Antler Length Research Articles

Variation in stable carbon (δ13C) and nitrogen (δ15N) isotope compositions along antlers of Qamanirjuaq caribou (Rangifer tarandus groenlandicus).

Annual antler growth begins in the spring and is completed by late summer for male caribou (Rangifer tarandus groenlandicus) from the Qamanirjuaq herd (Nunavut, Canada), aligned with both the spring migration and a seasonal dietary shift. Antlers may provide a non-lethal means of studying short- and long-term changes in caribou ecology through incorporated isotopes of carbon (δ13C) and nitrogen (δ15N). We sampled the antlers of 12 male caribou from the Qamanirjuaq herd culled in September 1967. We predicted that serial sampling of antlers would reflect the known seasonal dietary change from lichen to grass-like and shrub diet based on rumen contents from individuals culled during the same period. The δ13C and δ15N were analyzed in food sources and every 3 cm along each antler's length. The carbon isotope compositions of collagen (δ13Ccol) varied by ~0.5‰ among individuals and within antlers, while the carbon isotope compositions of antler bioapatite (δ13CCO3) increased by 1-1.5‰ from pedicle to tip. Values of δ15Ncol increased within antlers by 1-3‰ from pedicle to tip and varied by 3‰ among the individuals sampled. Antler collagen was lower in δ15Ncol by ~1‰ relative to bone collagen. Bayesian mixing models were conducted to test for changes in dietary proportions from antler isotope compositions. Mixing models did not indicate significant dietary shifts for any individual during antler formation, showing consistently mixed diets of fungi, horsetail, lichen, and woody plants. Increases in δ15Ncol in antler tissue could, therefore, correspond to subtle seasonal dietary changes and/or the physiological stress of antler tissue development.

Ivermectin decreases parasite load, testosterone, and potentially antler length in a group of captive red deer males (Cervus elaphus)

Secondary sex traits (SSTs) can favour males in intra-sexual competition, allowing females to reliably assess their quality. They can also be connected to other aspects of fitness, such as resistance to parasites and pathogens, as parasites have negative effects on the development of SSTs. Antlers are one of the most recognizable examples of SSTs whose development is regulated by testosterone and reflects the actual condition of the bearer. Elevated testosterone can exaggerate the size of SSTs while impairing the function of the immune system (“The Immunocompetence Handicap Hypothesis”) posing a trade-off between antler development and immune function. In this study, we experimentally manipulated the parasite load in captive red deer (Cervus elaphus) males with Ivermectin during antler development for two consecutive years. Expecting an inverse proportionality between parasite load and antler size, we hypothesized the treated deer to have larger antlers than the untreated ones. Our results showed that, following the immunocompetence handicap hypothesis, parasite load was positively associated with testosterone levels. However, the application of Ivermectin suppressed the parasite load of the treated animals but did not lead to the development of larger antlers. Instead, it significantly suppressed the concentration of testosterone in the treated animals, whilst the animals that had higher testosterone also had the highest parasite load. Our findings show that Ivermectin can potentially decrease the levels of testosterone and, consequently, antler size. These findings have important implications for the management of captive populations, especially in contexts where the development of large trophies is desired.

Natal environmental conditions modulate senescence of antler length in roe deer

It is now broadly admitted that female reproductive senescence – a decline in reproductive performance with increasing age – occurs in most species, at least among birds and mammals. Although information is more limited, male reproductive senescence has been regularly inferred from the decline in the size or performance of phenotypic traits that underly male reproductive success, particularly secondary sexual traits. However, the degree to which environmental conditions influence the pattern of senescence in sexual traits remains largely unknown. From the analysis of two long-term studies of populations of European roe deer (Capreolus capreolus) subjected to markedly different environmental contexts in the wild, we tested the hypothesis that harsh natal and/or current conditions should lead to earlier and/or stronger rates of senescence in the length of fully-grown antlers than good natal and/or current conditions. We found evidence of similar patterns of antler length senescence in both populations, with an onset of senescence around 7 years of age and a decrease of length by about 1–1.5 cm per additional year of life from 7 years of age onwards. We found that good early-life conditions delay senescence in antler length in roe deer. Our results also revealed that senescent males seem to be unable to allocate substantially to antler growth, confirming that antler size is, therefore, an honest signal of male individual quality. By modulating age-specific allocation to secondary sexual traits, natal and current conditions could influence female mate choice and male–male competition over mates, and as a result age-specific reproductive success, and should be accounted for when studying the dynamics of sexual selection.

