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Figure 19.1. Neonatal mortality (<1 month of age) and survival to 1 year of age in captive-born giant panda cubs, 1963 to 2003 (first year survival includes cubs born through 2002). Data are from Xie & Gipps (2003). ■ , Number live births in captivity; neonatal mortality (%); A, surviving first year (%).

animals (Figs. 19.2 and 19.3). Of the 115 cubs born in those 26 years, only 13.9% (i.e. 16 cubs) lived to breeding age (i.e. more than four years of age).

During these early years of attempted breedings, it was apparent that reproductive success in both sexes was compromised. Females failed to enter oestrus, and of those that did, many failed to mate, conceive or sustain a pregnancy. Males often refused to copulate, generally because of serious aggression toward females (see Chapter 14). The latter was the incentive to test the feasibility of assisted breeding, virtually always by artificial insemination (AI). However, in many cases it was difficult to obtain high-quality ejaculates, and the sperm often died soon after collection.

These frustrations motivated managers to develop more systematic efforts to learn about the biology of the species and to take an applied approach. For example, to circumvent behavioural incompatibilities that prevented natural mating, serious experiments with assisted breeding began in the mid 1970s. The first cub produced by AI with fresh sperm was born at Beijing Zoo in 1978. Two years later, the first cub from AI using frozen-thawed sperm was produced at Chengdu Zoo. Thereafter, success with AI was somewhat sporadic but gradually improved with the advent of detailed sperm biology studies, including creating methods to maintain good sperm viability in vitro before deposition into the female. Successful AI was an important milestone because it overcame one of the primary challenges to consistent reproduction: behavioural incompatibility between the sexes. This accomplishment was significant because it provided the technology to maintain gene diversity, which is currently one of the highest priorities of the modern breeding programme (see Chapter 21). In this context, it was realised early on that moving genes via sperm could be much more cost-effective and less stressful than moving animals from one breeding facility to another. Furthermore, the ability to cryopreserve viable sperm could maintain valuable panda genes in 'suspended animation' indefinitely, to be used even in future generations. Throughout the 1980s and 1990s, this type of research progressed, as did the routine use of AI at various Chinese breeding centres. Nonetheless, the refusal of individual giant pandas to mate remained an important issue, as it still does today. And no manager has been naive enough to believe that the captive population should be sustained by assisted breeding alone. On the contrary, a substantial number ofstudies have been initiated over the years to understand the behaviour of this species, largely for the purposes of promoting natural breeding (Maple et al., 1997; see also Chapters 11 and 14).

Figure 19.2. Ex situ giant panda population from 1936 to 2003, represented by the number of individuals alive on 31 December of each year (including the cubs produced in that year). Data are from Xie and Gipps (2002). (a) The total number of giant pandas and the proportions of the population that are captive born versus wild-caught. (b) The percentage of captive-born and wild-caught individuals in the population from 1936 to 2003. A, wild caught; captive born; ■, total.

Figure 19.2. Ex situ giant panda population from 1936 to 2003, represented by the number of individuals alive on 31 December of each year (including the cubs produced in that year). Data are from Xie and Gipps (2002). (a) The total number of giant pandas and the proportions of the population that are captive born versus wild-caught. (b) The percentage of captive-born and wild-caught individuals in the population from 1936 to 2003. A, wild caught; captive born; ■, total.

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