Wednesday, 18 July 2007

#23 A Frog in the Grass

Some of Australia's frogs are struggling to survive, with loss of habitat due to urban and industrial sprawl being a major contributor to their decline, so to find frogs happily living in your backyard garden is a delightful surprise.

The Spotted Grass Frog is a real cutie

Limnodynastes tasmaniensis, Spotted Grass Frog (or Spotted Marsh Frog), is a relatively common frog of the eastern states. But as with most frogs, they are more likely to be heard than seen.

Occasionally I'll uncover one when working in the garden, and it's always exciting to realise I am creating healthy frog habitat.

Creating frog habitat

Creating a frog-friendly environment in your yard is easy, and very satisfying. Frogs need moisture, shelter and food, in cat-free surroundings. Planting layers of shrubs, ground-covers and trees, as well as providing shelter in the form of rocks and logs, and a container or pond of healthy water is all that is necessary. Once the habitat is created, the frogs should eventually move in.

Notice the different colour and patterning of two Spotted Grass Frogs inhabiting the same environment

My backyard was completely bare 4 years ago, but with the introduction of grass, gardens, shrubs, mulch, water, and a bit of messiness, the frogs have moved in. I have found three species of frogs in my backyard. As frogs are primarily nocturnal, my frog encounters are mostly accidental. During the day, frogs will shelter under rocks and logs, amongst grass or other ground-hugging vegetation, or under objects in damp shady areas.

Frogs feed on insects, so they are great little predators to have in the garden. Keeping your garden free of chemical pesticides, herbicides and fertilisers will help ensure a healthy environment for frogs and their food source.

If the water you are providing for frogs comes from a town water supply, keep in mind that it will contain chemicals. Standing tap water in the sun for a week will remove chlorine. Take care not to allow household septic outflow to pool, as this contaminated water creates health hazards for all animals, both wild and domestic.

Here is another example of colour variation of the Spotted Grass Frog

Frogs and tadpoles should not be moved from one location to another, as this risks introducing disease and deadly fungi to frog populations. As frogs absorb chemicals through their skin, it is unwise to handle them, but if it is unavoidable, ensure your hands are washed and damp, and keep handling to a minimum.

Spotted Grass Frog, Limnodynastes tasmaniensis

This common little beauty grows to about 50mm in length (but more commonly, 40mm) with the female larger than the male. As illustrated in my images, colour and patterning is variable. Some specimens will have a stripe running down the middle of the back, but all have a raised fold running from just under the eye to the arm. There is slight webbing between toes, but not between fingers.

Notice the raised fold starting under the eye and ending at the arm. The skin is smooth with small bumps.

The main breeding season occurs between August and March when males call from the waters edge concealed by vegetation. Their call is a very rapid succession of "uk-uk-uk-uk-uk" repeated at intervals. Tadpoles take between 3 and 5 months to complete the metamorphosis, but length of time will vary according to the water temperature.

Spotted Grass Frogs are well camouflaged

These delightful little blotched frogs should start calling for a mate as winter draws to an end. Here is an internet page with more information and a link to their call. Keep a listen out for them as the nights begin to warm up in eastern Australia. Frogs Australia Network is an excellent internet site a comprehensive list of Australian frogs and links to information and calls.

As human population increases, pollution and habitat destruction means that frogs and other native wildlife struggle to maintain healthy populations. By creating some frog-friendly areas within your little bit of space, you will not only be able to enjoy having these beautiful creatures around you, but you can feel genuine satisfaction that you are making a positive difference.


Evan said...

Good blog Gaye, I was wondering when frogs would eventuate on your blog!

Three species is very low number for any area in Australia, but especially the Hunter Valley. My mum's farm (which is very far from any bush land) near Gloucester has 14 species. This number would increase to around 20 if there is natural bushland bordering or on the property.

I recommend you go out on a wet night in the upcoming season (late Spring and Summer) and search for some frogs. You are bound to double, if not triple, your species count in one good night.

Just out of interest. I know you get the Ornate Burrowing Frog, what is the other species you have found?


Gaye from the Hunter said...

Hello Evan, I was hoping you'd find my frog blog :)

The third frog I've seen here is the Green Tree Frog, Litoria caerulea.

Well, I'm really intrigued to know that I should have more species of frogs here, and I'll be looking forward to going on some night walks in the warmer weather. I've done this before, and have heard them calling (especially following summer rain), but have been unable to locate any - they stop calling as I approach the sound, even though I tread softly and slowly.

