MIGRATION PERIODS FOR BIRDS COMMONLY FOUND TO COLLIDE WITH TORONTO TOWERS The red areas make up 13 weeks in the spring and 15 weeks in the fall.

JAN

FEB

MAR

APR

MAY

JUN

JUL

AUG

SEP

OCT

NOV

DEC

WEATHER CONDITIONS KNOWN TO EFFECT BIRD COLLISION RATES Collision rates vary depending on peak migratory activity within each migration period.

Examples of variables include: A cloudless cool day in late September is likely to be SEVERE whereas a cloudless warm day in late September is likely to be MODERATE. A rainy night in mid-March is likely to be CALM whereas a rainy night in mid-May is likely to be MODERATE. A warm night in mid-May with rain moving in before dusk is likely to be CALM whereas a warm night in mid-May with rain moving in after midnight is likely to be SEVERE.

DAYTIME COLLISION RATES

NIGHT TIME COLLISION RATES