Measuring Large African Predators
by HO de Waal, University of the Free State
Conversations among wildlife enthusiasts, especially hunters, usually include references to the size of animals. Although specific dimensions may be referred to, interpretation by the audience is open to differing perceptions. Acceptingvariation as a basic principle of biology means that body dimensionsof animals must vary. Although some body measurements can be taken with great accuracy, differences in measuring techniques contribute to variation. Applying standard procedures when collecting data for morphometric analysis can reduce this variation.
Dr. G.L. Smuts took body measurements from 158 male and 186 female African lions in the Central District of the Kruger National Park between 1974 and 1978. Smuts et al. (1980) stated: “Despite many wild lions (Panthera leo)
having been handled both dead and immobilized in the past, surprisingly little has been published on aspects of their growth or even the average weights or body dimensions of adult specimens. ”In this regard, Dr. B. Bertram described already in 1975 how he weighed large male lions single-handedly. "Weighing large animals does not necessarily require huge tripods, trees, spring balances and teams of assistants. I am grateful to Dr J.M. King for suggesting the use of bathroom scales for weighing immobilized lions. I carried six lengths of angle iron and four wooden planks 30 cm wide; all were 120 cm long, and so fitted conveniently into a small vehicle. These components could be bolted together in 4 min to produce a platform roughly 120 cm by 200 cm. This was placed close to the back of the immobilized lion, which was then rolled over onto it and pushed to the centre of the platform. A set of low flat bathroom scales was placed underneath each end. With the platform with the lion then balanced on the two sets of scales, the reading of each scale was taken; their sum, minus the weight of the platform, gave the weight of the lion. With this system, it was possible to weigh a lion of 200 kg alone and without assistance, and with a minimum of disturbance. A slightly larger platform with four sets of scales would enable one to weigh considerably heavier animals."
Why then are animals and specifically the larger African predators not measured when the opportunity arises? Measuring the bodies of immobilized large animals is time consuming and has to compete with activities such as collecting bio- logical samples (e.g. blood), fitting radio collars or just the inevitable time constraints of a tourist hunter on a two or three week safari. Furthermore, animals are often subjected by operators to a range of different measuring techniques. The African trophy hunter may register trophy size of animals in three major record books (SCI, Rowland Ward, CIC). RW and SCI measure the greatest length and width of the skull and add the two figures (RW method 17, SCI method 15), CIC uses the Boone & Crockett method which also scores the total of greatest length and width, however measurements are taken on the cranium without the lower jaw attached. The scores are measured to the nearest 1/16 of an inch. Only SCI lists the body measurements of darted carnivores. The score is the sum of the length of body including tail between pegs;circumference of chest and circumference of head, measured to the nearest 1/8 of an inch (SCI Method 16-D). It is optional to provide the weight of the animal in this category.
However, the procedure of registering trophies in record books is not satisfactory because of an important bias. Only data of the some animals are registered since many hunters do not register their trophies at all and the SCI record book is restricted to SCI members only. Rowland Ward’s 26thedition lists only about 500 lion skulls over a period of about 100 years. Important data is therefore lost to science and conservation efforts.
In February 2002, ALPRU (African Large Predator Research Unit, University of the Free State) started a database on the body mass and dimensions of large African predators. We developed standardized procedures to measure specimens and record data collected from dead or immobilized large African predators. For example, for an adult male African lion, with its mane extending down to the abdomen, 45 variables are taken. The objective is to develop non-invasive techniques to determine whether wild animals might have been subjected to subnormal growth and development; primarily as result of their habitat and food variation. Are the animals large enough and well developed for their age?
There is a concern that trophy quality of African lions is declining. Recently Karyl Whitman [African Indaba (2), 14- 15] suggested that measurements of lion skull size and body size should be recorded for all legally hunted African lionand a qualitative mane assessment should be introduced.
The procedures proposed by ALPRU can assist here. We suggest that professional hunters should measure all variables on all hunted large predators. Measuring instructions are available on request. African Indaba and the African Chapter strongly recommend that members should cooperate with ALPRU in data collection. Please contact them at African Large Predator Research Unit (ALPRU), Dept Animal, Wildlife and Grassland Sciences (70), Faculty of Natural and Agricultural Sciences, University of the Free State, PO Box 339, Bloemfontein 9300, RSA. Email: ALPRU@sci.uovs.ac.za.
References: Bertram, B.C.R., 1975. Weights and measures of lions. East African Wildlife Journal
13, 141-143. Smuts, G.L., Robinson, G.A. & Whyte, I.J., 1980. Comparative growth of wild male and female lions (Panthera leo)
. Journal of Zoology, London