** This is the second field update from Adair McNear. Adair is studying and filming the reproductive behavior of an endemic treefrog, Chiromantis hansanae, in Thailand as part of Sinlan Poo’s PhD research at the University of SIngapore **

 

Chiromantis hansenae female and her eggs. Photo by Adair McNear.

August 10th, 2012: We’ve been having a dry spell so the frogs’ activity has dropped, although the past few days have been wetter, so breeding should pick up again soon. In the meantime I thought I’d share how we’re collecting data on the frogs – and incidentally, collecting awesome video of the frogs’ behavior – because it’s a pretty cool method! When we locate a newly laid clutch of eggs, we set up a timelapse camera on a tripod that runs 24 hours a day (at night we switch on a low intensity light, just enough so we can see if the female is still present).

 

Time lapse camera "watching" a clutch of treefrog eggs. Photo by Adair McNear.

With this continuous surveillance, we end up with 4 or 5 days-worth of footage to then analyze. It takes about 5 days for the eggs to mature into tadpoles, which then drop into the water and hatch. The female is present and sitting on her clutch about 80% of this time, which understandably is mostly her remaining still, and not too fun to film in real time. However, with the timelapse footage, we’ve been seeing condensed views of the females attending to their clutches. These have included predation attempts from ants and carnivorous katydids, with one female managing to fight off a katydid twice her own size! Another female had to scare off a male Chiromantis hansanae who was fruitlessly attempting to mate with her (the females are not receptive when they are guarding their clutches). I’ve attached some photos of one of the timelapse cameras set up in the field, and a couple of cropped screenshots that it has captured. ~ Adair McNear

 

Chiromantis hansenae female leaping away from her eggs. Screenshot by Adair McNear.

Chiromantis hansenae stands guard over her eggs at night. Screenshot by Adair McNear.

 

 






Tags: , , ,



Leave a Reply

Your email address will not be published. Required fields are marked *