Turkey-sized Moa?
The smallest moa are always being described as "turkey-sized": I've done it myself. But is this really true? Could this be another mindlessly-copied comparison, like the "fox-terrier sized" Eohippus that Gould wrote about? My only turkey experiences have been on Thanksgiving, and I'm not sure that the thing on a platter has much resemblance to a real live galliform, let alone a moa. How big is a turkey anyway?
After digging around in the library, here are some reasonable turkey weights. Male turkeys are much bigger than females, like most game-birds. They scrap a lot, and have vicious spurs on their legs. A female wild turkey is about 3.5 kg (8 lb), while a male can get twice as big, around 8 kg (18 lb). But wild turkeys are svelte compared to the things we roast for the table. A male domestic turkey is an enormous bloated object, up to 30 or 35 pounds (around 16 kg). Unlike wild turkeys, these guys don't fly so well. Sixteen kilograms is the maximum weight for a flying bird these days (though we have fossils of much larger fliers, so that's not a hard-and-fast limit).
How big were the smallest moa? The weights Worthy and Holdaway (2002) calculated were 27 kg for Pachyornis mappini and 20 kg for Euryapteryx curtus. These are about three times the size of a male wild turkey, and quite a bit bigger than even the largest domestic turkeys (my body mass estimates for these moa species are even greater, but I'm being conservative here). This makes these little moa about the same mass as rhea (Rhea americana is about 25 kg, Pterocnemia pennata about 20 kg); Dwarf cassowary (Casuarius bennetti) are a little smaller, but it's hard to get accurate figures. So, no, moa were not turkey sized. The smallest species weighed as much as the smallest ratites alive today.