WIRES ENVIRONMENTAL SNIPPETS - BIRDS ON FARMS
Today it is universally recognised that protecting natural ecosystems and maintaining biodiversity on farms are fundamental elements of sustainable agriculture.
A healthy bird community removes between 50-70% of leaf eating insects and so play a valuable role in keeping farm trees alive. Birds are therefore critical in maintaining tree health.
The Birds on Farms Survey found that in order to achieve sustainable farming practices which include approaches such as integrated pest management, a few simple guidelines can be applied. They are;
Management of one third of the farm should be sympathetic to the local vegetation, thus local native vegetation should cover at least 30%min of the total farm area
Native vegetation cover should be in patches of 10ha and linked by strips at least 50m wide
Manage at least 10% of the farm area for wildlife
Maintain a range of tree ages
Leave fallen trees to break down naturally
Maintain shrub cover over at least one third of the native vegetation area
Maintain native vegetation around water, dams, wetlands and riparian zones
Here are some interesting stats that came out of the sudy:
Bird diversity increased by 30% for every 10 large trees present at a farm site.
A critical age for planted trees appears to be between 5 & 10 yrs, after which bird diversity is significantly greater
For every 10 fallen trees present at a farm site, the diversity of ground-dwelling birds increased by 30% and bark-foraging birds by 70%.
Total bird diversity was greater in farm sites with leaf litter, particularly when the litter was present in dense clumps.
In farm sites where understorey shrubs were present, there was a 31% increase in the diversity of woodland-dependant birds.
Ground-nesting birds were almost 3 times as diverse where understorey was present.
A river or creekline resulted in a 21% increase in diversity of woodland-dependant birds.
Small birds were 28% more diverse and ground-nesters were 29% more diverse when waterways were present. With the addition of features such as dense scrubby vegetation, shallow wet areas for birds to feed, islands or dead trees for birds to roost, or fencing to exclude stock, there was a14% increase in waterbird diversity. The presence of 2 of these features resulted in a 28% increse, 3 resulted in a 42% increase in diversity, and so on.
Small foliage-gleaning birds were 26% less diverse in farm sites where exotic trees had been planted instead of native trees. By contrast exotic birds were about 5 times more diverse in these sites.
Bird diversity is re-established about 15 yrs after the removal of stock from a heavily grazed site. This increase in diversity continues, reaching a maximum diversity after about 25yrs.
It takes a min of 80 yrs for trees to start producing hollows. 1 in 5 Australian birds require nest hollows for breeding. If no large old hollow bearing trees are available then establish nest boxes for species such as the barn owl, the laughing kookaburra, sugar & squirrel gliders.
Other birds you may want to attract to your farm include, The Eastern Yellow Robin, White-throated Treecreeper, Superb fairy-wrens, Brown Thornbills, Yellow-faced Honeyeaters, Bush Stone-curlew, Flycatchers, Golden whistlers, Speckled Warblers, Spotted Pardelope, Herons, Kingfishers and finches etc
The Birds on Farms book is available from Birds Australia. This provides a fuller description of the guidelines mentioned above. An interactive program is available at the Birds Australia website-www.birdsaustralia.com.au/remnants. This program can be used to diagnose the general health of your farm, and gives more suggestions on how to improve bird diversity on your farm.
24hr Rescue Hotline 66281898
Ref; Birds on Farms, Ecological Management for Agricultural sustainability by Geoff Barrett