The relationship between food habits, molar wear and life expectancy in wild sika deer populations
Editor: Andrew Kitchener
Functionality of cheek teeth is essential for ruminants to masticate plant materials thoroughly and promote microbial degradation in their rumens. Thus, an excessive rate of tooth wear is expected to lead to premature loss of tooth functionality, and hence to reduced longevity. So far, however, the relationships between food habits, molar wear and longevity have not been investigated. We first compared molar wear rates among nine sika deer Cervus nippon populations with different food habits. We then investigated correlations between molar wear rate and two ecological factors, percentage of graminoids in diet and annual precipitation, relating to intrinsic and extrinsic abrasiveness of the ingested food, respectively. Secondly, we estimated ‘retained molar durability’ (molar height at a given age divided by wear rate) at successive ages for each population, and tested for correlation between molar durability and life expectancy among populations. The M1 and M3 wear rates differed among the populations and showed a positive correlation with graminoid consumption and a negative correlation with precipitation, suggesting that both ecological factors influence molar wear rates in the Japanese sika deer. M3 durability had a stronger correlation with life expectancy than M1 durability, especially at the older age stages. This implies that the influence of M3 durability on life expectancy becomes stronger at the time when the M1 is severely worn and loses its functionality, and is therefore more important for life span elongation than the M1. These results are concordant with the fact that the M3 is the most hypsodont molar in many ungulates. In the Japanese sika deer, microevolutionary acquisition of hypsodonty appears to be the case in a northern population (the Kinkazan Island), whose molar wear rates are extremely rapid due to their food habits.
Table S1. References used in calculating the percentage of graminoids in the diet of local sika deer populations.
Table S2. Matrix of pairwise comparisons with Holm correction for M1 wear rate among nine female sika deer populations. The order of populations is from fastest (Kinkazan) to slowest (Fukuoka). Significant differences are shown in italic (P<0.05) and bold (P<0.01).
Table S3. Matrix of pairwise comparisons with the Holm correction for M3 wear rate among nine female sika deer populations. The order of populations is from fastest (Kinkazan) to slowest (Fukuoka). Significant differences are shown in italic (P<0.05) and bold (P<0.01).
Table S4. Molar durability retained at each age and life expectancy of the female sika deer populations.
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1996). Food habits of sika deer on the Boso Peninsula, central Japan.
1999). Nitrogen content in feces and the diet of sika deer on the Boso Peninsula, central Japan.
2004). Disposable-soma senescence mediated by sexual selection in an ungulate.
1977). Analysis of vertebrate populations. New York: John Wiley & Sons Inc.
2004). The demographic consequences of releasing a population of red deer from culling.
1985). Ungulate cheek teeth: developmental, functional, and evolutionary interrelations.
Acta Zool. Fenn.
2002). Fossil mammals resolve regional patterns of Eurasian climate change over 20 million years.
Evol. Ecol. Res.
1999). Deer of the world. Shrewsbury: Swan Hill Press.
2005). Phylogenetic variation in the silicon composition of plants.
Hokkaido Institute of Environmental Sciences (1997). Results of a survey related to sika deer and brown bear sighting on Hokkaido. Sapporo: Hokkaido Institute of Environmental Sciences (in Japanese).
1979). A simple sequentially rejective multiple test procedure.
Scand. J. Stat.
1988). An estimation of tooth volume and hypsodonty indices in ungulate mammals, and the correlation of these factors with dietary preference. In
Teeth revisited: Proceedings of the VIIth International Symposium on Dental Morphology: 367–387. D.E. Russell,
J.P. Santoro &
(Eds). Paris: Muséum national d'Histoire naturalle du Paris.
1995). Correlations between craniodental morphology and feeding behavior in ungulates: reciprocal illumination between living and fossil taxa. In
Functional morphology in vertebrate paleontology: 76–98. J.J. Thomason
(Ed.). Cambridge: Cambridge University Press.
2002). The origins and evolution of the North American grassland biome: the story from the hoofed mammals.
Palaeogeogr. Palaeoclimatol. Palaeoecol.
1988). On the means whereby mammals achieve increased functional durability of their dentitions, with special reference to limiting factors.
Biol. Rev. Camb. Philos. Soc.
2000). Seasonal food habits of a sika deer population in the warm temperate forest of the westernmost part of Honshu, Japan.
2005). Dental senescence in a long-lived primate links infant survival to rainfall.
Proc. Natl. Acad. Sci. USA
1998). Foraging conditions, tooth wear and herbivore body reserves: a study of female reindeer.
1999). Consequences of harvesting on age structure, sex ratio and population dynamics of red deer Cervus elaphus in central Norway.
2003). Decelerating and sex-dependent tooth wear in Norwegian red deer.
2008). Hypsodonty in ungulates: an adaptation for grass consumption or for foraging in open habitat?
J. Zool. (Lond.)
2007). The relationship between tooth wear, habitat quality and late-life reproduction in a wild red deer population.
J. Anim. Ecol.
1980). Estimation of sex, age, and season of death using mandibles of Cervus nippon excavated from an archaeological site.
Archaeol. Nat. Sci.
1986). Preliminary memorandum of classification, distribution and geographic variation on Sika deer.
Honyurui Kagaku (Mamm. Sci.)
(in Japanese with English abstract).
2007). Correlations between feeding type and mandibular morphology in the sika deer.
J. Zool. (Lond.)
2007). Do silica phytoliths really wear mammalian teeth?
J. Archaeol. Sci.
Shimane Prefectural Government. (2002). A survey on the sika deer (Cervus nippon) in Misen mountainous region on the Shimane Peninsula, Japan. Shimane: Shimane Prefectural Government
1988). Tooth wear by food limitation and its life-history consequences in wild reindeer.
1994). Molar wear rates in ruminants – a new approach.
Ann. Zool. Fenn.
2006). Ecological history of sika deer. Tokyo: University of Tokyo Press (in Japanese).
2009). Geographical variations in food habits of sika deer: the northern grazer vs. the southern browser. In
Sika deer: biology and management of native and introduced populations: 231–238. D.R. McCullough,
S. Takatsuki &
(Eds). Tokyo: Springer.
2009). Food habits of sika deer on Kinkazan Island, northern Japan with reference to local variations, size effects, and comparison with the main island. In
Sika deer: biology and management of native and introduced populations: 113–123. D.R. McCullough,
S. Takatsuki &
(Eds). Tokyo: Springer.
1986). The relationship between the fat content of Svalbard reindeer in autumn and their death from starvation in winter.
(Special Issue), 311–314.
2006). Survival and cause-specific mortality rates of female sika deer in eastern Hokkaido, Japan.
2007a). The ecology and evolution of tooth wear in red deer and moose.
2007b). Evidence for a trade-off between early growth and tooth wear in Svalbard reindeer.
J. Anim. Ecol.
2007c). Bigger teeth for longer life? Longevity and molar height in two roe deer populations.
1999). A record of acorn eating by sika deer in western Japan.
2001). A comparative test of adaptive explanations for hypsodonty in ungulates and rodents.
J. Mamm. Evol.