This chapter comprises the following sections: names, taxonomy, subspecies and distribution, descriptive notes, habitat, movements and home range, activity patterns, feeding ecology, reproduction and growth, behavior, parasites and diseases, status in the wild, and status in captivity.

INTRODUCTION

Historically, the breeding of giant pandas in ex situ programmes has been difficult due to behavioural incompatibility and interanimal aggression. Because some individuals fail to mate naturally, the potential loss of valuable genes is a major concern to effective genetic management (see Chapter 21). Consistently successful artificial insemination (AI) would allow incorporating genetically valuable males with behavioural or physical anomalies into the gene pool. This strategy becomes even more powerful when used in the context of a genome resource bank (GRB), an organised repository of cryopreserved biomaterials (tissue, blood, DNA and sperm) (see Chapter 7). The use of sperm cryopreservation and AI allows the movement of genes among zoos and breeding centres without needing to transfer animals, which is both stressful and costly.

‘Assisted breeding’ refers to the tools and techniques associated with helping a pair of animals propagate, from AI to embryo transfer to cloning, among others (Howard, 1999; Pukazhenthi & Wildt, 2004). With the exception of AI, there is not much need for most other assisted-breeding techniques for the giant panda. As will be demonstrated here, AI is quite adequate for dealing with most cases of infertility or with helping to maintain adequate gene diversity in the captive population. In fact, the major breeding facilities, especially the China Conservation and Research Centre for the Giant Panda (hereafter referred to as the Wolong Breeding Centre) and the Chengdu Research Base of Giant Panda Breeding, routinely use AI to increase pregnancy success.

INTRODUCTION

The foundation of any managed breeding programme for animals living in captivity is a studbook. This is the chronological listing of animals in the historical captive population detailing birth and death dates, gender, parentage, locations, transfers and local identification numbers (Glatston, 1986). Analyses of these data provide critical information on past trends in population size, age-specific reproductive and survival rates, age structure, numbers of founders, degree of inbreeding, loss of genetic diversity and other measures useful for evaluating temporal changes in a captive population. This information then becomes the basis for making management recommendations to enhance the demographic and genetic security of the captive population (Ballou & Foose, 1996). Demographic security is needed to ensure that an adequate number of breeding-aged animals are available to reproduce at the rates needed to grow or maintain the population at its desired size. Genetic diversity is required for the population to remain healthy and to adapt to changing environments (i.e. experience natural selection).

The 2001 International Studbook for the Giant Panda contains detailed life history information on 542 giant pandas that have lived in zoos around the world (Xie & Gipps, 2001). The first entry, giant panda Studbook (SB) Number 1, is Su Lin, a wild-caught female who arrived at Brookfield Zoo on 2 February 1937 (see Chapter 1). A quick scan of the studbook leaves one with the impression that the captive population's dynamics are dominated by entry and subsequent death of wild-caught animals without sustainable reproduction.

INTRODUCTION

This book deals mostly with new biological knowledge and the use of that knowledge to benefit the giant panda by enhancing health, reproduction and management. It is an important strategy for modern-day zoo scientists, conducting ‘basic research’ to learn as much as possible about previously unstudied phenomena in any species, especially those that have received little, if any, attention.

In many ways, a scientist affiliated with a zoo is no different than a university research professor – both study mechanisms by using the scientific method to test hypotheses (Wildt, 2004). What is different about zoo science is the growing emphasis on results having practical uses – addressing issues that are relevant to allowing an animal to be better maintained in captivity, to allow it to thrive, reproduce and help sustain its species. In a perfect world that new knowledge will have duality of purpose, being useful to improving the conservation of in situ as well as ex situ populations. In fact, there now are many examples of ‘captive’ studies that have been useful for re-invigorating or re-establishing wild populations (e.g. golden lion tamarin, scimitar horned oryx, Florida panther, black-footed ferret, red wolf, California condor, among others). But having an in situ benefit is not an essential prerequisite to studying a species because the primary target is always the production of new knowledge – intellectual capital that improves our understanding of the wonders of biology and the natural world.

