Hams and Monitoring Enthusiasts Needed
To Help Researchers

by Joe Moell KØOV

Volunteer ham radio operators and VHF monitoring enthusiasts are helping scientists track the movements of endangered critters. With your scanner or extended-range hand-held transceiver plus an outside antenna, you could join in and perhaps make valuable contributions. Read on for all the news of past and upcoming projects.

Biologists want to know about the effects of habitat, diet, dispersal, migration and predation on many species of concern. Radio tracking is an important tool for them. However, it's not easy for a few researchers to track the ones that move large distances, such as migratory birds. They sometimes use small aircraft to increase radio tracking range, but that's very expensive and requires consistent good weather. What they need is a large number of widely-spaced receiving stations, covering the entire possible migration area. That's not financially practical either, but there are many radio hobbyists scattered out there. Why not have them help?

In 1998 at the request of Helen Trefry, a Canadian biologist, Homing In readers in central and western states began carefully tuning their receivers each fall and spring, listening for weak dit-like signals from radio tags on Western Burrowing Owls. We have since provided volunteer support to Burrowing Owl researchers in the state of Washington and the provinces of Saskatchewan and Alberta, as you can read in the Owl Project History page of this site. These project have helped scientists learn the migratory habits of these threatened birds, which have been shown to travel almost 2200 miles to their winter homes in Mexico and southern states.

Since then, the informal Biotrackers group has participated in studies of Saw-whet Owls, Sandhill Cranes, American Woodcocks, Purple Martins, Mexican Long-nosed Bats and Indiana Bats. Year 2008 was the second year of the Loggerhead Shrike project. Read on to find out how you can help them by listening to VHF radio in your home and vehicles.

Loggerhead Shrikes -- Second year effort in fall 2008

Monitoring help has been requested for a continuing study of Eastern Loggerhead Shrikes. Here is a description of the project by Joe Crowley of the Department of Integrative Biology at University of Guelph, Ontario, Canada:

"The Loggerhead Shrike is a fascinating bird that, despite being a songbird, is also a bird of prey and often impales its prey on hawthorn spines, barbed wire fences, or other sharp objects. This bird, once common throughout Canadian grasslands, is now critically endangered and only a few dozen individuals remain in the wild. In 2001, Wildlife Preservation Canada began a captive breeding and release program in Ontario. Beginning in 2007, we have radio-tracked these shrikes to monitor their survival and dispersal patterns and to identify migration routes and wintering grounds. Although hundreds of birds have been successfully reared and released in Ontario, few have returned in consecutive years. Very little is known about these birds once they leave Ontario, and this research will allow us to better assess the success of the captive-breeding program and help to identify migration routes and wintering grounds."

Here is the request for fall 2008 monitoring, received from Tara Imlay, an intern with the program:

"Once again, Wildlife Preservation Canada, the University of Guelph and York University have teamed up to track Eastern Loggerhead shrikes on their migration from the summer grounds in Ontario to the unknown location of their overwintering grounds. The birds equipped with transmitters are from a captive breeding program currently underway to help bolster the endangered population.

Very little information is known about these endangered birds, in particular, we know very little about their movements and survival after leaving the summer grounds and we are uncertain of where they overwinter. These overwintering sites may have a profound impact on survival. These birds are often found in grasslands, pastures and hayfields and require barbed wire or hawthorn trees on which to impale their prey.

We would great appreciate any help in monitoring the frequencies of these birds as they migrate south. Our transmitter batteries are expected to last until the end of November. Thank-you for your time."

There is no assurance of the migration paths or stopover sites, but these birds are expected to head south from Ontario toward Florida.   However, they may overwinter somewhere north of Florida.  Therefore, Tennessee, North Carolina and bordering states to the south are particularly important target areas. These radio tag signals are very short "dits" that repeat at approximately one-second intervals. Read this article to get a better understanding of this type of signal and how to identify it.

If you hear a tag signal, make careful note of the date, time, exact frequency, your location (preferably with GPS coordinates), and any unusual signal characteristics. Make tape recordings and/or digital audio files if you can, for analysis and verification. Post your report via e-mail to the biotrackers mail list (see below) or send it to k0ov@homingin.com. If you spot a banded Loggerhead Shrike, please record and report the color and order of the bands on each leg.

The monitoring period for this study concluded at the end of November 2008. No further monitoring is requested at this time.

Read about the Loggerhead Shrike captive breeding program in this article from the Toronto Star.

More information on this and other projects will be posted on this Homing In site page as received. For e-mail notification of these updates, subscribe to the Biotrackers mailing list by sending e-mail to biotrackers-subscribe@yahoogroups.com. The subject line and text are ignored. To prevent spam, only subscribers may post and all new subscriptions must be approved by the List Moderator.

At other pages of this site, you will find ideas for suitable receivers and antennas, a sample tag signal file, plus other tips on hearing and verifying wildlife tags. There are also stories of previous volunteer wildlife monitoring/tracking efforts,

Text copyright © 2008 Joseph D. Moell. All rights reserved.

In the photo: Loggerhead Shrike by Alec Monro

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