Sunday, November 2, 2014

Raptor and non-raptor count summaries 20 October-1 November 2014

Raptor migration has been excellent the last twelve days, including a peak
of 1205 Red-tailed Hawks on October 25th. Red-tails, Rough-legs, eagles, and goshawks have been dominating the flight, with good counts of Rough-legs and goshawks throughout the period. Eagle numbers have not peaked yet, which leaves us something to count in November!

juvenile Red-tailed Hawk migrating over Hawk Ridge- backlighting shows a reddish cast to the tail, which is relatively rare for juveniles- nevertheless, we know this is a Red-tail because of the overall shape with rounded wings and bulging secondaries, the heavy belly band, the wrist commas, and of course the dark patagium (also known by a few as the patagial streak- which is just a fancy way of saying the leading edge of the wing between the body and the wrist is dark)

Finches have dominated the non-raptor flight the last twelve days, which is fairly typical for late October. Indeed, about 60,000 finches have been seen so far this season, which reestablishes Duluth as one of the premier places to see finch migration (after last year’s virtual absence of finches). Pine Siskins continue to amaze us in mind-numbing numbers. The season total is now over 40,000 siskins, and it seems likely that many more are to come, since the blistering pace of migration does not seem to be slowing down. We have had three days of over 4,000 birds, including 4762 on October 19th, 4389 on October 23rd, and 4708 on November 1st. These little guys are on the move, and they do not seem to be stopping! It will be interesting to hear about how far south these flocks move in the coming winter. It is going to be a long hard winter for sure!

But despite this almost overwhelming flight of siskins, the highlight of the last week and a half has to be the record high count of 5122 Purple Finch that occurred on October 24th. This event truly was overwhelming, as a continuous stream of large flocks of Purple Finches moved down the shore, all very high overhead, such that many flocks were only detected by their calls, and so it seems likely that many additional flocks were probably missed that were not directly overhead. At times there were several layers of flocks overhead, a hundred or more in each flock.  It was one of those days when you know that the number of birds is way more than you can possibly hope to find and count, but it is nevertheless wonderful to stand witness to such an event. This is more than double the high count of Purple Finches set four days previous when 2241 were seen on October 20th, which brings the season total to over 14,000. Perhaps more than any other group of birds, the finch flights seem to be completely unpredictable, as this Purple Finch flight occurred on a beautiful sunny day with south winds and a high of nearly 70 degrees!

Small numbers of other finches have also been moving through, but it seems likely that none of these other species will have significant invasions, since these events usually develop by late October. In fact, perhaps the best finch forecast for Minnesota is to watch the numbers counted at Hawk Ridge-Lester River. Our season totals so far are 10 Pine Grosbeaks, 14,696 Purple Finches, 5 House Finches, 229 Red Crossbills, 33 White-winged Crossbills, 243 Common Redpolls, 40,471 Pine Siskins, 2,667 American Goldfinches, and 76 Evening Grosbeaks.

Large flock of 169 Pine Siskins migrating down the shore. The large tight flocks are so helter-skelter they resemble blowing leaves and are very difficult to count! They are like little demons, constantly shifting position in the flock, while the whole flock twists and turns and swirls
Another large flock of Pine Siskins, showing 172 individuals (out of much larger flock of 250+). I have often noticed that many of the large finch flights, especially siskins, occur on heavily overcast days when plumage details are difficult to see, so we often rely on flock size and shape and dynamics, and the flight of individual birds in each flock to identify them. One of the keys to identifying finches, which all undulate to some degree, is to note the quickness and spacing of each undulation. Siskins undulate very quickly, with very  brief pauses between each burst of wingbeats.
Close-up of migrating Pine Siskins, showing relatively dark streaked bodies and short notched tails. The similarly sized American Goldfinches (more uniform buff-yellow coloring) and Common Redpolls (colder gray-white coloring) both have longer tails

Common Raven migrating over Hawk Ridge- a total of 1376 have been counted so far this season, with more to come throughout November. It remains somewhat of a puzzle where all of these ravens are going.

Snow Bunting trying to hide among the dead leaves along a road-side as it feeds on weed seeds. The beautiful buff feather edging blends well with the leaves, which is perfect for fall, but note that this is one of those birds who achieve breeding plumage through feather wear, so as the winter progresses, the brown tips will wear off and the bird will become much more black and white. For whatever reason, relatively few Snow Buntings have been seen this season.
Karl Bardon
Count Director
Hawk Ridge Bird Observatory

No comments:

Post a Comment