Species . | Body mass (kg) . | Body length (m) . | Maximum relative running speed (body length s-1) . | References . |
---|---|---|---|---|
Proboscidae | ||||
Loxodonta africana | 6000 | 6.75 | 1.40 | 2,7 |
Elephas maximus | 4000 | 5.95 | 1.18 | 1,2 |
Perissodactyla | ||||
Ceratotherium simum | 2000 | 3.78 | 1.79 | 5,7 |
Diceros bicornis | 1200 | 3.38 | 3.60 | 5,7 |
Equus caballus | 350 | 2.50 | 7.56 | 5,7 |
Equus zebra | 300 | 2.35 | 7.35 | 2,7 |
Tapirus bairdii | 250 | 2.08* | 5.18 | 5,6 |
Equus burchelli | 235 | 2.32 | 8.16 | 5,7 |
Equus hemionus | 200 | 2.25 | 8.40 | 5,7 |
Artiodactyla | ||||
Hippopotamus amphibius | 3800 | 3.98 | 1.70 | 2,7 |
Giraffa cameolopardalis | 1075 | 4.27 | 3.80 | 5,7 |
Bison bison | 865 | 2.80 | 5.40 | 5,7 |
Bos sauveli | 800 | 2.16 | 3.62 | 2,7 |
Syncerus caffer | 620 | 2.75 | 5.60 | 5,7 |
Camelus dromedarius | 550 | 2.85 | 3.03 | 5,7 |
Taurotragus oryx | 511 | 2.63 | 7.20 | 5,7 |
Alces alces | 384 | 2.77 | 5.47 | 5,7 |
Cervus elaphus | 300 | 2.15 | 9.04 | 2,7 |
Connochaetes gnu | 300 | 2.21* | 10.97 | 2,6 |
Hippotragus equinus | 226.5 | 2.28 | 6.65 | 5,7 |
Connochaetes taurinis | 216 | 1.98* | 10.88 | 5,6 |
Alcelaphus buselaphus | 136 | 1.98 | 10.94 | 5,7 |
Damaliscus lunatus | 130 | 1.63 | 11.63 | 5,7 |
Oreamnos americanus | 113.5 | 1.40 | 6.36 | 5,7 |
Rangifer tarandus | 100 | 1.70 | 12.71 | 5,7 |
Lama guanacoe | 95 | 1.73 | 8.77 | 5,7 |
Ovis canadensis nelsoni | 85 | 1.45 | 8.96 | 1,5 |
Phacochoerus aethiopicus | 85 | 1.20 | 12.38 | 2,7 |
Odocoileus hemionus | 74 | 1.39* | 11.87 | 5,6 |
Capra caucasia | 70 | 1.58 | 7.71 | 2,7 |
Ovis ammon | 65 | 1.50 | 10.80 | 2,7 |
Gazella granti | 62.5 | 1.31* | 16.67 | 5,6 |
Odocoileus virginianus | 57 | 1.27* | 13.59 | 5,6 |
Dama dama | 55 | 1.53 | 11.51 | 5,7 |
Aepyceros melampus | 53.25 | 1.30 | 9.76 | 5,7 |
Antilocapra americana | 50 | 1.25 | 21.60 | 2,5,7 |
Capreolus capreolus | 50 | 1.23 | 13.17 | 2,7 |
Rupicapra rupicapra | 50 | 1.10 | 9.82 | 2,7 |
Antilope cervicapra | 37.5 | 1.20 | 23.63 | 5,7 |
Saiga tatarica | 35 | 1.20 | 18.00 | 5,7 |
Antidorcas marsupialis | 34 | 1.30 | 20.15 | 2,7 |
Gazella subgutturosa | 30 | 1.03* | 25.51 | 2,6 |
Procapra gutturosa | 30 | 1.22 | 17.78 | 2,7 |
Capra aegagrus | 30 | 1.40 | 8.68 | 2,7 |
Gazella thomsonii | 20.5 | 0.904* | 24.19 | 5,6 |
Madoqua kirki | 5 | 0.620 | 18.29 | 5,7 |
Carnivora | ||||
Ursus maritimus | 265 | 2.35 | 4.60 | 1,7 |
Ursus arctos | 251.3 | 2.25 | 5.76 | 5,7 |
Panthera tigris | 161 | 2.10 | 7.20 | 5,7 |
