birding-aus

Fires and Birds (long)

To: Birding-aus <>
Subject: Fires and Birds (long)
From: Michael Todd <>
Date: Thu, 22 Feb 2001 00:58:17 +1100
Hello Stuart, Craig and others,

As is usually the case with these kind of things, the importance and impact of burning on flora and fauna depends on where and what you are talking about. If talking about northern Australia then the frequency and timing of fire is crucial in the survival of many animals including birds. Of course what is good for one species can be bad for another. In the case of finches, the habitat of the Star Finch on Cape York Peninsula has almost certainly been maintained by regular and widespread burning of the grasslands. Without the fire, the grasslands are invaded by shrubs, particularly Melaleuca spp. Anyone who gets the chance should take a look at the Nifold Plain grassland on Lakefield NP, with the Melaleuca advancing at the edges. You can almost watch them spreading! The grassland which supported Stars here was once much larger than it is now.

On the other hand, the white-bellied subspecies of the Crimson Finch is probably negatively affected by fire. Being relatively poorly adapted for dispersal (short round wings) it requires undergrowth for shelter, particularly the dense canegrass (Chionachne cyathapoda). Large fires towards the end of the dry season can clear large areas of all shelter leaving the Crimsons exposed to predation. Ironically, fire on a smaller scale can help the Crimsons as it reduces the likelihood of large fires later in the dry season by reducing fuel loads as Stuart suggested in his email. The Chionachne is resistant to burning earlier in the wet season and so can form natural fire breaks and shelter for the Crimsons. You can add Purple-crowned Fairy-wren to this scenario as it occupies similar habitat elsewhere in northern Australia and would be even more affected by large fires.

The Golden-shouldered Parrot is hanging on by the skin of its teeth (if it had them) thanks to specific burning regimes which are probably putting some other species at a disadvantage. But what else can you do? It is likely that the current climatic situation is favouring the spread of certain habitats (and the flora that live in them) at the expense of the others. It has been shown that the rainforest is spreading at the expense of tall eucalypt forest in north Queensland threatening the northern Yellow-bellied Gliders, Tropical Bettongs etc. See research by Graham Harrington. Grasslands are on the way out and it was probably only the regular burning carried out by aboriginal people that kept the grasslands and their Star Finches alive on Cape York. If we want to keep this habitat and I suggest that we do then we have to burn. Exactly how and when we go about it can be controversial and is a difficult situation but there can be no doubt that burning is crucial.

Stuart says that fuel reduction burns simplify the flora of an area. I'm sure that this can happen in some environments. However, some areas that are not burned at all can become much less floristically diverse than those that are burnt. I hate to keep going back to the same examples but on the Nifold Plain, good Tussock Grassland habitat can have something like 20 different species of seeding grasses in a relatively small area during the end of the wet season. On the other hand, ex-grassland that has become a Melaleuca woodland is far less diverse in terms of grass species. Grasses are unfortunately often overlooked- well, I admit, they are buggers to identify. There are many references to comments made by early settlers in Australia of the change in the undergrowth they noticed within the first 50 years of white settlement in SE Australia. Unfortunately, there is probably little chance of knowing exactly how these communities functioned back in the late 1700's but it seems likely that they were being maintained by regular burning regimes. Maybe they were floristically less diverse than the same communities are today. They certainly must have been quite different to what we have today in terms of their fauna. You only have to look at some of the mammals that used to exist in SE Australia that are now long gone. The Tasmanian Bettong (Bettongia gaimardi) for example used to be distributed right up the east coast of Australia into SE Qld! It disappeared so fast after white settlement that there are only a few specimens in museums from the mainland. The habitats must have been very different then.

However, we may not be able to go back to what it was like 200 years ago. Certainly with some animals it is too late as they have gone extinct (eg. Eastern Hare Wallaby). We also don't know what the flora composition of the communities were, particularly with the grasses, which were assaulted by the trampling and grazing of cattle and sheep on top of the change in burning regime. So, do we try to recreate what it was like 200 years ago or forty years ago, which is probably closer to what it might have been like 40,000 years ago, give or take a few species of giant kangaroos. This becomes a question of philosophy. There is no right or wrong - just a lot of uncomfortable compromises.

There are probably no easy answers. Some species will be negatively affected whether you burn or not. Its a no-win situation. Many small birds may require dense undergrowth without burning, Chestnut-rumped Hylacola and Southern Emu-wren spring to mind from my home area of Lake Macquarie. However, places that have had no burning for many years lack the Spotted Quail-thrush and Painted Button-quail. Its also easy to only think from a particular perspective, ie birdwatchers only thinking about the birds. What about all the other animals and their requirements re fire. Common Dunnarts require fire to keep the understorey open and the Brown Antechinus out. If there is no fire then the undergrowth thickens up and the Brown Antechinus and the rats move in- bad news for the dunnarts. Its a complicated matter.

I hope I haven't bored too many people with my rambling! I think I'll go do some burning for those dunnarts. Only kidding!

Cheers,

Mick Todd

Michael Todd
Toronto, NSW, Australia
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