INTRODUCTION

As for many highly specialised carnivores, breeding giant pandas in captivity has had sporadic gains and setbacks over its 40-year history (see Chapters 1 and 19). Although many husbandry issues have been addressed successfully, we are still learning about behaviour and its relevance to ex situ management. This chapter updates the state of captive breeding at the China Conservation and Research Centre for the Giant Panda in the Wolong Nature Reserve (hereafter referred to as the Wolong Centre). We also provide details of our scientifically guided husbandry and management strategies that are contributing to a rapidly growing database of scholarly knowledge as well as to recent improvements in reproductive success.

Even with our limited knowledge about giant pandas in nature, it appears that, in the presence of plentiful natural resources and the absence of human disturbance, giant pandas mate, become pregnant and rear offspring without problem. Thus, reproduction is not a limiting factor to wild population viability (Lu et al., 2000). Because this is not the case for the ex situ population, we can surmise that reproductive problems are rooted in the captive environment – a place that fails to fully meet the needs of at least some individuals. In principle, and with a proper understanding of species-salient factors, it should be possible to create captive environments that result in, or even surpass, reproductive rates occurring in the wild. Targets for improvement include health, nutrition, husbandry and behavioural management, this chapter concentrating on the latter two factors.

INTRODUCTION

While many recent advances have been made in the breeding of giant pandas ex situ, historically this species has never reproduced well in captivity. Sexual incompatibility, health problems, low fecundity and a juvenile mortality rate in excess of 70% have contributed to low reproductive success (O'Brien & Knight, 1987; O'Brien et al., 1994; Peng et al., 2001a, b). Wild- and captive-born giant pandas, particularly those captured at a young age, traditionally had difficulty producing offspring in captivity upon becoming adults (Lu & Kemf, 2001). As a result, the ex-situ giant panda population has not been self-sustaining and, until recently, its growth has relied on introducing animals captured from nature. In some cases, this included individuals that appeared ill (rescues) or cubs that were believed to be neglected or abandoned by their mothers. Later field studies, however, revealed that females often leave cubs alone for four to eight hours while foraging, and in one documented case for 52 hours (Lu et al., 1994). Recently, China has placed a general moratorium on capturing wild giant pandas for captive breeding (Lu & Kemf, 2001), a move that forces the breeding community to develop a self-sustaining population.

The goal, however, is not only ensuring demographic self-sustainability but also the maintenance of genetic diversity. The deleterious effects of inbreeding are well recognised (O'Brien, 1994a; Frankham, 1995; Hedrick & Kalinowski, 2001; Frankham et al., 2002).

INTRODUCTION

The goal of the giant panda ex situ breeding programme is to produce healthy, genetically diverse and reproductively sound offspring. However, reproduction in this species has been poor, in part, due to lack of male libido or aggressive behaviours towards conspecific females. Although giant panda breeding facilities have made progress in producing more surviving young, only about 29% of captive male giant pandas have ever sired offspring (Lindburg et al., 1998), and most of these males were wild born. Of the 104 giant pandas in the ex situ population in China in 1996 (at the time of the first masterplanning meeting in China; Zheng et al., 1997; see also Chapter 2), there were 33 adult males of reproductive age (6–26 years old). Only five (15.2%) had ever mated naturally and sired young. This was the main reason for ‘male reproduction’ being a primary target of the Biomedical Survey conducted under the umbrella of the Conservation Breeding Specialist Group (CBSG) (see Chapter 2).

We had three goals, the first being to measure the presence or absence of any obvious physiological or anatomical abnormalities. The second was to learn more about species reproductive biology, specifically comparing males of different ages, successful versus unsuccessful breeders and wild-born versus captive born. Our approach also allowed a third opportunity: studies that would enhance our understanding on how better to use male gametes (sperm) to advance genetic management (see Chapter 21). In this case, our focus was on:

1. sperm morphology and acrosomal integrity;

2. testes development during the breeding season;

3. […]