Iberian Red Deer Research Articles

Ecological effects of game management: does supplemental feeding affect herbivory pressure on native vegetation?

Context Supplemental feeding of large mammalian herbivores is a common management tool mainly aimed at promoting healthy populations and at increasing productivity and trophy sizes. Such management measure may indirectly affect herbivore effects on plant communities through altered foraging patterns. The quantification of the ecological effects of large herbivore management is important for designing holistic management and conservation programs. Aims Here we aimed at quantifying the ecological effects of supplemental feeding of Iberian red deer, Cervus elaphus hispanicus, on the composition of and on the browsing effects on Mediterranean woody plant community. Methods An experiment was set up in a hunting rangeland located in central Spain, where female deer were kept in enclosures with either exclusive access to natural forages or with additional ad libitum access to a nutritionally rich concentrate. The experiment also included a control area where deer were absent. Key results We observed significant differences in browsing impacts among the supplemented, non-supplemented and control areas, and such effect varied for the different plant species. Plant species which nutritional content complemented that of fodder were more highly consumed, for instance, Erica spp., which digestible fibre content is higher and N content lower than that of provided fodder. The presence of deer and the concentrate supplied, instead, did not influence the relative abundances of shrub species. Conclusions Artificial supplemental feeding provided to ungulates led to increased browsing on plant species which nutritional composition complemented that of the supplement provided. Implications So as to alleviate herbivory impact on all shrubs, we suggest that composition of supplemental feeding should adjust both to the natural forage availability and quality and to ungulate requirements across seasons.

Fecal-FT-NIRS as a Noninvasive Tool for Assessing Diet Quality of Mediterranean Deer

In order to assess the diet quality of two Mediterranean deer species we developed and validated a Fourier transform near-infrared diffuse reflectance spectroscopy methodology on feces (Fecal-FT-NIRS) for the determination of acid detergent fiber (ADF), neutral detergent fiber (NDF), lignin, C:N ratio, and enzymatic digestibility of organic matter (EDOM). We used rumen contents and fecal samples from 149 red deer (Cervus elaphus hispanicus) and 111 fallow deer (Dama dama) from southeast Spain (n = 520 observations). Spectra from the feces were related with rumen conventional chemical analysis through chemometric regression with partial least-squares (PLS). Specific predictive equations from red and fallow deer data separately were generated, as well as merged equations after pooling all deer samples. All the predictive equations had a high linearity with high correlation coefficients (r = 0.8 – 0.99). The selected equations had a reliable accuracy considering the root-mean-square errors of prediction (RMSEP), calibration (RMSEC), and cross-validation (RMSECV) in relation to the range of values for which the NIRS calibration was set for each parameter. Broad-based equations from combined samples were demonstrated as being useful for all nutritional parameters determination in red and fallow deer simultaneously. Equations obtained for the red deer data were also successfully applied to fallow deer and vice versa for NDF, ADF, C:N, and lignin determination, while for EDOM assessment the specific equations for each species were more accurately applied. Once validated, the Fecal-FT-NIRS technique can be considered as a suitable noninvasive tool for monitoring deer diet quality variations in Mediterranean environment. This method has the possibility to overcome interspecific barriers of direct fecal analysis by using rumen digesta as its reference method.

Variation of spermatogenic and Sertoli cell number detected by fine needle aspiration cytology (FNAC) in Iberian red deer during and out of the breeding season.

The aim of the present study was to evaluate spermatogenesis in Iberian red deer, a short-day seasonal breeder, using the fine needle aspiration cytology (FNAC) technique. Reports on spermatogenesis in deer are limited and here, for the first time, FNAC has been used to evaluate changes in such physiological process during and out of the breeding season. Testes were collected from 51 stags from November 2010 to February 2011. The Sertoli index and spermatic index were significantly higher during the breeding season than out of the breeding season (P=0.0477 and P=0.0125, respectively). A similar pattern was described by histological analysis, in which both Sertoli cell number per tubular cross-section and Johnsen score decreased significantly from the breeding season to the non-breeding season (P=0.0131 and P=0.0010, respectively). Data provided by FNAC were correlated with histology: the Sertoli index was positively correlated with Sertoli cell number per tubular cross-section (P=0.0015), whereas the spermatic index was correlated with the Johnsen score (P=0.0497). The results of the present study indicate that FNAC is a reliable technique to evaluate spermatogenesis in Iberian red deer and suggest that Sertoli cell number is not stable in these species, reaching highest values during the breeding season.

