Australian Housemates Find 1,150 Unique Species by Surveying Their Backyard

Have you ever wondered how much biodiversity is in your own backyard?

Three housemates in Brisbane, Australia, decided to challenge each other to find out. Not only did they identify 1,150 unique plant, fungi and animal species in their suburban backyard, they wrote an academic research paper detailing the perhaps surprisingly extensive biodiversity to be found in urban landscapes, a press release from the University of Queensland (UQ) said.

Ecologist Dr. Andrew Rogers, taxonomist Dr. Russell Yong and mathematician Dr. Matt Holden, colleagues from UQ who share a house in Annerley, a suburb of Brisbane, made the most of their time during the COVID-19 lockdowns of 2020 to take a year-long survey of their backyard.

“We asked a large number of ecologists and conservation scientists how many species they’d expect to find in this setting and they predicted only 200,” Holden said in the press release. “But after 60 days of surveying, we’d already discovered 777 species. It shows suburban houses and apartments could have far more biodiversity than ever imagined, especially when it comes to insects.”

Rogers first thought of the idea for a species count when he was about to vacuum cobwebs and it made him think about how many spiders might be living on the property.

“The three of us soon envisioned a plan to comb through the house and backyard in search of other critters that resided alongside us,” Holden said in the press release.

Among many other species, the roommate researchers’ census uncovered eight different kinds of reptiles, 56 spider species, 56 birds — including laughing kookaburras, tawny frogmouths, white ibis, rainbow lorikeets and spotted doves — and 436 species of moths and butterflies.

“Blue-tongued skinks hibernated under the garage and at night blue-banded and teddy-bear bees slept in the hedges under the front window,” Holden said.

The study, “The house of a thousand species: The untapped potential of comprehensive biodiversity censuses of urban properties,” was published in the journal Ecology.

The friends also found three species not recorded in the Atlas of Living Australia, the country’s leading database on biodiversity: a sandfly, a mosquito and a flatworm responsible for worldwide declines in native snail populations.

“The house was a complex ecosystem of species interacting – we stumbled upon the moth Scatochresis innumera, which as a caterpillar spends its whole time feeding inside the dung of a Brushtail Possum before emerging as an adult,” Holden added. “The Parilyrgis concolor is another moth species whose caterpillar lives in spider webs and devours spider poop to survive.”

Holden pointed out that other suburban homes could have similar biodiversity living within their walls and yards.

“It depends on how people tend to their homes and gardens – keeping low maintenance trees and shrubs and eliminating manicured lawns and pesticides will significantly boost the number of critters found,” Holden said. “You don’t have to go travelling to connect with Australia’s diverse range of species, just look in your own backyard.”