Panthera leo | 155.8 | 1.95 | 8.17 | 5,7 |
Carnivora | ||||
Ursus americanus | 93.4 | 1.65 | 7.85 | 1,5 |
Acinonyx jubatus | 58.8 | 1.31 | 22.67 | 5,7 |
Panthera pardus | 52.4 | 1.41 | 11.49 | 5,7 |
Crocuta crocuta | 52 | 1.30 | 13.46 | 5,7 |
Canis lupus | 35.3 | 1.22 | 14.13 | 5,7 |
Hyaena hyaena | 26.8 | 1.11 | 12.13 | 5,7 |
Canis familiaris | 25 | 0.966* | 18.73 | 2,6 |
Lycaon pictus | 20 | 0.940 | 20.11 | 2,7 |
Canis latrans | 13.3 | 0.875 | 20.06 | 5,7 |
Meles meles | 11.6 | 0.736 | 11.01 | 5,7 |
Canis aureus | 8.8 | 0.830 | 18.22 | 5,7 |
Procyon lotor | 7 | 0.508 | 12.77 | 5,7 |
Canis mesomelas o adustus | 7 | 0.631* | 25.66 | 2,6 |
Vulpes fulva | 4.8 | 0.678 | 28.69 | 5,7 |
Nasua narica | 4.4 | 0.540 | 13.50 | 5,7 |
Urocyon cinereoargenteus | 3.7 | 0.584 | 29.59 | 5,7 |
Mephitis mephitis | 2.5 | 0.330 | 13.09 | 5,7 |
Primates | ||||
Gorilla gorilla | 127 | 1.66* | 5.20 | 2,6 |
Homo sapiens | 70 | 1.36 | 7.93 | 2,7 |
Presbytis | 13 | 0.515 | 19.40 | 2,7 |
Rodentia | ||||
Marmota monax | 4 | 0.450 | 9.60 | 2,7 |
Uromys caudimaculatus | 1.18 | 0.270 | 16.63 | 4,7 |
Sciurus niger | 1.078 | 0.338* | 19.17 | 4,6 |
Spermophilopsis leptodactylus | 0.6 | 0.278* | 34.98 | 2,6 |
Spermophilus undulatus | 0.6 | 0.278* | 19.43 | 2,6 |
Spermophilus citellus | 0.5 | 0.261* | 18.59 | 2,6 |
Sciurus carolinensis | 0.5 | 0.261* | 30.98 | 4,6 |
Sciurus vulgaris and persicus | 0.4 | 0.243* | 22.25 | 2,6 |
Spermophilus beldingi | 0.3 | 0.220* | 15.92 | 2,6 |
Rattus | 0.25 | 0.190 | 13.78 | 2,7 |
Spermophilus saturatus | 0.222 | 0.199* | 30.06 | 4,6 |
Tamiasciurus hudsonicus | 0.22 | 0.198 | 20.51 | 2,7 |
Spermophilus tridecemlineatus | 0.125 | 0.164* | 20.02 | 4,6 |
Spermophilus tereticaudus | 0.1126 | 0.159* | 25.82 | 3,6 |
Neotoma lepida | 0.1106 | 0.190 | 24.30 | 3,7 |
Mesocricetus brandti | 0.11 | 0.175 | 13.89 | 2,7 |
Tamias striatus | 0.1 | 0.323 | 14.21 | 2,7 |
Dipodomys deserti | 0.0976 | 0.152* | 26.73 | 3,6 |
Ammospermophilus leucurus | 0.0759 | 0.153 | 30.45 | 3,7 |
Pseudomys nanus | 0.061 | 0.130* | 30.02 | 4,6 |
Zymomys argurus | 0.0605 | 0.131 | 25.56 | 4,7 |
Dipodomys microps | 0.056 | 0.126* | 45.05 | 2,6 |
Tamias amoenus | 0.051 | 0.122 | 42.94 | 1,4 |
Microtus pennsylvanicus | 0.05 | 0.121* | 24.51 | 2,6 |
Pseudomys australis | 0.05 | 0.121* | 36.54 | 4,6 |
Heteromys dasmarestianus | 0.05 | 0.148 | 22.88 | 4,7 |
Dipodomys ordii | 0.0478 | 0.119* | 31.89 | 3,6 |
Lyomis pictus | 0.042 | 0.116 | 40.03 | 4,7 |
Chaetodipus baileyi | 0.0391 | 0.112* | 29.99 | 3,6 |
