Mallee Frog Blog

Our dry September is over. October started the same way but has finished with two big rainfall weeks, of about 40mm each. The first big rain was enough to bring calls from the pobblebonk and spotted marsh frogs at the pond. Curiously, no calls from the dam. Compared to other times when we've had big rainfall events, the dam has been very quiet. Only tonight, after the second big event, have I heard a spotted marsh frog calling from the dam.

The dam is very different this year. Last year it was an irregularly irrigated grassland. This year it's been a proper dam, and the greywater is growing grass in the dam next door. The shallowest the water has become is probably about 30cm, and it is about double that again now. There is abundant insect life on the water, but much less dead plant material, and shelter in and around the water. There is heaps of shelter around the dam itself though. It's difficult to understand why there seems to be so much less frog activity (as measured by calls) this year. Maybe they're all just out and about and busy.

Other things we've noticed - our sparrows have disappeared. Could it be the mouse bait? And we've had three wild ducks spend some time on the pond and dam, although I haven't seen them in the last fortnight. There are some great owl noises some nights. I'll have to sneak out one day and follow them and see if they are really owls! 2010 has been a really different year.

Not much has been happening on the frog front. We had five lots of spawn on the pond in mid September, and the odd pobblebonk and spadefoot call, but they have gone quiet since. It hasn't rained much either. Last night we accidentally left a hose trickling in the garden and tonight, while heading out to shut the ducks in, my daughter found...

  A pobblebonk! He was hopping around near a garden light, probably bulking up on insects. 

It keeps raining and the frogs are happy. Today the pond spotted marsh frog is calling in the middle of the day. I just hope he doesn't attract the ducks!

I haven't posted on the frogs for a while. We've had a wet winter, but it's also been quite cool, and they've been very quiet. Could also be that the ducks have discovered the frog pond every so often and they've been scared!

Tonight I stood outside and for the first time this winter heard a single spotted marsh frog call, from the pond. Listening closer, I realised I could hear a lot of frog calls, coming from the direction of Manangatang. I could make out spotted marsh frog, spadefoot toad and pobblebonk. It must be noisy in there! Weird that we aren't hearing more here. The dam has been full of water all winter, and now it's nice and clear fresh water (not the greywater). Maybe they liked the anonymity of the greywater? Actually the pond has also become quite clear. 

The greywater is currently running into the big dry dam next door, and has created a frog habitat par excellence. Lots of grass and a cascade of ponds as the greywater spills down and infiltrates. There must be some there now.

It stopped raining for a while here and all went quiet with the frogs. In the last week we've had 16mm and it's raining again now. Since the rain started, we've been hearing the Mallee Spadefoot Toad calling again (currently other species are quiet). The same thing happened last year. The district will be alive with them in a few nights time!

Since taking the greywater out of the dam it's become quite clear - enough that it's possible to see the dam weed at the bottom. The level has gone down quite a bit because the weather has been so warm and dry, but there's still plenty there. Another reliable catchment dam has remained full of water this year despite the heat. Amazing season!

There has always been a family of Western Grey Kangaroos (think that's the right thing to call them) hopping up and down our road, about 500m from the dam, but they've rarely been close to the houses. In the last month I've seen tracks in our front paddock, and in the last week have had to give way to them a couple of times as they hopped away from the dam (I guess they're drinking from it and not the greywater!). It's good to see them around - I hope the dam stays wet and we continue to see them.

Yesterday we had a gentle 5mm, on top of 20+mm earlier in the week. There has been another decent rainfall between this and the last time I wrote (mid Feb). This seems like the wettest summer/autumn for years, although I think 2004/5 and 1999/2000 were similar.

The frogs have been loving it. The runoff dam is as full as I've seen it and will probably keep a decent depth of water throughout the winter, even if it's dry. Today I took the greywater out of that dam, and I'm going to run it into another dam and see if we can get some things happening there. I don't think the nutrients are good for the dam with water in it - it was getting some scum on it before it rained - and the vegetation at the edge (which could use the nutrients) keeps getting drowned.

The frogs have been going crazy the last couple of nights, mostly spotted marsh frog calls. This morning there were three egg masses on the pond, and at least four egg masses just on one side of the dam. There may have been more but it's a bit slippery to go walking around too much. Looking at the dam there is plenty of tadpole activity, and there have been many dragonflies too. There are also locusts around in the paddocks near the dam but none actually around it, as far as I can see. They would be good frog feed!!!

The frogs also seem to have the mosquitoes under control. It hasn't been too bad outside, but they are definitely around. Probably more with water collecting on old machinery etc. rather than the pond or dam.

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.