Three species of Ibis

purple-black bird on lawn
Straw-necked Ibis in Sherriff Park, Mundingburra

Australia is home to three species of ibis and all of them live in the Townsville region (in fact they are all widespread, occurring throughout Queensland, NSW, Victoria, most of the Northern Territory and parts of WA and SA) but they are by no means equally common here.

The Australian White Ibis, Threskiornis molucca, is by far the most common and has featured in numerous posts here on Green Path, Percival’s Portrait being the most recent.

The mostly-black species should logically be called the Black Ibis but no, it’s the Straw-necked Ibis, Threskiornis spinicollis. The reason for its name is clear enough in the photo above (but I still think Black would be better).

The Straw-necked Ibis is much rarer around town than the White, outnumbered at least 10:1. Even so, it is more common than the Glossy, which I have never seen in town and rarely seen anywhere else – and the only place I have photographed one is at Billabong Sanctuary.

purplish wading bird beside billabong
Glossy Ibis

The Glossy Ibis, Plegadis falcinellus, is noticeably smaller than the other two (50-60cm rather than 60-75) and doesn’t share their habit of feeding on land, preferring to keep to shallow water.

Ibises and Spoonbills, all large wading birds, comprise the family Threskiornithidae. Wikipedia’s article on the order they have been assigned to (Pelicaniformes) says that there is considerable debate about their evolutionary history but that pelicans, egrets and herons  are among their next-nearest relations. Back in the real world, ibises and our two species of spoonbill often forage together in mixed groups, sometimes with Magpie Geese, Whistling Ducks, Cormorants and other species.

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