Alex Slavenko

So this should be a last resort tactic, and only employed after careful consideration of all biological, legal and ethical implications and careful testing. But we think it can be done, and might be beneficial. So we do think the option should be on the table, and we encourage discussion.

Fin.

Parrots often hybridise in captivity and the wild. Adding eastern genetics might ugment genetic diversity and adaptive potential through genetic mixing, and maybe even broaden the western realised niche breadth, faciliating range expansion. But there are also risks such as outbreeding depression.

Fire rips through habitat of critically endangered parrot Experts estimate 11,000 hectares of core habitat for the critically endangered parrot has been lost to a recent fire.

Now, the western ground parrot is in really big trouble. Only two extant populations remain, and one of them likely suffered a fair bit from recent wildfires (www.abc.net.au/news/2026-01...). We end our paper with a potentially controversial recommendation: should we try hybridising the two species?

That way we ended up with two species - one pretty widespread in the temperate coastal heathlands of Australia's southeast, and one restricted to the Mediterranean coastal heatlands of Australia's southwest. Enter Europeans, invasive predators & pathogens, habitat clearing and changing fire regimes.

However, as the Nullarbor plain dried up, a biogeographic barrier was formed, which likely led to the formation of an eastern and western population. Then, what we think happened is that the eastern incipient species experienced a really big niche expansion by spreading to more mesic habitats.

So putting it together, we get a pretty interesting story - platycercine climatic niches are shaped by their occupied biomes. The extents of these biomes have shifted through time. The ancestral ground parrot was likely distributed in the Mediterranean biome along Australia's southern coast.

Proportion of the Nullarbor plain classified as either Mediterranean or arid biome through time.

This analysis indicates that the 2Mya mark is more or less when the Nullarbor plain switches from pre-dominantly meditteranean to predominantly arid, which what is also indicated by lots of geological and fossil evidence.

To look at it from another angle, we esimated paleobiomes by training a random forest classifier for biome based on extant bioclimatic layers and a biome map for Australia, then projecting it backwards through time on paleoclimate layers. Notice the expanding extent of the arid biome.

The SDMs certainly support this - notice how habitat suitability in the Nullarbor plain fluctuates at first, then drops to pretty much 0 after 2 Mya, more or less the upper boundary for the divergence date estimate based on phylogenomic analysis (doi.org/10.1206/0003...).

A species assemblage approach to comparative phylogeography of birds in southern Australia In order to compare demographic histories of ten broadly co-distributed birds that are wholly or patchily discontinuous in semi-arid habitats between the continent's south-west and south-east mesic z....

We also constructed SDMs and projected them backwards in time using paleoclimatic layers. This was important to test a long-standing hypothesis that their divergence was driven by the progressive aridification of the Nullarbor plain during the Pleistocene–Holocene.
doi.org/10.1002/ece3...

Phenogram showing evolution of climatic niche dimensions in Australian platycercines.

What about thermal maxima? The greatest support was for a non-phylogenetic white noise model. Not that surprising: heat tolerance is considered more physiologically constrained than cold tolerance, meaning weaker phylogenetic signal in thermal maxima. And that's what our data certainly look like.

Parameter estimates from fitted trait evolution models, showing rates and optima for three climatic niche dimensions.

The fitted evolutionary models then support different adaptive optima for thermal minima and rainfall for different biomes. Essentially, temperate biomes associated with cold and wet niches, tropics with warm and wet, arid and mediterranean with dry.

Phylogeny of Australian platycercines, with observed (at the tips) and inferred (pie charts at internal nodes) biome occupancy histories.

Basically, we used historical biogeographic models to infer likely biome histories. These tell us, for instance, that the ancestral ground parrot was likely a Mediterranean biome species, or that the ancestor of the genus Neophema was likely a temperate biome species.

A map showing the extent of different biomes in Australia, based on a simplified four-biome classification scheme.

How did these differences in realised niches evolve? We fitted some trait evolution models to try and uncover these, and see if climatic niche dimensions (temperature maxima and minima, rainfall) co-evolve with occupied biome, using a simplified four-biome classification scheme for Australia.

Dendrogram showing species clustering based on habitat similarity.

The ground parrots also have very unique habitat requirements, as we can see in this dendrogram showing habitat similarity clusters. They really like coastal heathlands. But they're also quite different from one another, with a lot of western records from mallee woodlands and shrublands.

