Renovations lead to productivity gains

March 12, 1994|By David Michael Ettlin | David Michael Ettlin,Sun Staff Writer

Forget about that snow and ice. In the Baltimore Zoo's Reptile House, spring has been slithering out all over -- all winter long.

In the nine months since the building's renovation, its inhabitants have been on a veritable breeding spree with 13 amphibian and reptilian species giving birth.

And judging by the behavior this week of the large crocodile monitor lizards in the center cage, more offspring may be on the way soon. Now don't get the wrong idea -- we're talking about courtship behavior. But their keepers remain hopeful, because the species has been bred in captivity only once.

The proud curator, Anthony Wisnieski, noted that in the 40 years before the renovation, 21 species were bred at the Reptile


What has made the difference is not any change in the quality of care, he and other zoo officials emphasized, but the modern equipment that enables keepers to adjust lighting, temperature and humidity to simulate the environment most conducive to the love life of each species.

Programmable thermostats were unheard of when the Reptile House was built in 1938 -- first serving as an aquarium and, since 1948, to display lizards, turtles, snakes and the like.

Mr. Wisnieski took a visitor on a back-room nursery tour, showing off such babies as the mildly venomous mangrove snakes --glossy black serpents with yellow spots that form rings -- born Jan. 21, in the tropical warmth of the Reptile House. People in the world outside were chipping out of winter's worst ice storm at the time.

A bearded dragon -- one of two born Dec. 3 -- sits comfortably in the palm of the curator's hand, a miniature version of the %J 18-inch-long adults. The Australian lizards are named for skin flaps under the chin that expand to frighten predators.

"In Australia, they call this type of lizard dragons, and monitor lizards, they call goannas," Mr. Wisnieski said. "That's why we give animals scientific names."

So just to eliminate any confusion, remember that the bearded dragon is really Pagona vitticeps.

Holding out one of five tiny Costa Rican spiny toads, Mr. Wisnieski said, "These guys were a real accomplishment for us." The zoo is believed to be the first to successfully breed the species in captivity.

At metamorphosis from the tadpole stage during November, all five "toadlets" could have fitted together on a dime -- with room to spare for friends. They were so small, Mr. Wisnieski said, that the staff had to figure out what to feed them. The fruit flies fed to adults were much too large, so the staff gave them the nearly microscopic parasitic mites that live on fruit flies.

Blue poison dart frogs abound -- children and grandchildren of the ones Mr. Wisnieski acquired for the National Aquarium when he worked there. Each frog is identified genetically for breeding through markings on the body, each "like a fingerprint," the curator noted.

The staff is keeping a close watch for eggs after matings by the green tree pythons and blood pythons, and on two eggs produced by the threatened Egyptian tortoises -- an animal that, like the crocodile monitors, has been bred in captivity only once.

Mr. Wisnieski said there is "no one set recipe" of environmental conditions for all species to breed -- and that shows the importance of behavioral studies made in the wild, he said.

"For the spiny toad we had to make a rain chamber. We used a recirculating filter that would pump water into a pan with numerous holes drilled into it above the tanks."

The Reptile House will be celebrating its breeding successes with a postpartum (or posthatchum) "baby shower" from 10 a.m. to 3 p.m. today and tomorrow -- a chance for the public to see many of the young animals that are not normally on exhibit. (The young don't stay with the parents, which are not particularly maternal and can in some species be cannibalistic.)

Visitors might even be lucky enough to catch the crocodile monitors in action.

Admission to the building, in Druid Hill Park several hundred yards from the main zoo entrance, is 50 cents. Children under age 2 and members are admitted free.

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