The Influence of Trophy Measurement in Cape Buffalo
by Winston Taylor, Environmental Biology, Oxford Brookes University
Editor’s Note: Winston Taylor’s scientific paper (Full Title: The Influence of Trophy Measurement on the Age of Sport Hunted Buffalo, Syncerus Caffer (Sparrman), in the Zambezi Valley, Zimbabwe, and its Implications for Sustainable Trophy Hunting, 2005) has been adapted to the format of African Indaba. Due to time constraints the author could not be consulted prior to publication, hence errors and omissions are the editor’s fault.
Conserving wildlife in Africa is often difficult as it conflicts with humans and their activities. “One way to make conservation gains”, particularly in the African context, “is to capitalize on the importance of wild species in human livelihoods”. The “sustainable harvesting of plants and hunting of animals has often turned out to be a highly effective conservation measure” (Hutton, 2004). Sport hunting has a long and involved history in Africa. The appeal of the classic “African Safari” was stimulated by the likes of Ruark and Hemingway in their numerous tales of hunting and adventure in the wilds of Africa.
Hunting is an important tool in conservation although it must not be seen as conservation in itself. Commercial hunting is of great value in both the economic and ecological sense. Low offtakes of trophy animals provide good financial returns with minimal investment. Sport hunting is also a major force behind the preservation of wildlife and wild places.
The growing fragmentation of species’ habitats over the last century has led to the emergence of community based conservation whereby local communities are encouraged to value wildlife through both non-consumptive and consumptive activities (e.g. hunting) from which they receive multiple benefits. Prior to these new “radical” ways of tackling conservation, much of colonial Africa was subject to state-centric “fortress conservation”, in which rural Africans were seen as the enemy of conservation and degraders of the environment. Community conservation on the other hand encourages, through the concept of “sustainable development”, that species, habitats and biodiversity, should be seen as exploitable and managed through conservation and developmental goals.
Villagers are given a share in license fees paid by wealthy clients and suddenly see a species, such as buffalo or elephant, not as a menacing crop raider but as a highly valuable asset which should be protected. Clients will also be charged a range of fees by the government, collected either directly or on the government’s behalf by the safari operator. Such fees are likely to include a conservation fee, firearms and ammunition permit fees, trophy export fees, airport fees etc. It is through such systems that hunting can be used as a tool in conservation. However, if hunting is to be pursued in areas where wildlife resources are finite, a tight management regime has to be employed in order to ensure its sustainability. Incorrect management of the hunted wildlife would result in unstable population dynamics, diminished gene pools and ultimately loss of species from an area.
The African Cape buffalo, Syncerus caffer, is one of the classic African trophies, and consequently a key species in safari hunting. In Zimbabwe (total hunting earnings 1998: US$23 million) it is the second most important species, in monetary terms. Sport hunting is where the future of the Cape buffalo lies especially outside of formally protected areas.
Buffalo are classed as one of the “Big 5”. The very nature of buffalo make them a desirable trophy, if not the ultimate big game trophy for the hunting sportsperson. They are unpredictable and thus difficult and dangerous to get close to, hence the hunters’ skills are tested to the full and the true characteristics of a hunt – fear, fascination and adrenaline - are evoked.
Maintaining a high market value for buffalo hunting relies upon the provision of quality trophies, achieved through the implementation of trophy quota systems. Offtakes need to be carefully regulated and within biological limits. Buffalo populations typically grow at about 7% p a; however, in order to ensure quality trophies offtakes should be limited to 2% p a.
It is of concern that immature buffalo are being over hunted because of the combined effect of high off-take quotas, and the possible influence of inappropriate measurement systems. There are currently two systems of trophy measurement: the SCI method established in 1978 and the Rowland Ward method from 1892. The latter is the system of trophy measurement most traditionally used by hunters worldwide. When scoring buffalo, RW takes only the spread of the horns into account, such that older animals may score equally as well as younger animals. SCI however, in an effort to produce a more all round score, includes the depth of the curl and the width of the bosses. The use of the SCI system, with which the majority of North American clients, who form 60% of visiting clients, are familiar, is believed to be contributing to younger individuals being shot whereas the use of the RW method is believed to be supportive of more sustain- able off-takes in the long term.
