The relationship between tooth wear, habitat quality and late‐life reproduction in a wild red deer population

Abstract

Summary1. Molar tooth wear is considered an important proximate mechanism driving patterns of senescence in ungulates but few studies have investigated the causes of variation in molar wear or their consequences for reproductive success. 2. In this study, we assessed molar tooth wear at death among red deer Cervus elaphus of known age on the Isle of Rum, Scotland. 3. First molar height showed a decelerating decline with age. In females, the rates of molar wear with age varied with location of home range and individuals experiencing low resource competition showed reduced molar wear. We suggest that this spatial variation in molar wear is related to differences in the availability of high-quality grazing habitat and levels of resource competition. 4. There was no evidence that females with more heavily worn molars had reduced reproductive performance late in life or that first molar height was associated with reproductive senescence.

Mortality in a Predator-free Insular Environment: the Dwarf Deer of Crete

“…The relatively large number of adults with heavily worn molars in the Candiacervus age profiles might therefore indicate a low reproduction rate in the Gerani 4 and Liko populations. However, as Nussey et al (2007) showed for Cervus elaphus on the Isle of Rum, this need not have been the case: these authors found no evidence that their index for estimating stage of tooth wear (first molar height) was associated with reproductive senescence. Absence of correlation may be due to the fact that, although molar height lessens over the years, molar surface area changes little, or may perhaps even increase somewhat as the tooth loses loph relief.…”

“…That the absence of predation as a factor may have no obvious effect on the mortality profile is shown by studies of the red deer of Rum. For this population, the most important causes of death are starvation, weather-related factors (including natural winter mortality), accidents, and parturition (not relevant to juvenile mortality), yet the mortality profile (Nussey et al, 2007) is very similar to that of continental African large herbivores. In some years, juvenile mortality on Rum has run to nearly 60% (Clutton-Brock et al, 1985).…”

“…Absence of correlation may be due to the fact that, although molar height lessens over the years, molar surface area changes little, or may perhaps even increase somewhat as the tooth loses loph relief. Thus, the total effect of vertical wear on digestive efficiency may be limited (Nussey et al, 2007). Making an analogy between Cer.…”

Age‐related changes in molar topography and shearing crest length in a wild population of mountain Gorillas from Volcanoes National Park, Rwanda

“…Furthermore, dentally senesced sifaka mothers experience decreases in infant survival, particularly during seasons of resource scarcity (King et al, 2005), indicating that extreme dental wear and the concomitant loss of compensatory shearing crests can have severe fitness consequences. This phenomenon is not unique to primates: similar cases of female reproductive success being negatively affected by tooth wear have been documented in cervids (e.g., Skogland, 1988;Nussey et al, 2007). Given the hypothesized link between dental senescence and fitness, it is important to understand how the morphology of great ape teeth changes to sustain function throughout life.…”

Age structure changes and extraordinary lifespan in wild medfly populations

“…For studies in which the sample sizes are large and the data collection in the field is longitudinal, the long lifespans of species studied necessitate the construction of costly databases assembled over several decades (Clutton-Brock et al ., 1982;Charmantier et al ., 2006;Nussey et al ., 2007).…”