Factors affecting antler growth period and casting date in red deer

AbstractAntlers are unique structures because they grow rapidly and are cast annually, representing an important energetic and mineral cost for deer. Variables related to the timing of antler growth, such as date of antler casting and length of growth period, therefore, should be affected by somatic resources and availability of food. We examined the effects of body and antler weight, age, and climatic variables, on antler casting date and the period of time antlers were grown as well as possible random effects of individual, year, cohort, and pedigree, based on 244 antlers in a population of 109 males of Iberian red deer (Cervus elaphus) over a 17-year study from 1999 to 2016. Body weight affected casting date, with heavier males casting antlers earlier than lighter males. Antlers also grew faster and were cast earlier among older males than young males. Antler weight influenced casting date and the duration of the growth period: males with heavier antlers cast them earlier and grow them faster than males with light antlers. Nevertheless, age and antler weight interacted; as such, older males grew their antlers slower and delay casting date because they produce heavier antlers, in contrast to younger males, where those with the heaviest antlers grow them faster and cast first. The date of the end of antler growth also influenced casting date, so that antlers that took the longest to develop were cast later than those that finished growing early. We conclude that older and heavier males cast their antlers earlier and grow them faster than younger and lighter males, likely to correlate the subsequent antler growth with the spring peak in plant nutrients, but that this early development is limited physiologically by the size of the antlers.

Pressure Algometry Validation and Determination of Efficacy of Articaine Hydrochloride Ring Block in Antler Removal in Red Deer (Cervus elaphus)

Simple SummaryRed deer (Cervus elaphus) are farmed in New Zealand for the production of velvet antler. Velvet is harvested as living antler tissue, and currently lignocaine is the only licensed local anaesthetic approved for deer antler removal in New Zealand. The use of lignocaine is not without consequences, including drug residues in harvested velvet antler tissue and its short acting analgesic effect. This study was designed to determine the effect of local anaesthetic, articaine hydrochloride as an alternative treatment and to establish the baseline measurements of mechanical nociceptive threshold in 40 male yearling red deer. Ten of the forty enrolled deer were selected for the articaine efficacy study. The mechanical nociceptive thresholds were measured using a handheld algometer applied at 4 points; the cranial, medial, caudal and lateral aspects of the base of each antler. The force applied, which resulted in a movement by the animal, was recorded in newtons (N). This study showed that nociceptive threshold response in deer could be reliably measured, and articaine proved to be a promising alternative for velveting the deer antlers.New Zealand deer farming centres on the production of meat and velvet antler. Velvet antler removal is a painful procedure and currently, New Zealand Animal Welfare regulations dictate surgical removal of velvet antlers under lignocaine anaesthesia. To improve our knowledge on the efficacy and duration of other local anaesthetics to mitigate pain after antler removal, it is important to accurately assess and quantify pain arising from antler removal. Therefore, the current study was designed to validate mechanical nociceptive threshold (MNT) testing using a Wagner hand-held algometer, and to apply this methodology to assess the efficacy and duration of action of articaine for antler removal in deer. Baseline force (N) required to elicit the nociceptive response was recorded in 40 yearling male red deer on three alternate days. Ten of the 40 animals were selected for antler removal after administration of 4% articaine hydrochloride as a ring block. The duration of analgesic efficacy of articaine was assessed by algometry across 5 time points. There was a significant difference in MNTs among the three days (day 3 versus day 1 (p < 0.0001), day 2 versus day 1 (p < 0.0001), and day 1 versus day 2 (p < 0.01)). Positive correlations were observed between weight, antler length and thresholds. The MNT values remained above 20N for 6 h after removal of velvet antlers under the articaine ring block. This study provides valuable information about the use of MNT in red deer. These findings lay a foundation for future studies in the topics of peri-operative and postoperative pain management in deer antler removal, and a possible alternative use for articaine.