Dipodomys merriami | 0.035 | 0.108* | 80.31 | 2,6 |
Notomys cervinus | 0.035 | 0.108* | 35.14 | 4,6 |
Pitymys pinetorum | 0.03 | 0.102* | 17.97 | 2,6 |
Tamias minimus | 0.0293 | 0.101* | 44.74 | 3,6 |
Rodentia | ||||
Zapus trinotatus | 0.0285 | 0.100* | 38.44 | 4,6 |
Peromyscus leucopus | 0.025 | 0.0961* | 30.89 | 2,6 |
Napeozapus insignis | 0.025 | 0.0900 | 25.80 | 2,7 |
Notomys alexis | 0.0245 | 0.0955* | 37.04 | 4,6 |
Perognathus parvus | 0.0244 | 0.0954* | 35.39 | 3,6 |
Peromyscus eremicus | 0.0198 | 0.0889* | 39.77 | 3,6 |
Peromyscus truei | 0.0193 | 0.0882* | 43.78 | 3,6 |
Onychomys torridus | 0.0193 | 0.115 | 24.29 | 3,1 |
Peromyscus maniculatus | 0.0182 | 0.0865* | 41.84 | 3,6 |
Chaetodipus fallax | 0.018 | 0.0862* | 40.12 | 3,6 |
Zapus hudsonicus | 0.018 | 0.0862* | 27.89 | 2,6 |
Pseudomys hermannbergensis | 0.018 | 0.0862* | 39.49 | 4,6 |
Mus musculus | 0.016 | 0.0800 | 43.88 | 2,7 |
Leggadina forresti | 0.0155 | 0.0820 | 41.51 | 4,7 |
Peromyscus crinitus | 0.0137 | 0.0786* | 39.14 | 3,6 |
Microdipodops megacephalus | 0.0123 | 0.0759 | 38.79 | 3,7 |
Perognathus longimembris | 0.0089 | 0.0681* | 39.26 | 3,6 |
Lagomorpha | ||||
Lepus arcticus | 4.6 | 0.549* | 31.49 | 2,6 |
Lepus alleni | 4.4 | 0.541* | 35.96 | 2,6 |
Lepus europeus | 4 | 0.524 | 37.12 | 1,2 |
Lepus townsendii | 3.5 | 0.501* | 30.19 | 2,6 |
Lepus californicus | 2 | 0.415 | 41.59 | 1,2 |
Oryctolagus cuniculus | 1.9 | 0.400 | 37.80 | 2,7 |
Lepus americanus | 1.5 | 0.377 | 35.77 | 1,2 |
Sylvilalagus | 1.5 | 0.343 | 31.49 | 2,7 |
Marsupialia | ||||
Macropus spp | 50 | 1.22* | 14.42 | 4,6 |
Macropus eugenii | 4 | 0.477 | 22.64 | 1,4 |
Bettongia penicilata | 1.1 | 0.365 | 18.35 | 4,7 |
Potorus tridactylus | 0.998 | 0.329 | 17.56 | 4,7 |
Isoodon obesulus | 0.718 | 0.320 | 12.07 | 4,7 |
Dasyuroides byrnei | 0.12 | 0.225 | 31.68 | 4,7 |
Monodelphis brevicaudata | 0.0745 | 0.159 | 19.86 | 4,7 |
Antechinus flavipes | 0.052 | 0.155 | 29.03 | 1,4 |
Antechinus stuardii | 0.0315 | 0.123* | 39.26 | 4,6 |
Antechinomys laniger | 0.025 | 0.104* | 38.76 | 4,6 |
Sminthopsis macroura | 0.02 | 0.0961* | 40.54 | 4,6 |
Sminthopsis crassicaudata | 0.017 | 0.0892* | 34.82 | 4,6 |
Cercatetus concinnus | 0.015 | 0.0845 | 15.92 | 4,7 |
Myrmecobius fasciatus | 0.48 | 0.0950 | 39.60 | 4,7 |
Species . | Body mass (kg) . | Body length (m) . | Maximum relative running speed (body length s-1) . | References . |
---|---|---|---|---|
Proboscidae | ||||
Loxodonta africana | 6000 | 6.75 | 1.40 | 2,7 |
