Field Reports

Follow the Raptor Migration

A birder peers through a spotting scope.

Hawk Watch Coordinator Phil Brown uses a spotting scope to get a better view of passing birds.

Biologists regularly record up to 15 different raptor species from platform at the Pack Monadnock Raptor Observatory. From mid-September through mid-October, significant daily and seasonal flights of Broad-winged Hawks, Sharp-shinned Hawks, Northern Goshawks, Peregrine Falcons, Ospreys, and Bald Eagles are possible. Mid-October through mid-November often brings Golden Eagles and Northern Goshawks.

During the migration season, detailed reports — including hourly raptor count and weather data, non-raptor observations, special notes, season totals, and next-day forecasts — are posted at the end of each day on hawkcount.org, an online database managed by the Hawk Migration Association of North America (HMANA). Historic migration data are also available via hawkcount.org, and you can find annual summaries of Pack Monadnock migration data from recent years here. Hawk Watch Coordinator Phil Brown also provides regular in-season updates below.

The Pack Monadnock Raptor Observatory is a project of the Harris Center for Conservation Education and New Hampshire Audubon, in partnership with the State of New Hampshire Department of Natural and Cultural Resources, Division of Parks and Recreation.

Updates from the 2021 Season

September 23, 2021

Peak Migration at Pack

A kettle of Broad-winged Hawks, as observed from Pack Monadnock Raptor Observatory on September 20, 2021. (photo © Meade Cadot)

A kettle of Broad-winged Hawks, as observed from Pack on September 20, 2021. (photo © Meade Cadot)

It’s late September, the peak of raptor migration! The Pack tally stands at 6,820 total raptor migrants, the majority of which have been Broad-winged Hawks. On the big day of September 14, our team tallied 1,706 total birds, the first of three 1000+ days during “Broad-winged Week.” While these numbers are impressive, it appears that most of the Northeast’s flight may have passed to our west this year (as evidenced by larger tallies on a line from Clarry Hill, Maine through central New Hampshire and Putney Mountain, Vermont), though there are surely still a few more Broadies in the pipeline. And speaking of Broad-wings, check out where the Harris Center’s three tagged birds – Thelma, Monadnock and Harris – are now!

Raptor Release

A rehabilitated Red-shouldered Hawk, taking flight after being released back to the wild at Pack Monadnock on September 19, 2021. (photo © Judd Nathan)

A rehabilitated Red-shouldered Hawk takes flight at Pack Monadnock on September 19, 2021. (photo © Judd Nathan)

We are delighted to see that many folks are more comfortable visiting the hawk watch this year, and it has been great to catch up with many of you. On September 19, we celebrated the start of International Hawk Migration Week with the return of Raptor Release Day! This year, a Broad-winged Hawk, Red-shouldered Hawk, and American Kestrel all got second chances at life after injuries or illnesses immobilized them. These birds were picked up by good Samaritans such as Nancy Delaney, who rescued the juvenile Broad-winged Hawk in Hollis, and which was rehabilitated by Maria Colby and her organization, Wings of the Dawn. The event was intentionally kept smaller than in the past for added COVID safety, but was still a huge success, especially for the raptors!

Kestrel and Osprey Numbers

Also on September 19, we witnessed the largest single-day flight (45) of American Kestrels in the history of the Observatory! Hawk watches are particularly concerned about these charismatic kestrels as their numbers have been declining in many parts of the country for decades, but there have been some recent signs of that their populations may be stabilizing.

A graph showing the American Kestrel tally for the 2021 season as of 9/23/21, as compared to the long-term average, as observed from Pack Monadnock Raptor Observatory. (graph © Levi Burford)

A graph showing the American Kestrel tally for the 2021 season thus far, as compared to the long-term average. Click image for a larger view. (graph © Levi Burford)

Osprey numbers have been a little closer to average at this point, which is encouraging to see. The mean average is heavily influenced by earlier years, when we were seeing stronger flights than in more recent seasons. By the end of September, we should know if Ospreys are staying on track for an average or above-average season, or if their own long-term decline continues.

A graph showing the Osprey tally for the 2021 season as of 9/23/21, as compared to the long-term average, as observed from Pack Monadnock Raptor Observatory. (graph © Levi Burford)

A graph showing the Osprey tally for the 2021 season thus far, as compared to the long-term average. Click image for larger view.
(graph © Levi Burford)

Monarch Butterfly Migration

Monarch Butterfly numbers, as many have noted, are up this year. The Pack total of 868 this fall already ranks as this the third-highest tally since we started counting in 2005. We expect daily counts to slow down, but they will continue in small numbers through mid-October.

Looking Ahead

An Osprey in flight. (photo © Judd Nathan)

Expect good numbers of Osprey (pictured), American Kestrel, Northern Harrier, and Sharp-shinned Hawk in the week to come.
(photo © Judd Nathan)

This weekend promises to be an excellent one for hawk watching with the passing of a cold front tonight into tomorrow. The long-range forecast looks equally favorable. Expect good tallies of American Kestrel, Osprey, Northern Harrier, and Sharp-shinned Hawk in the coming week, as late September is peak or near peak for this suite of species. One cannot rule out another big flight of Broad-wings, either! Raptor and overall bird diversity is also at its highest in late September , and it is not uncommon to record 40 bird species from the platform on a good day.

