Field observations of Phoebis sennae migration

[Cody Nash]

Hello, I am a student studying animal behavior and my class observed the
exceptional migration of Cloudless Giant Sulphurs (Phoebis sennae) this
year.  I was wondering if anyone else has data pertaining to P. sennae
migration or can direct me to current research on how butterflies navigate
during migration.  I'm including our observations below if anyone is
interested.

Thanks!
Cody Nash

Field Observations:
Time: September 24th, 1998 between 1 and 4pm central time.
Location: Rhodes College at Memphis, TN.  Observations were taken as the
butterflies crossed the football field.
Although numerous species were present (monarchs, frittilaries, other
sulphurs) P. sennae was the only species for which data was recorded.  P.
sennae were passing at a rate of 5-10 individuals per minute.  Most flew at
an altitude of 5-30 ft under powered flight.  Wind was 0-5mph SE, temp 85 F,
clear skies: a perfect day for observations.

Heading    Rate(m/min)  Note: Mean heading: 136, Mean rate: 211
165    354
165    140
80    242
165    328
180    291
140    221
122    169
102    169
108
108
140
120    172
110    174
180    267
120    185
160    319
130    336
180    165
124    664
118    307
106    227
180    75
140    172
90    175
110    174
120    204
120    171
120    198
160    150
100    177
165    299
160    130
190    156
120    180
130    266
180    82
150    102
150    22
119    149
123    198