Elephas maximus | 4000 | 5.95 | 1.18 | 1,2 |
Perissodactyla | ||||
Ceratotherium simum | 2000 | 3.78 | 1.79 | 5,7 |
Diceros bicornis | 1200 | 3.38 | 3.60 | 5,7 |
Equus caballus | 350 | 2.50 | 7.56 | 5,7 |
Equus zebra | 300 | 2.35 | 7.35 | 2,7 |
Tapirus bairdii | 250 | 2.08* | 5.18 | 5,6 |
Equus burchelli | 235 | 2.32 | 8.16 | 5,7 |
Equus hemionus | 200 | 2.25 | 8.40 | 5,7 |
Artiodactyla | ||||
Hippopotamus amphibius | 3800 | 3.98 | 1.70 | 2,7 |
Giraffa cameolopardalis | 1075 | 4.27 | 3.80 | 5,7 |
Bison bison | 865 | 2.80 | 5.40 | 5,7 |
Bos sauveli | 800 | 2.16 | 3.62 | 2,7 |
Syncerus caffer | 620 | 2.75 | 5.60 | 5,7 |
Camelus dromedarius | 550 | 2.85 | 3.03 | 5,7 |
Taurotragus oryx | 511 | 2.63 | 7.20 | 5,7 |
Alces alces | 384 | 2.77 | 5.47 | 5,7 |
Cervus elaphus | 300 | 2.15 | 9.04 | 2,7 |
Connochaetes gnu | 300 | 2.21* | 10.97 | 2,6 |
Hippotragus equinus | 226.5 | 2.28 | 6.65 | 5,7 |
Connochaetes taurinis | 216 | 1.98* | 10.88 | 5,6 |
Alcelaphus buselaphus | 136 | 1.98 | 10.94 | 5,7 |
Damaliscus lunatus | 130 | 1.63 | 11.63 | 5,7 |
Oreamnos americanus | 113.5 | 1.40 | 6.36 | 5,7 |
Rangifer tarandus | 100 | 1.70 | 12.71 | 5,7 |
Lama guanacoe | 95 | 1.73 | 8.77 | 5,7 |
Ovis canadensis nelsoni | 85 | 1.45 | 8.96 | 1,5 |
Phacochoerus aethiopicus | 85 | 1.20 | 12.38 | 2,7 |
Odocoileus hemionus | 74 | 1.39* | 11.87 | 5,6 |
Capra caucasia | 70 | 1.58 | 7.71 | 2,7 |
Ovis ammon | 65 | 1.50 | 10.80 | 2,7 |
Gazella granti | 62.5 | 1.31* | 16.67 | 5,6 |
Odocoileus virginianus | 57 | 1.27* | 13.59 | 5,6 |
Dama dama | 55 | 1.53 | 11.51 | 5,7 |
Aepyceros melampus | 53.25 | 1.30 | 9.76 | 5,7 |
Antilocapra americana | 50 | 1.25 | 21.60 | 2,5,7 |
Capreolus capreolus | 50 | 1.23 | 13.17 | 2,7 |
Rupicapra rupicapra | 50 | 1.10 | 9.82 | 2,7 |
Antilope cervicapra | 37.5 | 1.20 | 23.63 | 5,7 |
Saiga tatarica | 35 | 1.20 | 18.00 | 5,7 |
Antidorcas marsupialis | 34 | 1.30 | 20.15 | 2,7 |
Gazella subgutturosa | 30 | 1.03* | 25.51 | 2,6 |
Procapra gutturosa | 30 | 1.22 | 17.78 | 2,7 |
Capra aegagrus | 30 | 1.40 | 8.68 | 2,7 |
Gazella thomsonii | 20.5 | 0.904* | 24.19 | 5,6 |
Madoqua kirki | 5 | 0.620 | 18.29 | 5,7 |
Carnivora | ||||
Ursus maritimus | 265 | 2.35 | 4.60 | 1,7 |
Ursus arctos | 251.3 | 2.25 | 5.76 | 5,7 |
Panthera tigris | 161 | 2.10 | 7.20 | 5,7 |
Panthera leo | 155.8 | 1.95 | 8.17 | 5,7 |
Carnivora | ||||
Ursus americanus | 93.4 | 1.65 | 7.85 | 1,5 |
Acinonyx jubatus | 58.8 | 1.31 | 22.67 | 5,7 |
Panthera pardus | 52.4 | 1.41 | 11.49 | 5,7 |