In safari hunting adult buffalo bulls are selected for their trophy value. Sexual maturity is reached at 4-5 years; however, in most cases the trophy is still considered undesirable at this stage. A quality trophy is most likely a buffalo bull aged between 7 and 12 years. Professional hunters have to rely principally on the characteristics of the bull’s horns in order to determine its potential trophy quality and a possible age for the animal.
As a trophy reaches its full potential (its prime) the boss hardens forming ridges and the fully grown horns are curved in a hook shape. The tips of the horns are still sharp at this stage, but as the animals age the horn tips are worn down and the bosses become progressively smoother. Such individuals are often found in “bachelor” groups away from breeding herds; the hunting of such groups of individuals is less likely to result in the offtake of immature individuals.
However, since these groups will join the herds for breeding purposes, being able to judge the relationship between age and trophy size on a more rigorous basis would allow hunters to make better informed decisions. In doing so, the offtake of immature bulls can be prevented, which in turn would be beneficial for the sustainability of quality trophy offtake.
The SCI measurement system is thought to favor younger “soft-bossed” bulls whose horns are still yet to lose their sharp tips. It is such animals that tend to make the record books but only because the measuring system favors animals with such attributes. Of the top three scoring buffalo bulls in the SCI record books, only one is “hard-bossed”, the other two are still “soft” (i.e. still young). Hunting buffalo at this age is likely to cut short their genetic contribution within the population.
Establishing a relationship between age and trophy size using each respective scoring system would hopefully allow for better selection on an age basis and hence would contribute to the sustainable hunting of high quality trophies. It would also shed light on the importance of scoring system use and the possible need for adjustments. This study looks specifically at the relationship between the age of hunted bulls and their respective trophy sizes using, RW and SCI scoring methods. Furthermore, the age of each hunted buffalo was determined to within one year using Taylor’s age determination methods.
The study area was the Middle Zambezi Valley with hunting concessions managed by Parks & Wildlife Authority and settled Communal Land where CAMPFIRE (Communal Areas Man- agement Program for Indigenous Resources) is operational.
Dande South and Dande Communal Land are operated by Ingwe Safaris with about 45 buffalo bulls on quota out of an estimated population of 1,053 (representative of approximately ½ to ¾ of the buffalo population as aerial census results for the area were inconclusive). Dande North (CAMPFIRE) and Dande Safari Area (Parks and Wildlife) are operated by Swainson’s Safaris. Between the two areas there are about 100 buffalo bulls currently on quota out of an estimated population of 4,037 buffalo. Buffalo populations are moving freely between the two safari areas. Chewore North (Parks and Wildlife) is operated by Big Five Safaris with 55 buffalo bulls on quota from an estimated buffalo population of 1,964.
The safari areas collectively hold significant numbers of large game, ranging from elephants, hippo, buffalo, and big cats (lion, leopard) to large and small antelope. The safari operators in- volved are highly reputable and constitute some of the biggest names in safari hunting in southern Africa.
At the start of the hunting season, I requested the operators to retain and tag the lower jaws of each shot buffalo. Both RW and SCI scores were measured and recorded for each trophy. The mandibular molars were extracted from the lower jaws and the age of each shot buffalo determined. I also had the opportunity to discuss views with both clients and professional hunters. The data set obtained represents approximately two thirds of the male buffalo on quota in the concession areas for the year 2004. A total of 91 samples were collected; 29 from Dande South, 30 from Chewore North and 32 from Dande North. The data sets from Chewore North and Dande South are probably representative of the trophy buffalo populations within those areas; the data set from Dande North represents just under half of the quota for the area.
