b 1936 1942 1948 1954 1960 1966 1972 1978 1984 1990 1996 2002
Figure 19.3. (a) The number of reproductive-age giant pandas (five years or older on 1 August of each year) in the ex situ population. (b) The percentage of reproductive-age males and females producing live-born cubs (1936 to 2003). Data are from Xie and Gipps (2003). ▲ , males; O, females; ■, total.
The Focus on improving cub survival, assisted breeding and maximising inter-institutional communication (1990 to the present)
During the first 26 years, 115 cubs were born from 77 pregnancies with a neonatal survival rate of 37%. From 1990 to 2002, 179 cubs were born from 126 pregnancies, with 71% of neonates surviving. The captive-born population has grown from one panda born in 1963 to 112 at the end of 2003 (including surviving cubs born in the autumn of 2003; see Fig. 19.2). In 1997, the number of captive-born animals outnumbered wildborn (and captured) animals in the ex situ population (see Fig. 19.2). Since then, divergence in the size of these two groups has increased dramatically and reflects the improvements in captive breeding efficiency. This increase in the captive-born population has been attributable to more females having the chance to reproduce (due to the use of AI) and enhanced cub survival (due to improved husbandry).
Improvements in cub survival have been particularly profound. In those early years, much of the early cub loss was due to the almost 50% incidence of twinning and the 'natural' loss of one cub through maternal rejection of both cubs and/or a variety of dam-related incompetencies (see Chapter 13). Efforts to assist dams by supplemental feeding and the partial hand-rearing of cubs first succeeded at Chengdu Zoo in 1990, when a set of twins survived to adulthood. Two years later, the Beijing Zoo hand-reared a cub that had been rejected by its mother and had never nursed from the dam (complete hand-rearing). This was a milestone in that the cub, although presumably never obtaining immuno-logical protection afforded by colostrum, did not succumb to neonatal sepsis which causes most neonatal mortalities in this species (see Chapters 13 and 16). The use of commercial milk formulae, improved sanitary conditions and the novel technique of twin swapping (see Chapter 13) have resulted in a steady rise in neonatal survival over the past decade (see Fig. 19.1). These efforts have also been bolstered by partnerships between panda breeding centres that had little experience with hand-rearing and institutions (often international) whose personnel were skilled in these methods (see Chapter 13). This resulted in a rapid transfer of knowledge and technologies. At the same time, similar cooperation occurred in reproductive biology studies, including those that focused on improving AI using fresh or thawed spermatozoa (see Chapter 20).
Although international partnerships were critical to progress, there was also more communication among Chinese breeding facilities. To oversee and coordinate breeding recommendations and research priorities within China, the Chinese Committee of Breeding Techniques for Giant Pandas was established in 1989. This committee, comprised of scientists and administrators from zoos, nature reserves, universities, research facilities and government agencies, meets annually (usually in November or December), and prior to the impending breeding season.
Information is shared in scientific presentations and through small working groups that allow face-to-face interaction. This annual meeting has recently been opened to international holders of giant pandas. The Committee has also worked closely with the Conservation Breeding Specialist Group (CBSG) of the IUCN-World Conservation Union's Species Survival Commission. In fact, it was through this annual committee meeting that CBSG worked with various stakeholders to initiate the Giant Panda Biomedical Survey (discussed throughout this text). CBSG has also been instrumental in catalysing various contemporary actions involving genetic management, from helping organise paternity testing (see Chapter 10) to annual breeding recommendations based on mean kinship (see Chapter 21).
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