Analysis of trophy parameters in Fallow deer (Dama dama) in Hungary, 1998-2016

The assessment of the trophy quality in Fallow deer (Dama dama) is often based on the measured values of the individuals with the largest antlers. However, there is little knowledge about the reliability and representativity of this approach.&#x0D; In our study, we analysed the trend of the annual number of evaluated trophies between 1998 and 2016, the age distribution of the harvested bucks, and the temporal variation in the values of trophy weight and antler length during the study period on the population level and in the case of the best quality antlers. The data were examined in 3 estimated age classes (young: up to 4 yrs, middle-aged: 5-9 yrs, old: from 10 yrs). The groups (year × age class) were characterized by the median, while the largest values were picked in each group by selecting the lowest value among the individuals belonging to the upper 1%, 5% and 10% of the sample size.&#x0D; The annual number of the presented trophies increased from 894 to 3,795 with an exponential trend. The proportion of the age classes changed significantly. The proportion of the young bucks increased by 10.2%, while the proportion of the middle-aged individuals decreased by 9.9%.&#x0D; The median of the weight showed no trend in the complete dataset. In the young age class, it increased until 2006, then decreased until 2016. In case of the middle-aged and old individuals, the median and the strongest values at each threshold also increased. The median of the complete dataset, as well as the middle-aged and old bucks, stagnated in the case of antler length. It showed an 8.5 cm decrease between 2007 and 2016 in the young age class. In general, the difference between the group median and the largest values showed the highest variability in case of the 1% threshold. We found a strong correlation between the group median and the strongest values only in two cases (Top 10% and 5% threshold, trophy weight of middle-aged bucks).&#x0D; Our results suggest that in Fallow deer, the assessment of the trophy quality based on only the largest antlers may be misleading in several cases, especially in the young age class or if the complete dataset is treated as one group. However, the trend of the largest trophy weight in the middle-aged and old age classes may refer to the trend of the median in the relevant groups.

Effect of Ca and P supplementation on the haematological parameters and content of selected minerals in the blood of young farmed fallow deer males (Dama dama)

The aim of the study was to assess the effect of supplementation of feed rations with increased calcium and phosphorus doses on the haematological parameters and plasma zinc (Zn), phosphorus (P), magnesium (Mg), copper (Cu), calcium (Ca), and iron (Fe) content as well as the body weight and the growth and development of the first antler in farmed fallow deer (Dama dama Linnaeus, 1758). The mean level of erythrocytes (RBC), haemoglobin (HGB), and haematocrit (HCT) was increased in the Ca- and P-supplemented group after the treatment period. The change was statistically significant (p < 0.05) in the case of RBC and HCT. The other haematological parameters (mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), and platelet count (PLT)) were reduced. An increase in the Zn content was observed in the plasma of slaughtered animals. The concentration of other minerals (P, Mg, and Cu only in group II receiving a higher level of Ca and P in the feeding dose; Ca and Fe only in group I supplemented with a lower content of Ca and P in a nutritional dose) in blood plasma decreased slightly after the supplementation period and declined further after the slaughter. Noteworthy, there was a significant increase in the plasma Cu and Fe levels in group I in group II, respectively, in the post-supplementation period. No significant differences were observed in the body weight between the groups, but there was a beneficial effect of the higher Ca and P dose in the feed ration for the farmed fallow deer on the length of the first antler (p < 0.05). The antlers of animals in group II were on average 2.3 cm longer than in group I.

The influence of early-life allocation to antlers on male performance during adulthood: Evidence from contrasted populations of a large herbivore.

To secure mating opportunities, males often develop and maintain conspicuous traits that are involved in intrasexual and/or intersexual competition. While current models of sexual selection rely on the assumption that producing such traits is costly, quantifying the cost of allocating to secondary sexual traits remains challenging. According to the principle of allocation, high energy allocation to growth or sexual traits in males should lead to reduced energy allocation to the maintenance of cellular and physiological functions, potentially causing them to age faster, with impaired survival. We evaluated the short-term and delayed consequences of energy allocation to antlers early in life in two contrasted populations of roe deer, Capreolus capreolus. Although most males mate successfully for the first time in their fourth year, antlers are grown annually from the first year of life onwards. We tested the prediction that a high level of allocation to antler growth during the first two years of life should lead to lower body mass, antler size and survival during the early and late prime stages, as well as to reduced longevity overall. Growing and carrying long antlers during the first years of life was not associated with any detectable cost in the late prime stage. The positive association between antler growth in early life and adult body mass instead supports that fawn antler acts as an honest signal of phenotypic quality in roe deer. For a given body mass, yearling males growing longer antlers displayed impaired performance during their late prime. We also found a trend for a short-term survival cost of allocation to relative antler length during the second year of life. Yearling males that grow long antlers relative to their mass might display a fast life-history tactic. We argue that differential allocation to secondary sexual traits generates a diversity of individual trajectories that should impact population dynamics.

