A family of pygmy possums and an orange-eyed gecko are living as roommates at Monjebup Nature Reserve in western Australia. Alex Hams, a land conservation manager at Bush Heritage Australia, an independent organisation that purchases and manages to land for conservation, discovered a nest box at the Monjebup Nature Reserve in western Australia in mid-June.
It was a nest box for western pygmy possums, but Hams was surprised to see a reptile with the marsupials. Inside the box, pygmy possums and a small, orange-eyed gecko were living together, Bush Heritage Australia wrote on Twitter and Facebook.
The lizard is a southwestern spiny-tailed gecko. Pygmy possums are tree-dwelling marsupials, which are mammals endemic to Australia, Wallacea and the Americas. A distinctive feature in most marsupials is that they carry their young in a pouch.
Pygmy Possums And Southwestern Spiny-Tailed Geckos
Pygmy possums can be as large as 12 centimetres from head to tail, and as small as five centimetres. Weighing between 10 grams and 50 grams, pygmy possums have large eyes, large ears and long whiskers. They also have a soft fur coat which is fawn to grey on top and white underneath.
There are four species of pygmy possums, namely Western Pygmy Possum, Eastern Pygmy Possum, Tasmanian Pygmy Possum, and Long-tailed Pygmy Possum. The Long-tailed Pygmy Possum is found in Australia, Papua New Guinea and Indonesia, while the other three species are endemic to Australia.
The southwestern spiny-tailed gecko, also known as the soft spiny-tailed gecko, is a lizard species endemic to Australia. They are arboreal species and capable climbers.
“The Most Extraordinary Surprise”: Bush Heritage Australia
Bush Heritage Australia wrote on Facebook that seeing a gecko and a family of pygmy possums sharing the same house is the “most extraordinary surprise”. The organisation said the team at the Monjebup Nature Reserve experienced a “jaw-dropping moment” when they peered into a nest box only to discover an orange-eyed southwestern spiny-tailed gecko cosied up with a family of western pygmy possums.
According to the Facebook post, ecologist Angela Sanders said: “The photos surprised us all”.
Geckos are occasionally found in boxes. However, they have never been seen with possums. “My best guess is that it is getting warmth from the possums. There is limited natural habitat for these animals in the revegetated area, so the boxes are providing vital shelter for them until the vegetation develops to a stage of providing cracks and crevices and loose bark,” Sanders said.
According to an article published by the New York Times, Hams said the pygmy possums and the gecko were climbing all over each other and neither seemed to mind. He added that they were more concerned about the big human heads that were peering in through the top. This was something he had never seen before.
In the following two weeks, Hams returned to the site and saw that nothing had changed. The pygmy possum mother, her litter of babies, and the two-to-three-inch gecko had not moved to any other place. The pygmy possums and the gecko were genuine roommates, and shared a crowded space that was no more than eight inches deep, the article stated.
Mr Hams said the boxes are small, and added that pygmy possums are so tiny that one could fit a whole family of them in the hand.
Several Australian mammals and birds depend on natural hollows for shelter. The interior of the box has a similar setup. Hams said the pygmy possums use the eucalyptus leaves from nearby trees to establish the nest.
Why Were The Gecko And Pygmy Possums Sharing The Same House?
According to Conrad Hoskin, a gecko expert from James Cook University in Australia, the pygmy possums and the gecko would have no interest in eating each other because possums consume nectar and insects and geckos feed on insects and spiders. Hoskin said that the gecko may be getting something from its nestmates, according to the article.
He explained that the gecko will get some benefit from being in the warmth of those little mammals, and he suspects the presence of the gecko is neutral to the possum.
According to Euan Ritchie, a professor in wildlife ecology and conservation at Deakin University in Melbourne, the pygmy possum has made a nest out of all the leaves and twigs, which is exactly the sort of habitat reptiles like. He further said that reptiles like structural complexity and this is a great place for a gecko to hang out.
While the pygmy possums and geckos are cosied up in the same box, the mammals are unlikely to share their box with spiders. In 2019, dozens of social huntsman spiders took over one of the boxes. In the same year, a huntsman spider reportedly ate a pygmy possum in Tasmania. Around five per cent of the 103 boxes on the Monjebup Nature Reserve are estimated to be the domain of spider colonies, the article stated.
Dr Ritchie said tree hollows have been massively depleted around Australia because of logging, and pygmy possum habitat has become extremely fragmented. According to Dr Ritchie, hollows are likely to form in 100 to 150 years, depending on the tree and habitat.
The vegetation on Monjebup is very young and undeveloped. It is only nine or 10 years old, and there are no habitats like natural hollows or crevices. Therefore, the nest boxes are the prime habitat, Sanders said. Also, animals that would not normally cohabit are forced together because there is so little habitat, she explained.
Bush Heritage Australia has placed artificial boxes on Monjebup Nature Reserve, which provide shelter for tiny honey possums and pygmy possums.