Addax

Addax Addax

Order: Artiodactyla                                                                                               Family: Bovidae                  

Scientific name: Addax nasomasculatus                                                             U.S. common name: Addax

Status in the wild: Listed as endangered by IUCN; Appendix 1 of CITES 

Major threats: Hunting and habitat loss 

Geographic range historically: Western Sahara and Mauritania to Egypt and Sudan: possibly Palestine and the Arabian Peninsula

Geographic range currently: Northeastern Niger, north-central Chad, the border of northwestern Mali and eastern Mauritania, introduced into Tunisia  [1]

Habitat: Desert and semi-desert areas and gravel plains

Circadian cycle: Most active at night and at dawn and dusk, resting during the heat of the day. 

 

Size

 

General range                       male                                       female                                                    birth

 

Head to rump length:                               1200-1750                      

Tail length:                                               250-350 mm

Head & tail length:                                  1450-2100 mm               

Shoulder height:                                      950-1150 mm                 

Weight:                                                      60-135 kg                         100-135 kg                             60-90 kg                                                  5 kg            

Sexual dimorphism:  Males are larger than females. Both sexes have horns.                                                                                                

 

Reproduction

 

Mating Season: Throughout the year in captivity. 

Birthing season: Birth peaks in winter and spring for both captive and wild populations. 

 Gestation period: 257-264 days

Estrous cycle: Lasts 24-48 hours

Monestrus/polyestrus: Polyestrous

Courtship: Dominance displays are prominent within the hippotragine courtship. Females react aggressively to males unable to dominate them, but when an

                    adult male approaches in low stretch, females respond by urinating. The male then urine tests. During the mating march, the male follows closely,

                    he sniffs and may rub his face or horns on the cow’s croup. Foreleg lifting tests the female’s willingness to stand for mounting. The male also

                    rests his chin on the female’s croup as a mounting prelude. 

Copulation: The copulatory posture is an upright, firm grasping of the female’s loins. 

Number of mammae: Four 

Interbirth interval: 355 days

Sexual maturity: Males are mature at 24 months, females during their second or third summer. 

Other information: Females usually isolate before and for at least a week after calving, remaining within view of the hiding place during the early part of the

                                   concealment period. 

                       

 

 

Rearing and young

 

Young called: Calf

Number of young (range): One 

Condition of young: Precocial

Eyes open: At birth              

First leave pouch/den/hide/nest: Calves remain concealed for up to six weeks. 

Weaned: 23-29 weeks

 

 

General

 

 

Life expectancy: Up to 25 years in captivity. 

Social structure: Move in herds of 5-20 animals led by an old male.  A group of captive females were observed to establish a dominance hierarchy, the oldest

                              animals ranking the highest. In a semi-captive population, the males established territories and attempted to keep the females within their

                              territory.  

Unique behavior(s): In a mixed group the males leave small piles of pellets, while the females scatter their dung. 

Senses: Vision, olfaction, and hearing are the most important senses. 

Coat & coloration: The coat on the body and neck are grayish brown in the winter, but in summer the body coloration becomes sandy almost white. The

                                  legs, hips, belly, ears, and facial markings are white, and the tuft of hair on the forehead is dark brown to black.  

Dental Formula: 0/3 I, 0/1 C, 3/2-3 PM, 3/3 M = 30-32 total 

Diet: Desert vegetation including shoots and leaves. Addax are the most desert adapted of the antelope and can subsist without drinking.

 

 

Sources

 

Nowak, Ronald M. (ed.) 1999.Walker’s Mammals of the World Vol. 2 (6th edition).  The John Hopkins University Press, Baltimore and London.

Macdonald, David (ed.). 1987.  The Encyclopedia of Mammals.  Facts on File Publications, New York.

Estes, Richard D. 1991.  The Behavior Guide to African Mammals.  The University of California Press, Berkeley.

Kingdon, Jonathan 1997. The Kingdon Field Guide to African Mammals.   Academic Press, London.

Alden, Peter C. et al. 1995. National Audubon Society Field Guide to African Wildlife.  Alfred A. Knopf, Inc., New York

 

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