TT bachacs for North American zoos

The ants have been taken to facilities at the Toronto Zoo, Cincinnati Zoo and Botanical Gardens, and the Toledo Zoo.

The week-long exercise came to an end last Wednesday and was undertaken in collaboration with the Zoological Society of Trinidad and Tobago (ZSTT).

The team’s specific objective was to collect small young colonies of the forest “bachac” or leaf-cutting ant (Atta cephalotes) for eventual public educational display in North American zoos and museums. Trinidadians best know these insects as serious agricultural pests. However, in natural forest systems they are highly beneficial insects which act as “Mother Nature’s pruners,” stimulating primary plant productivity and improving forest growth.

One of the new homes for the ants is the Toronto Zoo in Canada which is a 710-acre facility located in the Rouge Park, the largest urban wildlife park in the world. Toronto Zoo is considered Canada’s premiere zoo. The zoo is geographically divided with Africa, Indo-Malaya, the Americas and Australasia having large pavilions to hold tropical plants and animals.

Invertebrates (like ants) have been displayed since 1978 and an invertebrate rearing facility was built in 1986 to supply captive raised invertebrates for display. The zoo has approximately 4,000 animals not including fish and invertebrates.

The other bachac recipient facility is the Cincinnati Zoo and Botanical Garden, in Ohio, USA. It is a 70-acre zoo located in southwest Ohio. It is the second oldest zoo in the United States (est. 1875) and is consistently rated as one of the top three zoos. It is especially well-known for breeding gorillas, small cats and Sumatran rhinos. Its highly popular World of the Insect exhibit (or Insectarium) features a diversity of live insects, related arthropods, and small insectivorous vertebrates (dart frogs, green snakes, etc) from around the world, including several species originally collected in Trinidad (Hercules beetles, zebra bugs, giant tropical roaches).

The zoo has also been actively involved with Trinidad’s Blue and Gold Macaw Re-introduction Programme.

The third facility — the Toledo Zoo is located in northwest Ohio, USA. It was established in 1900 and is routinely rated as one of the top zoos in the United States. It is well know for much of its exhibitory; some of the most popular displays include the ground-breaking Hippoquarium, the Arctic Exhibit which exhibits polar bears and two seal species, the African Exhibit which displays large African hoof stock, and one of the most diverse zoo aquariums in the country. The most important conservation projects undertaken by the Toledo Zoo include the spray toads of Tanzania, the Aruba Island Boa, and four butterfly conservation programmes including the Karner Blue butterfly which has been successfully re-introduced into Ohio.

The field team participants who came to Trinidad to collect the ants included Tom Mason, Curator of Invertebrates and Birds, Toronto Zoo; Lydia Attard, Curatorial Keeper of Invertebrates, Toronto Zoo; Randy Morgan, Curator of Invertebrates, Reptiles and Amphibians, Cincinnati Zoo & Botanical Garden and Brad Palicki, Invertebrate and Aquarium Keeper, Toledo Zoo.

Leaf-cutters are an unusual example of an ant species which has taken up farming or an agricultural lifestyle (growing fungus for food using leaf bits), as opposed to most ants which are hunter-gathers. In the last few decades, these ants have been increasingly recognised as important public educational display animals because of the following fascinating behaviours and discussion points:

1) Active leaf cutting and carrying along long well-organised trail systems.

2) Highly social behaviour in matriarchal (female-dominated) colonies or family groups consisting of a queen-mother and worker-daughters.

3) Task-specialised workers according to their size showing a strong division of labour and unparalleled cooperation.

4) Advanced system of chemical communication (pheromones).

5) Sophisticated mutualistic relationships with other organisms (their fungus gardens and antimicrobial-secreting bacteria)

Mature colonies are huge and may contain several million workers, including thousands of large, painfully-biting soldiers, thus excavating them is nearly impossible. One member of the field team said: “We painstakingly searched for the ‘baby’ or one-year-old colonies consisting of a young mated queen, and only a few hundred workers and a small clump of fungus.

“Once we found them, they were relatively easy to dig up and we temporarily held them in small plastic field containers until they get to our respective zoos. They are then established in larger aquaria and provided with local plants for their fungus gardening activities. After several years of daily care, their populations will grow to a size that makes an effective educational display.”

The group thanked the Emperor Valley Zoo which provided lodging and facilitated field logistics; the Wildlife Section-Forestry Division, Ministry of Agriculture which graciously facilitated acquiring the field collecting permit and wildlife export licenses.

The group also thanked the people of Trinidad. “A diversity of local people offered suggestions for possible field work sites, directions when we were temporarily lost or confused (which occurred several times daily), and acknowledged us when passing with friendly greetings and smiles. From our hearts to you, ‘Thanks to everyone who went out of their way to help us.’”