Tactics and Vectors analses of data of butterfly migration in southern Ontario Table VII

Tactics and Vectors 98/99

Compass Bearings Hypothesis

Suns' Azimuth Hypothesis

Expansion-Contraction Hypothesis

Never Go Back Hypothesis

Analyses of Pooled Field Data: Descriptive Statistics

Descriptive statistics for pooled directional data for 1978, 1979, and 1981 Monarch butterfly (Danaus plexippus) migrations in Southern Ontario. Ś Up Ś Tables: Ś I, II, III, IV, V, VI, VII, VIII a, VIII b, IX, X, XI, XII Ś
Table VII* Proportion of migrating of Danaus plexippus soaring in circles for eight wind conditions Data were grouped according the category of flight behaviour and wind direction at the time of the observation.
		*Number and percentage of migrating D. plexippus* in each flight category for each wind condition**
Wind	N	Soaring		Soaring in Circles
		Num.	%	Num.	%

North	53	38	71.7	28	52.8
Northeast	64	47	73.4	41	64.1
East	150	104	69.3	46	30.7
Southeast	131	64	48.9	30	22.9
South	15	3	20.0	3	20.0
Southwest	35	13	37.1	3	8.6
West	20	12	60.0	8	40.0
Northwest	107	68	63.6	44	41.1
Population	575	349	60.7	203	35.3

* Adapted from Gibo, D. L. 1990

Definitions of abbreviations and symbols: N = number in sample, Num. = in flight behaviour category.

Comments

Maximum proportions of circling and soaring migrants were observed with North and Northeast winds. A Northeast wind is a direct tailwind to a Southwest course. A North wind is a combination tailwind and right crosswind to a Southwest course.
Minimum proportions of circling migrants were observed with Southwest winds. A Southwest wind is a direct headwind for a Southwest course.