I spent a year living in Australia when I was young and irresponsible. I lived out in the country, and spent a good amount of time keeping the paddocks in a good condition. This is a nice way of saying I shovelled manure for a year; the horse breeder I was living with said that this was good for the health of her horses. On reflection, there's better ways to spend a year than gathering dung out of a paddock with a wheelbarrow and piling it up in a compost heap. If the supposed health benefits of keeping a horse paddock manure free are a fantasy, I for one do not ever want to know - because it would mean that a significant part of a year of my life was wasted on a load of horseshit.
I was out in the paddock one day, far from the house, farther still from any neighbouring house - you're lucky if you can even see the neighbours' houses when you live in the country - and what do I hear? I hear the sound of a television. I thought it must have been astronomically loud if I could hear it where I was - loud enough to split the eardrums of anyone in close proximity, possibly even loud enough to stop their brains working. There wasn't much on this phantom television, either. It was simply someone watching some kind of gothic documentary: I could hear the crows.
Then I saw the crows. There was a murder of them in a tree making a racket as only crows know how. At this point I remembered something I'd read just the week before: There are no crows in New Zealand. Having been born in the 20th century I knew perfectly well what crows sound like thanks to television and movies, but because I grew up in New Zealand I subconsciously associated the sound of crows with the idea of people watching television. Having never heard the sound of crows outdoors, my brain filled in the blanks with the only possible source for the sound it knew. Once my brain had got itself sorted out, I proceeded to be delighted by finally seeing and hearing them in person.
Before any humans came to New Zealand there were two species from the Corvidae family here: The Chatham Islands Raven (Corvus moriorum), and its relative, the New Zealand Raven (Corvus antipodum). However, they are both long extinct, and probably weren't sending birthday cards to each other when they were alive, given the distance between mainland New Zealand and the Chatham Islands. By the time Europeans made it to New Zealand, both species of ravens had been wiped out, meeting the same fate as most other interesting New Zealand birds that became extinct: They were eaten.
It turns out there actually is a relative of the crow in New Zealand today: Corvus frugilegus, the rook. Introduced by the crazy colonists sometime between 1862 and 1874, they were supposed to keep down pest insects and remind colonists of home (just how crazy were the colonists? Pairs of cheetahs were released in New Zealand, and probably only survived for a week). Naturally, the rooks made a dent in the local ecology - rooks eat worms and small insects, but are also partial to small birds and their eggs. Amazingly enough, the introduction of so many species was sometimes justified because the range of fauna here was not considered to be broad enough.
Rooks are not very widespread in this country, and that might be because they also eat grains when their usual food is scarce, and unfortunately for the rook grain crops are not grown in vast quantities in New Zealand (of course, if the rooks ate sheep they'd be able to spread everywhere). These obscure birds are apparently found in the Hawkes Bay, Manawatu, southern Wairarapa, and Canterbury; with other nearby areas having control programmes. How rare are they? I've lived in the first three places and never seen any rooks, which is a crying shame as far as I'm concerned.