April 24 [Day 59] (Valley View site) I arrived at the site at 1100 and found 15 cm of fresh snow and 0C, but the day was mainly sunny with 20-90% cumulus cloud cover and the temperature rose by mid afternoon to 4C. Ground winds were mainly SW gusting to 35 km/h until 1600 after which they became light, but ridge winds were NW-WNW moderate to strong all day. The first migrant raptor was a juvenile Golden Eagle at 1138 but movement was initially slow with only 6 migrants seen before 1500. Between 1500 and 1700 we recorded 18 of the day’s 29 migrants including 12 of 17 Golden Eagles before movement again slowed with the last Golden Eagle moving north at 2013. The highlight of the day was the season’s 5th Gyrfalcon, an adult grey morph bird, that was first seen soaring with and being mobbed by a resident Prairie Falcon at 1623. Both birds moved north and when due east of us the tables were turned as the Gyrfalcon aggressively pursued the Prairie Falcon driving it back south. I had never seen these two species soaring together before and their size and shape difference was very striking: the Gyrfalcon was obviously female and the Prairie Falcon male. The 2 Merlins (adult male and female columbarius) brought the count total to19, one more than last spring’s count. Three of the day’s migrant Red-tailed Hawks were adult dark morph “Harlan’s”, and after only 1 adult Golden Eagle had been counted during the last week 6 came through today along with 1 subadult and 10 juveniles. The most remarkable of the day’s records, however, was a Mourning Cloak butterfly flying high to the north at 1208 when the air temperature was still only 1.5C: the radiant heat from the strong sunshine was obviously sufficient to get it moving. 9.5 hours (655.2) BAEA 3 (406), SSHA 1 (25), RTHA 5 (138), GOEA 17 (2580), MERL 2 (19), GYRF 1 (5) TOTAL 29 (3330)