Photo credit: www.sciencedaily.com
Research from the University of Otago in Ōtākou Whakaihu Waka reveals that Aotearoa has been increasingly welcoming new avian species from around the globe since the onset of the Ice Age, providing valuable insights into potential future migration trends.
The Ice Age brought significant transformations to the landscape of Aotearoa, shifting it from extensive forests to more open grass and shrubland. This led scientists to explore which of the current and recently extinct bird species are direct descendants of ancient lineages that evolved over millions of years, and which ones resulted from more recent migrations.
By analyzing mitogenome data from nearly all extant and recently extinct bird species on the New Zealand mainland, researchers found that several species, particularly those thriving in grassy and shrubby environments, such as the pīhoihoi (New Zealand pipit) and the pūtangitangi (paradise shelduck), likely migrated to Aotearoa from Australia at the beginning of the Ice Age.
Dr. Pascale Lubbe, the lead author from the Department of Zoology, points out that claims suggesting these newcomers lack an “iconic New Zealand” essence are somewhat misguided.
“Frequent invasions by various species are actually a hallmark of New Zealand’s biological history throughout geological time,” Dr. Lubbe explains.
“Indeed, many of our most recognizable endemic species, which can only be found in this region—such as the Haast’s eagle, the kakī (black stilt), and the fantails—were also introduced during the Ice Age.”
This research, published in the journal Molecular Ecology, delves into the evolutionary relationships among Aotearoa’s bird populations and their counterparts abroad, examining the points at which they diverged into unique species.
Although extensive studies of the country’s flora and fauna have been conducted for over a century, much of this prior research largely focused on individual species.
“Our method takes a comprehensive view of the global origins of nearly all endemic bird species, offering a holistic perspective on their evolution,” Dr. Lubbe states.
The findings suggest that patterns of colonization are influenced by the habitat preferences of invading species across geological timescales.
In light of the current trends associated with climate change, understanding these historical evolutionary patterns is crucial for interpreting the fast-evolving dynamics of today’s ecosystems, which are increasingly unpredictable.
“With a significant portion of New Zealand’s forests being cleared for agricultural purposes, numerous Australian bird species have made their way here over the last century. Examples include welcome swallows, silvereyes, plovers, and Australian coots,” Dr. Lubbe notes.
She also emphasizes the likelihood of this trend continuing: “We should anticipate that more Australian species will establish themselves in New Zealand’s environment moving forward, bringing with them potential biosecurity challenges, particularly if forest cover continues to diminish.”
“This risk is amplified if our native species face extinction, effectively leaving gaps in their ecological roles,” she adds.
Source
www.sciencedaily.com