Reindeer antlers: visual indicators of individual quality?

Fluctuating asymmetry (FA) in ornamental characters may reflect developmental stability in the translation from genotype to phenotype. Antlers of reindeer show FA, are visually conspicuous ornaments and are important in intraspecific assessment. We show that there is a negative relationship between size and asymmetry in visual antler characteristics (i.e., antler length and number of tines) among free-ranging male reindeer in rut. This indicates that individuals that develop large ornaments are better able to buffer developmental stress than individuals that develop small ornaments. There is no relationship between asymmetry in antler length and asymmetry in jaw length, suggesting that symmetry in antlers does not reflect overall body symmetry. This difference may be caused by trait-specific sensitivity to developmental stress. Such stress may partly be caused by parasites, which show a positive association with asymmetry in antlers, but no relationship to asymmetry in jaws. Our results indicate that antlers may be exposed to directional selection in a visual signaler-receiver system and that information about parasite burden may be obtained from evaluation of asymmetry in antlers developed under exposure to a multitude of environmental stresses. Received: 8 October 1996 / Accepted: 13 January 1997     

Does fluctuating asymmetry of antlers in white-tailed deer (Odocoileus virginianus) follow patterns predicted for sexually selected traits?

Secondary sexual characters have been hypothesized to signal male quality and should demonstrate a negative relationship between the size of the trait and degree of fluctuating asymmetry because they are costly to produce. We collected morphometric and antler data from 439 white-tailed deer (Odocoileus virginianus) in Oklahoma, USA, in order to determine whether measures of antler asymmetry follow the patterns predicted for sexually selected characters. Relative fluctuating asymmetry was negatively related to antler size for all deer and within age groups up to five and a half years of age. We did not detect an association between asymmetry and antler size among deer that were six and a half years or older. When categorizing deer by antler size, we found that deer with small antlers (< or = 33rd percentile) had greater levels of relative asymmetry than deer with large antlers (< or = 67th percentile). The relative asymmetry of antlers was negatively related to age and was greatest in deer that were one and a half years old. Relative asymmetry was also negatively related to carcass mass, inside spread, skull length and body length. These data suggest that asymmetry in the antlers of white-tailed deer may be a reliable signal of quality and, as such, may be important in maintaining honesty in intrasexual advertisements during the breeding season.     

Taxonomic Notes on the Swedish Domestic Reindeer, Genus Rangifer

In order to study the taxonomic relationship between domestic mountain and forest reindeer in Sweden nine skull characters on 126 and 62 animals, respectively, were measured and analysed. In addition antler width and shape of antler beam in cross-section were also measured. The differences indicate that the two groups of domestic reindeer are not entirely identical, although the differences are clearly not as plain as has been claimed. Comparing these results with earlier results it also appears that domestic forest reindeer are more in accordance with Rangifer tarandus tarandus than with R. t. jennicus , thus supporting the theory that possible influence of the latter subspecies on domestic reindeer has been considerably reduced as a result of long and intense cross breeding between the two groups of domestic reindeer.     

Age-related changes in the testicular and antler cycles of reindeer, Rangifer tarandus

A total of 111 male reindeer of various ages was shot in all months of the year to study the relationship between the seasonal changes in testicular activity and the antler cycle. From the changes in testis weight, seminiferous tubular tissue area and plasma testosterone values and the occurrence of spermatogenesis, it is concluded that calves attain physiological puberty in their first year, during which they also complete an antler cycle. The amplitude of the cyclical change in testis weight and plasma testosterone values increases with age and can be correlated with the earlier onset of events in the spermatogenic and antler cycles of older animals. The duration of the spermatogenic and testosterone cycles of reindeer is short, and is inversely related to the long period spent without antlers. It is suggested that testosterone strongly influences the antler cycle of reindeer males.     

Development and design of a novel loading device for the investigation of bone adaptation around immediately loaded dental implants using the reindeer antler as implant bed

The assessment of the behavior of immediately loaded dental implants using biomechanical methods is of particular importance. The primary goal of this investigation is to optimize the function of the implants to serve for immediate loading. Animal experiments on reindeer antlers as a novel animal model will serve for investigation of the bone remodeling processes in the implant bed. The main interest is directed towards the time and loading-dependant behavior of the antler tissue around the implants. The aim and scope of this work was to design an autonomous loading device that has the ability to load an inserted implant in the antler with predefined occlusal forces for predetermined time protocols. The mechanical part of the device can be attached to the antler and is capable of cyclically loading the implant with forces of up to 100 N. For the calibration and testing of the loading device a biomechanical measuring system has been used. The calibration curve shows a logarithmic relationship between force and motor current and is used to control the force on the implant. A first test on a cast reindeer antler was performed successfully.     

