Visitors passing along the Porcupine Ridge Road in recent weeks have noticed that trees on both sides of the road, both in the National Heritage Park and the Upper Loddon State Forest, are looking extremely stressed, presenting a desolate sight. The cause appears to be a plague of lerps. Such a plague usually reflects a decline in the number of woodland birds which normally feed on lerps. [SEE OUR AUGUST 16 REVISION OF THIS ASSESSMENT]
This decline is alarming from many points of view. The current condition of this bush is an indicator of the connection between biodiversity and forest health. Castlemaine Field Naturalists report that the ‘decline in bushland birds is alarming.’ Their
monthly bird counts at the Spring Gully/Fryerstown Road intersection reveal that the number of species seen, and the number in each species, have been declining for some time. The counts for 2012 are
April Scarlet Robin (1)
May Aust Raven (1)
DSE draft fire operations plans propose big burns to the south and west of this area [see our report below].
Something we should consider in relation to this article is that research shows animals and birds spend most of their time in gullies and along creeks and rivers so it’s not normal to see large numbers of birds on ridge lines.As there has been an abundance of rain in the last 2 years that has resulted in much growth and an increase in food supply its easy to understand why birds wouldn’t bother to fly up to the top of a hill to search for it where as in the drought years they would be searching far and wide.I have noticed that large numbers of birds gather on north facing slopes in winter for shelter from the cold south winds.This could explain why there are few birds on Porcupine Ridge which is very exposed to the south,also lack of under storey plants in that area could be another reason.I have noticed large numbers of birds south of Castlemaine this year and in the evening flocks of birds fly in from the north to shelter.
Thanks all for the theories on this. I’ve seen several lerps infestations over the years in this Porcupine Ridge area, but none to compare to what is currently happening. As i look from our place on Italian Hill over the Fryers Ranges and back to Porky Ridge, I can see swathes and patches of seriously browning forest in many directions. It’s distressing. And it’s hard to tell from a distance whether this is the red-brown of some juvenile foliages or yet more destruction. I also noticed another patch of infestation on the Midland Hwy heading down to Daylesford near the Chocolate Mill. With the past lerps, although they mined the leaves, they never seemed to take the whole trees to the point of stress where it looked like they were really dying (like now) – this arvo i noticed bark starting to come off some of these trees in a way i hadn’t seen before. Oh i am worried.