Art and Science of Nature

Understanding the Beauty of the Natural World

Archive for July, 2010

Make My Skin Crawl

Fringe of a dry forested hillside ringed by expansive sugar cane fields north of Kinloss, Jamaica. Photo: Richard L. Goldberg. © 2009.

While shooting a series of macro photos on a dry forested hillside in Jamaica I noticed a rather bold and brazen ant strutting his stuff on a small limestone rock. The ant seemed to match the description of Solenopsis invicta, the scientific name for the much dreaded fire ant; also referred to as RIFA, or Red Imported Fire Ants.

Possibly Solenopsis invicta, the much dreaded fire ant near Kinloss, Jamaica. Photo: Richard L. Goldberg © 2009.

Its reddish-brown head and body with a brown abdomen was the tip off that my encounter with the 5mm hymenopteran was not something to just brush-off. I immediately checked to see that I did not unearth an entire colony before kneeling down on the forest floor to photograph the ant interloper — wait a minute! Was I the intruder on the isolated hillside ringed by large expanses of sugarcane fields?

Photographing an ant species on the floor of a dry forested hillside north of Kinloss, Jamaica. Who's the intruder? Photo: Alan Gettleman.

Just mentioning the name fire ant is enough to make a person’s skin crawl. Get stung by one and you can expect intense soreness and swelling for days. Stumbling onto and getting stung by a colony of fire ants is enough to take down an able-bodied outdoors man for the count. Numerous video clips on YouTube show people succumbing to attacks by fire ants; not the type of material that you are likely to see on America’s Funniest Home Videos. There is nothing funny about being attacked by a colony of fire ants, and not just for the obvious reason.

Black ants, red ants, sugar ants, crawling ants, mad ants, biting ants, rain ants, soldier ants, and duck ants are just some of the biting ant species found in Jamaica as listed on an official notification “potential invasion of the fire ant” published by the Biodiversity Branch of the National Environment and Planning Agency of Jamaica. The introduction of Solenopsis invicta, has now been confirmed in Jamaica. The notification states that no other ant species can inflict a sting as bad as the fire ant. The South American native ant species has been introduced into a number of other West Indian islands, the U.S. mainland and as far away as Taiwan and Australia.

A close encounter with a dry limestone hillside, an ideal habitat for ants in Jamaica. Photo: Richard L. Goldberg © 2009.

Ants in Jamaica are especially abundant among the dry limestone forests of central and western Jamaica. Leaf litter, tree trunks and open limestone cliff faces are especially good habitats where ants are frequently found in large numbers; the same habitats that we hike through in search of capturing other Jamaican lifeforms on film. So it is not uncommon to have RIFA encounters. Sure, ants of any type are a nuisance to people whether the biting type or not. Yet the impact of introduced ants on indigenous species is far more troubling.

Fire ants are aggressive, especially when provoked by disruption of their colony. Though one of the best know ants to inflict painful stings, the fire ant is not the only aggressive ant species.

Anolis lizard foraging in the foliage at night in the Cockpit Country of Jamaica. Photo: Richard L. Goldberg © 2009.

The myrmicine ant Crematogaster brevispinosa, a species related to the common household ant (Myrmica molesta) is known to make unprovoked attacks on juvenile and possibly adult Anolis lineatopus, an arboreal iguanid lizard native to Jamaica. In fact, when caged with almost 40 C. brevispinosa under laboratory conditions, a juvenile A. lineatopus died within hours. It seems then that such aggressive behaviors by ants can influence the local distribution and abundance patterns of animals sensitive to it such as the Anolis. This conclusion was based on a field study in Kingston, Jamaica where there was a direct correlation between the abundance of the ant with the lack of the lizard and vice versa.

Though known to feed on other insects and invertebrates, this small Jamaican centipede species lives side-by-side without harming the pulmonate snail, Dentellaria sloaneana in a delicate balance that allows both species to survive in the same habitat. Photo: Richard L. Goldberg © 2010.

It may take many tens of thousands of years for native species to find a balance in its environment. Introducing an aggressive species like fire ants into a pristine environment will quickly and negatively put the natural balance out of kilter. The University of Mona study between ants and anolids is just one of hundreds of similar ecological investigations that have revealed that introducing non-native species can and do have significantly negative impacts on native faunas.

The Tree Frog is just one of the many native Jamaican species that can be negatively and quickly affected by the introduction of non-native species. Photo: Richard L. Goldberg © 2010.

National wildlife management agencies continually monitor the introduction of invasive species within the borders of a country. The next time you return from overseas and grumble over the numerous questions your customs card asks about bringing back living plants or animals, or spending time on a rural farm, it is because non-native species can accidentally and easily be brought back in your bags; yes, even a fire ant! More than your skin will be crawling if one of these species successfully hitches a ride in your duffel bag!