
(26.5 ± 0.4) (50.8 ± 0.1) (73.6 ± 0.1)
Mosadi 9 12 211 213 ± 0.6 – 217 ± 1.1 – 216 ± 0.4 –
(26.1 ± 0.3) (49.8 ± 0.1) (76.3 ± 0.1)
Sappi 8 18 255 – 254 ± 0.5 – 258 ± 0.5 – 258 ± 0.8
(29.2 ± 0.1) (62.6 ± 0.1) (115.7 ± 0.1)
Sharu 8 19 257 – 258 ± 0.4 – 258 ± 0.6 – 260 ± 0.4
(37.3 ± 0.1) (68.4 ± 0.1) (120.1 ± 0.1)
Chikwenya 9 19 259 – 254 ± 0.4 – 258 ± 0.9 – 257 ± 0.3
(30.8 ± 0.1) (66.6 ± 0.3) (119.1 ± 0.1)
Mana 8 19.5 262 – 263.5 ± 0.8 – 264 ± 0.2 – 266 ± 0.5
(32.4 ± 0.1) (66.1 ± 0.1) (119.1 ± 0.1)
Michael 8 19.5 266 – 267 ± 1.2 – 264 ± 0.3 – 264 ± 0.8
(30.3 ± 0.2) (62.4 ± 0.1) (115.2 ± 0.1)