The average age of the sampled buffalo was 8.01 years. The majority of the buffalo shot (76%) were between 6 and 8 years old; the remaining 24% comprised mostly of 9 and 10 year-olds, with less than 6% of the hunted population being 11 years or older. 3% of the buffalo were considered to be truly immature (5 years in age).
Dande South exhibited the largest proportion of “young” trophies, with 52% of the sampled quota being 7 years or younger in age (25% are 6 years old). The oldest trophy is only 10 years old. Dande North exemplified a greater proportion of older trophy animals, and contains the highest percentage (40%) of 7 - 8 year-old trophies (animals in their prime). Yet there is still a relatively large percentage (25%) of young individuals (6 year olds) being shot. 16% were 10 years old and 6% reached 12 years. Chewore North has a relatively normal age structure within its hunted sample of trophy bulls, with the greatest number of bulls (35%) being shot at the prime age of 8 years. 16% of the trophies are 6 years old. There is however a sharp decline in trophies of 9 years or older and a “tail” of older animals.
Given the results of earlier studies, a more plausible explanation is that few 9, 10, 11, and 12 year-olds are being shot because bulls are being taken before they reach that age. The sustainability of trophy hunting is brought therefore into question. Data on trophy ages obtained from Big Five Safaris indicate that trophy age has been relatively stable over the previous 4 years; average ages ranging from 8.7 to 9.9. Ageing of buffalo bulls has also been taking place in Dande North, with the average age ranging from 8 in 2001 to 10 in 2002 and back to 9 in 2003. However, it has since been established that teeth had not been extracted resulting in overestimation of the actual ages. This said the data is still relevant since it provides evidence of relative stability in trophy age in Chewore North and Dande North.
According to estimated population figures from an aerial census in 2001, the offtake in all three areas exceeds the recommended 2% pa. The estimated buffalo population of Dande North in 2001 was 4037; more recently the same population, from visual estimates on the ground, is judged to be about 5500 animals. If this is the case then the set quota for 2004 is just under the recommended 2%. Although Chewore North and Dande South both have large buffalo populations, the evidence suggests that the recommended offtake of 2% pa has been exceeded. It is also likely that that quota setting is affected by the different management systems employed between Chewore North and Dande North and South.
It would appear that the average trophy scores (from Chewore North, Dande North and Dande South) are satisfactory for the majority of clients. Whether this is really the case or not is an interesting question. The nature of the desired trophy changes somewhat depending on the client nationality; European clients, especially German and Austrian, tend to prefer “character” trophies, which are usually older animals, the emphasis being on trophy individuality and not size or score. American clients, (60% of the safari client) are inclined towards hunting individuals for their trophy size.
But hunting and trophy selection is not an exact science. Ul- timately a client will shoot the trophy which, in his mind, is best, and has the backing opinion of the professional hunter, who after all is the client’s “visual measurement method.
Hunting buffalo is no easy task, and the absence of any truly mature animals could be attributed to the “pressures” of hunting and ultimately, chance. The “pressures” of hunting involve limited time frames, fussy clients, “co-operative” buffalo and of course an element of luck. Whilst these previous two scenarios are possible, the most obvious factor explaining the lack of old trophy buffalo is simply that there are very few old buffalo within the population. Death by natural means is more likely to occur as buffalo age, and is usually around 14 years or older amongst unexploited (protected) wild buffalo populations.
The average Rowland Ward (RW) score was 36.98 inches with “40 inch” buffalo considered the bench mark for a good quality trophy. The average SCI score was 96.26 inches, just short of the bench mark SCI trophy score of 100 inches.
Correlation between trophy size and animal age using the RW method indicate that scores decrease minimally with age. The SCI scoring method indicates in contrast the possibility of a strong relationship between trophy size and animal age and scores decrease markedly with age. The difference becomes apparent in the different classification of a “record trophy”.