Crocuta crocuta | 52 | 1.30 | 13.46 | 5,7 |
Canis lupus | 35.3 | 1.22 | 14.13 | 5,7 |
Hyaena hyaena | 26.8 | 1.11 | 12.13 | 5,7 |
Canis familiaris | 25 | 0.966* | 18.73 | 2,6 |
Lycaon pictus | 20 | 0.940 | 20.11 | 2,7 |
Canis latrans | 13.3 | 0.875 | 20.06 | 5,7 |
Meles meles | 11.6 | 0.736 | 11.01 | 5,7 |
Canis aureus | 8.8 | 0.830 | 18.22 | 5,7 |
Procyon lotor | 7 | 0.508 | 12.77 | 5,7 |
Canis mesomelas o adustus | 7 | 0.631* | 25.66 | 2,6 |
Vulpes fulva | 4.8 | 0.678 | 28.69 | 5,7 |
Nasua narica | 4.4 | 0.540 | 13.50 | 5,7 |
Urocyon cinereoargenteus | 3.7 | 0.584 | 29.59 | 5,7 |
Mephitis mephitis | 2.5 | 0.330 | 13.09 | 5,7 |
Primates | ||||
Gorilla gorilla | 127 | 1.66* | 5.20 | 2,6 |
Homo sapiens | 70 | 1.36 | 7.93 | 2,7 |
Presbytis | 13 | 0.515 | 19.40 | 2,7 |
Rodentia | ||||
Marmota monax | 4 | 0.450 | 9.60 | 2,7 |
Uromys caudimaculatus | 1.18 | 0.270 | 16.63 | 4,7 |
Sciurus niger | 1.078 | 0.338* | 19.17 | 4,6 |
Spermophilopsis leptodactylus | 0.6 | 0.278* | 34.98 | 2,6 |
Spermophilus undulatus | 0.6 | 0.278* | 19.43 | 2,6 |
Spermophilus citellus | 0.5 | 0.261* | 18.59 | 2,6 |
Sciurus carolinensis | 0.5 | 0.261* | 30.98 | 4,6 |
Sciurus vulgaris and persicus | 0.4 | 0.243* | 22.25 | 2,6 |
Spermophilus beldingi | 0.3 | 0.220* | 15.92 | 2,6 |
Rattus | 0.25 | 0.190 | 13.78 | 2,7 |
Spermophilus saturatus | 0.222 | 0.199* | 30.06 | 4,6 |
Tamiasciurus hudsonicus | 0.22 | 0.198 | 20.51 | 2,7 |
Spermophilus tridecemlineatus | 0.125 | 0.164* | 20.02 | 4,6 |
Spermophilus tereticaudus | 0.1126 | 0.159* | 25.82 | 3,6 |
Neotoma lepida | 0.1106 | 0.190 | 24.30 | 3,7 |
Mesocricetus brandti | 0.11 | 0.175 | 13.89 | 2,7 |
Tamias striatus | 0.1 | 0.323 | 14.21 | 2,7 |
Dipodomys deserti | 0.0976 | 0.152* | 26.73 | 3,6 |
Ammospermophilus leucurus | 0.0759 | 0.153 | 30.45 | 3,7 |
Pseudomys nanus | 0.061 | 0.130* | 30.02 | 4,6 |
Zymomys argurus | 0.0605 | 0.131 | 25.56 | 4,7 |
Dipodomys microps | 0.056 | 0.126* | 45.05 | 2,6 |
Tamias amoenus | 0.051 | 0.122 | 42.94 | 1,4 |
Microtus pennsylvanicus | 0.05 | 0.121* | 24.51 | 2,6 |
Pseudomys australis | 0.05 | 0.121* | 36.54 | 4,6 |
Heteromys dasmarestianus | 0.05 | 0.148 | 22.88 | 4,7 |
Dipodomys ordii | 0.0478 | 0.119* | 31.89 | 3,6 |
Lyomis pictus | 0.042 | 0.116 | 40.03 | 4,7 |
Chaetodipus baileyi | 0.0391 | 0.112* | 29.99 | 3,6 |
Dipodomys merriami | 0.035 | 0.108* | 80.31 | 2,6 |
Notomys cervinus | 0.035 | 0.108* | 35.14 | 4,6 |
Pitymys pinetorum | 0.03 | 0.102* | 17.97 | 2,6 |
Tamias minimus | 0.0293 | 0.101* | 44.74 | 3,6 |