1690 Comparison of linear model and artificial neural network using antler beam diameter and beam length of white-tailed deer (Odocoileus virginianus)

1690 Comparison of linear model and artificial neural network using antler beam diameter and beam length of white-tailed deer (Odocoileus virginianus)

Red deer bone and antler collagen are not isotopically equivalent in carbon and nitrogen.

Bone and antler collagen δ(13) C and δ(15) N values are often assumed to be equivalent when measured in palaeodietary, palaeoclimate and palaeocological studies. Although compositionally similar, bone grows slowly and is remodelled whereas antler growth is rapid and remodelling does not occur. These different patterns of growth could result in isotopic difference within antler and between the two tissue types. Here we test whether red deer (Cervus elaphus) bone and antler δ(13) C and δ(15) N values are equivalent, and whether intra-antler isotopic values are uniform. Bone and antler were isotopically analysed from six stags that lived in a temperate maritime climate on the Isle of Rum, Scotland. Multiple antlers from different years were sampled per individual, together with a single bone sample per individual. Up to 12 samples were taken along the length of each antler (total of 25 antlers, 259 samples) so that a chronological record of the isotopic composition during antler growth could be obtained. Collagen was extracted and its δ(13) C and δ(15) N values were measured by continuous-flow isotope ratio mass spectrometry. Intra-antler collagen isotope signatures vary, and show that not all antlers from an individual or a growth year are equivalent in carbon and nitrogen isotopic ratios. δ(15) N values typically increase with distance along antler length, but no overall trend is observed in δ(13) C values. An isotopic offset is visible between bone and antler, with bone δ(13) C and δ(15) N values being higher in most cases. Bone and antler collagen δ(13) C and δ(15) N values are not isotopically equivalent and are therefore not directly comparable in palaeodietary, palaeoclimate and palaeocological studies. Bone and antler collagen isotopic differences probably relate to differential metabolic processes during the formation of the two tissues. Intra- and inter-antler isotopic variations probably reflect the isotopic composition of an individual's diet rather than physiological parameters, and may have the potential to provide high-resolution individual-specific information in modern and ancient cervid populations. Copyright © 2016 John Wiley & Sons, Ltd.

Modeling the impact of selective harvesting on red deer antlers

ABSTRACTHunting is a common component in the management of ungulate species. Despite its widespread use, the influence of selective harvesting on phenotypic trait change is still ambiguous, and represents a critical gap in our understanding of the responses of wild populations under harvest. Using the long‐term red deer (Cervus elaphus) dataset (1972–2012) from the Isle of Rum National Nature Reserve, Scotland, we assessed the relationship between antler length and key demographic processes (i.e., survival, recruitment, antler growth, parent‐offspring trait correlation) for the male component of the population. We then constructed the first integral projection model for this species to examine the effects of simulated trophy hunting on 2 population‐level parameters: the stable antler size distribution and the relative reproductive value of males. When male mortality rates due to hunting were &lt;20%, the effect on antler size distribution and the reproductive value function were relatively small. However, as mortality due to hunting increased to 50% in large individuals, the direct effects of hunting on mean antler size and reproductive value became evident. Our model acts as a useful starting point to investigate the ecological and evolutionary consequences of hunting in red deer. © 2016 The Wildlife Society.

Phenotypic and Reproductive Parameters of Barking Deer Under Management Condition of Chittagong Zoo

The study was conducted to know about the phenotypic parameters and reproductive parameters of barking deer under feeding management at Chittagong Zoo. Data were collected for a period of 3 months from 04 deer from 1 st September 2013 to 30th November 2013 on all age groups. The deer were kept within an open enclosure measured as 66.52 m2 with a fence of chain link mash, 3.6m in height. Available feeds supplied to deer were gram, rice bran, green gourd, pumpkin, carrot and amloki. The coat color was reddish and “V” Shaped black colored forehead and black colored muzzle. The ear length of males and females were 3.5±0.5 and 3.5 inch. The length of foreleg for male and female were 20 and 19 inch and the length of hind leg for male and female were 22 and 21 inch. The length of antlers was 3 inch. Distance between ear of male and female were 3.7 and 3.6 inch. The average birth weight of males and females were ranging from 1-1.5 kg and 0.5-0.7 kg, males and females weaning weight were ranging from 10-12 kg and 08-10 kg respectively. Adult male’s and female’s weight were ranging from 25-30 kg and 20-25 kg. It was also observed that the weaning age, length of estrous cycle, age at first fawning and gestation length were ranging from 4-6 months; 12-20 days, 14-18 month and 6-7 month, respectively.

