monarchs in New Zealand

Kenelm Philip fnkwp at
Wed Apr 15 13:40:40 EDT 1998

	James Adams suggested that if Monarches migrate from the North
Island to the South Island of New Zealand, that would indicate magnetic
rather than solar cues are used.

	That is not a _necessary_ conclusion from the data, if what is
meant is that all Monarchs migrate to the south to hibernate. Remember
that western US Monarchs migrate towards the coast, which for some
means going west. Whether solar cues, or magnetic field cues, are being
used is not ipso facto obvious from the mere fact of migration.

	There was a fascinating paper read at the Ottawa Lep. Soc.
meeting in 1986 about how western Monarchs can be trapped in the foot-
hills of desert mountain ranges on their way to the coast. Apparently
what they are 'looking' for is certain humidity and temperature con-
ditions, which can be matched by conditions at that time of year in
certain small valleys at the base of these desert ranges. Once settled
in these valleys, they fall prey to the local fauna and do not survive.

	So it's quite possible that somewhere in the mountains on the
South Island is a valley with the correct climate--and it doesn't
matter to the Monarchs whether it's north or south of where they are
migrating from.

							Ken Philip
fnkwp at

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