9th October is International Migratory Bird Day
You can read a lot about migratory bird routes, events to celebrate the day, and some of the current conservation problems here: https://www.worldmigratorybirdday.org
Birds do not understand international political boundaries.
I’ve seen some comments recently in social media denouncing the birds that dare to arrive in Australia from other countries to the detriment of our natives, in particular the channel-billed cuckoo.
Yes, the crows, currawongs and other large native species probably cringe when they hear the first calls of the season. They probably don’t quite understand why but they certainly don’t like them. We often see crows chasing this cuckoo (the world’s largest cuckoo) across the sky. I’m told it is often the male they’re chasing, while the female quickly slips back and lays an egg in the nest of the bird doing the chasing. The foster parent’s understanding of what is happening when faced with a large hungry chick that isn’t theirs is rather limited, as they will continue then to feed it while their own chicks have been tossed out by either the parent cuckoo or the newly hatched one.
But are the cuckoos really interlopers, and does it make sense for us to moralise about what they do?
There are plenty of native cuckoos that never eave Australia, and do exactly the same thing, usually to smaller bird species than the targeted by the channel bill.
Is the change-billed cuckoo one of our own native birds or an intruder? Many of them never leave Australia anyway, although most fly up to Papua New Guinea or Indonesia for the winter. Their breeding grounds are here so I would say they are very definitely native, as are the koels, another cuckoo which also spend the winters up north and come down here to breed. Both these cuckoos, as well as eating insects, eat rainforest fruits and disperse their seeds, so play an important ecological role while they’re here. Dollarbirds (rollers, not cuckoos) also visit us from up north to breed here in summer. No humans influenced their decision to come here. And some do’t actually leave Australia anyway, apparently deciding the weather in Far North Queensland in winter suits them well enough to not need to travel further.
So yes, I’d say very definitely they are all native to Australia.
And cuckoos can’t help being cuckoos. No matter what our feelings for the nestlings they destroy or the poor foster parents having to feed the strange “adopted” infant, it is an instinct the cuckoos are born with, and the only way they know how to breed. And some of our other native birds – currawongs, crows, kookaburras, even shrike-thrushes – often help themselves to nestlings of smaller birds as an easy meal.
And during the days of Covid, when we can’t travel to other countries, I rather enjoy knowing that these birds have been traveling to places I’d love to be visiting myself. Also, the arrival here of channel-billed cuckoos, koels and dollarbirds here in the Scenic Rim, southeast Queensland, reminds me that summer is on its way.
We don’t have the enormous influx of migratory forest birds that some of the other continents have, but there are quite a few that make north-south movements. Some others make altitudinal movements, like the golden whistlers and grey fantails that tend to frequent the valleys in winter, presumably because insects are more active in the lower altitudes during the coldest months, and return to mountain forests to breed. Some of the frugivorous birds (wompoo fruit doves, rifle birds and bowerbirds) tend to do the same, but there is less fruit for them in winter in the valleys nowadays since most of the lowland rainforest was cleared many decades ago. That clearing is probably responsible for Coxen’s fig parrot being now critically endangered or possibly already extinct.
But it is the shorebirds who get the most attention for their migrations, and they tend to come from much further afield – Japan, Siberia etc.
One birder from Europe asked me to take him overnight to a coastal area a couple of hundred kilometres north of Brisbane, which I did, not being entirely clear as to why he wanted that. When he got there he was very disappointed, saying “Where are they all?” He had been advised it was a great spot for waders, which, yes, it was, but not in winter! Had he done a bit more homework or told us why he wanted that trip, he could have been informed that most of the birds he wanted to see would only be there in the warmer months. We did at least still see beach stone-curlews and other non-migratory shorebirds and quite a few forest birds.
It is always exciting to see the eastern curlew, as we sometimes do on Coochiemudlo Island or in the less densely-populated parts of the Gold Coast, probing for crabs and molluscs in today mud-flats. This large, long-billed visitor is an endangered species, so it is encouraging to be reminded that it still exists on our planet and continues to make its often-hazardous journeys each year. It breeds in China and Russia, only coming to Australia to avoid the northern hemisphere winter, as many of our other shorebirds do.
An overview of the 37 species of shorebirds that travel, often over very long distances, to Australia each year, and some of the major problems they now face, can be viewed here, and downloaded as a pdf: https://birdlife.org.au/documents/Shorebirds-FactSheet.pdf.
Our tours don’t visit shores as often as freshwater wetlands, but one of the migratory birds we often see, again avoiding the northern winters, is the marsh sandpiper, at Eagleby Wetlands during the warmer months.
Yes, most of our migratory shorebirds don’t actually breed in Australia, but they are still considered native to Australia and to all the other countries they visit on their journeys, as they willingly bring themselves here, not brought by humans, and it is essential to their existence that they have places where they can stay warm and find plenty of food while avoiding the cold conditions up north. And as I said above, birds don’t understand our political boundaries.
Our whales are also migratory, coming from the Antarctic to our relatively warm winter waters to breed each year, but that’s another story …