Balance of nature: man making a bad balance (Introduction)

by David Turell , Sunday, November 06, 2016, 14:40 (2939 days ago) @ dhw

This is a story of feral hogs and rabid bats. The feral hogs were an introduced species that got on the loose. The bats take advantage:

https://www.washingtonpost.com/news/energy-environment/wp/2016/11/04/brazils-invasive-p...

"For nearly three decades now, invasive wild pigs have been spreading throughout Brazil, uprooting native plants, damaging soil quality and destroying crops. There are even reports of the pigs attacking livestock. But while they’re considered a nuisance by most, at least one group seems to be benefiting from them: Brazil’s residents vampire bats.

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"In other words, it’s a classic example of how one human action — introducing a species that becomes an invader and colonizes new ecosystems in a destructive way — can have cascading and damaging effects that ultimately come back around and hurt humans, themselves.

“'Vampire bats…carry infectious disease, a lot of infectious disease,” said Felipe Pedrosa, a Ph.D. student at Sao Paolo State University and one of the new paper’s authors. “And one of these diseases is rabies.”

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"Today, the incidence of rabies infections in vampire bats varies by location — it tends to be anywhere from about 1 to up to 10 percent, according to the authors of the new paper. Some farmers routinely vaccinate their livestock against the disease, but the feral pigs, which can also carry rabies, are another story and “may therefore pose a serious threat by spreading the disease,” the authors write.  

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"They found that, in addition to preying on livestock like cattle, the bats also feed on wild animals including tapirs, deer and feral pigs. The videos and photos from the Pantanal region suggested there was about a 2 percent chance that a pig might be attacked by a vampire bat on any given night. In the Atlantic Forest, this chance rose to 11 percent.

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"A study published last year in Science, for instance, used a genetic technique to investigate what species the bats prey on most frequently. The results indicated that vampire bats were about seven times more likely to prey on pigs than one would expect would happen by chance alone — in other words, the bats were likely actively seeking out the boars.  

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"There have been feral pigs in Brazil for up to 200 years, research suggests, when a few domestic pigs escaped and went wild in the Pantanal region. But a large-scale, country-wide invasion can be traced back to the 1990s, when wild boars were imported from Europe and Canada for use in high-quality meat products. In Brazil, many farmers bred these boars with the domestic pigs that already existed in the country. Eventually, the government stopped permitting the importation of wild boars, and many of the interbred pigs were released — accidentally or intentionally — into the wild.

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"The Brazilian government has established a program allowing the killing of feral pigs, he noted, but added that rigorous restrictions on the purchase of firearms has kept the number of participants fairly small so far. He and other scientists are currently involved in helping federal environment agents come up with better plans to address the pig problem in the future.

"In the meantime, “vampire bats feeding on the constantly spreading feral pigs may therefore be viewed as a potential risk to wildlife, livestock and humans,” the researchers write."

Comment: There is a moral here. A naturally attained balance of nature works correctly until some outsider organism is introduced with no prior study as to the possible consequences. History is replete with the examples, especially in Australia. Everybody has to eat somebody, but a new body is disruptive unless proven otherwise. The bush of life provides for balance, as the oak/ acorn study shows.