Rats! Lord Howe's owls may be sent home to roost

[depakid]

No place like home ... Tasmanian masked owls, which were introduced to Lord Howe Island in the 1920s, have thrived.
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SOMETIMES, no matter how much your family needs you, going home is not an option. In Tasmania, masked owls are an endangered species - as few as 650 pairs are left. But on Lord Howe Island, the same species has thrived following their introduction to the island and they now live in densities unheard of elsewhere.

Perversely, however, that is a bad thing because Tasmanian masked owls were deliberately introduced to World Heritage-listed Lord Howe between 1922 and 1930. Like the old lady who swallowed a fly, the owls were set free to control black rats, which were introduced to the island from a wrecked ship in 1918.

The 1920s owl introduction program was no half-hearted measure. Up to 100 individuals, from a number of different species, were all brought to the island and released in a desperate effort to control the rats. These included the eastern Australian subspecies of the southern boobook, the Tasmanian masked owl, the Australian barn owl and the American barn and great horned owls.

Today only the masked owls survive and their main prey is rats, which they consume in large numbers but nowhere near enough to control the vermin. The owls are found throughout the island, from the summit of Mount Gower to sea level, and they may have a population of up to 50 pairs.

In Tasmania or on the mainland, an area the size of Lord Howe would support only three pairs. However, on Lord Howe owl density has been maintained even though at least 108 were shot in a culling program between 1988 and 2006.

Now the Lord Howe Island Board is planning a one-off rat eradication program for the next few years and the island's managers and scientists fear that unless the introduced owls are removed they will be forced to hunt Lord Howe's native species.

The board has employed an environmental consultant, David Milledge of Landmark Ecological Services, to help work out what to do with the birds. Mr Milledge's preference is for the owls to be returned to Tasmania, but that is not straightforward, because the Lord Howe Island masked owls have changed in both size and behaviour.

More: http://www.smh.com.au/environment/conservation/rats-lord-howes-owls-may-be-sent-home-to-roost-20100622-yvs2.html

[xchrom]

1. well whatever -- please don't kill them. nt

[petronius]

2. That's quite a conundrum. I wonder though, since the introduced owls

apparently out-competed the native owl species, if it wouldn't be better to leave some to fill that niche. (I'm also wondering whether 'complete rat eradication' is anything more than a pipe-dream.)

Lord Howe I looks like a truly incredible place - yet another entry for the 'spots I want to visit' list...