Saturday, September 5, 2015

Count summary August 15th to September 5th, 2015


Hawk Ridge Bird Observatory has begun another season of counting birds, both raptors and non-raptors. We have a great team this year including count director Karl Bardon, counter Alex Lamoreaux, and count intern Kaija Gahm. Official counting began on August 15th as always, although migrants had started moving into the area as early as July 3rd when the first Cape May Warbler was seen in flight moving down the shore. It has already been an incredible season very busy with birds, and I hope this pace continues for the rest of the fall. August was only average for raptors (968 counted), but both Merlins (30 counted) and Cooper's Hawks (22 counted) had their best August ever at Hawk Ridge.

The songbirds and other non-raptors seem to be on a record pace, with over 150,000 already counted! Most of this total occurred on September 1st, when an incredible flight of 91,667 non-raptors overwhelmed the counters. Most of this flight was neotropical migrants, including 28,054 Common Nighthawks, 45 Eastern Kingbirds, 233 Catharus thrushes, 21 Scarlet Tanagers, 198 Rose-breasted Grosbeaks, and 33,758 warblers (the largest flight of warblers ever recorded in Minnesota), but there were also shorter distance migrants moving as well, including 9 Red-headed Woodpeckers, 1085 Blue Jays, 12842 Cedar Waxwings, and 1563 Red-winged Blackbirds. It is interesting in that this flight occurred on a relatively hot and humid day with only light south winds and a relatively calm lake, conditions that have produced similar flights of neotropical migrants in the past. I certainly welcome any opinions on what triggers these massive flights of such widely diverse species. The flight on September 1st was clearly the largest flight of birds I have ever witnessed on the North Shore, and it is difficult to emphasize just how many birds were involved, or how difficult and overwhelming it was to try to quantify such a large and simultaneous flight of so many different species of birds. Try to imagine that for every minute during the first hour after sunrise, there were roughly 300 Common Nighthawks, 300 warblers of various species (but mostly unidentified of course), several flocks of Red-winged Blackbirds or Cedar Waxwings, flocks of Blue Jays, a handful of larger passerines such Eastern Kingbird, Rose-breasted Grosbeak, Swainson's Thrush, Scarlet Tanager, and Baltimore Oriole, a flock of American Goldfinches or Purple Finches, and of course several hundred unidentified small passerines. Then, imagine that this is only what was occurring along the shore within sight of one individual, while at the same time similar numbers of birds are also moving inland over Hawk Ridge a mile away, and large numbers of birds were also reported moving inland even further about three miles. Taken as a whole, the scope of this migration is almost unimaginable, certainly involving many hundreds of thousands of individuals in a single event.

Although I doubt that another flight of this magnitude will occur this season, it is exciting to realize that we are still only at the beginning of the season. The peak of non-raptor movement doesn't happen until late September and early October, so we may be in for quite a show as the migration progresses.

August is the time for Common Nighthawks, and this August was the best season we have ever had for them! On August 27th there were thousands of nighthawks feeding unusually low to the ground in Duluth, often swooping down below tree-line as in this photo- certainly an uncommon view of a nighthawk since they tend  to be seen overhead as they migrate down the shore. On August 29th a total of 13,723 were tallied, mostly in the evening, and since the birds were so low it seemed everyone in Duluth noticed them. They were literally everywhere! But as amazing as this evening was, an even larger flight of 28,084 Common Nighthawks was seen on September 1st, the third highest count ever recorded for MN. The most interesting aspect of this latter flight was that most of the migration occurred early in the morning beginning before sunrise, when a continuous stream of nighthawks raced between the counting locations. Over 51,000 nighthawks have been counted from the Ridge and during the evening counts at the Lester River apartment, the best season ever.
Another shot of a Common Nighthawk catching a bug over the Hawk Ridge counting platform. The erratic swooping and twisting of these bird's flight is because they are catching insects in the air, and with binoculars you can sometimes see them catch their prey. They can reportedly eat 300-500 or more mosquitoes in one evening!
A flock of Cedar Waxwings passing down the shore during a record flight of 12,842. This is just a few hundred more than the previous record count of 12,612 on 29 August 2010. We have now counted over 35,000 Cedar Waxwings passing by this season, most of which were during a sharp peak period 29 August-2 September.
Northern Waterthrush in flight during the mass migration on September 1st. As many as 18 Northern Waterthrushes were seen during this event, but identifying individual warblers was a real challenge when such overwhelming numbers of birds were in the air, and most were left unidentified. A total of 33,758 warblers were counted, the highest total ever recorded for MN in a single day, although this represents a combined count from two separate locations on the shore and on the ridge. This amazing count is encouraging since migrant warbler numbers along the North Shore appear to have declined significantly after non-raptor counts were done at the Lakewood Pumping station in the 1980s. The highest previous count  of warblers was 29,335 at Lakewood on 1 October 1988.

Rose-breasted Grosbeak in flight during the mass migration on September 1st. This sight was repeated 198 times on the 1st, a record high count for MN. Conditions were heavily overcast, challenging for photography and for subtle identifications, but luckily Rose-breasted Grosbeaks are flying field marks, with bold white outer wing patches, heavy bodies, stout beaks, long tails, and undulating flight. This bird is a second-year male. 

Juvenile Broad-winged Hawk attacking the owl decoy at Hawk Ridge. This spunky little guy dove at the owl at least eight times, often calling his plaintive whistle, trying his best to look, act and sound fierce.
Juvenile Red-tailed Hawk attacking the owl decoy at Hawk Ridge. Good numbers of young Red-tails have already been seen this season, so we are hoping it will be a great fall for Red-tails! (especially since all three counters, Alex Lamoreaux, Kaija Gahm, and Karl Bardon have a soft spot for these awesome birds).
submitted by
Karl Bardon
Count Director
Hawk Ridge Bird Observatory


2 comments:

  1. Thank you all for all the work you do up there. I love to see the updates especially the non raptors ( also the butterfly and dragonfly observations were neat) I'm on the north side of the twin cities so sometimes what you see filters down here. The day and two after your massive flight of nighthawks there were thousands everywhere down here. Again thanks for all you do I really appreciate it and I'm a fan!

    Chris

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  2. Awesome summary, Karl! Keep up the good work.

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