The Science Behind Cute and Cuddly

By: Emily Hines for The Smithsonian Associates blog

If I had a knack for science, I would definitely have studied to be an animal conservationist. The thought of spending my day with animals both big and small is heaven, but I often forget just how much science goes into being a veterinarian or working in conservation like Pierre Comizzoli, a reproductive physiologist at the Smithsonian Conservation Biology Institute.

Comizzoli has jokingly been called the “father of Bao Bao,” as it was his and his colleagues’ efforts that led to the adorable giant panda’s birth. I know I do not just speak for myself when I say that I would LOVE to be able to play with the Zoo’s celebrity cub, but what most of us don’t know is the hard work that went into Bao Bao and many of the other animals at the zoo.

“The phrase ‘zoo’ has evolved quite a bit,” said Comizzoli, mentioning how zoos now are far more interested in scientific efforts and reintroducing animals into the wild than they were when they first originated.

“The zoo is a place for family time and seeing the animals, but it is also a place for science and conservation,” he told the audience.

This is good news considering every day in the news we hear that more and more animals are added to the endangered species list, or worse – the extinct list. The limited number of remaining animals proves to be a problem for reproduction. If too few animals are left to revive the species, their offspring may be inbred. This leads to a decrease in what Comizzoli calls “genetic diversity.”

If animals across a species have diverse genetic makeups, then they will pass on the best genes to their offspring as generations go on and produce even more diverse offspring. If the makeups are not diverse, as is the case in inbred animals, then they keep passing along the same traits. Many of these traits may be negative and because of inbreeding will never be eradicated from the species.

To combat this, scientists have begun assisting in the reproduction of endangered species in captivity. The stress of being in captivity means that reproduction may not occur naturally, so scientists have developed methods to help with this, and to promote genetic diversity. With these methods they can reintroduce beneficial genes into a population.

Processes such as in vitro fertilization and artificial insemination are used to assist in the conservation of these endangered animals. Freezing reproductive materials in liquid nitrogen is a big part of these efforts. While it might seem as easy as freezing an egg or reproductive tissue (sometimes they can freeze an entire ovary, imagine the size of an elephants!), it is much more difficult and scientific than that. Cryobiology, the official term for the collection and storage of biomaterials for conservation and biomedical science, is a growing field.

Each species’ genetic material reacts differently to the processes and therefore must be studied closely and have an individual procedure. Each animal’s reproductive behavior is also different and must be taken into consideration.

For example, Comizzoli pointed out the interesting fact that wild cats, most of which are endangered, ovulate at different times across species. For some, it is induced by mating, and for others it is spontaneous, oddly enough. To figure this out took many years of studying the animal’s behavior and numerous tests.

There are many success stories that Comizzoli touched on, the first of course being very dear to most of our hearts – Bao Bao. In the 1990s there was a very low number of Giant Pandas in China and the rest of the world. Those in captivity had stunted development and poor genetic diversity due to inbreeding, which made reproduction difficult on conservationists’ part.

The solution they devised was to use artificial insemination. They also separated the males and females because, after studying giant pandas in the wild, they found that males and females interacted very little outside of mating. To make matters difficult, there is only one period of time during the year that female giant pandas can reproduce, so they had to time the artificial insemination exactly.

The effort was a huge success with 300 pandas now in captivity, which can lead to greater genetic diversity in the population. It is unknown exactly how many giant pandas are in the wild, but it is estimated to be about 1,600. However, the destruction of the giant pandas’ natural habitat has caused population fragmentation, which leads to inbreeding because of how the species is separated across their remaining habitat.

Work is being done to restore and reconnect their natural habitats so groups of giant pandas can mix, and with this comes the possibility for reintroducing those animals in captivity back into the wild.

With all of this in mind, Comizzoli stressed the importance of “filling the gap between technology and ecology, and creating a link between the lab and the field.” Without technology none of this conservation would be possible. Scientists at the Smithsonian’s National Zoo and institutions around the world are working to create more cost and time effective ways of conserving our planet’s endangered species.

A lot of science goes into creating these cute cuddly animals we love to visit and see pictures of, and next time I am at the zoo oohing and ahhing over Bao Bao, I will make sure to remember that.

For more information on cryobiology at the Smithsonian’s National Zoo check out this article from the Zoogoer.