Erratum to: Mitochondrial D-loop phylogeny signals two native Iberian red deer (Cervus elaphus) Lineages genetically different to Western and Eastern European red deer and infers human-mediated translocations

Erratum to: Mitochondrial D-loop phylogeny signals two native Iberian red deer (Cervus elaphus) Lineages genetically different to Western and Eastern European red deer and infers human-mediated translocations

The tragedy of the commons: unsustainable population structure of Iberian red deer in hunting estates

Hunting can influence population structure with consequences in ecological and evolutionary processes. Populations of Iberian red deer (Cervus elaphus hispanicus) in Spain occur under two different management regimes: fenced and unfenced (open) estates. We compared census data, hunting bags and data from hunted individuals between both types of estates. Harvest on stags was moderate in fenced estates but strong in open ones, probably due to the competition between neighbouring landowners over the same deer populations. On the contrary, female culling was low in open estates compared to fenced ones. As a result, populations in open estates have mostly young males and strongly female-biased sex ratios. Female-biased population structure in open estates did not result in higher number of males being harvested per year compared with fenced estates, probably due to negative effects on development, survival and reproduction, and harvested males were younger, and hence, with smaller antlers. There is published evidence for undesirable effects of biased population sex ratio and age structure in these red deer populations. Our results indicate that this type of management may be unsustainable and recommend that harvest on males in open estates should be reduced and that on females increased, in order to maintain a more balanced population structure that may allow sustainable population dynamics and the operation of natural evolutionary processes.

An integrative assay to quantify the nutritional quality of the selected diet of two Mediterranean free-living deer by faecal-FT-NIRS

Integrating the interaction between cell wall components through a lignin and neutral detergent fibre ratio as a cell wall digestibility (CWD) index may provide a suitable method for diet quality and fibre digestibility estimation. Predictive faecal-Fourier-transform (FT)-near infrared reflectance spectroscopy (NIRS) equations useful for CWD determination were developed as an integrative assessment of the digestibility and quality of the diet selected by red (Cervus elaphus hispanicus) and fallow (Dama dama) deer in southern Spain. A chemometric regression was used from spectra of faeces and wet chemical rumen contents analysis as reference data coupled with partial least-squares. The accuracy and feasibility of the equations obtained for red and fallow deer samples separately were evaluated, as well as after pooling all samples for both species. The predictive equations had a high linearity with correlation coefficients (r) ranging between 0.89 and 0.99, as well as a reliable accuracy considering the errors of prediction (RMSEP 0.57–0.87), calibration (RMS 0.04–0.45) and cross-calibration (RMSECV 0.80–1.12) in relation to the range of values for which the NIRS calibration was set for each parameter, giving very good RER (residual error value) indices (7.44–13.23). The ability of the calibration equations to predict new samples from the same deer populations was also assessed through an external validation. Equations obtained for the red deer data were successfully applied not only to red deer but also to fallow deer, and vice versa. Feasible CWD simultaneous determination in red and fallow deer was also obtained by using the broad-based equations. There was variation of the CWD index throughout the year and differences between the two deer species. A lower CWD of the forage was recorded in red deer, while a lower CWD ratio was detected at the end of winter coinciding with the highest browsing levels in both species. This technique has potential to enable closer examination of the non-grass variables and distinguish between browse and herbage feeding behaviour. The faecal-NIRS method of CWD ratio determination is a useful, non-invasive tool for monitoring variations in the diet quality of Mediterranean deer in their natural environment.

Sex and age-class differences in calls of Iberian red deer during the rut: reversed sex dimorphism of pitch and contrasting roars from farmed and wild stags

Stag rutting calls differ among subspecies of red deer Cervus elaphus. Studying sex-, age-, and subspecies-related vocal variation may highlight the forces driving this evolution. This study presents the first bioacoustical comparison of oral calls produced during the rut by Iberian red deer Cervus elaphus hispanicus stags, hinds and calves and compares the acoustics of nasal and oral calls of hinds and calves. Also, it provides the first comparison of rutting roars between farmed and wild stags. Call maximum and mean fundamental frequencies (f0max and f0mean) were higher in farmed than in wild stags. Moreover, hinds had lower f0max and f0mean compared with both farmed and wild stags. The call minimum fundamental frequency (f0min) was indistinguishable between all groups of adults, irrespective of sex, farming and nasal versus oral vocal emission. In calves, but not in hinds, oral calls had higher f0max and f0mean compared with nasal calls. The higher fundamental frequencies in farmed as compared with wild stags may have resulted from emotional arousal due to human presence at recordings or from the higher body conditions of stags reared under a farm. The comparison of our results with previously published data on various subspecies of red deer suggests that there are different pathways of vocal ontogeny in eastern and western branches of Cervus elaphus and that the acoustics of stag and hind calls are more similar within the various subspecies than they are among the subspecies.

