Talking Point: Westbury bird haven worth saving
By Sarah Lloyd
1 July 2020
Fallen trees, messy understorey - the new prison site has exactly what birds need to survive as habitat declines, says Sarah Lloyd
For many years the planned site of the northern prison on the Birralee Rd (or the Westbury Reserve as I've always known it) has been among my favourite places to watch, record and photograph birds.
I have seen wedge-tailed eagles, masked owls and the pure white form of the grey goshawk.
However, I don't visit the site just to see these rare and threatened species; rather, my interest is its abundance of smaller bush birds, many of which are known to be declining.
This bush is surprisingly secluded given its proximity to a very busy road. It does not have the giant eucalypts characteristic of Tasmania's southern forests, nor the ancient Gondwanan myrtle-beech of the North-West and northeast rainforests.
To the uninitiated, this parcel of crown (our) land looks degraded with log-strewn ground, dead and dying trees and a messy understorey. But for many birds this is a haven - they need these things to survive, breed and thrive.
Wedge-tailed eagles - and many other species - perch on dead limbs where they can scan the landscape for prey or danger.
The migratory dusky woodswallow, satin flycatcher and black-faced cuckoo-shrike require dead limbs and partially dead trees for their nesting sites.
Dense understorey is essential nesting habitat for the small and medium-sized bush birds that play crucial roles in the ecosystem; the nectar-feeders pollinate plants, the seed eaters spread seeds to other locations and the insect eaters help to control potential pests. Cavity nesting species need eucalypts that can take up to 80 years to form hollows large enough for tiny striated pardalotes, and many centuries for larger species such as the masked owl.
Suitable trees are abundant at the site, but are disappearing from the surrounding landscape as more bush remnants are cleared and scattered paddock trees cut down to make way for pivot irrigators.
Tasmania has a high number of endemic species - that is, species found nowhere else on Earth.
The endemic yellow-throated honeyeater, strong-billed honeyeater and dusky robin have complex nesting and foraging requirements, which are all provided by the habitat at the site. These iconic species, each one an important component of Tasmania's biological heritage, are declining alarmingly. The number of predatory species (grey goshawk, brown goshawk. wedge-tailed eagle and masked owl) recorded in a relatively small area attests to the richness and suitability of the site for breeding and shelter for these large birds.
Raptors (hawks and eagles) roam far and wide in search of prey, feeding primarily on introduced species such as rabbits, rats and mice.
It is often thought that birds can simply move elsewhere when bush is cleared.
But elsewhere is rapidly disappearing. For instance, about 30 years ago the bush across the road from the crown land was converted to a plantation of non-native eucalypts that provided limited foraging and nesting habitat once the trees grew.
More recently, the eucalypts were harvested to make way for a pine plantation, which provides virtually nothing for birds. These rapid changes to vegetation are occurring across Tasmania and are having a dire impact on the survival of many bird species. The overall impact of the prison is likely to be considerably larger than the 10-15ha building footprint because of the constant lighting that will be required around the facility. Studies indicate that strong night lights have a serious impact on all plants and animal.
Birds can be attracted to lights and killed after crashing into buildings, migratory birds can be thrown off course. The entire reproductive cycle of birds is strongly correlated with day length, which will be artificially extended to last for 24 hours.
Night lights are well known for attracting insects - food for many birds - to their deaths. Insect populations throughout the world are being decimated.
The clearing of this habitat is another step towards local and regional extinction. Birds matter.
In an age of a climate emergency, a pandemic and a biodiversity crisis, it's time for permanent protection of Westbury Reserve and to find another site for the prison.
Tasmanian naturalist Sarah Lloyd was awarded the Australian Natural History Medallion by the Field Naturalists Club of Victoria in 2018. This year she received an Order of Australia Medal for services to conservation and the environment.