The rural area where I live is very much cleared, although the Hunter River is only about 200 or so metres away. Due to the steep banks, the river is not easy for me to reach and is on private property (although I do have permission to access the land). It is a dairying area with unimproved grazing. Lucern is grown a few kms up the road.

The only real stands of native vegetation here are the casuarinas down at the river. I have planted many native shrubs on my land (which is only a large house-block).

I've uncovered some of the frogs from my blog just this week (under carpet underlay that I use for my compost heap), but there is very little calling going on. The frogs seem to have relocated, and I have made a shelter in that protected spot for a blue tongue lizard that I 'rescued' yesterday.

Thanks for your interest.


Evan said...

To find a calling frog, it usually takes some time. What you have to do is get as close to the call as you think you can, and then wait for the frog to call again.

This involves turning off your torch and waiting for a few minutes. Then you just figure out its exact location. It may take a few attempts. Depends on the species of frog and how practiced you are. Can take up to an hour for some cryptic species, and there are some which call so infrequently that you end up giving up. Also hepls to have 2 or more people so you can triangulate.

If you record all the different frog calls that you hear this coming summer (which looks like it will be a wet), just email them to me and I will be able to ID them for you.

There are only a couple species in your area that prefer the streams/rivers to a pond. So check out the local dams and frog ponds.



Gaye from the Hunter said...

I have a recorder now, so I'll get stuck into this in Summer. All the farm dams are full so there should be plenty of calling going on as it warms up.

Denis Wilson said...

Hi Gaye

I've been slow to get back to this blog. Too busy putting out press statements re our "win" on the Aquifer (first round decision).
Great froggy photos. I have the Pobblebonk here, and some smaller, different sounding ones, but getting IDs for them is always a problem, unless you know a frog freak. Evan's offer to identify your calls sounds very encouraging. My only photo is of a brownish Tree Frog, which came up onto the window one night, to catch moths. Of course, my photos show only the underside, and the toes. Not the markings on the back. Interesting shot, but not diagnostic - at least not for me, who doesn't know much about frogs, anyway.

Thanks for that link to the frog website. It is excellent, but I cannot play the sounds yet. I need to get that right settings on my computer.



Esperance Blog said...

Hi Gaye, frogs have such character, or maybe it's just their big eyes, but which ever, they are delightful creatures to have around.

Your spotted march frog certainly has a range of ornamentation/coloration, which unless there is something quite specific (like the folds of skin you specify), they can to the casual observer be very confusing to identify. These lesser known markers make blogs like yours a valuable educational contribution.


Gaye from the Hunter said...

hi Jack, and thank you for your interest and comment.

I certainly learn a lot observing the local wildlife inhabitants, and asking questions of knowledgeable people and consulting reputable information sources.

As you know from your own nature blog, it is very satisfying to record ones observations and share them with as many people as possible. So much can go unnoticed, and it is great to be able to highlight details.


Gaye from the Hunter said...

hi Denis,

the work that you and others are doing on the plight of the aquifer is commendable. I have been following it with interest.

I imagine Evan would consider your term "frog freak" a compliment, just as I consider it a compliment when I am referred to as a "fungus nutter" or similar :)

I am going to put a fair bit of effort into trying to identify frog calls this summer. It will be very interesting to know what other species of frog inhabit the local area.

Thank you for your interest.


David Young said...

Hi Gaye,
I believe a recording exists with different species of frogs to help with IDing. I'm not sure were to get it, though The Australian Museum may be able to help locate it.

Gaye from the Hunter said...

hello David,

"Frogs Australia Network" is an excellent internet site with a comprehensive list of Australian frog species with links to information and calls - a great one to save in your "favourites"


Evan said...

Hi Gaye,

The frogs are just starting to call again, have you been able to hear any other species which you couldn't previously?


Gaye from the Hunter said...

hello Evan,

The frogs are calling here too. There are puddles in the paddock adjoining my yard that have frog spawn rafts. I haven't investigated, either day or night, as I have been unwell with a 'bug' of some sort. But I do plan to check out the frog activity in the paddock.

I find it difficult to separate calls from the frog noise, but I think the night time chorus contains two sounds. But as you indicate I should have more frog species, I am anxious to check this out more thoroughly.

I have a recorder (although it is not digital) so I will make a recording and go from there.

Thank you for your continued interest.