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Animal Family Matters

Raine and Thunder, Milwaukee County Zoo’s youngest Dall sheep, have family trees as long and complex as those of any royal family. When Raine and Thunder were born last spring, zookeepers weren’t sure which males of the Zoo’s six-member Dall sheep herd had sired them. Could it be the late alpha-male Mr. Toronto or his son, Denali? The two had been alternated in their outdoor exhibit to avoid sparring and competition for females. “It would be impossible at this point to know who Raine’s or Thunder’s father is,” says interim Zoo registrar Emily Polkinghorne. “We never assume anything unless we can be absolutely certain.”

Gathering information about animals is one of Polkinghorne’s jobs. As registrar, she keeps records on everything from birth dates to ancestors of the Zoo’s more than 1,800 inhabitants. “Good record keeping is essential to maintaining a healthy and genetically diverse animal collection,” says Polkinghorne. “You shouldn’t breed an animal if you can’t trace its history.”

Polkinghorne pores over zookeepers’ reports on day-to-day happenings at the Zoo and puts information into the electronic Animal Records Keeping System (ARKS). This database keeps records of each animal’s life, from its “personality” to its feeding habits to identifying marks. If a zookeeper noticed that a lion made an unusual noise one day, Polkinghorne would add that fact to the database. “All this information can be used by our Zoo and other institutions to learn more about animals in captivity and in the wild,” she says. Once a month, she sends her reports to the International Species Information System (ISIS), which collects animal data on about two million animals from 500 zoos. This information is then used by zoos and conservation programs that the Association of Zoos & Aquariums (AZA) has developed, such as Species Survival Plans (SSPs). SSPs outline conservation plans for endangered animals and give zoos breeding recommendations.

A zoo registrar’s job can be like a treasure hunt. “We can’t always get everything we’d like,” says Polkinghorne. She works closely with zookeepers and curators to track an animal’s history when possible. “Zookeepers are my eyes to each animal’s life.” Still, it’s hard to trace lineage because some animals live in large groups and are not monogamous. “Bats can mate with several different bats each day. So chances are we will know who a bat’s mother is, but not the father.” Even calculating when some ani- mals are born is tricky. Red kangaroos, for example, don’t stick their heads out of mom’s pouch till 150 days after birth.

Polkinghorne sees the benefits of her data-gathering when- ever the Zoo is looking for a good breeding match for an animal. Thanks to data from registrars, ISIS creates highly detailed animal family trees that look very much like human ones. These family trees show everything from when and where an animal was born to whether there is any inbreeding in its lineage. Just like humans, animals that are close relatives are not a good match. “Zoos avoid

Emily Polkinghorne, interim Zoo registrar, stands at the Dall sheep exhibit.

inbreeding because it has many harmful side effects and doesn’t genetically represent the species,” says Polkinghorne. “In the wild, animals have strategies to guard against inbreeding, but with declining populations there is a chance that it can happen.” Lack of genetic diversity could result in animals that cannot adapt to changes in the environment. “If animals can’t adapt, they may become extinct.” Animals that come from a large population in the wild are a far better match because they bring fresh genetic material to zoo collections. Zoos, however, try not to take animals out of their natural habitats. Adds Polkinghorne: “This is why management of captive populations is so important.”

Modern record-keeping methods and computer programs have added a wealth of knowledge about animal breeding, she says. Until the electronic ISIS system was established in 1975, records were kept in logbooks by hand and were often spotty. The Zoo has kept track of its animals since 1893, but record keeping was not computerized until 1987, says Bess Frank, curator of large mammals. Even now, not all zoos have registrars, although many have unofficial record keepers. Polkinghorne is one of 130 mem- bers of the Zoological Registrars Association (ZRA), a group promoting standards in zoological record keeping.

Polkinghorne, a former zookeeper and registrar at the Racine Zoo, took over the job for a year when the Zoo’s longtime registrar, Karin Schwartz, went on leave in August 2006. Polkinghorne appreciates the importance of records. Keeping good records not only helps zoologists manage current animals better, but it also helps future generations, she says. “In the future, information will be easier to find because zoos are joining together to standardize their data.”

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    By Julia Kolker

Alive WINTER 2007


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