Rodentia | ||||
Zapus trinotatus | 0.0285 | 0.100* | 38.44 | 4,6 |
Peromyscus leucopus | 0.025 | 0.0961* | 30.89 | 2,6 |
Napeozapus insignis | 0.025 | 0.0900 | 25.80 | 2,7 |
Notomys alexis | 0.0245 | 0.0955* | 37.04 | 4,6 |
Perognathus parvus | 0.0244 | 0.0954* | 35.39 | 3,6 |
Peromyscus eremicus | 0.0198 | 0.0889* | 39.77 | 3,6 |
Peromyscus truei | 0.0193 | 0.0882* | 43.78 | 3,6 |
Onychomys torridus | 0.0193 | 0.115 | 24.29 | 3,1 |
Peromyscus maniculatus | 0.0182 | 0.0865* | 41.84 | 3,6 |
Chaetodipus fallax | 0.018 | 0.0862* | 40.12 | 3,6 |
Zapus hudsonicus | 0.018 | 0.0862* | 27.89 | 2,6 |
Pseudomys hermannbergensis | 0.018 | 0.0862* | 39.49 | 4,6 |
Mus musculus | 0.016 | 0.0800 | 43.88 | 2,7 |
Leggadina forresti | 0.0155 | 0.0820 | 41.51 | 4,7 |
Peromyscus crinitus | 0.0137 | 0.0786* | 39.14 | 3,6 |
Microdipodops megacephalus | 0.0123 | 0.0759 | 38.79 | 3,7 |
Perognathus longimembris | 0.0089 | 0.0681* | 39.26 | 3,6 |
Lagomorpha | ||||
Lepus arcticus | 4.6 | 0.549* | 31.49 | 2,6 |
Lepus alleni | 4.4 | 0.541* | 35.96 | 2,6 |
Lepus europeus | 4 | 0.524 | 37.12 | 1,2 |
Lepus townsendii | 3.5 | 0.501* | 30.19 | 2,6 |
Lepus californicus | 2 | 0.415 | 41.59 | 1,2 |
Oryctolagus cuniculus | 1.9 | 0.400 | 37.80 | 2,7 |
Lepus americanus | 1.5 | 0.377 | 35.77 | 1,2 |
Sylvilalagus | 1.5 | 0.343 | 31.49 | 2,7 |
Marsupialia | ||||
Macropus spp | 50 | 1.22* | 14.42 | 4,6 |
Macropus eugenii | 4 | 0.477 | 22.64 | 1,4 |
Bettongia penicilata | 1.1 | 0.365 | 18.35 | 4,7 |
Potorus tridactylus | 0.998 | 0.329 | 17.56 | 4,7 |
Isoodon obesulus | 0.718 | 0.320 | 12.07 | 4,7 |
Dasyuroides byrnei | 0.12 | 0.225 | 31.68 | 4,7 |
Monodelphis brevicaudata | 0.0745 | 0.159 | 19.86 | 4,7 |
Antechinus flavipes | 0.052 | 0.155 | 29.03 | 1,4 |
Antechinus stuardii | 0.0315 | 0.123* | 39.26 | 4,6 |
Antechinomys laniger | 0.025 | 0.104* | 38.76 | 4,6 |
Sminthopsis macroura | 0.02 | 0.0961* | 40.54 | 4,6 |
Sminthopsis crassicaudata | 0.017 | 0.0892* | 34.82 | 4,6 |
Cercatetus concinnus | 0.015 | 0.0845 | 15.92 | 4,7 |
Myrmecobius fasciatus | 0.48 | 0.0950 | 39.60 | 4,7 |
Body mass and body length estimates correspond to those of average adult specimens.
Source of data on body mass, body length, and maximum running speed are indicated for each species: 1, Eisenberg(1981); 2, Garland(1983); 3, Djawdan and Garland(1988); 4, Garland et al.(1988); 5, Garland and Janis(1993); 6, Silva(1998); 7, Nowak(1999).
Values obtained from Silva's(1998) allometric equation.