Human visitation to the Observatory has been moderate thus far, with 1,330 total visitors, including a few school groups – an element we missed altogether in 2020. We anticipate increased visitation in the coming weeks with additional school groups on some weekdays and leaf peepers on weekends as the colors start to turn. To guarantee your admission to the park on such busy days, please continue to use the Miller State Park advanced reservation system.

Thank You

A big thank you to sustaining business partner, The Jack Daniels Motor Inn of Peterborough, and to all our other first-time and sustaining donors! To become a supporter, please contact Phil Brown by email or select “Pack Monadnock Raptor Observatory” as the program for your online donation. Our gratitude to all!

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September 7, 2021

Back at Pack!

Visitors and biologists look for hawks from the Pack Monadnock Raptor Observatory platform on September 6, 2021. (photo © Phil Brown)

Visitors and Pack Monadnock Raptor Observatory staff look for hawks from the Observatory platform on September 6, 2021.
(photo © Phil Brown)

The Pack Monadnock Raptor Observatory is up and running for a 17th consecutive season! This long-term raptor migration monitoring project once again welcomes visitors, including school groups, to the summit of Pack Monadnock in Peterborough, where a staff biologist and team of volunteers will be documenting the raptor migration daily through mid-November. The site is open to the public during our usual early fall hours of 9 a.m. to 5 p.m. daily, although advance reservations with Miller State Park are now strongly recommended. Plan ahead to enjoy the spectacle. You can get more information about visiting the Hawk Watch here.

The Start of the Season

Two Common Nighthawks migrate past the Pack Monadnock Raptor Observatory on September 6, 2021. (photo © Andre Moraes / raven.digital)

Common Nighthawks migrate past the Pack Monadnock Raptor Observatory during the first week of September.
(photo © Andre Moraes / raven.digital)

The first week at the Observatory bore witness to over 200 migrating raptors and featured some of the finest weather in which to observe them. We tallied early-season migrants such as Osprey, Bald Eagle, Sharp-shinned Hawk, and Broad-winged Hawk, and also noted an early Northern Goshawk and a few early Peregrine Falcons – the latter of which delighted many spectators as it sparred with the local Ravens and a young Cooper’s Hawk.

In addition to raptors, our team monitors and records all species of birds and some migrating insects – including the many migrating warbler species, lingering Common Nighthawks, Chimney Swifts, and swallows of this past week, as well as migrating Ruby-throated Hummingbirds and Monarch Butterflies, which appear to be off to a strong start.

The Week Ahead

A graph depicting Monarch Butterfly numbers, as counted from the Pack Monadnock Raptor Observatory between 2007 and 2020. (graph by Levi Burford)

Click the image for a larger view.

The upcoming week looks generally favorable for migration to continue to build, as we approach the peak of Broad-winged Hawk migration over the next two weeks. In addition to hundreds (or more) of Broad-winged Hawks, we expect to see an increase in falcons including the American Kestrel, as well as Ospreys and Northern Harriers. We also expect a continued uptick in migrating warblers and overall bird diversity as we reach the peak of fall migration for many other bird species. Data analysis conducted by seasonal raptor biologist Levi Burford has shown that Monarch Butterflies reach two peaks (see graph) in early-mid September, too.

Broad-winged Hawk Tracking

A Broad-winged Hawk with a satellite transmitter "backpack" affixed to the middle of its back. (photo © Brett Amy Thelen)

“Monadnock” — a female Broad-winged Hawk tagged in Dublin, New Hampshire in June 2021 — shows off her new satelitte transmitter. (photo © Brett Amy Thelen)

This year, we’re also excited to share news of a new Broad-winged Hawk monitoring collaboration with Hawk Mountain in Pennsylvania. During the summer of 2021, Harris Center staff and volunteers located and monitored nine Broad-winged Hawk nests in the Monadnock Region (including four on lands conserved by the Harris Center), and Hawk Mountain biologists affixed GPS and cellular transmitters to three adult birds at these nest sites. Thanks to these technologies, we (and you!) can now track these hawks as they migrate to South America over the next several weeks. This exciting new project is a natural fit for the Harris Center, as we seek to expand our knowledge of raptors breeding in the Monadnock Region — and learn more about their incredible migration to, and wintering ecology in, the tropics of Central and South America. Raptors truly connect our world!

Thank You

The Pack Monadnock Raptor Observatory is supported by individuals, including many sustaining donors; local businesses, including Nature’s Green Grocer; and foundations, including the Gilbert Verney Foundation. To become a supporter, please contact Phil Brown by email or select “Pack Monadnock Raptor Observatory” as the program for your online donation. Our gratitude to all!

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Contact Us

For more information on the Pack Monadnock Raptor Observatory or to volunteer, please contact Hawk Watch Coordinator Phil Brown.