In early August, research staff from South Australia’s Department for Environment and Water visited Boolcoomatta to conduct some Yellow-throated Miner trapping, as part of a project to investigate the genetics of its closely related cousin the Black-eared Miner, which is one of Australia’s rarest birds.
The Black-eared Miner has a restricted distribution, mainly confined the Murray-mallee region around the SA/Victorian border. In South Australia, the stronghold for this species is Gluepot Reserve near Waikerie.
Threats to this species include habitat removal and degradation and interbreeding or hybridisation with the Yellow-throated Miner (a phenomenon that has been previously described in New Zealand Parakeets in the mid-1990s, also linked to species co-inhabiting highly modified environments).
A publication in 2001 (Intraspecific phenotypic variability in the black-eared miner (Manorina melanotis); human-facilitated introgression and the consequences for an endangered taxon. Biological Conservation 99, 145-155) led to a revision of museum specimens, however the taxonomic status of Black-eared Miners still remains somewhat controversial.
This study is being conducted to help understand the genetics of Black-eared Miners and includes the collection of blood samples from pure Black-eared Miners, hybridized birds, and out-samples of Yellow-throated Miners, which is where Boolcoomatta fits into the story.
For a couple of days in August, the Red Gums around the homestead dam were surrounded by mist nests, in an attempt to capture a few birds to sample.
Despite the ongoing dry conditions and the fact that the homestead dam dried up many months ago, there are still numerous birds using this habitat around the dry homestead dam for shelter, including our target species.
To successfully capture birds with mist nets relies on choosing pathways where birds are likely to fly. Usually nets are setup just before first light when conditions are still. During this trip, conditions were not ideal, with gusts of wind causing a frustrating number of attempts to out manoeuvre our targets. In addition, the typical August morning is fairly crisp, particularly before sunrise.
Initially it was looking like we were going to struggle to even catch one of these birds, as they flew over our nets, stayed high up in the Reg Gums out of harms way or flew off in the entirely wrong direction to where we had predicted.
Our perseverance paid off however, after numerous attempts and moving the nets out into the shadows we managed to capture three Yellow-throated Miners. Hopefully the samples collected can provide some insight into the genetic profile of these two species and help with the conservation of one of Australia’s most endangered birds.