As the trapping season at Lucky Peak winds down for the year we can reflect on some of the trends we have seen. One thing that stands out is that 2011 has been a huge year for owls. IBO has trapped and banded almost 500 Northern Saw-Whet Owls (pictured below), and over 60 Flammulated Owls! For Saw-Whet’s, this marks the highest trap total since the inception of owl trapping in 1999 when over 800 Saw-Whet’s were banded. The number of Flammulated owls banded is also unusually high. Some of the reasons why owl numbers fluctuate so much between seasons is not well understood, but may be related to fluctuations in prey abundance (small mammals and insects).
It has also been a good year for raptor trapping, and as the total number of migrating birds decreases, trappers at IBO get excited about the possibility of trapping some “sexy” birds. Towards the end of the season, birds migrating from farther north tend to show up in small numbers, giving trappers the opportunity to trap and handle rarer birds such as Merlins, Northern Goshawks, and Peregrine Falcons. It has already been a good year for Merlins, and it continued over the weekend as IBO Research Director Dr. Jay Carlisle trapped his first adult male Merlin (pictured below).
Northern Goshawks are another raptor species we biologists get excited about. Goshawks are part of the Accipiter genus of raptors, and are closely related to Sharp-Shinned and Cooper’s Hawks. Goshawks are the largest member of this genus weighing upwards of 1,000-grams, almost twice as much as a Cooper’s Hawk. Goshawks breed in the conifer forests of Alaska, Canada, and the American Rocky Mountains preying on birds and mammals as large as rabbits. IBO traps around 25 individuals per year, and we were lucky enough to trap a juvenile male on Friday, October 21st. After banding the bird, IBO director Dr. Greg Kaltenecker let his daughter Ayla release the bird. I managed to snap this photo of the little 5 year old (almost 6 as she told me) releasing her first Goshawk!
Before heading up to Lucky Peak for my weekend fixin’ of field work, I managed to convince fellow graduate student Rob Miller to let me accompany him on a day of trapping at Boise Peak. Boise Peak is another trapping station run by IBO, and is located approximately 5 miles north of Lucky Peak along the Boise Ridge. Here the business is strictly about trapping raptors, as no songbird or owl work is done, and very few visitors make the drive up the rough, washed out road to the top of the mountain. Boise Peak generally traps fewer birds than Lucky Peak, but the diversity of birds trapped tends to be greater as a lot of Northern Goshawks and larger Falcons are trapped here. We managed to trap 13 birds on Wednesday, including a young Cooper’s Hawk who’s mouth was literally full. His crop was so full of food that it was overflowing out of his mouth, and he still wanted more as he tried to come and take our dove lure! Click on the picture below to get an even closer look. Would you still want to eat more food if you were this full? You might if you still had thousands of miles to travel to your wintering grounds…
Photo by Rob Miller
On Friday we made our way up to Lucky Peak where we were fortunate enough to be joined in the trapping blind by Merlin Systems founder Ed Levine and Peregrine Fund neotropical raptor biologist Marta Curti. They showed a group of students various telemetry and transmitter equipment used to mark birds in the field to determine their movements. They also showed us how to place these transmitters properly onto birds so as not to harm them. This was accentuated by the fact that 2 more merlins were caught on Friday and Saturday. Along with merlins trapped on Sunday and Monday, Lucky Peak went 4 consecutive days with a merlin trapped, which is outstanding! See part 4 of this blog series for more info on merlins. But just for fun, here is another picture of the merlin we trapped last week.
Photo by Rob Miller
Saturday night brought out more owl trapping, including more Flammulated Owls! Owl bander Jethro managed to catch 2 Flammulated and 2 Saw-Whet owls before having to close the mist-nets due to high winds. The picture below of one of these Flammulated Owls and might just be the cutest thing you ever saw, these guys are so tiny! How can something so cute be so understudied, with such little known about it’s basic biology? Makes you think.
The weekend of September 23, 2011 was the busiest of the year at Lucky Peak. It was so busy in fact that the number of visitors (75+) on Saturday actually outnumbered the songbird and raptor trap total (~55) for the day! It was a great day to be up on the mountain interacting with the public as several large groups were in attendance. IBO was hosting their first raptor workshop from Friday-Sunday, and around 15 individuals from all over the country were in attendance. The main goal of the workshop was to help these folks gain field experience in raptor identification skills. On Saturday they spent most of the day at hawkwatch looking for migrating raptors and learning how to ID them in flight. Birds were also brought up from the trapping station for a close up look at key identification features. Pictured below is fellow Boise State University Raptor Biology graduate student Patrick Kolar showing off a female Sharp-Shinned Hawk to the workshop.
The highlight of the weekend bird-wise came on Friday afternoon as we managed to trap a male Merlin. Merlin’s are similar in size to their falcon cousin the American Kestrel, but nest almost exclusively throughout Alaska and Canada. They can be distinguished from kestrels by their overall darker appearance (usually), lack of russet coloring on their back, and lack of strong facial markings. Merlin’s migrate to the continental US in the fall and winter where they are found in usually much smaller number than kestrels. Pictured on top is the male Merlin we trapped on Friday. For comparison I have also included a picture of a male American Kestrel I trapped in Boise last winter.
Photo by Rob Miller
Photo by Neil Paprocki