By Dr Claire Greenwell (CCWA) and Isobel Armstrong (Clean State)
In early September, CCWA’s Citizen Science team and volunteers headed back out to Bowgada on Badimia Country, in WA’s mid-west, to continue work on a biodiversity assessment project for Carbon Neutral.
Bowgada is part of WA’s Yarra Yarra Biodiversity Corridor – an integrated project designed to protect and connect patches of ‘remnant bushland’ across the Wheatbelt of WA’s mid-west. Remnant bushland is scarce – over 90% of all land in the WA Wheatbelt has been cleared for agriculture since colonisation commenced in the 1830s. This has far-reaching implications for the ecological communities of the area. To mitigate the risk of extinction of the Eucalypt Woodlands of the WA Wheatbelt, the remaining remnant vegetation has been listed under state and federal legislation as a threatened ecological community.
In recent years, the Yarra Yarra catchment has become a hotspot for carbon farming, with the view of increasing tree cover through afforestation and creating a carbon sink. Afforestation involves planting new trees, where a forest did not exist before – for example, on disused farmland. Ideally plantings consist of a diverse mix of species, native to the local area. These projects are aided by the emerging market for carbon farming and carbon credit schemes.
Carbon Neutral has implemented several carbon farming afforestation projects in the Yarra Yarra region. CCWA’s Citizen Science program is helping to monitor these new plantations, to see how birds are responding to ecosystem development in restoration. This is assessed by comparing bird communities found in the afforested habitats with those found in the remnant habitats.
Birds, bats and scats
Across the weekend, our team of volunteer botanists, geologists, ornithologists, and bird watchers undertook a series of flora and fauna surveys across the planted and remnant vegetation habitats. This particular property boasts more than 1,000 hectares of remnant woodland in addition to the 700+ hectares of land allocated for carbon afforestation.
Each morning, the bird watchers were up before dawn to record the avifauna heard or seen at a range of sites – including the banded iron ridge, mixed eucalypt woodland (e.g. York Gum Eucalyptus loxophleba, Gimlet Eucalyptus salubris), and Bowgada scrub (Acacia ramulosa) – vegetation types of the remnant bushland, as well as within the plantations.
Our team spotted a diverse mix of bird species across the various habitats. Among the highlights were Crimson Chats, Western Yellow Robins, Black-shouldered Kites and a Barn Owl. However, the paddocks were bustling with open woodland/grassland specialists – attracted to the area by recent rainfall and an abundant food supply. Rufous Songlarks, Brown Songlarks and White-winged Trillers - migratory resource nomads - were present in large numbers, as were Little Button-quails.
After the morning bird surveys, the team spent the afternoons searching for signs of the threatened Western Spiny-tailed Skink Egernia stokesii badia). This reptile has relatively narrow microhabitat requirements and the vast majority shelter in large, fallen hollow logs in open York Gum woodland. However, they are occasionally found in artificial habitats such as abandoned farm dwellings or railway sleeper piles.
The remaining Mid-west-Murchison population of skinks is extremely limited in its range, due mainly to the loss of suitable habitat in the northern Wheatbelt. As such, evidence of the skink would be important for future conservation of this threatened species. Unfortunately, we weren’t successful in spotting any skinks or their scats but hope to undertake further searches in the future.
In addition to the bird and skink surveys, our team was led by Nic Dunlop on a nocturnal microbat search. Armed with bat meters, capable of detecting their usually inaudible ultrasonic echolocation calls, we waited, in the dark. The bat meters display the ultrasonic calls on a spectrogram and since each species has a unique frequency range, it allows bats to be identified in-situ. Unfortunately, it was a cold evening with little bat activity and only White-striped Bats were detected.
Staff from the WA climate solutions network, Clean State, joined renowned botanist Cate Tauss on the Bowgada trip to assist in surveying vegetation across the remnant bushland. The team learned how to set up quadrats and how to conduct species-area curve surveys to determine the biodiversity of a habitat. They also learned how to take soil samples, and how to tag, label and press plant species for assessment. The rich species assemblage sampled among the various vegetation types further highlighted the high value of this remnant bushland.
Overall, it was an excellent trip. Our sincere thanks to the volunteers who took time out of their busy schedules to assist over the weekend.
Thanks to Carbon Neutral for their support of the project and for providing a comfortable base at the homestead for our team.
MEDIA INFORMATION: The Conservation Council of WA (CCWA) is the state’s foremost non-profit, non-government conservation organisation representing more than 100 environmental organisations across Western Australia.
For more information, visit: ccwa.org.au.
CONTACT: For any enquiries relating to this release, please contact Robert Davies
08 9420 7291 / 0412 272 570 or by email, [email protected]