Foetal Stages of Antler Development

Foetuses of reindeer, Rangifer tarandus tarandus L., were collected at slaughter and studied for structural primordial stages of pedicle formation and antler growth. Fresh foetuses studied in January and February exhibited a round, pale area with an epidermal infolding or groove at the site of the future antler development. Also, in an ethanol-fixed caribou foetus from Alaska, an epidermal invagination could be seen in the area of later pedicle formation. No protruding bone or cartilage was observed as primordial stages of antler growth in reindeer foetuses collected from 10 November to 26 April. It is concluded that an epidermal infolding exists in the foetus of telemetacarpal cervids such as reindeer and caribou.     

Antlers—a Mineral Source in Rangifer

In a calving area on western Hardangervidda, Norway, shed antlers of female reindeer, Rangifer tarandus tarandus L., have been collected for several years. Many of these antlers have been chewed on by reindeer. In the literature antler chewing has been reported to take place on both shed and unshed antlers. Our observations support these findings. Based on the present observations it is suggested that the antlers may subserve the mineral householding of the animals under special conditions. The female reindeer has to pass through a nutritionally marginal season which often coincides with calving. Bringing the bony antlers to the calving areas seems advantageous in the maintenance of calcium balance. The growth of antlers may therefore be looked upon as part of a mineral saving strategy. The mineral stored in the antler thus represents a reserve to be used during pregnancy and lactation. This is in contrast to the common view that shedding of antlers is just waste of mineral when there is a great need for calcium.     

Variation of wing venation in Elachistidae (Lepidoptera: Gelechioidea): methodology and implications to systematics

We introduce a method to transform wing venation data to a numerical form so that the venation pattern can be analysed and compared regardless of wing size and displacement of the pattern. We use the method for assessing the intraspecific variation and asymmetry within the individual of relative positions of forewing veins in ten species of elachistid moths. Both the intraspecific variation and intra-individual asymmetry were found to be greater than the differences frequently used as systematic characters on various levels within Elachistidae, and to some extent in other Lepidoptera. At least in Elachistidae, major alterations to the current classification will have to be made. Wing characters subject to intraspecific variation should not be used to delimit groups unless they are based on examination of population samples and supported by other characters.     

What, if anything, does visual asymmetry in fallow deer antlers reveal?

Fluctuating asymmetry (FA), small directionally random deviations from perfect bilateral symmetry, is thought to reflect individual quality. Furthermore, it has been suggested that FA in secondary sexual characters can be used to assess mate or opponent quality during inter- or intrasexual competition. Studies on fallow deer, Dama dama, have suggested that FA in antlers reflects individual dominance, or the existence of a directional asymmetry (DA) with right antlers being consistently more developed than left antlers. To test these conflicting hypotheses, we analysed relationships between age, dominance and asymmetry in the number of antler points on mature fallow deer males during four rutting seasons in a single population. Age and dominance were only weakly correlated. The number of antler points displayed a pattern of DA (more points on the right than on the left side) that increased with age. Although dominance tended to increase with the total number of antler points, there was no relationship between the level of DA and dominance. These results failed to support the hypothesis that antler asymmetry visually reveals individual quality in fallow deer. Copyright 2000 The Association for the Study of Animal Behaviour.     

Repeatability of size and fluctuating asymmetry of antler characteristics in red deer (Cervus elaphus) during ontogeny

Fluctuating asymmetry (FA) has been suggested as a measure of the sensitivity of development to a wide array of genetic and environmental stresses. It has been also suggested that antlers in red deer could be important during social and rutting displays. We used antler measurements of 51 males that were measured over subsequent seasons, from 3–8 years of age, and analysed three antler traits: antler weight, length, and the number of antler tines (antler size). We calculated absolute and relative FA. All three size traits were highly significantly intercorrelated. By contrast to this, the FA of the three traits, did not show such relationships. With increasing age, antler size and FA also increased. When testing the repeatability of FA and antler size, there was a principal difference in the pattern between FA and antler size, with the latter being much more consistent than the former. This suggests that antler size, not FA, may be a good predictor of the bearer's quality in mate selection. This fits well with the good-genes hypothesis that the development of extravagant secondary sexual characters can be an honest advertisement of heritable male quality.  © 2007 The Linnean Society of London, Biological Journal of the Linnean Society , 2007, 91 , 215–226.     

Aspects of nitrogen and mineral nutrition in Icelandic reindeer,Rangifer tarandus

Nitrogen and mineral (Fe, Mg, Na, K, and Ca) compositions of foodstuffs consumed by and dung produced by male, pregnant and lactating female adult Icelandic reindeer and calves were determined during May of 1992. Iron levels in foodstuffs are consistently above the reported toxicity level for similar-sized sheep (0.5 ppt) and may lead to iron toxicity when consumed by reindeer during periods of high lean body mass catabolism. Male and female reindeer meet nutrient requirements for all measured elements and nitrogen with the possible exception of calcium for males during antler growth.     

