Research · A Migration Running Out of Time: Banded Dotterels Reach Australia Later Every Year

Research · A Migration Running Out of Time: Banded Dotterels Reach Australia Later Every Year

New Zealand's banded dotterels (double-banded plovers) make one of the Southern Hemisphere's most unusual migrations — flying west some 3,000 km across the Tasman Sea to winter in Australia. A new study from the Max Planck Institute for Biological Intelligence, published in the journal Ibis, analysed citizen-science observations from eBird and found the birds arrived in Australia about four days later each year on average between 2014 and 2025. With return departures to New Zealand unchanged, their stay on Australian non-breeding grounds has shrunk by roughly a quarter in just over a decade.

The researchers link the delay to a southward shift in the winds circling Antarctica, driven by human-caused warming, which has made calm, mild autumn and winter weather increasingly common in New Zealand since the 1950s — weakening the cue to leave. It is a clean example of how climate change can compress a migration not by destroying habitat at either end, but by quietly erasing the time window in between.

Original: read here