Mitochondrial D-loop phylogeny signals two native Iberian red deer (Cervus elaphus) Lineages genetically different to Western and Eastern European red deer and infers human-mediated translocations

Native red deer (Cervus elaphus) in Western Europe might at least partially derive from refugial populations which survived in the Iberian Peninsula during the last glacial maximum, and that expanded northwards at the onset of the Holocene. However, the phylogeny and genetic structure of red deer populations in the Iberian Peninsula are still poorly known. This study was planned, in a first step, to reconstruct the phylogenetic relationship of the main red deer populations extant in Spain by the analyses of an extensive sample of mitochondrial DNA sequences. Results indicate that sequences from these populations can be assigned to one of two deeply divergent mtDNA lineages (South-Western and Central-Eastern) with molecular divergence nearby the 2 %. In each lineage were respectively found sixteen and thirteen different haplotypes. It was evidenced that they may be allopatrically distributed in Spain with 86.6 % sequences of the South-Western lineage at the South-Western side and the 65 % sequences of Central-Eastern lineage in the Central-Eastern side. These mitochondrial lineages might have originated in two distinct refugial populations during the last glacial maximum. Genetic data also reveal instances of admixture between native populations and translocated European red deer, which belong to at least three distinct subspecies. Gene introgression was mainly due to red deer from Western European populations. The genetic contribution of red deer translocated from Eastern Europe (C. e. hippelaphus) or North Africa (C. e. corsicanus, C. e. barbarus) was apparently less deep. The extant phylogenetic relationship and evidences of genetic admixture suggest that sound conservation actions for the native Iberian red deer should severely restrict the introduction of alien red deer and, when possible, avoid admixture between the South-Western and Central-Eastern mtDNA lineages.

Why do cervids feed on aquatic vegetation?

Consumption of aquatic plants is rare among cervids, despite the common occurrence of this form of vegetation. However, the paucity of literature reporting on this feeding behaviour suggests that Na (but also other minerals), protein, and the ubiquitous availability of aquatic vegetation may play a role in its consumption. We present results quantifying those factors that regulate the consumption of aquatic plants in the Iberian red deer. We focussed our study primarily on two questions: (i) what nutritional values are red deer seeking in the aquatic plants?; and (ii) why do red deer primarily use aquatic plants during the summer? A comparison of the seasonal variations in Na content between terrestrial vs. aquatic vegetation did not fully support the hypothesis that aquatic plants are being consumed more in summer because of any seasonal variation in Na availability. The Na content in the aquatic vegetation was adequate all the year-round; whereas, the Na content in the terrestrial vegetation was consistently deficient. However, a greater summer content of essential minerals and protein in the aquatic vegetation may be the cause for their consumption exclusively during the summer. We suggest that seasonal variations in the consumption of aquatic vegetation by cervids is primarily driven by temporal variations in the nutrient content, combined with seasonal variations in the physiological demands for these nutrients.

Sperm Population Structure and Male Fertility: An Intraspecific Study of Sperm Design and Velocity in Red Deer1

Sperm design and velocity play key roles in influencing sperm performance and, therefore, can determine fertilization success. Several interspecific studies have demonstrated how these features correlate, and it has been hypothesized that selection may drive changes in these sperm traits. Here, we examine the association between sperm design and swimming velocity in a study conducted at an intraspecific level in Iberian red deer (Cervus elaphus hispanicus). We addressed how the structure of different sperm subpopulations, based on sperm morphometry and velocity, are interrelated and, in turn, how they associate with fertility. Our results show that males with high fertility rates have ejaculates with high percentages of spermatozoa exhibiting fast and linear movements and that these are highly correlated with a large proportion of spermatozoa having small and elongated heads. On the other hand, males with low fertility are characterized by a subpopulation structure in which slow and nonlinear as well as small and wide spermatozoa are predominant. These findings provide insight regarding how sperm size and velocity are interrelated and how they both are associated with fertility.

