Mallee Frog Blog

Today we had 28.5mm rain in several thunderstorms, and the frogs in the dam must be in heaven. Accordingly I heard a couple of Mallee Spadefoot Toads calling tonight. I imagine there's a fair bit of water back in the dam now and they will be busy.

A few days ago I went down there and pulled out a cumbungi plant that I'd missed. Interesting that it hadn't really spread as much as the others had - perhaps because it's been a bit cooler? I am very hopeful that the cumbungi might be gone for the moment. There has been no sign of it coming back in either dam or pond.

The other big frog action - in the last post I mentioned plenty of calling from the pond - on Feb 6 there were three egg masses down there. The frogs in the pond have since quietened down. That pond must be thoroughly over-populated now! Tadpoles everywhere. Food for the frogs I suppose. When I was wandering around in the dam the other day I only saw one big fat black tadpole. The water has been fairly shallow there - it might all change now. 

We've also had plenty of cockatiels in the last month. 

The frogs have been mostly quiet since Christmas, when it started drying out. The dam has had water and has had plenty of tadpole action going on in it but not so much calling. The pond water has been quite clear. I switched the water off when it was raining and only remembered to turn it on a week or so ago when it started looking very shallow.

The increased water level didn't trigger frog calling straight away (it was relatively hot) but the remnants of a cyclone are now heading towards us together with low pressure and the frogs in the pond (all spotted marsh frogs) have become very vocal. The frogs in the dam have been quiet - perhaps because the water level has continued to fall.

I have just returned from a pleasant half hour wading around the dam and pond getting rid of Cumbungi. Cumbungi is a water weed that fills the runoff dams in Manangatang. When we had active dams here there were a few infestations too. It grows all around in the shallower water and makes it very difficult to get to the edge - also speeds water use and harbours mosquitoes etc. 

I spotted the first plants in the dam a few weeks ago (they stood out as the only green things in it) and they have been spreading amazingly quickly. Every time I went down to the dam there seemed to be twice the number as a few days before. Then I checked the pond and found a similar infestation there. I think the birds must have brought in seeds from the Manang dams. The seeds are fluffy and would travel with birds quite easily. That would also explain both the dam and the pond having a similar scale of infestation.

I had to do something today before it became too late (and before it rained and the water in the dam was too deep to do anything)! I pulled out the weeds and as much of their root systems as I could. The root systems are quite impressive:

and there was a fair bit of material (the pile on the left is from the dam and on the right from the pond. The dam plants are probably greener because of the better nutrient supply):

About a week after the first 35mm, we had another 45mm over a couple of days. That caused some grain damage, but has created frog heaven. The dam has been as full as I've ever seen it (after rain) - at least 60cm of water with most of the winter vegetation submerged.

Frogs have been calling crazily each night since then, mostly the Pobblebonk and Spotted Marsh Frogs, although we did hear some Spadefoot calls early on. They can be heard kilometres away. A real audio beacon for other frogs. There have been few calls from the pond (maybe I just can't hear them!). I haven't had a look for a week but when I went down to the dam this morning there were at least three egg masses, all on the eastern side of the dam. The water will be thick with tadpoles soon.

On October 17 we drafted off 100 of the tadpoles from the glyphosate container for Brian Barry's pond at Cocamba. They've had the pond installed for the same amount of time as us but haven't heard any frogs there yet - also not spotted in surveys by BCG's Jon Starks. The project has finished and we were keen to repopulate it.

The funny thing was, we got there and were sure we saw a frog slip under the surface as we walked up to the pond. It may or may have not been but it now has plenty of company.  Brian's pond is beautiful and clear, with some lovely vegetation around it. Once the tadpoles had been emptied in we could see them swimming around in the centre of the pond quite clearly.

For the last four weeks it's been pretty quiet on the frog front. The dam had nearly dried out (apart from the sump we dug last year to keep the tadpoles alive) and we'd had some really hot weather. It was just too hot to keep the tadpoles on the back verandah - and I wasn't keeping up with the pace of frog emergence. I was taking the frogs down to the dam because there seemed to be way more food there for frogs, and enough moisture for them to get by even if the sump dried out. In the end I decided just to dump the whole lot back into the sump a couple of weeks ago and they seem to have been fine there.

Over the last couple of days we've had 34mm of beautiful, steady rain and it's put about 30cm of muddy water in the dam. The frogs tonight are going crazy! They started today (spotted marsh frogs) and this evening we can hear all three species - spadefoot, spotted marsh frog, and pobblebonk. The pobblebonk seems to be exclusively from the dam but the other two are coming from both dam and pond. Amazing sounds.

In early October we took some tadpoles inside and had them living in a glass bowl on the kitchen table - a chance to see them more regularly and take some better photographs. 

This tadpole (we think it's a spadefoot) is just starting to get legs - they are sticking out just above the faeces captured on its way out at the same time. The mouth is open and you can see the row of dark teeth around the edge. The green thing in the background is a pea!

and this is one of the same tadpoles after it has grown front legs, and absorbed much of its tail. It is sitting on a limestone rock. The insect we put nearby for food but didn't really see them eat any - which is why we released them down at the dam after a while. Didn't want them to starve!

We went on to release these frogs down at the dam (Oct 17). This one is feeling proper land for the first time, after experiencing a glyphosate container and a glass bowl with a limestone rock in it as 'home' for the last month or so.

Over the last week we've had an amazing 45mm of rain, which has put some more water into the dam and renewed calling from the frogs there. Spotted marsh frog calls mainly, but I think I hear the odd spadefoot as well.

The pond frogs have faith in the season and have spawned again - this their sixth batch of eggs for 2009. These ones (photo below) seem smaller than the others I've seen - not sure why that is. 

The tadpoles on the back verandah have been growing and the rain seemed like an ideal opportunity to release some back into the dam. I did this on Saturday afternoon (photos below). There seem to be 39 of them in the bowl that we put back in. For a little while they were stunned, perhaps because the water was a bit colder than what they came out of, but soon they started nibbling on the bottom and getting back into the swing of tadpole life. I hope that some of them survive to make froglets. They are already getting back legs and will probably enjoy the dam environment better than the glyphosate containers (despite the carefully constructed shelves for them to rest on).

There is a second generation of eggs in the pond tonight. There has been regular spotted marsh frog calls from the pond and it seems they have been busy. Somewhere underneath all the vegetation the first generation of tadpoles should all be growing too. We haven't had rain for a while but the calls have been ongoing.

The tadpoles we rescued from the dam continue to grow. We're looking forward to Jon (BCG) finishing his next survey so we can possibly release them into some other ponds - and reduce the population in glyphosate containers on the back verandah. At the moment they're being fed on frozen spinach, silver beet and broccoli leaves and seem quite happy but the water gets dirty quickly (there's lots of them). Love the flurry that happens when you disturb them eating. At night you can hear the frenzy going on!

Noreen found this frog in mum's garden today. We've had 2, 2.25 mm rainfall events in the last two days and perhaps it figured it was time to get out and about. I think it may be a pobblebonk (Limnodynastes dumerili) but would be happy to be set straight!