The Decade is Down for the Count

Perhaps the one of the most interesting things to observe as a counter is the seasons changing from the lookout. Thursday, August 15 was a different world full of green leaves and air thick with the haze of late summer. That day, we observed our first official migrant – an osprey travelling on south westerly winds. Since, we’ve counted a total of 12,984 migrants passing over the lookout. Though that 12k total sounds awe-inspiring, it’s actually 28% below our 10-year average. According to David Barber, our senior research biologist and raptor count specialist, this has been our lowest count in the past 10 years, a bleak harbinger for the closing of the decade. Of the 16 raptor species we observe, 13 of them were below their 10-year average. One explanation for the poor season could be the lack of strong, prolonged cold fronts, resulting in less than optimal migration conditions. In response, the birds could have migrated by an alternative route. Another possibility is that some of the late season migrants have yet to pass through the region, suggested by the strong final count day.

Other big watch sites in the east, such as Cape May, also have experienced a decline in migrants this year. Of course, conclusions can’t be drawn until our count has been added to the vast HMANA hawkcount.org database that includes small and large watch sites from all over the continent. Accurate speculation about population trends cannot be achieved without collaboration from local and national hawk watch sites. For example, easterly winds during the third week in September pushed migrating birds further west. As a result, some central Pennsylvania watch sites had outstanding broad-winged counts where ours faltered.

Although the Autumn 2019 count seems to be a foreboding end to the current decade, we are reminded of the immense value that long-term hawk watch sites hold for raptor monitoring and conservation. Without consistent, standardized collection of migration data we would have not been able to detect these declines in migrants. Not only can we compare this year’s data to the last ten years of count data, we also have access to more than 80 years of raptor migration data thanks to the first hawk watch site in North America – Hawk Mountain Sanctuary. Our Sanctuary now serves as a model for raptor migration sites all over the world. In fact, all hawk watch sites in North America can trace their roots back to training at Hawk Mountain. The founding of HMANA in 1974 was significantly influenced by the board members of the Sanctuary. To this day, Hawk Mountain continues to be highly involved with HMANA, and this remarkable partnership has resulted in the collaboration of over 300 North American hawk watch sites all contributing to long-term raptor migration data.