Re: hawkesbury&sydney birds

Keith Brandwood wrote "It appears to me that bird populations around Sydney are well down in numbers this autumn."

I think the reason is a simple as drought!  I appreciate that the coast is not as badly drought stricken as western NSW (it's raining in Dubbo!!!!!).  However, the fact that Sydney's water supplies are nearing record lows suggests that not all is well.

Drought affects flowering and seed set of plants, insect numbers as well as opening up of the structure of the forest as plants shed leaves or die.  The consequences are less resources (affecting breeding and survival) and, potentially leaving survivors open to greater predation rates.  

On predators - some prey items such as insects might be scarcer so they rely more on what is available.  Those birds that do attempt breed might suffer higher predation rates.

This may explain lower numbers of smaller birds but what about Keith's pigeons?  Wonga Pigeons are looking for Acacia seed.  Are they setting fruit in these drier conditions?  Brown Cuckoo-doves are looking for fruiting "rainforest" plants?  Are they stressed and therefore not setting fruit?

All food for thought.

Cheers

David Geering
Regent Honeyeater Recovery Coordinator
Department of Environment & Conservation
P.O. Box 2111
Dubbo  NSW  2830
Ph: 02 6883 5335 or Freecall 1800 621 056
Fax: 02 6884 9382



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