The minimum score for the SCI record book is 100 inches. The minimum score for RW is 42 inches. Of the 91 samples taken over the duration of this study, only 4 were eligible for entry into the RW record book, whilst an astounding 34 were eligible for entry into the SCI record book. In terms of RW, only 20 of the buffalo had a trophy score equaling or exceeding the bench mark of 40 inches. The implications of this are that clients are more likely to aim for trophies with an SCI score of 100; not only have they succeeded in achieving the “100 inch” bench mark, but they also have the opportunity to have their names written down in the annals.
We conclude that there is a significant difference between the RW and SCI scoring systems relative to animal age and younger animals’ trophy attributes are biased by the SCI scoring system in relation to older trophy animals. Trophy bulls are most likely to be shot in their prime when all attributes of the animals horns are considered to be most appealing to the hunter. This is reflected in the average trophy age of 8 years. The average age for the three sample areas in this study is “pulled up” by the presence of a “long tail” of older individuals. The current high offtake of 6-8 year-olds in this study is possibly a sign of a downward trend in relation to buffalo offtake age, and if so, the notion of sustainable trophy hunting is at risk.
Statistical analysis shows that there is a significant relation- ship between trophy size and age when using the SCI measurement system and not the RW system. Furthermore, the SCI system is shown to favor younger animals more than previously thought. RW trophy scores on the other hand, decline only minimally with age. The point is that a buffalo bull that scores well on the SCI scale is likely to be a young, if not immature individual. If trophy buffalo are being and continue to be shot at ages, which on average are progressively younger, the sustainable hunting of quality trophy buffalo in the Middle Zambezi Valley is doubtful over the long term.
Possible reasons for this are 2-fold. The quotas set by local councils, whilst allowing sustainable offtake, are too high for sustained trophy quality. Secondly, professional hunters and their clients are ultimately responsible for trophy selection; their attitudes towards selection are important. Adopting the “if I don’t take it now, the next hunter will” attitude is an unfortunate reality, particularly in relation to young animals that already possess all the attributes of a good trophy. The manner and method of hunting is also important; hunting individuals out of herds, will most often result in the offtake of younger bulls, whilst the hunting of “bachelor” groups is more likely to result in the offtake of an indi- vidual in or beyond its prime.
The SCI scoring method uses attributes of the buffalo’s horns which are best developed in young animals, and whilst this is the case, young animals will continue to be shot. At the same time, RW scoring methods are also inadequate since different buffalo populations have different genetic tendencies for larger or smaller outside spreads. As a result alternative scoring methods have been proposed by Gandy and Reilly (2004). It is based upon a “multiplication factor that is created by dividing the horn tip space measurements, the mean of the two individual horn lengths and then squaring the result”. Thus a good trophy will exhibit typical attributes of an old animal:
- a wide tip space in relation to individual horn lengths
- a wide outside spread
- large boss widths
- small boss space (distance between inner edges).
However this last factor, as acknowledged by the authors, and observed during the data collection in this study, is subject
to increase in older animals (12+ years of age). It has also been suggested that the current SCI system be adjusted by weighting the boss scores by doubling them, thereby encouraging hunters to take older animals with better developed bosses.
The sustainable hunting of trophy quality buffalo relies upon setting realistic quotas, which in the cases of Chewore North, Dande North and Dande South, would result in a cutting back of the present quotas. Not only is a sustainable quota important, but so too is the trophy selection by professional hunters and their clients; sustainable hunting necessitates that offtake does not include young animals.
The adaptation of current scoring systems to favor older animals would be an important step in allowing the establishment of an older “trophy” population.
The hunting industry is important not only to the economy of Zimbabwe, but also to the many people whose livelihoods are reliant upon it. Zimbabwe has long been regarded as a premier safari destination; the high standards of professionalism within the safari industry and the high quality hunting offered, have together created this reputation.
Maintaining the quality of hunting also involves maintaining and ensuring trophy quality, for all species alike, such that the country and future generations will still be able to benefit from the industry, as they do today.