Kirtland’s Warbler Migration Blitz

Kirtland’s Warbler Migration Blitz 2017

Fig. 1. Kirtland’s Warbler is a rare and endangered warbler that nests primarily in shorter Jack Pine forests of Michigan, Ontario, and Wisconsin and winters in beach scrub of the Bahamas. Its stopover habitat, however, is very poorly known.

Catching a glimpse of the endangered Kirtland’s Warbler is a lifelong dream for many birders. Relatively few have had the opportunity to see these large, charismatic warblers due to their extremely limited breeding range, unique habitat requirements, and small population size. But even fewer have been able to observe these birds outside of their Jack Pine breeding areas in Michigan, since they stop for short periods only as they migrate to and from their wintering grounds in the Bahamas. This year, we want to challenge you all to help us find migrating Kirtland’s Warblers, and help inform management efforts to bring back this endangered species. We will be reaching out to birders to try our Kirtland’s Warbler Migration Protocol to see if we can find Kirtland’s Warblers and get more information about their stopover behavior and habitat.

For 2017, we will be targeting these states:

  • Florida
  • Georgia
  • Ohio

If you’d like to participate, please send us an email <xxx link> and sign up as a surveyor on our Google Sheet.

Kirtland’s Warblers were on the brink of extinction throughout the 1970’s and 80’s, when numbers were estimated to be as low as 200 males. Range-wide fire suppression and high rates (~70%) of brood parasitism by Brown-headed Cowbirds led to loss of breeding habitat and poor reproductive success. State and federal agencies responded quickly by controlling cowbird populations and creating thousands of acres of new Jack Pine breeding habitat. This highly effective management has allowed the population to substantially recover, with over 2300 singing males counted in 2015!

Fig. 2. Identification of Kirtland’s Warbler is not something most birders are very comfortable with. Their yellow underparts with black streaks can resemble Magnolia or Prairie Warblers, but watch for the broken white eye ring, dark lores, large size, and persistent tail pumping of Kirtland’s. Prairie Warbler can do occasional tail wagging, but only Palm Warbler pumps their tail more than Kirtland’s.

Now, we need your help to find the critically important stopover areas.  Although the Kirtland’s Warbler populations are recovering, global climate change and human development are increasingly threatening the species during other times of the year, such as on their wintering grounds and during migration. Recent research suggests that about 40% of all Kirtland’s Warbler mortality occurs during either spring or fall migration, and this could hamper the success of management efforts on breeding areas. To lower mortality rates during migration, we need to first identify key resting and refueling stopover sites that Kirtland’s use during migration. This is where we need you!

Although sightings of Kirtland’s are rare during migration, scientists at the Smithsonian Migratory Bird Center recently tracked 27 male Kirtland’s Warblers using small light-level geolocators. Using the tracking data, they were able narrow down the time and location for three important stopovers in Florida, Georgia, and Ohio for the first time ever in this species.

Fig. 3. Kirtland’s Warblers seem to make two or three stopovers during April and May, focused on Florida, Georgia, and Ohio. This map shows actual stopover information from male Kirtland’s fitted with light-level geolocators. The blue, purple, and red areas seem to be areas that multiple birds stopped on their migration and will be the focal areas for this pilot study.

The Cornell Lab of Ornithology and the Smithsonian Migratory Bird Center are teaming up to launch the 2017 Kirtland’s Warbler Migration Blitz. By carrying out playback assisted surveys in key stopover regions in Florida, Georgia, and Ohio, you can help us pinpoint the locations of their stopover sites.  Data from the Blitz will be used to determine what types of habitats they use during migration, and help us identify potential threats to migrating individuals. Your participation is key to improve our understanding of Kirtland’s Warbler migration, and to help us ensure that this endangered species thrives for decades to come.

How to participate

We recommend getting a speaker for broadcasting the audio recording. We can recommend the JBL Clip (about $40-50) but there are a wealth of options that should work equally well. These speakers can sync to your phone over Bluetooth or can be plugged in with a cable.

Make sure to print out the protocol and the Kirtland’s Warbler questionnaire, in case you find a warbler.

  1. Download and print our protocol, including the Kirtland’s Warbler questionnaire
  2. Download the survey recording
  3. Sign up as a Kirtland’s Warbler surveyor here
  4. Prepare and plan. Charge your smartphone and speaker, bring a clipboard with the protocol, and plan your route.
  5. Conduct your survey. If the weather is too windy or it is raining hard, do your survey another day.
  6. Report your results to eBird

Good luck to all who participate! We hope you find one!

Fig. 4. An inquisitive male Kirtland’s in a Jack Pine. Do Kirtland’s use similar stunted pine habitat for stopover on migration? Or do they prefer quite different deciduous habitats? This survey will try to help answer those questions.