After last year's cancellation due to COVID-19, the forum was back this year. I was asked to do a short talk about movements of flagged birds out west in recent years.
NZ dotterel chicks being close to fledge have been regularly flagged at some west coast locations in the past 3 breeding seasons. Multiple sightings have been recorded and submitted by some keen observers, allowing us to gain some insights about the movements of these birds. I put together a few slides showing some of the most interesting patterns I observed and presented them in the forum.
The analysed dataset confirmed that the juvenile population is highly mobile along the coast. Multiple records show how juvenile birds appear in different parts of the coast, sometimes not far apart in time. For example, CHJ who was flagged at Karekare in 2018, has confirmed sightings at Bethells beach, Anawhata, Piha and Karekare. Not long after having been seen at Bethellls in October 2020, CHJ is seen in the inner Manukau harbour, roughly 50km away (along the coastline). Perhaps moving to the southern Manukau or on its way to traverse the Auckland isthmus.
CHR, a Piha bird flagged in February 2019, has confirmed sightings at both the Manukau and the Kaipara harbours (May and October 2019). These are places known to host post-breeding flocks of NZ dotterel. Later on, CHR is seen again at the west coast (Karekare) with a partner. The next year, 2020, the pair is seen actively nesting at a Karekare site, hatching two eggs on their second attempt after the first clutch got washed out. CHR is a great example of a bird that goes wandering on its first year and then comes back to its place of origin (or very close to) to breed.
Some of the other records provided useful insights as to how far away some of the birds can go, presumably looking for a suitable mate.
It is going to be interesting to have a look at the dataset in a few years time. An increase in the number of records may allow for better understanding of movement patterns and perhaps of dispersal rates too.
The whole talk is available in PDF here.
Thanks to the Auckland Council Biodiversity team and the volunteers for organising the event.
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