Assisted Reproduction in Female Rhinoceros and Elephants – Current Status and Future Perspective

Abstract

Over the last few decades, rhinoceroses and elephants became important icons in the saga of wildlife conservation. Recent surveys estimate the wild Asian (Elephas maximus) and African (Loxodonta africana) elephant populations to be, at most, 50 250 and 637 600 respectively. For the five rhinoceros species, black (Diceros bicornis), white (Ceratotherium simum), Indian (Rhinoceros unicornis), Javan (Rhinoceros sondaicus) and Sumatran rhinoceros (Dicerorhinus Sumatrensis), the population estimates of 3610, 11 330, 2400, 60 and 300, respectively, are of even greater concern. Protected against habitat loss, poaching and left undisturbed, rhinoceros and elephants reproduce well in the wild. But small and decreasing populations make successful captive management of these taxa increasingly important. In captivity, however, most populations face possible 'extinction' because of historically poor reproductive performance. From the first descriptions of the reproductive anatomy and the oestrous cycle (Laws 1969; Kassam and Lasley 1981; Balke et al. 1988a,b; Plotka et al. 1988; Godfrey et al. 1991) to the present use of advanced assisted reproduction technologies, researchers have strive to understand the function and dysfunction of the reproductive biology of these charismatic species. This paper reviewed the current knowledge on rhinoceros and elephant reproduction biology, reproductive cycle, gestation, dystocia, reproductive pathology, oestrous induction and artificial insemination, sperm sexing, IVF and contraception, and how this knowledge is or might be used to aid species conservation for maximal reproductive efficiency and enhancement of genetic management.

Feasibility of sex-sorting sperm from the white and the black rhinoceros (Ceratotherium simum, Diceros bicornis)

“…Sex-sorted spermatozoa suitable for AI or IVF might become an important management tool for captive wildlife populations as unbalanced sex ratios create difficulties with management of small populations, particularly in large, slow-reproducing mammals [50,51]. The methods developed in this study mark a substantial step toward the successful application of sex-preselection technology in the rhinoceros.…”

Proboscidea

“…Other complications include incisional dehiscence and surgical infection. 28 The most commonly performed surgeries in elephants are dental surgeries. When the calves were finally passed, the bodies were neither mummified nor macerated.…”

“…Congenital cardiac abnormalities have been reported in calves. 28 These tumors may get quite large with necrotic centers that may break off and pass down the urogenital canal. Surgical colics include a variety of strangulating obstructions.…”

“…Cycle length may vary between cows but usually is consistent for an individual. 28 Sexual maturity occurs in elephants between the ages of 4 and 12 years. Ovulation occurs following the second LH peak.…”

Female Elephant Reproduction

“…The most recent accomplishments include successful manual semen collection, sorting, and freezing, as well as artificial insemination with fresh, chilled, or frozen semen. 9 Nevertheless, several aspects of the female reproductive process remain unknown. Ongoing research efforts and the enhanced understanding of elephant reproductive physiology represent key factors for in situ and ex situ conservation of these magnificent creatures in the future.…”