Ungulate Biology, Health and Management in the 21st century: the Tables are Turned in the Iberian Peninsula

Ungulate Biology, Health and Management in the 21st century: the Tables are Turned in the Iberian Peninsula

Effects of feed supplementation on mineral composition, mechanical properties and structure in femurs of Iberian red deer hinds (Cervus elaphus hispanicus).

Few studies in wild animals have assessed changes in mineral profile in long bones and their implications for mechanical properties. We examined the effect of two diets differing in mineral content on the composition and mechanical properties of femora from two groups each with 13 free-ranging red deer hinds. Contents of Ca, P, Mg, K, Na, S, Cu, Fe, Mn, Se, Zn, B and Sr, Young’s modulus of elasticity (E), bending strength and work of fracture were assessed in the proximal part of the diaphysis (PD) and the mid-diaphysis (MD). Whole body measures were also recorded on the hinds. Compared to animals on control diets, those on supplemented diets increased live weight by 6.5 kg and their kidney fat index (KFI), but not carcass weight, body or organ size, femur size or cortical thickness. Supplemental feeding increased Mn content of bone by 23%, Cu by 9% and Zn by 6%. These differences showed a mean fourfold greater content of these minerals in supplemental diet, whereas femora did not reflect a 5.4 times greater content of major minerals (Na and P) in the diet. Lower content of B and Sr in supplemented diet also reduced femur B by 14% and Sr by 5%. There was a subtle effect of diet only on E and none on other mechanical properties. Thus, greater availability of microminerals but not major minerals in the diet is reflected in bone composition even before marked body effects, bone macro-structure or its mechanical properties are affected.

Roaring high and low: composition and possible functions of the Iberian stag's vocal repertoire.

We provide a detailed description of the rutting vocalisations of free-ranging male Iberian deer (Cervus elaphus hispanicus, Hilzheimer 1909), a geographically isolated and morphologically differentiated subspecies of red deer Cervus elaphus. We combine spectrographic examinations, spectral analyses and automated classifications to identify different call types, and compare the composition of the vocal repertoire with that of other red deer subspecies.Iberian stags give bouts of roars (and more rarely, short series of barks) that are typically composed of two different types of calls. Long Common Roars are mostly given at the beginning or at the end of the bout, and are characterised by a high fundamental frequency (F0) resulting in poorly defined formant frequencies but a relatively high amplitude. In contrast, Short Common Roars are typically given in the middle or at the end of the bout, and are characterised by a lower F0 resulting in relatively well defined vocal tract resonances, but low amplitude. While we did not identify entirely Harsh Roars (as described in the Scottish red deer subspecies (Cervus elaphus scoticus)), a small percentage of Long Common Roars contained segments of deterministic chaos.We suggest that the evolution of two clearly distinct types of Common Roars may reflect divergent selection pressures favouring either vocal efficiency in high pitched roars or the communication of body size in low-pitched, high spectral density roars highlighting vocal tract resonances. The clear divergence of the Iberian red deer vocal repertoire from those of other documented European red deer populations reinforces the status of this geographical variant as a distinct subspecies.

Spectrographic analysis points to source–filter coupling in rutting roars of Iberian red deer

Source–filter coupling is the rarest acoustic phenomenon not only in Iberian red deer, but in any mammal. In most mammals, sound production can be well described in the framework of source–filter theory. The vocal output is the result of combined work of the larynx (the source) and of the supralaryngeal vocal tract (the filter). The source–filter theory suggests the independence of source and filter. Thus, vocal tract filtering should not affect the fundamental frequency (f0) of the sound created in the larynx. Spectrographically, the source is mostly characterized by the f0 and its harmonics, while the filter by the vocal tract resonances, i.e., formant frequencies. Nevertheless, a non-independent (coupled) source and filter can be proposed when the vocal folds start oscillating at one of the formant frequencies. Coupling between source and filter has been found in human singers and predicted for red deer Cervus elaphus by a computer modeling approach. This study describes different modes of phonation in a natural bout of rutting calls of Iberian red deer Cervus elaphus hispanicus and the transition from a chaotic mode to a probable source–filter coupling mode. This phenomenon might be involved in the production of extremely high-frequency bugles of North American and Asian subspecies of C. elaphus.

