Bird migration

Q: Why do birds fly north in winter? A: Because it’s too far to walk!

There were some strange early myths (Audubon.org) about where birds went in winter: they buried themselves in mud; they turned into other species (when no one was looking); or like today’s Artemis II crew, they went to the moon!

Early aviculturists noticed that some caged bird species would get restless in autumn and even all fly to one end of their enclosure. In 1822, some German villagers shot down a White Stork that had a spear made from an African wood impaled in it – some early physical evidence that birds flew between continents.

Much more is known these days about where birds go, thanks to bird-banding, mist-netting, satellite telemetry tracking, and sound monitoring.

The term migration describes periodic, large-scale movements of populations of animals. Movements of a smaller scale are often referred to as dispersal, nomadism, or vagrancy. Bird movements at all levels are a response to seasonal changes, weather patterns, food availability, day length, even genetic makeup – usually a combination of several factors.

Australia is the destination of some of the world’s longest bird migrations. Many of our shorebird species fly thousands of kilometres annually to spend summer here and when autumn/winter arrives, they fly north as far as Alaska and Siberia. A Bar-tailed Godwit holds the record for the longest non-stop flight of any bird, with a 13,560km continuous flight from Alaska to Tasmania (ABC News).

L: Eastern Curlew, Port Albert (Russia/East China)
R: Sharp-tailed Sandpiper, Hollands Landing (Siberia)

Most of Australia’s migratory shorebird species use the ‘East Asian – Australasian Flyway’ (EAAFP explanatory YouTube video - 6min).

While we do not get long-distance shorebirds in West Gippsland, we do get Latham’s Snipe that spend our winter in Japan – they will have left here by now. Other things are happening right now in our district too: the Pied Currawongs, Scarlet Robins, and Flame Robins are beginning to arrive from their summer lodgings up in the high country; Rufous Whistlers and Australian Reed Warblers have gone north; Silvereyes and Pardalotes have dispersed; etc.

Birds on the move. Top row: Scarlet Robin, Australian Reed Warbler, Rufous Whistler
Bottom row: Silvereye, Spotted Pardalote, Flame Robin

Here today, gone, back tomorrow (notwithstanding climate change).