Endangered black-eared miner to be scrutinized by researchers to learn extent of cross-species breeding

Endangered black-eared miner to be scrutinized by researchers to learn extent of cross-species breeding

One of Australia’s most vulnerable bird species became endangered due to decades of agricultural land clearing, but a loss of habitat is not the only thing putting the birds at risk.

The black-eared miner resides in old growth mallee trees in South Australia and parts of Victoria, and is adored by birders and twitchers who visit the region.

Their distinctive facial markings make them look like superheroes wearing a mask and they don a bright neon yellow-orange beak to contrast against their light gray feathers.

But spotting a genetically pure black-eared miner has become increasingly difficult to do.

The species has been mating with the yellow-throated miner, harmonizing their genetic integrity and bringing extinction one step closer.

To protect the at-risk bird and learn more about the extent of the hybridization, the Murraylands and Riverland Landscape Board will lead a 13-month collaborative project backed by $125,267 in federal government funding.

Cosying up with the wrong species

Bird-watchers are more likely to spot hybrids (pictured) than a pure black-eared miner.(Supplied: Sandy Horne)

Ecology team leader Wendy Stubbs said the problem first started when mallee vegetation was cleared for agricultural purposes.

As a result, the black-eared miner’s habitat was eaten by goats, rabbits, kangaroos, and other herbivores who could access water all year round when they were not historically able to.

This open landscape is the preferred habitat of the yellow-throated miner, and before too long the species were living in the same neighborhood, cozying up together, and creating hybrid hatchlings.

Hatching a plan

While you cannot blame the birds for getting friendly with such a similar-looking suitor, breeding between the species impacted the genetic integrity of the black-eared miner and puts their population at great risk.

a bird with gray feathers and an orange beak
Researchers estimate there are only 200 colonies, consisting of up to 20 birds each, of endangered black-eared miners.(Supplied: Murraylands and Riverland Landscape Board)

As part of the collaborative project, a team of ecologists will visit most of the 200 black-eared miner colonies to take genetic samples for analysis.

“This will not only tell us the level of breeding that’s been occurring between the two species, but it will also help us understand how easy it is to determine how pure the bird is from what the bird looks like,” Dr Stubbs said.

Researchers will also strategically remove key yellow-throated miners from black-eared miner habitat to reduce mating rates between the two species.

Hybrid birds gray with yellow beaks
Researchers want to explore the correlation between the hybrid bird’s appearance and genetic makeup.(Supplied: Sandy Horne)

Dr Stubbs said each aspect of the project will help inform future conservation efforts.

“If we’re doing research, it’s to better inform management activities that we can actually do to manage some of these threats,” she said.

“What we want to do is understand the genetics … whether we’ve actually got issues of in-breeding because the population sizes are small.


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