Application of Discriminant Analysis on the Forest Muturu Cattle in Different Locations in Southern Zone of Nigeria

About 238 mature Forest Muturu cattle were sampled from Southern Nigeria (Enugu, Imo, Delta, Anambra and Ebonyi) States. Discriminant analysis was performed on the effects of location using body weight and body linear parameters. Horn length was the only parameter selected for stepwise discriminant analysis to separate the populations of forest Muturu bulls. Horn length, muzzle circumference, body length, chest girt and ear length were the selected parameters by stepwise discriminant analysis to separate the forest Muturu cows populations. The strength of the canonical correlation model to explain the variations between the groups 0.615, 0.450, 0.364 and 0.335 for functions 1, 2, 3 and 4 respectively among cows and 0.71, 0.59, 0.50 and 0.29 for functions 1, 2, 3 and 4 respectively among bulls. Location was found to influence body parameters. There is need to carry out further study to assess performance characterization of the Forest Muturu cattle in Nigeria to identify the superior genetic grades base on economic traits which may be useful in establishing necleous breeding center.

Evidence of phenotypic plasticity along an altitudinal gradient in the dung beetle Onthophagus proteus

Background High altitude insects are an ecologically specialized group and possess a suite of adaptions which allow persistence in the inhospitable conditions often associated with mountain tops. Changes in body coloration and reductions or increases in body size are thought to be examples of such adaptions. Melanic individuals, or individuals containing high levels of eumelanin, possess several traits which increase resistance to ultraviolet radiation and desiccation, while aiding thermoregulation. Trait variation is often observed in dung beetles and is associated with dimorphism and sexual selection. In this study, we identified trait changes which occur across an altitudinal gradient by measuring morphological color and body size traits in a montane insect. Methods Using standard digital photography and Image J, we examined individuals of Afromontane dung beetle Onthophagus proteus. Individuals were classified according to sex and color morph to identify intrasexual variance. Nine morphometric traits were measured per beetle to identify patterns of morphology across discrete 500 m altitude segments. Results The results of this study provide one of the first descriptions of trait changes associated with elevation in an African dung beetle. We suggest that color polymorphism in Onthophagus proteus might be at least partly driven by environmental factors as there is significantly increased melanism with increasing elevation and significant differences in color hues between altitude bands. We also suggest changes in horn length are density dependent, as we observed an increase in cephalic horn length at high elevations where O. proteus is the most abundant species.

Characterization of indigenous cattle genotypes based on linear body traits in the humid tropics

Selection for trait of interest is a major problem in cattle production when faced with the challenge of varied growth traits in different genotypes. Low understanding of the production potentials of these cattle breeds constitute problems in effective improvement of physical body characteristics. A total of 18 cattle was used to characterize the Nigerian local cattle genotypes based on quantitative traits. Three genotypic groups {White Fulani (WF), N'Dama (ND) and White Fulani x N'Dama (WFxND)} crosses were used for the experiment. Experimental design was a completely randomized design (CRD) with genotypic group as major factor of interest. Quantitative traits measured were body length (BDL) (cm), hip height (HHT) (cm), heart girth (HG) (cm), horn length (HL) (cm), tail length (TL) (cm), ear length (El) (cm) and neck length (NL). Results showed that there were significant differences (p<0.05) in body length in weeks 99 – 111 and 112 – 124 with the White Fulani and N'Dama genotypes having longer bodies. The values ranged from 33.00 to 39.29cm in WF, 39.49 to 39.59cm in N'Dama and, 18.25 to 32.90 in WF x ND. There were significant (p<0.05) differences in hip height of cattle in age interval of 99-111 and 112-124 weeks of age, with the White Fulani and N'Dama genotypes having highest hip. The genotypes showed significant (p<0.05) differences in heart girth in 99 and 124 WOAwith the White Fulani and N'Dama genotypes having widest heart girth. The genotypes showed significant (p<0.05) differences in horn length in all the weeks with White Fulani showing superiority. The genotype had longer horns in the White Fulani and followed by WF x ND across the week intervals. The values ranged from 14.99 to 15.20cm in WF, 5.75 to 10.19cm in N'Dama and, 3.00 to 4.29 in WF x ND. The tail length of the three genotypes showed significant (p<0.05) differences in 99-111 and 112-124 WOA. Higher values were obtained in White Fulani genotype which showed longer tails than the N'Dama and WF x ND. There were significant (p<0.05) differences in neck length of the cattle genotypes in 112-124 WOA. Higher values were obtained in White Fulani genotype which showed longer neck than the N'Dama and WF x ND. White Fulani could be used to enhance growth of Nigerian indigenous cattle in the study area. The present findings could assist in the design of long-term genetic improvement programmes for cattle production in Nigeria.