Reproductive timing in a lekking mammal: male fallow deer getting ready for female estrus

A lek is an aggregated male display that females attend for the purpose of fertilization. A male needs to climb the relative hierarchy to be available for mating when the peak of female estrus occurs. We analyzed the link between timing of lek use by males in relation to age, phenotype, territoriality, and mating success. For more than a decade, we collected radio-tracking data and behavioral observations of a lekking mammal, the fallow deer (Dama dama). Competitively stronger males (i.e., older and heavier males with larger antlers) moved to the lek before less competitive ones. However, an early arrival did not guarantee the territory defense for a longer period nor higher mating success. The early arrival seemed to be a necessary but not sufficient condition to be a successful male in a lek. In fact, the ability to defend a territory for longer was related to age, body mass, antler length but not arrival time. We accordingly argue that males move to the lek early because they need to engage in male–male interactions and scent-marking activities. Successful males left the lek later than unsuccessful ones. The latter did not attempt to compensate for their low mating success by remaining in the lek, likely adopting alternative strategies outside of it. Adult males seeking for a chance to defend the territory and mate have to move to the lek early and stay there until the end of the rut, though this does not guarantee them a higher mating success.

Long or Heavy? Physiological Constraints in the Evolution of Antlers

The evolution of the investment in exaggerated secondary sexual traits is a topic of great interest for scientists. Despite antlers in the family Cervidae being one of the most interesting allometric structures, the nature of the relationships between antler and body size, and the influence of physiological factors driving the evolution of these characters, still remain unclear. In this paper, I examine these relationships in depth using the largest sample size ever studied (43 species). Under the hypothesis that antler growth may be limited by skeleton size as this process requires the allocation of huge amounts of mineral resources to the antlers, skeleton-related variables may more accurately explain these allometric relationships. The existence of physiological constraints should therefore be more clearly highlighted when studying the relationships between body size variables and the relative investment in the antler (measured as length or mass of antler per kg of skeleton). Results show that antler length is best described as being linearly related to head-body length rather than other measurements of size, and antler weight has a quadratic relationship with body mass. However, the relative investment in antler length (related to skeleton mass) is independent of body size variables, while the relative investment in antler mass has a quadratic relationship with shoulder height. The results obtained for antler mass reflect the existence of physiological constraints in the evolution of antlers, which are greater for larger sized species. On the other hand, the evolution of antler length may be linked to other factors, most probably sociobiological and biomechanical ones.

Allometric variation in the antlers of cervids: a comment on Lemaître et al.

Lemaitre and colleagues used conventional allometric methods to examine the relationship between length of antlers and mass of the body in males of 31 species in the mammalian family Cervidae [[1][1]]. Logarithmic transformation failed to linearize the bivariate distribution, so the authors fitted

Study on the Changes in Enzyme and Insulin-like Growth Factor-1 Concentrations in Blood Serum and Growth Characteristics of Velvet Antler during the Antler Growth Period in Sika Deer (Cervus nippon).

This study was conducted to investigate changes in blood enzyme parameters and to evaluate the relationship between insulin-like growth factor-1 (IGF-1), antler growth and body weight during the antler growth of sika deer (Cervus nippon). Serum enzyme activity and IGF-1 concentrations were measured in blood samples collected from the jugular and femoral veins at regular intervals during the antler growth period. Blood samples were taken in the morning from fasted stags (n = 12) which were healthy and showed no clinical signs of disease. Alfalfa was available ad libitum and concentrates were given at 1% of body weight to all stags. The experimental diet was provided at 9 am with water available at all times. There were no significant differences in alkaline phosphatase, aspartate aminotransferase, and alanine aminotransferase during antler growth, but alkaline phosphatase concentrations increased with antler growth progression, and the highest alkaline phosphatase concentration was obtained 55 days after antler casting. Serum IGF-1 concentrations measured from blood samples taken from the jugular vein during antler growth, determined that levels of IGF-1 was associated with body weight and antler growth patterns. Serum IGF-1 concentrations were higher at the antler cutting date than other sampling dates. Antler length increased significantly during antler growth (p<0.001), and there was a similar trend to between right and left beams. Body weight increased with antler growth but was not significant. Consequently it appeared that serum alkaline phosphatase concentration was related to antler growth and both antler growth and body weight were associated positively with IGF-1 concentrations during antler growth.

