Spring has sprung and the migratory waders are back in Roebuck Bay. These are birds that breed in the far north of the northern hemisphere taking advantage of their short summer period of great abundance. The abundance is so great that the hatchlings feed for themselves. That’s a great saving in effort for the parents but at the expense of a long flight to escape the coming winter and capitalise on abundance elsewhere.
In those species that breed across a range of latitudes those that breed furthest north generally winter further south than those that breed in the southern part of their range. This leapfrog pattern of migration appears to have been brought to science’s attention by J A Palmén as long ago as 1874. One particularly good example of this is the Common Ringed Plover Charadrius hiaticula. Those that breed in southern Sweden or Britain winter in southern Europe whereas those breeding in the arctic mostly take the trip to Africa.
Mostly, but for the last three or four years a single bird has been turning up a stone’s throw from the Broome Bird Observatory in Roebuck Bay. This is presumably the same individual which must make it a leapfrog champion. There have been sightings of Common Ringed Plover further south but they are decidedly rare here in Oz.
I caught up with the Roebuck regular last week …
bobmcgee 