Annual variation in body composition of roe deer (Capreolus capreolus) in moderate environmental conditions

Abstract

Patterns of growth and seasonal variation in body mass, kidney fat level, and bone marrow fat level were investigated in a roe deer population south of Paris. Size dimorphism was not apparent until the deer were 2 years of age, following a second period of rapid growth in males during spring-summer. No differences between the sexes in fat accumulation or in the periodicity of the annual fat cycle were observed. However, annual cycles of adult body mass were asynchronous between the sexes. Carcase mass was stable for much of the year, but one marked seasonal decline was observed in animals of each sex. For females (April -August) this reflected investment in late gestation and lactation, but among males (April-November) it was presumably linked to the costs of rutting. Contrary to reports for other ungulates, no over-winter decline in adult carcase mass, kidney fat level, or bone marrow fat level was observed, possibly because winters were mild. All four fat indices (kidney fat index, three bone-marrow fat indices) declined over spring -summer. This seasonal cyclicity does not match the energy requirements of reproductive activity, suggesting that the fat cycle is intrinsic, linked to seasonal metabolic variation in roe deer. We suggest that carcase mass is a more reliable index of condition in roe deer.RCsurnC : La croissance et les variations saisonnikres de la masse corporelles, de la graisse perirenale et de la graisse de la moelle osseuse ont ete etudies chez une population de Chevreuils. Le dimorphisme quant B taille n'apparait qu'B l'ige de 2 ans, B la suite d'une seconde periode de croissance rapide chez les miles au printemps et en ete. L'accumulation des graisses et la periodicite de leur cycle annuel ne diffkrent pas chez les miles et les femelles. Cependant les cycles annuels de la masse corporelle des adultes ne sont pas synchronises entre les deux sexes. La masse de la carcasse est relativement constante, mais une chute saisonnibe marquee se produit chez les deux sexes. Chez les femelles (avril-aoQt), elle correspond B l'investissement energetique important au moment de la gestation et de la lactation. Chez les miles (avril-novembre), elle est sans doute attribuable aux depenses energetiques liees au rut. Aucune diminution de la masse de la carcasse, de la graisse perirenale ou de la graisse de la moelle osseuse n'a ete observee chez les adultes au cours de l'hiver; ce resultat atypique peut Ctre dQ aux hivers doux. De plus, les quatre indices des graisses ont diminuk entre le printemps et 1'Cte. Cette cyclicite saisonnikre suggkre une origine intrinskque au cycle annuel des graisses, lie aux variations saisonnikres du metabolisme chez l'espkce. Nous recommandons l'utilisation de la masse de la carcasse comme indicateur de la condition physique chez le Chevreuil.

A half a century of measuring ungulate body condition using indices: is it time for a change?

“…In contrast, roe deer are only slightly sexually dimorphic and rely on adjustment in food intake to offset the costs of reproduction ("income breeder", sensu Jönsson 1997; see Andersen et al 2000). As a result, their body reserves vary only weakly between seasons (Hewison et al 1996). These characteristics affect the quantity of fat stored around the kidneys; e.g., in our sample, fat weighed two to three times the weight of the kidney for adult fallow deer (fat/ kidney: 133±30 g/45 g±5.1 for females and 103 g±43/63 g± 4.8 for males), but the weight of the fat and the kidney were similar for adult roe deer (fat/kidney: 29.47±16.28 g/36.09± 9.2 g for females and 27.66±13.29 g/40.39±7.1 g for males).…”

Hoof Growth Rates of the European Roe Deer (Capreolus capreolus) for Dating the Hoof’s Isotopic Archive

“…Conversely, Harrison et al [15] found highest GR of bovine hooves in winter and explained these findings by differences in diet during the year. As wild animals change their behavior concerning feed, living environment or energy metabolism during the year [34][35][36], there are most likely also seasonally differing GR. However, varying GR by ±10% (yielding a 20% variation in total) hardly changed Figure 4.…”

Ranging behaviour and reproductive rate in the threatened population of roe deer in Gargano, South Italy

“…The reproductive success of our radiotagged does (fawns:female) was low in both years (0.8-1.3; Table I), contrasting with the normal productivity of roe deer does (European ssp: 2.04-2.44, Andersen & Linnel 2000;1.3-1.4, Saïd et al 2005;1.75, Macdonald & Johnson 2008; Italian ssp: productivity of the Italian roe deer does not seem to differ from that of the European subspecies, own data), especially when density is low (Vincent et al 1995), as in our population. In roe deer, body fat reserves are poor (Hewison et al 1996), compared to the other temperate and northern cervids (Holland 1990), with important effects when the energy expenditure is at its maximum (i.e. in does, in the last two months of pregnancy and in the first month of lactation; Mauget et al 1997).…”

“…in does, in the last two months of pregnancy and in the first month of lactation; Mauget et al 1997). Therefore, does allocate high levels of resources to reproduction compared to most other ungulates (Hewison et al 1996;Andersen et al 1998) and the survival of fawns is strongly affected by environmental variation, probably through the effects on maternal nutrition (Gaillard et al 1998). When food supply is poor in late spring and early summer, females reduce lactation, which is energetically expensive, and summer survival of fawns decreases (Sempéré et al 1998).…”