The relationship between large ungulate body weight and faecal pellet weight

Abstract

Summary The pelleted dung of mammals has been used in attempts to study animal numbers, habitat occupance and feeding habits. In this study the authors have collected whole pellet groups and samples of twenty random pellets from each group, for eleven species of African bovid. These samples have been studied in an attempt to establish a predictive relationship between mammal body weight and pellet dry weight. Samples were obtained from four study areas in South Africa in July and August 1977. A highly significant (P= < 0.001) linear relationship is shown to exist between ungulate body weight and the mean dry weight of whole pellet groups and random pellet samples. It is suggested that a power curve provides a better estimator of body weight from the random pellet samples (y) = 6.4387 x1.1223) than a linear regression. This method may be employed to establish a mean body weight for a population or individual weights for different age classes within a population. Such an age–class relationship is shown to exist for the Greater Kudu population at the Rhenosterpoort Nature Reserve in the Transvaal. The estimation of the water content of sun‐dried pellets demonstrates that correction factors can be established for use when oven drying facilities are not available. During the South African winter up to 40% of the pellet groups observed in Timbavati were attacked by coprophagous insects. Since such activity would be much higher in the wet season it is proposed that samples of twenty random pellets from each group provide a logistically more suitable estimator of mammal body weight than the collection of whole pellet groups. Résumé Les excréments de mammifères ont été utilisés comme matériel d'essai pour des études d'abondance d'animaux, l'occupation de l'habitat et les habitudes alimentaires. Au cours de cette étude, les auteurs ont récolté des groupes entiers d'excréments et des échantillons de vingt excréments au hasard dans chaque groupe, ceci pour onze espèces de bovidés africains. Ces échantillons ont étéétudiés en vue d'établie une relation prédictive entre le poids corporel du mammifère et le poids sec de l'excrément. Les échantillons furent obtenus dans cinq zones d'études en Afrique du Sud en juillet et août 1977. Une relation linéaire hautement significative (P= < 0.001) existe entre le poids corporel de l'ongulé et le poids sec moyen du groupe entier d'excréments et des échantillons d'excréments pris au hasard. Il est suggéré qu'une courbe de puissances fournit une meilleure estimation du poids du corps á partir d'échantillons d'excréments (y= 6.438 x1.1223) qu'une régression linéaire. Cette méthode peut être utilisée pour établir le poids moyen d'une population ou les poids individuels pour différentes classes d'âge dans une population. On montre qu'une telle relation à des classes d'âge existe pour la population de grands koudous dans la réserve naturelle de Rhenosterpoort dans le Transvaal. L'estimation du contenu en eau dans des excréments séchés au soleil démontre que des facteurs de correction peuvent ê...

Growth in the Sumatran elephant (Elephas maximus sumatranus) and age estimation based on dung diameter

“…Previous studies have already established the relationship between shoulder and foot measurements with age for the African and Asian elephant (Laws, 1966; Western et al, 1983;Sukumar et al, 1988;Lee & Moss, 1995), and investigated the relationship between dung and age for the African elephant (Jachmann & Bell, 1979, 1984Coe & Carr, 1983). These relationships between age and body (or bodyrelated) measurements form the basis for the growth models used to predict age.…”

“…In addition, estimating elephant age from a dung bolus diameter has advantages over previous attempts to estimate elephant age from dung pile weight, as it does not require that all originally deposited boli in a dung pile be measured (Coe & Carr, 1983). This is important given that dung boli can be separated from other boli at the time of deposition especially if the animal is moving or disturbed.…”

Forest elephant (Loxodonta africana cyclotis) stature in the Réserve de Faune du Petit Loango, Gabon

“…Boli size has been demonstrated to show a strong positive relationship with age (Coe & Carr, 1983;Jachmann & Bell, 1984).…”

“…Boli size was measured as the mean diameter of intact stools from every fresh dung pile encountered (those deemed to have been deposited within the previous 48 h; see also Barnes & Barnes, 1992) (n = 132 dung piles). Boli size has been demonstrated to show a strong positive relationship with age (Coe & Carr, 1983;Jachmann & Bell, 1984).…”

Understanding population dynamics of feral horses in the Tuan and Toolara State Forest for successful long-term population management

“…Dung counts are not influenced to the same degree by the difficulties associated with seasonal and diurnal variation in animal visual detection and the technique may also provide information on habitat use, and population distribution and size (Bennett et al 1940;Putman 1984;Chapman et al 1985;Lamoot et al 2004;Acevedo et al 2008;Mathur et al 2011). In some herbivore species, faecal shape and size can be used to identify the population sex and age structure, while in other species faecal chemistry permits assessment of animal dietary quality (Bubenik 1982;Sinclair et al 1982;Coe and Carr 1983;Maccracken and van Ballenberghe 1987;Pegard et al 2009). …”