Balance of nature: importance of ecosystems (Introduction)

by David Turell , Wednesday, August 04, 2021, 15:36 (997 days ago) @ David Turell

A study on an isolated island system, once disrupted, now recovering:

https://www.realclearscience.com/articles/2021/08/04/the_importance_of_giant_bird-eatin...

"On tiny Phillip Island, part of the South Pacific’s Norfolk Island group, the Phillip Island centipede (Cormocephalus coynei) population can kill and eat up to 3,700 seabird chicks each year.

"And this is entirely natural. This unique creature endemic to Phillip Island has a diet consisting of an unusually large proportion of vertebrate animals including seabird chicks.

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"This centipede can grow to almost one foot (or 30.5cm) in length. It is armed with a potent venom encased in two pincer-like appendages called “forcipules”, which it uses to immobilise its prey. Its body is protected by shield-like armoured plates that line each of the many segments that make up its length.

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"The centipede hunts an unexpectedly varied range of quarry, from crickets to seabird chicks, geckos and skinks. It even hunts fish — dropped by seabirds called black noddies (Anous minuta) that make their nests in the trees above.

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"From the rates of predation we observed, we calculated that the Phillip Island centipede population can kill and eat between 2,109 and 3,724 petrel chicks each year. The black-winged petrels — of which there are up to 19,000 breeding pairs on the island — appear to be resilient to this level of predation.

"And the predation of black-winged petrels by Phillip Island centipedes is an entirely natural predator-prey relationship. By preying on vertebrates, the centipedes trap nutrients brought from the ocean by seabirds and distribute them around the island.

"Up until just a few decades ago the Phillip Island Centipede was very rare. In fact, it was only formally described as a species in 1984.

"After an intensive search in 1980, only a few small individuals were found. The species’s rarity back then was most likely due to severely degraded habitats caused by pigs, goats and rabbits introduced by humans to the island.

"The removal of these invasive pests enabled black-winged petrels to colonise. Their population has since exploded and they’re now the most abundant of the 13 seabird species that breed on Phillip Island.

"They provide a high-quality food source for the Phillip Island centipede and have therefore likely helped centipede population to recover.

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"Now, thanks to the conservation efforts of Norfolk Island National Park, the island’s forest is regenerating alongside endemic species like the centipede, as well as the critically endangered Phillip Island hibiscus (Hibiscus insularis)."

Comment: when humans change the top predator by bringing in foreign animals, the ecosystem falls part. The giant bush of life is made of of many thousand such systems, which should not be disturbed