The Ecology of Browsing and Grazing II

Abstract

About fifty years ago, when I, as a young comparative anatomist, first looked at awild ruminant -- the European roe deer -- the basic thinking concerning the ecology,behaviour, physiology and anatomy of ruminants was based on domesticated grazers,namely sheep and cattle. I could not believe the customary view that the roe deer wasnothing more than a mini-cow with a choosy predilection for flowering herbs, tenderleaves and shoots. Already my comparison of a red deer stomach with that of a roedeer caused me to bring to mind the different evolutionary traits of cervids as comparedwith bovids, of which Europe has but a few wild species left. At that time, therewas no thought of integrated management of vegetation and herbivores: huntersaimed for higher game densities, foresters considered (and still do) browsers a pest,to be reduced if not eliminated from their planted forests, and advocates of animalwelfare agitated against hunting. All this has negatively influenced any seriousattempt to develop sustained yield concepts, certainly in Central Europe.Thus I was overwhelmed by the living demonstration of bovid evolutionary`explosion' and niche separation between extant species, when I came to studylarge herbivores in East Africa for ten years prior to decolonisation (the `Uhuru' of1963). When I first presented some of my morphological findings on Africanherbivores at a London Symposium in 1966, the audience encouraged me to extendand deepen my observations systematically. This lead in 1972, initially in collaborationwith the British botanist and wildlife researcher Don Stewart, to a classificationof ruminants into three feeding types -- first recognising a dichotomic evolutionwith numerous intermediate forms, a system in common use today.We have to remember that mammalian digestive tracts (of carnivores, omnivoresand herbivores) are extremely set and conservative -- the result of evolution; this isespecially the case with foregut-fermenting herbivores. Ruminant evolution beyondtragulids proceeded over more than 25 million years apparently not step by step(like a ladder), but frequently in parallel fashion, like the growth pattern of a bushor baobab tree. This is why we find extant frugivorous and browsing concentrateselectors (both large and small) in dominant numbers in three of the four ruminantfamilies, but almost no true bulk and roughage grazers (except the P{è}re David'sdeer) amongst the cervids. In contrast, we see most of the grazers, stimulated bychanging climate and following the spread of the grasses, amongst the Bovidae.vBrowsers, irrespective of the family they belong to, have retained their archaicmorphophysiological features, which evolved before grasses became the dominantplants under the then-prevailing climatic conditions. Browsers are poorly adapted todigesting the structural carbohydrates within grasses, yet browsers have successfullyremained within the large herbivore spectrum for more than 10 million years. If it isthe browsers that, according to the elaborate analyses and conclusions of this stimulatingbook, will be the prime winners of the global future, one can only hope and praythat the type of collaboration between scientists and ecosystem managers (includingforesters and agronomists) which the editors appeal for will come to pass.After a long and active life in the field of basic and applied herbivore wildliferesearch, I feel honoured and encouraged by the authors and especially by theeditors of this future-oriented volume to contribute a foreword, with all my goodwishes for a worldwide positive reception not only of this book but also of thefascinating animals which, I strongly believe, must remain the gentle modifiersof our landscapes and perhaps even of our anthropocentric view of this world'snature.