WPBO Owls Fall 2010

Monday, May 4, 2009

Short-eared Owl!

Short-eared Owl

We've been slacking a bit on the blog, but we've been very busy, I swear. May started off with a bang, and the first two nights of the month wiped us out. Already this month 51 Saw-whets, 24 Boreals, 28 Long-eareds, 6 Barreds, and 1 Great Horned have been banded. However, the highlight was a Short-eared Owl that was banded on the 1st. This is only the 2nd Short-eared ever to be banded by WPBO- what a beautiful bird. May 1st was actually the busiest night of the season so far, with 21 Saw-whets, 12 Boreals, 20 Long-eareds, and 3 Barreds being banded. Additionally, a Barred originally banded here by Keith and Wendy in the fall of 2007, and then recaptured last spring, was again recaptured on the 1st. It has gained weight both of the times it has been recaptured. We really thought this was going to be a poor spring for Long-eareds, but happily we were wrong. With 133 banded this is currently the 3rd best season here for these guys. Great Grays have been seen the last 3 days at the evening owl flights, including 3 on the night of the 1st. We get particularly excited when we recapture a Saw-whet we banded as a juvenile, and last week we had this spring's second recapture of one of the juveniles from the summer of 2007, very cool.

Great Horned Owl

Boreal Owl roosting

Tuesday, April 28, 2009

Viewing Snowy and Short-eared Owls at the Point

Nova showing Saw-whet & Boreal Owls to attendees

Our annual Spring Fling was held this past weekend, and the owls came through. Our nights were productive and many people had the opportunity to get close up looks at some of the 18 Saw-whets, 14 Boreals, and 5 Long-eareds banded this weekend. As we were giving the morning owl program on Saturday Andy radioed that a Snowy Owl was at the tip. It was amazing how quickly people forgot about the Saw-whet and Boreal we were showing them and raced out to see it, some people I'll tell ya. Actually we were right there with them. As we were watching the Snowy, a Short-eared Owl began flying around the tip and gave everyone nice looks as it came back up the beach. The Snowy spent the day out there, albeit mostly hiding behind a log, and at least 2 Short-eareds were regularly seen patrolling the Point for much of the morning.

We would like to give a big thanks to this year's Spring Fling attendees. Their generous pledges to this year's upcoming WPBO staff birdathon doubled last springs results. These pledges support the summer owl banding program we began in 2006. As long as we do our part on the birdathon, their pledges alone will fund 1/4 of this summer's research! We simply could not continue this project without the financial support of our members. We thank all of you who visited the banding, and/or attended our program on WPBO's owl research. Your enthusiasm and support are greatly appreciated.

Sarah & Great Gray Owl

Last year we had the pleasure of being visited by the wonderful young lady in the above photo. Sarah and her parents visited again a couple weeks ago, and we once again fell in love with her. She was hoping for a Boreal, but unfortunately had to settle for a Great Gray on the first night, poor thing. Obviously she was extremely happy about the Great Gray, and got her Boreal on the 2nd night. If ever we have met an owl researcher in the making, Sarah is it!

Thursday, April 23, 2009

Lots of Long-eareds

A very buffy female Long-eared Owl

We're busy getting geared up for the big Spring Fling weekend, but the Long-eareds don't care. The Saw-whets and Boreals have continued to trickle, but the Long-eareds were a big prescence last night and we banded 35. With a northwesterly wind blowing, 17 of these were caught throughout the night in one isolated net out on the bayside of the Point. Thirty five Long-eareds is a big number as far as banding is concerned, and they made for a busy night.

Despite it being a rough schedule for us, we are looking forward to the weekend. Spring Fling is our biggest annual event, and is a significant fundraiser for WPBO. We're hoping the Long-eareds continue and that this weekends attendees will be treated to some great evening flights, and some close up experiences with owls we capture for banding. We would like to send out an advanced thanks to those planning to attend this weekend. Your support is greatly appreciated! Check the website for program schedules and details if you are considering a last minute decision to join us.

Tuesday, April 21, 2009

With the exception of Long-eareds, things have slowed down a bit. During the last three nights we've banded 12 Saw-whets, 3 Boreals, and 43 Long-eareds. The Long-eareds put on a nice show last night. They were regularly being seen in the lighthouse beam, and we had one catch a songbird in flight right over us right as they were lit up by the beam. The weather has shut us down tonight, and it looks like it may do the same tomorrow night.

Andrew had a Snowy out at the waterbird count today, and it was joined by a second after we made it out there. They eventually drew the attention of a couple Ravens. The paler bird was more bothered, and allowed a Raven to flush it out over the Bay before it returned to the beach. The more marked, and larger bird was not in the mood to be mobbed. It faced off with the Raven, and was regularly hopping up to strike at it with it's talons. The Raven wisely thought better of the situation and after a few minutes left it alone.

Friday, April 17, 2009

More Big Owls

Great Horned Owl

Things were once again interesting at the Point last night. Along with 16 Saw-whets, 1 Boreal, and 4 Long-eareds, the 1st Great Horned and 3rd Great Gray of the season were banded. In addition to the 16 Saw-whets that were banded, 2 previously banded birds were also captured. The forecast for tonight looks promising, but if the forecast is correct things may slow down a bit the rest of the weekend.