Basically, it occurs over a really wide range of temperatures and rainfall zones. The western ground parrot's niche is tiny in comparison, but is also almost completely nested within the eastern ground parrot's niche. This indicates niche expansion in the eastern ground parrot following speciation.

Boxplots showing estimated climatic niche sizes, based on temperature extremes and annual rainfall patterns.

We first identified the realised climatic and habitat niches of all Aussie platycercines based on their occurrence records. There's a lot of variation, but the key result we want to point out is that the eastern ground parrot has an enormous climatic niche, much larger than all others.

Pezoporus is part of the subfamily Platycercinae, which includes Australian rosellas, bluebonnets, ringnecks, etc. but not lorikeets, lories or cockatoos. Platycercines are found throughout Australia, giving us a broad range of climates and habitats to compare and contrast.

We were interested in the dynamics of speciation between the two ground parrots, and particularly in how their climatic and habitat niches differ and how such differences evolved. But we also wanted a broader context for this comparison, so we included other close relatives in the analysis.

Occurrence record map for eastern (Pezoporus wallicus, in shades of green) and western (Pezoporus flaviventris, in shades of red) ground parrots. Darker colours represent older records.

The two species are ecologically similar, mostly inhabiting coastal heathlands in southeastern and southwestern Australia. However, while the eastern species is relatively widespread, the western is more restricted in distribution and has declined greatly over past decades.

Photo of a western ground parrot (Pezoporus flaviventris) in coastal heatland.

The other members of the genus are ground parrots. Currently two species are recognised, the eastern ground parrot (P. wallicus) and the western ground parrot (P. flaviventris, photo by Brent Barrett CC BY-NC-ND 2.0). In the past, P. flaviventris was considered a subspecies of P. wallicus.

Museomics and Salvaged Feathers Piece Together the Evolutionary History and Conservation Genomics of the Elusive, Critically Endangered Night Parrot (Pezoporus occidentalis) The Night Parrot is a critically endangered nocturnal bird of Australia's arid zone. The species was “lost” for most of the 20th century until its rediscovery in 1990. Extant populations are now know...

However, there are some pretty cool recent studies about night parrot - see the attached, as an example, which explored population structure and demographic history using genomics.

onlinelibrary.wiley.com/doi/full/10....

Illustration of night parrots (Pezoporus occidentalis).

First, a brief introduction to the focal taxa. The genus Pezoporus contains three species. One of them is the very cool and very enigmatic night parrot (P. occidentalis) which is occurs throughout the arid Australian interior but observations are sparse and its biology is poorly known.

Breaking New Ground: Niche Divergence and Expansion in Ground Parrots (Pezoporini: Platycercinae) Aim The two species of ground parrots (Pezoporus wallicus and P. flaviventris) are morphologically and behaviourally similar, yet geographically disjunct and genetically distinct. We investigated th.....

New paper alert! 🚨🌏🧪

We've just published a neat little study in Journal of Biogegraphy, looking at the climatic and habitat niches of ground parrots and how they've evolved. Let's dive in a bit deeper!

onlinelibrary.wiley.com/doi/10.1111/...

An excellent and thorough rebuttal of the extremely flawed paper by Wallach & Lundgren (2025).
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Macroevolutionary role reversals in the earliest radiation of bony fishes Troyer et al. examine lower jaw evolution in Silurian-Devonian bony fishes and find substantial differences in patterns of morphological disparity, rates of shape evolution, and functional diversity b...

Excited to announce that the 1st paper from my postdoc is now out in @currentbiology.bsky.social ! Using a large dataset of 3D preserved fossils, we explore the diversification of jaws in early bony fishes. 1/15
www.cell.com/current-biol...

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And to do this, they try to paint the conservation community as suffering from "bias, groupthink, and overconfidence" - all while their own very clear biases are showing in every page of this paper.

Compassionate Conservation | The International Wildlife Coexistence Network The king parrot is eating my pomegranates and teaching me to accommodate thieves in my life. Arian Wallach I don’t know what he wants from me,” says Arian W ...

Wallach & Lundgren are not dumb, nor are they bad scientists. They're disingenuous scientists. They know exactly what they're doing, which is trying to discredit the well-supported role of invasive predators in driving extinction, because they don't think we should kill invasive predators.

But as we've seen, their own sweeping claims are based on some pretty dodgy tactics, very liberal interpretation of some results, and consistent downplaying of any result that is inconsistent with their own preconceived idea - that foxes and cats did not (and do not) drive Aussie mammal extinction.