Monster Centipedes

The top predator on Philip Island is a 12 inch long centipede with armored plating and a venomous bite. This monstrous creature preys upon sea bird nestlings, lizards (skinks and geckos), and crickets. It also eats the vomited fish and squid parent birds regurgitated to feed their chicks. About half of its diet consists of vertebrates, an unusual ratio for a terrestrial invertebrate. Scientists estimate 11%-19% of black-winged petrel chicks are lost to centipede predation every year. However, centipedes don’t prey upon white winged petrel nestlings because they are larger and can defend themselves against the centipedes.

Phillip Island Centipede with a black-winged petrel. This species of centipede regularly feeds upon black-winged petrel chicks. 13 species of sea birds nest on Philip Island. Photo from the below referenced study.

Photo and location of Philip Island. Note how denuded the island is of vegetation. This is from feral pigs, goats, and rabbits all of which have been eradicated. Image also from the below referenced study.

Scientists think centipedes may be able to help restore the ecology of Philip Island. Originally, the island was covered with white oaks, Norfolk pines, and red legged grass; but sailors introduced goats, pigs, and rabbits as a food source, and the feral animals denuded much of the island of vegetation. People eradicated the animals about 40 years ago to save the island ecosystem. Centipedes eat the sea birds and transfer marine nutrients to the rest of the island in their feces. This added nutrition may help the trees and grass grow back faster.

This is the largest species of centipede that lives in Georgia. Scolocryptis sexspinosus. It grows to 3 inches long. I’ve seen this species in my yard. Photo from insectidentification.org.

The largest species of centipede in Georgia grows to about 3 inches long–1/4th the size of the Philip Island centipede. This species is known as the red bark centipede (Scolocryptis sexspinosus), and I have seen this species in my yard. They have a venomous bite that is painful to humans but not fatal. It can live up to 5 years and will molt its exoskeleton as it grows. They are predatory but not often seen because they are usually nocturnal and fossorial. Worldwide, there are 8000 species of centipedes. Though their name means 100-legged, their number of legs can vary from 54-354, depending upon the species. Centipedes don’t mate. Instead, the male drops off its sperm, and the female later comes along and engulfs it. Females defend their eggs, and some species even defend their young.

Reference:

Halpin, L; et. al.

“Arthropod Predation of Vertebrate Structures Trophic Dynamics in an Island Ecosystem”

The American Naturalist 198 (3) September 2021

Tags: black winged petrel, Philip Island centipede, red bark centipede