Our New Summer Owl Study

During the summer of 2006 WPBO conducted an exploratory owl banding research project at the Point. Our project ran 3 weeks, and our efforts resulted in the capture of 208 owls; 206 Northern Saw-whet Owls (NSWO) and 2 Long-eared Owls. Of the 206 NSWO captured, 200 were juvenile birds. While the spring and fall migrations of NSWO have become increasingly well studied across the continent, these results represent the first documentation of a significant concentration of juvenile NSWO during the post-breeding period.

Thanks in large part to generous donations made by two individuals and pledges to the spring staff birdathon, we have been able to continue and expand this study during the summer of 2007. We began on July 1st, and as of August 10th we have banded 542 owls; 539 NSWO and 3 Long-eared Owls. As in 2006, the majority of the NSWO we have banded this summer have been juveniles.

In addition to the regular data we collect on all owls, we are visually accessing fat stores and muscle mass on all of the juveniles. Among North American owls only NSWO and Boreal Owls have a juvenile plumage that is significantly different from adult plumage. The juveniles begin actively molting out of their juvenile plumage and into adult plumage during our study period. Detailed descriptions of the molt progression on each juvenile have been collected.

Owl banding Spring 2007

Several changes were made to the spring owl banding protocol in 2007. These changes were made in an effort to increase our captures, thereby increasing our data base and our knowledge of the owl migration at Whitefish Point. Owl banding data collected by WPBO during previous springs clearly demonstrated that the Saw-whet migration at Whitefish Point was already at its peak during the 1st week of April. Therefore, the start date of the spring owl research was moved up from the previous start date of April 1st to March 15th. Audiolure was also introduced to the spring owl research for the first time. Audiolure is simply the practice of broadcasting a recording of an owl's call to lure them into the research area. This is a technique implemented at every other owl migration banding site that we know of, and has been used during the fall season at Whitefish Point since the fall study began in 1993. It has been documented that this practice increases Saw-whet captures 5-10 fold.
This spring the calls of Northern Saw-whet and Boreal Owls were broadcast. As the data from previous seasons suggested would be the case, Boreals were at the bottom of their irruptive cycle and none were captured. We fully expect that Boreal Owl captures during the next irruption will increase significantly due to the use of audiolure. As for Saw-whets, the changes proved a huge success after just one season. We banded nearly 280 Saw-whets during March alone; the previous high for an entire spring season was 122. Our total captures for all owl species in March was 318, these results are also higher than the total captures of any previous spring season. The chart below demonstrates the effectiveness of the changes implemented in the spring of 2007.

General Information

Whitefish Point Bird Observatory (WPBO) conducts long-term owl migration studies in both spring and fall. WPBO began its oversight of the spring owl research at Whitefish Point (WP) in 1988, and began the fall study in 1993. A summer study was developed during the summer of 2006 when a dispersal of juvenile Northern Saw-whet Owls was discovered within the study area. These WPBO research projects have resulted in the banding of over 7,000 owls of eight species; Great Horned, Northern Hawk, Barred, Great Gray, Long-eared, Short-eared, Boreal, and Northern Saw-whet. This reasearch has established WP as one of the most diverse owl migration sites on the continent.

* Study periods:
Spring: March 15-May 31
Summer: currently July 1-August 31
Fall: September 15- October 31

**During the study periods nets are opened nightly, weather permitting , 1/2 hour after sunset and closed 1/2 hour before sunrise. Nets are not opened during periods of rain or high winds.

FAQs

Why do we band owls?
The owl banding project is the most effective way we have to monitor the number of owls migrating through Whitefish Point. For example, without the owl banding project just 3 Saw-whet Owls would have be documented in the spring of 2007. Through the owl banding project, 750 Saw-whets were banded and 32 that were already banded were caught. Without specific efforts to document the owl migration at Whitefish Point it would go virtually undetected. For more information on bird banding visit the Bird Banding Lab's website, which can be linked out of the WPBO website.

How do we catch and handle the owls?
All of the owls in our studies are captured in mist nets that are made specifically for bird banding. The mist nets we use are 12 meters long andabout 10 feet high. Due to the size difference between species that we catch two different mesh sizes are used. The nets are placed in openings among the trees at Whitefish Point. To help attract the owls into the netlanes audiolure is used. Audiolure is simply the broadcast of an owls call.In spring and fall both Saw-whet and Boreal Owl calls are broadcast, only saw-whet calls are broadcast in the summer. We do not wear gloves while getting extracting owls from the nets or during the banding and measuring proccess. Like many other things, these procedures are more difficult when wearing gloves. Extractions in particular are already difficult and would be virtually impossible while wearing heavy gloves. Yes, we do occasionally get bit or have the birds get us with their talons, and yes it does hurt. To band and weigh the owls they are placed in cans. This is the common practice when banding birds of prey and actually serves to calm the birds down.

What data do we collect?
Each owl is fitted with an individually numbered U.S. Geological Survey band. These bands are issued to federally licensed bird banders by the Bird Banding Lab in Maryland. The main measurments we collect are weight, tail and wing chord length. If the bird has flight feather molt, the molt pattern is recorded. These measurements and the molt patterns help us determine the age and sex of many of the owls that are captured. The data, including the band number is then submitted to the Bird Banding Lab for inclusion in their database.