Long-term trends and correlates of antler anomalies in roe deer

Length and structural complexity of antlers provide an indication of individual quality in many ungulates in the context of female mate choice and trophy hunting. Selectivity of hunters for individuals with various antler sizes may have bearing on the population structure. It is less well understood, however, whether and how antler anomalies may signal individual characteristics. We used data on 2,461 roe deer (Capreolus capreolus) males harvested by stalking during 1966–2011 in western Poland to test hypotheses explaining probability of occurrence of accessory, broken, and malformed antlers. By employing a multinomial logistic regression, we showed that the probability of occurrence of broken and malformed antlers increased in males older than 2 years. Probability of occurrence of accessory and, in young males, broken antlers was higher in individuals with increased body weight. Occurrence of malformed antlers decreased over the study period. Contrary to our prediction, we did not detect an effect of distance to forest on the probability of malformed antlers occurring. We conclude that the main premise of compensatory culling is not supported in roe deer. © 2014 The Wildlife Society.

Genetic effects on first antler growth in relation to live-weight of red deer farmed in New Zealand

Deer farmed in New Zealand for venison production are a composite of Cervus elaphus subspecies. Venison production systems target supply of yearling males for slaughter at live-weights of ≥95kg between 8 and 12 months of age when first antler development is occurring. If the antlers exceed 110mm they must be removed before the animal can be transported for slaughter which adds handling and costs which some producers consider unnecessary. We hypothesised that there are associations between live-weight and first antler development that are heritable and it would be possible to select sires on the basis of delayed antler development relative to live-weight of their progeny. Antler and live-weight measurements were recorded on 1033 male progeny from three elite recorded red deer breeding herds, DNA pedigree tested as sired by 106 different stags. Spline models were fitted to the antler length and live-weight data over time. Day-of-the-year was read off these splines to define traits of live-weight when antler length reached 50mm (WA50) or 80mm (WA80), and antler length when live-weight reached 95kg (AW95). The predicted traits were analysed using a single-trait animal model incorporating the extended pedigree of the animals involved to calculate three estimated breeding values (EBVs) WA50, WA80 and AW95. The three antler traits had high heritability estimates of 0.67–0.81 with standard errors of 0.10, and were moderately-highly correlated with weaning and yearling live-weight traits. The phenotypic standard deviation of WA80 of 8.35kg or 8.6% of the mean predicted live-weight and a genetic standard deviation or 6.86kg indicated good variation within the population, providing scope for genetically improving the current New Zealand breeding herd for delayed antler growth relative to live-weight. Such selection could reduce the number of rising yearling males requiring velvet antler removal prior to slaughter.

A Limit for Antler Length in Captive Marals

The main aim of this study was to estimate phenotypic correlations among live weight, withers height, rump height, chest depth, chest width, thoracic girth, body length, hip widths (between iliac tuberosities and between ischial tuberosities) and forelimb cannon perimeter with antler length measured during the growth of marals on a Kazakh farm. The data comprised 18 animals studied during their growth (at 18 months and at 24 months). In maral, the first period of antler productivity takes place at the age of 24 months. This fact should be taken into account in order to select the best animals for antler production, which is the main purpose for farming this species.

The allometry between secondary sexual traits and body size is nonlinear among cervids

Allometric relationships between sexually selected traits and body size have been extensively studied in recent decades. While sexually selected traits generally display positive allometry, a few recent reports have suggested that allometric relationships are not always linear. In male cervids, having both long antlers and large size provides benefits in terms of increased mating success. However, such attributes are costly to grow and maintain, and these costs might constrain antler length from increasing at the same rate as body mass in larger species if the quantity of energy that males can extract from their environment is limiting. We tested for possible nonlinearity in the relationship between antler size and body mass (on a log-log scale) among 31 cervids and found clear deviation from linearity in the allometry of antler length. Antler length increased linearly until a male body mass threshold at approximately 110 kg. Beyond this threshold, antler length did not change with increasing mass. We discuss this evidence of nonlinear allometry in the light of life-history theory and stress the importance of testing for nonlinearity when studying allometric relationships.