Sexual dimorphism and intercorhort variation in reindeer calf antler length is associated with density and weather

We analysed intercohort variability of live weight and antler length of 5,123 reindeer calves. We further assessed the influence of climate and density on the interannual variation in antler length, and discussed sex-specific resource allocation and response to climate variability. Antler length varied significantly among years and between sexes, with interaction between year and sex. Body weight and antler length were highly positively correlated, showed similar intercohort variability, and had a strong allometrical link, suggesting that antler length could be an equally reliable measure of calf condition as live weight. We found a relative measure of antler length (i.e. antler length corrected for the allometric effect of body mass) to be positively influenced by increasing density and May–June precipitation, and also decreasing May–June temperature. We attributed the effect of early summer weather to its influence on forage availability and quality as well as the level of parasitic insect harassment. Gender difference in both the allometric exponents and the interannual variability suggest that young males and females may have different tactics for relative resource allocation towards growth of antlers as compared to body mass. Because antlers are costly to produce, they may be an honest signal of individual quality for both sexes. However, we found gender-specific allometry, as female calves more than males appear to prioritize their antler growth over body mass, especially when resources are limited. Thus, our results suggest that environmental variation may influence the extent of sexual dimorphism in antler length. Electronic Supplementary Material Supplementary material is available for this article at     

Fluctuating asymmetry in antlers of fallow deer (Dama dama): the relative roles of environmental stress and sexual selection

Antler lengths were recorded of a total of 250 male fallow deer (Dama dama (L)). Animals sampled were from marked populations where the majority of individuals were of known age. Asymmetry in antler length was normally distributed with a mean not significantly different from zero, confirming that differences in length between the antler pair constitute a true fluctuating asymmetry (FA). We found no clear relationship between the degree of asymmetry in antler length of an individual male and either population density or actual body mass. We did, however, detect a significant relationship between asymmetry and deviation from maximum cohort bodyweight. If deviation from maximum weight within a cohort may be considered some index of competitive success or increasing environmental stress, this may suggest that asymmetry in antler length relates in some way to developmental stress suffered by the individual concerned. The degree of asymmetry recorded in antler length also showed a significant decline with animal age, with antlers of animals of 2 years or older showing significantly greater symmetry. This is consistent with a hypothesis that despite continued competition for resources, there is a changing balance of selection pressure as animals reach maturity, with increased pressure from sexual selection requiring males to produce significantly more symmetrical ornaments.     

Remains of Late Pleistocene reindeer from Chmielewo,northeast Poland

Reindeer (Rangifer tarandus L.) remains in Europe are well represented in Late Pleistocene sites in France, Germany, Ukraine, Poland and other countries. In a chalk mine at Chmielewo (near niardwy Lake, NE Poland) four antlers were recovered. Radiocarbon assays date the fossils to the end of the Pleistocene. All antlers belong to male reindeer. One of the discovered specimens is an uncast antler of the tundra reindeer form, while the others are of the woodland reindeer form. The uncast antler has distinctly visible parieto-frontal fixation of the beam to the skull that confirms its parallel position in relation to the ground.     

Strain rate dependence of the mechanical properties of reindeer antler and the cumulative damage model of bone fracture

Carter and Caler have produced a 'cumulative damage' model for the fracture of bone, based on creep experiments on human bone, which has been corroborated by monotonic tensile tests on bone, loaded at various strain rates. Monotonic tensile tests on reindeer's antler, which has a lower modulus of elasticity than human bone, produce very similar results. Unlike human bone, reindeer antler always shows a large post-yield strain, and it is possible to distinguish pre-yield and post-yield behaviour. The 'final stiffness' (ultimate stress/ultimate strain) is invariant with strain rate. This is confirmation that bone fractures when a certain amount of damage has accumulated. However, reindeer antler shows a considerable post-yield increase in stress. This is difficult to accommodate in a cumulative damage model.     

Genetic variation in domestic reindeer and wild caribou in Alaska

Reindeer ( Rangifer tarandus tarandus ) were introduced into Alaska 100 years ago and have been maintained as semidomestic livestock. They have had contact with wild caribou ( R. t. granti ) herds, including deliberate crossbreeding and mixing in the wild. Reindeer have considerable potential as a domestic animal for meat or velvet antler production, and wild caribou are important to subsistence and sport hunters. Our objective was to quantify the genetic relationships of reindeer and caribou in Alaska. We identified allelic variation among five herds of wild caribou and three herds of reindeer with DNA sequencing and restriction enzymes for three loci: a DQA locus of the major histocompatibility complex ( Rata-DQA1 ), K-casein and the D-loop of mitochondrial DNA. These loci are of interest because of their potential influence on domestic animal performance and the fitness of wild populations. There is considerable genetic variation in reindeer and caribou for all three loci, including five, three and six alleles for DQA , K-casein and D-loop respectively. Most alleles occur in both reindeer and caribou, which may be the result of recent common ancestry or genetic introgression in either direction. However, allele frequencies differ considerably between reindeer and caribou, which suggests that gene flow has been limited.     