Foraging sexual segregation in a Mediterranean environment: Summer drought modulates sex-specific resource selection

A large body of studies have linked sexual segregation in dimorphic ungulates with differential resource selection and nutritional requirements of the sexes. However, detailed patterns of sexual dietary preferences have rarely been assessed as keystone mechanisms of sexual segregation. We compared diet and nutritional selection by 3 sex-age classes in the Iberian red deer (Cervus elaphus hispanicus Hilzheimer) across reproductive states and according to seasonal fluctuations in resource availability in a Mediterranean environment. Foraging segregation between sexes was found during rut when female/juvenile selection of shrubs was higher than that of males. Observed foraging patterns relate to a stronger selection of nitrogen, tannins and lignin by females and juveniles, and fibres by males. Our findings are associated to the Mediterranean climate, where rut and lactation concur with a shortage period, the particularly dry summer. Foraging segregation between sexes during the rut could be shaped by a conjunction of factors such as the low quality of resources and different fitness enhancement strategies. We highlight both the importance of including the dietary component and providing a temporal framework when documenting ungulate sexual segregation, and the interest of considering regional conditions when addressing management of ungulates with a wide distribution.

Nutritional evaluation of the lipid fraction of Iberian red deer (Cervus elaphus hispanicus) tenderloin

The meat lipid fraction of psoas major muscle from 20 adult (10 males and 10 females) feral Iberian red deer (Cervus elaphus hispanicus) was characterized by quantification of total fat, total cholesterol, vitamin E and fatty acid (FA) composition, including detailed trans octadecenoate isomers and conjugated linoleic acid (CLA) isomeric profile.The total lipid content revealed a very lean meat (0.99g/100g of meat), with total cholesterol content averaging 55.6mg/100g of muscle. The FA profile displayed a very high PUFA level for ruminant meat (30.2g/100g FA). The 18:2 cis-9,trans-11 content was fairly low (0.26% of total FA) compared with other ruminant meats.The comparison of stags and hinds showed more similarities than differences. Nevertheless, hinds displayed superior contents of α-tocopherol and trans MUFA and a better n−6/n−3 ratio than stags.

Ontogenesis of the Reticulum with Special Reference to Neuroendocrine and Glial Cells: A Comparative Analysis of the Merino Sheep and Iberian Red Deer

The present study was designed to compare the differences in the ontogenesis of the reticulum in sheep (domestic ruminant) and deer (wild ruminant). A total of 50 embryos and foetuses Merino sheep and 50 Iberian deer were used, from the first pre-natal life until birth. The appearance of the reticulum from the primitive gastric tube was earlier in the sheep (22% gestation, 33 days) than in the deer (25% gestation, 66 days). In both cases, it displayed a primitive epithelium of a stratified, cylindrical, non-ciliary type. At around 48% gestation in the sheep (72 days) and 36% (97 days) in the deer, the reticulum was configured of four clearly differentiated layers: mucosa (with epithelial layer and lamina propria), submucosa, tunica muscularis and serosa. The stratification of the epithelial layer was accompanied by modifications in its structure with the appearance of the primitive reticular ribs. The primary ribs began to be formed first in the deer, at 117 days of pre-natal life (40% gestation) and later in the sheep (79 days, 53% gestation). The differentiation of the corneum papillae in the primary ribs coincided with the appearance of secondary reticular ribs. These structures began to be formed first in the deer, at 142 days of pre-natal life (51% gestation) and later in the sheep (83 days, 55% gestation). The presence of neuroendocrine cells (non-neuronal enolase-positive cells) in the reticular mucosa was not detected until 97 days (36% gestation) in deer and 81 days (54% gestation) in sheep. The presence of glial cells (GFAP-positive cells) occurred at around 142 days (51% gestation) in deer and at 112 days (75% gestation) in sheep. In conclusion, the presence of neuroendocrine and glial cells was detected in deer at earlier stages than sheep.

