Star and Crimson Finch Research

["Michael Todd" <>]

Hello all,

 

I've had some queries re how my finch work has been going so I thought I might give a quick review of what I've found so far. I won't go into too much detail and I'm hesitant to draw solid conclusions as I haven't analysed all the data yet, but I can give a general outline.

 

STAR FINCH

It looks as though there could be three subspecies of Star. Photographs that I've seen of specimens that were collected during the 1800's in NSW look quite different to Star specimens that I have seen and Stars that I have handled from further north. I need to look at more specimens though. This would support Schodde and Masons findings. The differences between the cape york form and the western australian are more subtle but still appear to be consistent. The question I think is how far the cape york form stretched across the gulf and south of the cape, and how far north the southern form actually came. My gut feeling is that the Cape york form may have gone a lot further south and the southern form may not have gone as far north as once thought. Once again I need to look at specimens again.

 

The Stars seem to be heavily reliant on the availability of water. While they are not as sedentary as has been previously suggested they are probably not as nomadic as many other finches may be. In northern Australia this requires that they have enough available surface water to last them through the dry, because there is plenty of water in the wet! They are a late wet season breeder not starting until near the end of the wet. If we assume that the stars that existed further south were similar in habits then they would have suffered badly from the effects of cattle and sheep around watersources during dry years. In northern Australia this damage is alleviated each wet by the lush growth that is stimulated by the rains.

 

CRIMSON FINCH

The black-bellied crimson finch that is distributed in northern Australia from the kimberly to the Leichardt River in QLD is faring much better than the white-bellied on Cape York and probably the black-bellied eastern QLD (don't have much info on this population). Crimsons particularly like open-forest places with long grass for shelter and this habitat is quite common along drainage systems in northern Australia. In contrast there is a lot less of this type of habitat on Cape York than you would think. So, there were probably a lot less white-bellieds than black-bellieds in the first place. Crimsons have short rounded wings poorly suited to long distance flight making them unable to cross large areas of unsuitable habitat to get to suitable habitat. The result of this is that local disturbances probably cause local extinctions rather than declines which can later recover. Another interesting difference between the 2 subsp. seems to be the behavioural flexibility of the black-bellies, coming right into towns and nesting in everything from buildings to boats. Boat-nesting has a low success rate when the boats are regularly used though!

 

Overall, I would say that it is the white-bellied Crimson that is most vulnerable because the populations are so small and spread out. The southern star is very close to extinction if not already there. The stars across the north are probably stable because of the constant regeneration of habitat each wet season but they need to be watched. There has probably been a decline through the gulf and certainly there has been the big decline away from the coast.

 

I hope this answers some of the questions.

 

Cheers,

 

Michael Todd
Finch Researcher
Tropical Savannas CRC
c/o Stephen Garnett,
EPA, PO Box 2066, Cairns, Qld, 4870