The Geo-Joint has often focused on the intricate balance of natural systems and how they are thrown off-kilter by the introduction of foreign species. In some cases, the invaders do not survive because of climate extremes in the new land; other times they are able to find a niche that is not too disruptive to those organisms already functioning there. Most often, though, there is a measurable shake-up in the ecology. Sometimes this interaction results in the extinction of competing species, causing ripple effects throughout the region. But we are now faced with an unwanted guest whose effects could go from local to worldwide.
Nobody is certain how the first kangaroos made their way into the Amazon rainforest. In 1963, a cattle rancher near Manaus, Brazil’s largest deep-Amazon city, imported five male kangaroos as an experiment to raise them for meat. Three soon died of diseases they contracted on the large, heavily-fenced ranch. Feeling the other two were probably doomed, and the endeavor uneconomical, the rancher shot one for its meat, but could not locate the last. He assumed it must have escaped, but wouldn’t get far thanks to the local panther population, and gave it no further thought. Two years later, the Jardim Zoológico de Manaus, the zoo in the city near the ranch, saw the escape of one female kangaroo. A late-night keeper had left a gate open, and once clear of the urban area in the dark, the hopping escapee could have made it into the heavy brush and forest and out of sight. Were these the Adam and Eve kangaroos in the Garden of the Amazon? It’s a big rainforest, but the two entered the jungle within a few miles of one another, and if the male had survived until the female escaped, they could have started a family.
Fifty-plus years later, we know this much: Those kangaroos, or some other kangaroos from another circumstance still unknown, have reproduced prodigiously. And unlike their widespread brethren back in the Land Down Under, they have broadened their diet. Mammalogists studying the Brazilian kangaroos have found that something caused these marsupials to turn away from their usual meals of grasses, flowers, leaves, and ferns, in favor of tree bark and tree wood. They speculate it may be a result of the vitamin or mineral content in the bark, but whatever the attraction, the rapidly increasing population seems to need enormous amounts of their new food source. Field measurements indicate these rainforest kangaroos are 20 to 30 percent larger than those in Australia. As their numbers grow, these animals are having a serious effect on the rainforest.
Where once crews of tree-cutters deep in the forest would find a few trees here or there obviously felled by gnawing, large areas throughout the Amazon Basin are being denuded by the voracious ‘roos. “Frankly,” says University of Orlando Forest Ecology Professor Randall Knowles, “we have almost stopped worrying about the human impact of deforestation in the Amazon. The kangaroo has surpassed us, and is threatening the very lungs of the planet.” The Brazilian government has mobilized teams of hunters to cut down on the population, but given the speed and stealth of kangaroos in the dense forest environment, it has been an ineffective solution.
Like climate change in its early days, this at first slow-moving phenomenon hasn’t penetrated the public consciousness deeply yet. But experts warn that at current rates of population growth, these kangaroos could decrease the remaining forest cover of Brazil by 35 to 45 percent by 2030. Combined with human activity, it would almost certainly be the death knell for an ecosystem so vast that the loss of its oxygen-producing and carbon-storing prowess could spell the end of the planet as we know it. But hope is on the way. A worldwide consortium of 1,300 forest scientists has convinced the United Nations to begin an intensive study and campaign to source solutions to the problem. The U.N. Commission for Rainforest Kangaroo Control (UNCRKC) will hold its inaugural meeting today, the 1st of April, in part sponsored by a Brazilian group, the Forest Outlook and Opportunity League (FOOL). We have to hope they find a way.
(We hope you enjoyed this tale, first posted on April 1st (hint, hint), and remember that even though we always strive to get all our facts straight, the Geo-Joint likes to have a little fun, too!)