A Non-Destructive Method for Distinguishing Reindeer Antler (Rangifer tarandus) from Red Deer Antler (Cervus elaphus) Using X-Ray Micro-Tomography Coupled with SVM Classifiers

Over the last decade, biomedical 3D-imaging tools have gained widespread use in the analysis of prehistoric bone artefacts. While initial attempts to characterise the major categories used in osseous industry (i.e. bone, antler, and dentine/ivory) have been successful, the taxonomic determination of prehistoric artefacts remains to be investigated. The distinction between reindeer and red deer antler can be challenging, particularly in cases of anthropic and/or taphonomic modifications. In addition to the range of destructive physicochemical identification methods available (mass spectrometry, isotopic ratio, and DNA analysis), X-ray micro-tomography (micro-CT) provides convincing non-destructive 3D images and analyses. This paper presents the experimental protocol (sample scans, image processing, and statistical analysis) we have developed in order to identify modern and archaeological antler collections (from Isturitz, France). This original method is based on bone microstructure analysis combined with advanced statistical support vector machine (SVM) classifiers. A combination of six microarchitecture biomarkers (bone volume fraction, trabecular number, trabecular separation, trabecular thickness, trabecular bone pattern factor, and structure model index) were screened using micro-CT in order to characterise internal alveolar structure. Overall, reindeer alveoli presented a tighter mesh than red deer alveoli, and statistical analysis allowed us to distinguish archaeological antler by species with an accuracy of 96%, regardless of anatomical location on the antler. In conclusion, micro-CT combined with SVM classifiers proves to be a promising additional non-destructive method for antler identification, suitable for archaeological artefacts whose degree of human modification and cultural heritage or scientific value has previously made it impossible (tools, ornaments, etc.).     

Ossification of the antler in the Lapland reindeer (Rangifer tarandus tarandus)

A histological and histochemical study of biopsy specimens from the Lapland reindeer antler indicated that the intercellular matrix of the cartilage that forms the partitions of longitudinal channels becomes calcified at virtually the initial stage of formation. The lacunae at the peripheries of the cartilaginous partitions are invaded by osteoblasts in a process comparable to endochondral ossification. The very centres of the partitions evidently become directly converted into bone without the presence of e.g. osteoclasts. The osseous partitions are remodelled by osteoclasts. The antler increases in diameter by periosteal apposition.     

Variation in larval chaetotaxy in Orthosia gothica (Lepidoptera: Noctuidae): effects of mother,sex and side,and implications for systematics

Insect larval characteristics, including chaetotaxy, are used widely in systematics, including for classification and phylogenetic reconstruction. Despite their common use, basic aspects of larval morphology, including intraspecific variation, effects of relatedness between individuals, sex and asymmetry, are little investigated. In the larvae of the noctuid moth Orthosia gothica, properties of shape and size were separated to examine their effects separately. Siblings were found not to cover the entire variation of a population, and therefore specimens originating from a single female do not represent independent samples. This methodological bias may potentially lead to wrong conclusions regarding species characteristics. We observed slight differences between the left and right sides of the specimens studied, implying that one side should be examined consistently in studying larval chaetotaxy. We found no differences between sexes, but this may apply only to the species examined here; in general, sex should be determined and accounted for. We discovered considerable variation in seta numbers, which further emphasizes the importance of sufficient material, particularly in cladistic analyses in which setal counts are often used as characters.     

Major-histocompatibility-complex-associated variation in secondary sexual traits of white-tailed deer (Odocoileus virginianus): evidence for good-genes advertisement

Abstract Good-genes hypotheses predict that development of secondary sexual characters can be an honest advertisement of heritable male quality. We explored this hypothesis using a cervid model (adult, male white-tailed deer, Odocoileus virginianus ) to determine whether antler development could provide an honest signal of a male's genetic quality and condition to adversaries. We compared antler, morphometric, hormonal, and parasitic data collected from hunter-harvested deer to characteristics of the Mhc-DRB (Odvi) , the most widely studied gene of the major histocom-patibility complex (MHC) in Artiodactyla. We detected associations between genetic characteristics at Odvi-DRB and antler development and body mass, suggesting that antler development and body mass may be associated with pathogen resistance in deer and thus may be an honest signal of genetic quality. We also detected associations between Odvi-DRB characteristics and serum testosterone during the breeding season, suggesting that certain MHC characteristics may help deer cope with stresses related to breeding activity. In addition, we observed a negative relationship between degree of antler development and overall abundance of abomasal helminths. Our observations provide support for the hypothesis that antler development in white-tailed deer is an honest signal of quality.