Milwaukee zoo's newest species find their footing — and have issues with some of their neighbors

The tortoises had to go. 

Aria, one of the Milwaukee County Zoo's new residents, is a relatively gentle, easy-going creature, as yellow-backed duikers go. But she and the tortoises ended up not being BFFs.  

So, shortly after Aria moved in with the two bongos — like the duiker, a type of African antelope — the tortoises living in the same area were sent packing.

Aria arrived from the Memphis Zoo in November, and when she moved to a public spot a few weeks ago, zookeepers noticed she was spooked by what she probably thought were slow-moving stones. 

"The yellow hair along her back fluffed up" when Aria saw the 80-pound tortoises, said Ryan Taylor, the zoo's pachyderm keeper who also is in charge of Aria. 

Aria, who celebrated her first birthday last month, is the first yellow-backed duiker at the Milwaukee zoo, and her new home is right next to the enclosure in the African savanna exhibit where three more new neighbors recently moved — all Thomson's gazelles. 

The half-brothers arrived from the San Diego Zoo in late April, and after their mandatory 30-day quarantine, Simon, Theodore and Alvin moved to the public outdoor area in late May. 

The last time the Milwaukee zoo had "Tommies" was in 2005.

"We used to have them in this exhibit for quite a few years," said Tim Wild, curator of large animals. "So we knew they worked well here." 

The Thomson's gazelles share a father; Theodore is 14 months old, Simon is almost 8 months old, and Alvin is the baby brother, at 6½ months. Whoever chose their names — "not me, the staff named them," said Wild — is evidently a fan of the animated series "Alvin and the Chipmunks."

Eventually, the gazelles' horns will grow long and straight, but right now, since they're still youngsters, their heads only sport nubs or very short horns. 

Yellow-backed duikers (rhymes with bikers) are forest-dwelling antelopes living primarily in central and western Africa and are considered threatened. With only 98 yellow-backed duikers living in North American facilities, it's a coup for the Milwaukee zoo to get one.

Wild populations of Thomson's gazelles, named after a late 19th-century Scottish explorer, have been decreasing in Africa. 

The Thomson's gazelles are sharing an outdoor living space with a couple of Southern ground hornbill birds and the zoo's half-dozen impalas, although the male impala is being kept apart from them.

Their grazing area looks tantalizingly close to the cheetah enclosure. Of course, the cheetahs immediately noticed the new denizens. 

"The very first day (the Tommies were outside), the cheetahs got a lot of exercise" pacing back and forth, Wild said.

Aria, Alvin, Simon and Theodore all graze on the grass in their enclosures, and their diet is supplemented with hay and fortified grain pellets fed to the gazelles at night. Aria loves carrots, cucumbers and sweet potatoes, and would eat apples as much as she could but is limited in her apple intake because of the high sugar content, said Taylor. 

Zookeepers gradually introduced Aria to her roommates, bongo sisters named Sydney and Zuri, by separating them with a mesh gate through which they could see and smell each other. Once they were allowed up close, it didn't take long for them to become friends. Zuri and Aria have bonded — they frequently touch noses. 

"Within half an hour, they were running around together, but in a playful way," said Taylor. 

The tortoises were another matter. Once zookeepers decided Aria and the tortoises were not getting along — apparently one-sided; the tortoises didn't seem to have a gripe — it was the reptiles who got the heave-ho. 

So zookeepers lifted them one by one into a wheelbarrow and drove them to a roomier area of the zoo where the Australian animals used to live.

Taylor, who had never seen a yellow-backed duiker before, visits Aria several times a day to work with her and help the animal become acclimated.

"Getting a new species is exciting for the keepers and the public," said Taylor.