Green Tree frog – Litoria Caerulea found at Kalaru
Why did the stowaway Green Tree Frog cause such a stir in Kalaru this summer? Steve Sass tells all and gives another good reason for getting to know your local frogs.
‘Lost Frogs’ is the term given to describe frogs that have been moved to a region where they do not naturally occur. In Australia, this translocation of frogs often occurs through the transportation of fresh produce, garden plants, landscape supplies and soils.
Lost frogs can threaten local frog populations. They can compete with local species for food and habitat, with the potential of displacing local species. Translocated frogs can also spread the amphibian disease known as Chytrid (pronounced ‘kit-trid’) fungus which is potentially fatal and has been attributed to the global decline in amphibian populations (Berger, Speare, & Hyatt, 1999).
In our region, at least two translocated frog species are known. These are the Eastern Dwarf Tree Frog (Litoria fallax) and the Green Tree Frog (Litoria caerulea).
The Eastern Dwarf Tree Frog has been heard around Tura Beach and Merimbula as well as a number of locations around Batemans Bay. This frog naturally occurs along the east coast of Australia from Sydney in the south to Rockhampton in the north. It is common around banana and pineapple plantations within its natural range. This, combined with its small size (around 2.5cm) makes it a perfect candidate to become a ‘lost frog’ when produce is transported to other areas. In Melbourne, the Eastern Dwarf Tree Frog is now commonly found in the vicinity of fresh produce stores and supermarkets, likely the artefact of a person with good intentions releasing the frog into their local bushland, creek or wetland. This species is now breeding in many parts of Melbourne.
In a recent case, a Green Tree Frog (Litoria caerulea) was captured by a local resident at Blackfellow’s Lake, Kalaru in January 2011. The resident knew that this species was not found locally and contacted me for advice. Our investigations revealed that the frog was most likely to have been a stowaway on a caravan that arrived from Queensland several weeks prior. With an abundance of tourists with caravans visiting the south coast, this scenario is likely to be the most common occurrence of translocation.
To minimise the risks to local frog populations, the NSW Department of Environment, Climate Change and Water has established procedures for dealing with translocated frogs (DECCW, 2011). In our region, either WIRES or NANA wildlife carer groups should be contacted. We can also be contacted at steve@envirokey.com.au for advice as to whether you have a translocated frog.
For the sake of our local frog populations, get to know your local species. If you hear or see any frog that you may not think is a ‘local’, take action!
For help with frog ID & info: http://frogs.org.au/frogs/ofNSW/The South Coast
References
Berger, L, Speare, R, & Hyatt, A.D (1999). Chytrid fungi and amphibian declines: overview, implications and future directions. In A Campbell (Ed.), Declines and disappearances of Australian frogs (pp. 23-33). Canberra: Environment Australia.
DECCW (2011). ‘Banana Box’ Frogs Retrieved 22nd January 2011, from
http://www.environment.nsw.gov.au/animals/BananaBoxFrogs.htm
from CMN Newsletter Summer 2011
