The Northern Sedge Frog or Northern Dwarf Treefrog (Litoria bicolor) is a tiny frog of wet grassy meadows, flooded grassy areas and vegetated ponds and lakes along the northern tier of Australia. They occur from the Kimberley region of Western Australia, across the "Top End" of the Northern Territory and also in the tropical northeastern parts of Queensland.
These area slender green or brownish frogs with a pale whitish lateral stripe from the upper lip all the way to the back legs. An adult is slightly over an inch long (3cm). They can have a greenish or tan dorsum and some individuals show a prominent dark stripe along the back as well.
The call of the Northern Sedge Frog is a series a short "chucks" followed by an insect-like buzzy trill. We heard this species calling day and night in grassy areas along waterways all across the top end of Australia.
I have tried to record this species before, but had a lot of difficulty hearing them. The problem was that I was in northern Queensland where this species is sympatric with the very similar Eastern Sedge Frog (Litoria fallax). These two species are very difficult to distinguish visually. The only way I was certain the frogs and recordings in this post are L. bicolor was that they were from the Northern Territory and outside the range of L. fallax.
Normally in my blog when that's a problem, there is an easy fix - they have different calls. However the calls of the Northern and Eastern Sedge Frogs are very similar to the ear and differ in subtle structural ways. I will create a separate "similar species" post discussing those two species.
_____________________
© Chris Harrison 2024
No comments:
Post a Comment