By Dr. Becker
There are only an estimated 1,864 giant pandas left in the wild, making them one of the most endangered bears in the world.1 Although their numbers have increased slowly in recent years, they remain threatened by roads and railways cutting through their native habitat.
This forest fragmentation makes it difficult for pandas to breed, as well as follow their food source, bamboo, which naturally dies off every 40 to 120 years.2 In order to sustain the panda population, captive-breeding programs were introduced in China in 1955, but the first captive-bred giant panda was not born until 1963.
The fact is giant panda reproduction is complex. Females are only fertile during one 36-hour period each year, and they typically give birth to just one cub every two years.3 It's been suggested that pandas are poor breeders, but in the wild they do just fine.
According to the World Wildlife Federation (WWF), long-term studies on wild pandas have shown their reproductive rates compare to that of other thriving species, like American black bears.4 The problems seem to creep up when breeding takes place in captivity.
Challenges to Breeding Giant Pandas in Captivity
In the wild, pandas are free to mate with pandas of their choosing, but in captivity this isn't the case. Oftentimes one or both parties are not interested in the other during captive-breeding efforts.
In some cases, researchers believe that captive-born bears also lacked the knowledge of how to mate, having never witnessed it or learned the behavior in the wild.
More recently, captive breeding efforts have become more clinical, with researchers and veterinarians monitoring female pandas' fertile period and using artificial insemination. But even then, there's no guarantee. According to Pandas International:5
" … female pandas can … experience pseudopregnancy — they aren't actually pregnant, but exhibit the same behaviors as pregnant pandas (decreased appetite, sluggishness, and even similar changes in hormones).
It's almost impossible to distinguish between the two since panda fetuses are often too small to be spotted on an ultrasound. It is often not until a baby panda is actually born that the pregnancy is confirmed."
More Choices Improve Captive-Breeding Programs
In most captive breeding situations, potential panda pairs are matched up based on their genetic compatibility. Recent research published in Nature Communications suggests that genetics alone may not be enough to ensure successful mating.6
What's missing? That certain "je ne sais quoi!" After all, who would want someone else choosing a mate for them?
In a study of more than 40 pandas living at a Chinese conservation and research center, researchers allowed pandas to choose between two potential mates. The results speak for themselves:7
• When the male and female pandas showed a preference for each other, there was an 80 percent chance of producing a cub
• When one of the pair showed a preference for the other, there was a 50 percent chance of producing a cub
• When neither of the pandas showed a preference for the other, there was a 0 percent chance of producing a cub
How do pandas show interest in each other? They have a number of methods of communicating their intents and desires, including:8
• Vocalizations, such as chirps and bleats
• Scent-marking on surfaces or objects
• For females, showing their angiogenital region or walking backward toward the male
• For males, doing a handstand and urinating
It's thought that providing more choices in mates may also help other species. Study author and conservation biologist Meghan Martin-Wintle, Ph.D., of the San Diego Zoo Institute for Conservation Research told Reuters:9
"Incorporating mate choice into conservation breeding programs could make a huge difference for the success of many endangered species breeding programs, increasing cost-effectiveness and overall success."
The Goal of Many Captive-Breeding Programs Is to Introduce Pandas Back to the Wild
There is controversy over whether captive-breeding programs for pandas are actually helping to increase wild panda populations. Some argue the programs, which cost millions, have little to show for decades' worth of breeding efforts.
Others suggest the time and resources given to captive breeding programs would have more impact if directed toward saving, protecting and expanding wild panda habitat.
As it stands, the goal of many captive-breeding programs is to eventually release more pandas back into the wild (where, as critics point out, they must have adequate habitat to sustain them).
Toward this end, so far such efforts have had mixed results. In 2006, the first captive-bred panda was released into the wild. Sadly, the panda, Xiang Xiang, died in 2007 after a fight with wild pandas.
Two other pandas were released in 2012 and 2013, along with a female, Xue Xue. Xue Xue also died within the same year she was released, with officials stating she lacked the necessary survival skills.
In late 2015, officials in China released the fifth captive-bred panda, a female named Hua Jiao. This time, the panda underwent a wilderness-training plan prior to being released, and officials are hopeful this will be the start to increasing wild panda populations.
Huang Yan, chief engineer of the China Conservation and Research Center for the Giant Panda (CCRCGP), told the Xinhua News Agency:10
"We have taken lessons from Xue Xue's case … Her parents are both bred in captivity and they lack the experience of surviving in the wild. Apparently, Xue Xue had few wilderness skills. So, this time, we chose Hua Jiao, whose parents are both born and living in the wild. We believe she will do better.
… We are hoping to introduce more artificially bred pandas into the wild to diversify the gene bank of local panda community."