I am happy to let you know that Colorado now has 7 regular Winter Raptor Surveys under the auspices of the HMA - Hawk Migration Association, formerly HMANA - Hawk Migration Association of North America.
Like Hawkcount, also managed by HMA, the data from these surveys can be used by researchers, so this is good citizen science.
Liza and I moved from New York to Denver in summer 2022. In New York State between the two of us we had 4 different Winter Raptor Surveys which we conducted as per the protocol of HMA once a month in December, January, and February. We had started doing them when we first heard of them in 2016. Once in Colorado we started 3 Winter Raptor Surveys in 2022 –
1. South and East Boulder,
2. Valmont Rd to Rabbit Mountain,
3. Rocky Mountain Arsenal NWR and the area West of Denver International Airport going up to Barr Lake,
4. Bennett to Jackson Lake, added in 2023.
Prior to 2022 there was a short lived WRS by Jillian and Patrick Glover and Deb Callahan in the St Luis Valley with 3 surveys between December 2019 and December 2020, but none since.
There is also an infrequent survey along NE I-76 conducted by the former coordinator of the WRS who lives in Illinois and who does this survey with her son whenever she visits a son in Colorado Springs, so that there are single surveys in 2019, 2021, 2023,and 2025.
The past few 4 years I had posted occasional reports in COBirds of some of the highlights of our WRS, encouraging Colorado birders to start their own WRS, including a link to the WRS website
Winter Raptor Survey – Hawk Migration Association (
https://www.hawkmigration.org/winter-raptor-survey/) offering my help if needed.
Robert Beauchamp started his own survey starting in 2022 incorporating the Nunn Raptor Alley Route, and completed 9 surveys, the last of which was in February 2025, unfortunately none this winter season. I don’t know him, I hope he is in good health.
This winter season looking at the Winter Raptors Survey website I was delighted to find that 3 new HMA WRS have been started in Colorado this winter season.
* Jeffco Foothills WRS by Audrey Hicks, Sharon Tanaka, Karolyn Chan, and Amy Walsh who have completed 2 surveys in December and January.
* El Paso County East of Colorado Springs WRS by Chris Nigro and Jennifer McLain who have completed 3 surveys in December and January. We we had thought it could be a productive area, but it was a little too far for us to go to.
* Arapahoe East WRS by Jason Zolle, Zak Hepler and Ryan Gannon who have completed 2 surveys in December and January.
Congratulations to all these birder surveyors, and may they continue their surveys into the future.
If you go to the WRS website
https://wrs.hmana.org/public_html/index.php if you click on Main In the left sidebar you can see all the surveys done this season all over the country.
If you want to hone in on Colorado, and especially see prior years surveys, click on Survey Map in the left sidebar, zoom in on the map to Colorado and click on one of the teardrop markers. You can then click on Survey Date and GO under the WRS Survey Summary and find all previous surveys. Each survey at the bottom of the page has Survey Totals by Species. Those who already have a WRS have additional access to notes on individual raptors on each survey.
Any birder or raptor enthusiast can do a Winter Raptor Survey on their own. It is a volunteer program. If you like raptors and know of an area with raptors you can develop your own route and follow it exactly the same way each time, as long as it doesn’t overlap an established route. Just follow the guidelines on the website. If you want any questions answered you can email the WRS coordinator.
If anyone is interested in starting their own route and needs advice or help, please feel free to contact me.
If you’re interested in starting one and don’t know of an area where there are a lot of raptors, the best way to figure out where to create your route is what we did, which is to look at eBird data for the past1-5 years for the location you are interested in – look up sightings for FH,RL, PrF, and GE – which will give you where you could see numbers of individuals of interesting wintering raptor species.
The dirt roads North and South of I-70 from Limon eastward is a good area, so also the area of Loveland and Fort Collins.
You can get general and specific information about the WRS programat
https://www.hmana.org/winter-raptor-survey/
If you do start a survey, you will find that you will learn a lot about wintering raptors especially their ID, as we have improved our ID skills since 2022. We had to learn all about Ferruginous Hawk, Prairie Falcon, and all dark morph raptors which are not found in the east.
Ajit I Antony
Central Park, Denver, CO