Taking advantage of the use of supervised learning methods for characterization of sperm population structure related with freezability in the Iberian red deer

Using Iberian red deer as a model, this study presents a supervised learning method, the Support Vector Machines (SVM), to characterize sperm population structure related with freezability. Male freezability was assessed by evaluating motility, membrane status and mitochondrial membrane potential of sperm after a freezing-thawing procedure. The SVM model was generated using sperm motility information captured by computer-assisted sperm analysis (CASA) from thawed semen, belonging to six stags with marked differences on their freezability. A total of 1369 sperm tracks were recorded for seven kinematic parameters and assigned to four motility patterns based on them: weak motile, progressive, transitional and hyperactivated-like. Then, these data were split in two sets: the training set, used to train the SVM model, and the testing set, used to examine how the SVM method and three other unsupervised methods, a non-hierarchical, a hierarchical and a multistep clustering procedures, performed the sperm classification into subpopulations. The SVM was revealed as the most accurate method in the characterization of sperm subpopulations, showing all the sperm subpopulations obtained in this way high significant correlations with those sperm parameters used to characterize freezability of males. Given its superiority, the SVM method was used to characterize the sperm motile subpopulations in Iberian red deer. Sperm motile data from frozen–thawed semen belonging to 25 stags were recorded and loaded into the SVM model. The sperm population structure revealed that those males showing poor freezability were characterized by high percentages of sperm with a weak motility pattern. In opposite, males showing good freezability were characterized by higher percentages of sperm with a progressive and hyperactivated-like motility pattern and lower percentages of sperm with a weak motile pattern. We also identified a sperm subpopulation with a transitional motility pattern. This subpopulation increased as the freezability of males improved, and may be used as indicative of overall sperm motility.

Vocal anatomy, tongue protrusion behaviour and the acoustics of rutting roars in free‐ranging Iberian red deer stags (Cervus elaphus hispanicus)

Roaring in rutting Iberian red deer stags Cervus elaphus hispanicus is unusual compared to other subspecies of red deer, which radiated from the Iberian refugium after the last glacial maximum. In all red deer stags, the larynx occupies a permanent low mid-neck resting position and is momentarily retracted almost down to the rostral end of the sternum during the production of rutting calls. Simultaneous with the retraction of the larynx, male Iberian red deer pronouncedly protrude the tongue during most of their rutting roars. This poses a mechanical challenge for the vocal tract (vt) and for the hyoid apparatus, as tongue and larynx are strongly pulled in opposite directions. This study (i) examines the vocal anatomy and the acoustics of the rutting roars in free-ranging male C.e.hispanicus; (ii) establishes a potential mechanism of simultaneous tongue protrusion and larynx retraction by applying a two-dimensional model based on graphic reconstructions in single video frames of unrestrained animals; and (iii) advances a hypothesis of evaporative cooling by tongue protrusion in the males of a subspecies of red deer constrained to perform all of the exhausting rutting activities, including acoustic display, in a hot and arid season.

Assessing red deer antler density with a hydrostatic method versus a new parametric volume-modelling technique using 3D-CAD

Two methods of volume measurement were compared, to develop a simple and reliable method for estimating the whole-antler density. We used 10 cast antlers, previously dried and weighed, from 10 different red deer (Cervus elaphus hispanicus) individuals. The volumes were determined by the traditional Archimedes method versus a new parametric volume-modelling technique using a ‘computer-aided design-three dimensions’ (3D-CAD), which is now being used in the biomedical industry in applications such as medical-implant design, tissue engineering and in developing a better understanding of anatomical functionality and morphological analysis. The process paths to follow in the generation of CAD models from cast antlers were described. The whole-antler density was estimated from the weight and volume measurement and a paired-sample comparison procedure was performed to assess differences between volumes as well as densities. Cast-antler weight ranged from 219.93 to 1857.9 g, and the volume estimated by the hydrostatic method was 732.45 ± 474.06 cm3 and by the CAD-3D method it was 730.65 ± 492.59 cm3. The DM density of the antler by the hydrostatic method (Density A) was 1.112 ± 0.120 g/cm3, ranging from 0.915 to 1.345 g/cm3 (Shapiro–Wilks, P = 0.449), and by the 3D-CAD method (Density B) it was 1.112 ± 0.158 g/cm3, ranging from 0.939 to 1.326 g/cm3 (Shapiro–Wilks, P = 0.751). There were no differences in the volume (t = 0.95, P = 0.37) or density (t = 0.54, P = 0.60) between the two methods and the correlation coefficient between Density A and Density B was 0.968. Both methods had similar reliability, although the computing process with the 3D-CAD system calculated antler volume faster than did the traditional hydrostatic weighing. 3D-CAD also avoided cast damage and the methodological problems with larger or smaller antlers or with floatability due to low density, which occur when using the hydrostatic method.