Face markings in Northern chamois: cues of dominance?

Black and white face markings in Artiodactyls are thought to be broadly associated with intraspecific communication. Evidence-based studies on the fine-scale mechanisms of signaling, however, are scant. The occurrence of black and white face markings is one of the most distinctive features of the Northern chamois Rupicapra rupicapra. Although their function is unknown, they might possibly signal fighting abilities: if so, the intensity of face color contrast should positively correlate with traits involved in aggressive contests, i.e. body mass and horn size. We collected data on face marking ‘blackness’ as a proxy of color contrast, dressed body mass and horn length on 103 chamois of either sex harvested during the hunting season of 2019 in the central Italian Alps. To investigate the relationship between color contrast and sex-specific body mass and horn length, we fitted an ordinal multilevel regression model in a Bayesian framework. Contrast score positively associated with increasing body mass in both sexes, but this relationship was much stronger in females than in males. Contrast score positively related with horn length in males but not in females. Our results offer some first insights into the potential correlates of chamois facial mask, suggesting that face markings might provide age-specific cues of mass-based dominance in females, while their role in males appears more uncertain. Behavioral studies on marked or hunted individuals in different environmental settings are necessary to confirm these findings, and provide further understandings of face color patterns in chamois.

Variation in an Extreme Weapon: Horn Performance Differences across Rhinoceros Beetle (Trypoxylus dichotomus) Populations

Japanese rhinoceros beetle (Trypoxylus dichotomus) males have exaggerated head horns that they use as weapons in combat over reproductive opportunities. In these contests, there is an advantage to having a longer horn, and there seems to be little cost to horn exaggeration. However, populations vary in the amount of horn exaggeration across this widespread species. Here, we examine four populations and quantify scaling and functional morphology of the horn. We then measure force production by the horn system in a combat-relevant movement. We find that not only does horn length vary among populations, but allometry of lever mechanics and force production varies in a complex way. For instance, some beetle populations make relatively long horns, but exert relatively low forces. Other populations make shorter horns and produce higher forces during fights. We suggest that this performance variation could be associated with differences in the intensity or type of sexual selection across the species.

Size-dependent seasonal activity for males of the dung beetle Copris acutidens (Coleoptera: Scarabaeidae)

This study aimed to determine differences in activities between two male morphs of the dung beetle Copris acutidens Motschulsky (Coleoptera: Scarabaeidae) during the reproductive period and to examine the size distribution of reproductive males that stayed in nests. The activities of two male morphs distinguished by a threshold value of body size were compared with those by horn length. Regardless of body size or horn length, earlier activity of minor males was observed during the reproductive period. The sex ratio showed the greatest female bias when minor males were the more abundant than major males, indicating that minor males were the most active when competition was the weakest and these could avoid direct combat with major males. In morphs distinguished by horn length, more major males than minor males stayed in nests with females although the major males became the most active from the middle of the reproductive period. Thus, longer horns may directly confer a competitive advantage to males, enabling them to stay in nests with females, whereas early activity of minor males does not always indicate the effect of horn length directly. Therefore, this behaviour may occur regardless of whether the morphs differ in body size or horn length.

Evidence for Male Horn Dimorphism and Related Pronotal Shape Variation in Copris lunaris (Linnaeus, 1758) (Coleoptera: Scarabaeidae, Coprini)

Male horn dimorphism is a rather common phenomenon in dung beetles, where some adult individuals have well-developed head horns (i.e., major males), while others exhibit diminished horn length (i.e., minor males). We focused on horn dimorphism and associated head and pronotum shape variations in Copris lunaris. We examined the allometric relationship between horn length (i.e., cephalic and pronotal horns) and maximum pronotum width (as index of body size) by fitting linear and sigmoidal models for both sexes. We then asked whether head and pronotum shape variations, quantified using the geometric morphometric approach, contributed to this allometric pattern. We found that female cephalic and pronotal horn growth showed a typical isometric scaling with body size. Horn length in males, however, exhibited sigmoidal allometry, where a certain threshold in body size separated males into two distinct morphs as majors and minors. Interestingly, we highlighted the same allometric patterns (i.e., isometric vs. sigmoidal models) by scaling horn lengths with pronotum shape, making evident that male horn dimorphism is not only a matter of body size. Furthermore, the analysis of shape showed that the three morphs had similar heads, but different pronota, major males showing a more expanded, rounded pronotum than minor males and females. These morphological differences in C. lunaris can ultimately have important functional consequences in the ecology of this species, which should be explored in future work.