HMANA Raptor Resources + FAQ

A hawk watch is a systematic and organized effort to collect standardized migration count data about diurnal raptors. Records include:

  • Species identities (including color morph, sex, and age classes when possible), numbers, quantities, and behaviors of seasonal migrant hawks.
  • Data on weather and observation conditions.
  • A measure of sampling effort that includes the number of observers and hours of observation.

Observations at a hawk watch are conducted regularly (daily or nearly daily) from a single monitoring site.

Observers count raptors at established hawk watches for recreational, educational, monitoring, and scientific purposes. The Hawk Migration Association of North America encourages new and existing hawk watches to educate people about the importance of raptors and collect scientifically valid data. These long-term data sets (e.g.,>10 years) can be analyzed to determine population trends and compared with data from other monitoring sites to monitor fluctuations in North American raptors’ overall and regional populations. There is much yet to learn about migrating raptors, especially in areas of the country where few sites are located, including the Adirondacks, southern states, Great Plains, Canada, and the West Coast.

Most hawk watches start in locations and seasons (e.g., Spring and Fall) where people already know raptors aggregate during migration, such as coastlines and mountain ridges. To find an excellent place to observe migrant raptors’ passage regularly, it may be necessary to try multiple sites throughout one or several field seasons. The best starting point is to visit several existing hawk watches and talk with the observers about their experiences and ideas. Most new hawk watches have learned the procedures and strategies of running a hawk watch through their association with an established hawk watch. A site that may have excellent coverage in one season may not serve well to cover the other field season, and most hawk watches only operate in one season of the year. The staff, board, and advisers of HMANA are willing to help with advice and information.

There are no formally stated or enforced rules, and there is no required certification or application procedure for starting an informal hawk watch, and most hawk watches operate independently. If you wish your observations to be practical as scientific data, you will need to adopt a formal standard protocol for the hawk watch. A sample protocol and data collection instructions are available from HMANA and in the above-cited book. The general protocol can be customized for use at a specific site. Generally, the value of your observations will be enhanced if observations are systematic. Repeating your counts at the exact location annually and ensuring consistency in your counting methodology is essential.

Most hawk counters are volunteers who live within 50 miles of the count site. Most counters are also members of other local birding organizations. 

You can send a note to the BIRDHAWK Listserve indicating your interest in contacting other hawk watchers in your area. Ideally, your hawk watch will have a small pool of qualified observers that can rotate in field data collecting duties.

Lots of people conduct their hawk watches informally for fun and the personal enjoyment of the birds. This simplifies the burden of recordkeeping, reporting, and ensuring systematic coverage of your watch. For your observations to be directly helpful as scientific data, they must be collected and reported in a standardized format, allowing them to be compared with other hawk watches.

HMANA scientists are only able to analyze individual site data collected following standardized methods. The more complete, consistent, accurate, and reliably reported your observations are, the more valuable they are as part of the ongoing Raptor Population Index project and other analyses for which the data are used.

Records should be submitted electronically to HawkCount for safe archiving and to make them available for population monitoring and other users. If a data contributor wishes to safely archive but not make data publicly available, such an option exists. Data archived in HawkCount is subject to data submission and use policies.

Your hourly observations, along with data about weather, time, other species present, and the number of observers, can be re-sent from HawkCount to local listserves, fellow observers, or other recipients. Anyone can register online to create a site profile and registration.

Once the data is submitted to the HawkCount database, it becomes part of the largest repository of raptor migration counts collected over North America. As stated above, you can choose to restrict access to your data or share it freely or on a limited basis with others. You retain at all times ownership of the data. Most sites, however, choose to distribute the data voluntarily.

HawkCount is connected to even larger observational record repositories such as Cornell University’s Avian Knowledge Network and the Global Biodiversity Information Facility. Researchers and decision-makers from all over the world can have access to it for various uses, primarily research and education. The primary benefit of the migration count data is a calculation of the population trends of hawks through the Raptor Population Index Project, which makes periodic analyses of the status of raptors across the continent.

The more frequently (days per week) and the more regularly (same hour period each day) you count, your data will be more valuable. If daily coverage cannot be ensured, you will want to cover at least 75% of the days of the migration period, during which 95% of your target species pass through your locality. Because of the differential timing of species migration, if you have multiple targets, the duration of your field season may well extend for more than 60-70 days per season. For data to be precious, you need to repeat the monitoring each year using the same protocol. Depending on the locality, most raptors migrate between the hours of 8 am and 4 pm in both migrations seasons, Spring and Fall.

The goal of consistent monitoring is not to count the highest possible number of migrants on the best migration days but rather to trust with following a standard methodology that minimizes variation due to location, the method for recording migrants, and other observer biases. For scientific purposes, counting on days with few migrant raptors is as crucial as counting on many raptors. It may be challenging to persuade volunteers to participate in counts in localities and dates when conditions for flight are adverse for good migration counts. Still, efforts must be made to ensure systematic coverage.

Locate your monitoring site in a place where you are safe, able to repeat your counts annually, get the best sample possible of the flight throughout the region and under different weather conditions, and have legally permitted access. You need to retain an unobstructed view of the flight path of raptors over the years.

Your site should offer some protection from bad weather, particularly lightning. Most areas overlook a natural feature such as a ridgeline, pass, shoreline, isthmus, or peninsula, which concentrate the stream of migrants. Test your possible location by spending a few hours observing during prime migration conditions in the early stages of establishing your hawk watch.

Utilize HMANA’s Jobs and Opportunities page on this website. Post a message seeking volunteers there and also on BIRDHAWK Listserv. Publicize your monitoring site and intentions among local media and the birding community. Retired and young people, people who work late shifts or few times a week, students, and the unemployed all make good prospects. You will need to observe and assess the reliability and quality of volunteers carefully.

Many hawk watches run on a team of finely trained volunteers with excellent skills. Still, there have also been instances where eager but untrained volunteers proved ineffective or unreliable observers. The best recruiting method is your site. Making your site a prominent, welcoming, friendly location should bring in a pool of regulars who may make a more serious commitment to the various tasks involved in the count. It is crucial to encourage an atmosphere of inquiry, learning, and sharing of identification tips at all times at a site where more senior hawk watchers can operate as mentors for new ones.

Successful, enduring sites place a high value on public education and outreach and foster an exchange of information about the activities and objectives of the site. Many sites keep a register or record of visitors who can be contacted as potential future participants, contributors, or site supporters. Beginners start their “ascent” ladder of qualifications, ending with them being promoted to the main counter. Refining the skill of hawk watchers may take a few field seasons of experience.

Workshops at the beginning of the field season with the official counting team to review data collection, identification, data recording instructions, work shifts and calendars, troubleshooting and anticipating problems, etc., help increase the quality of work. Another way to train observers is to send them to spend time at a well-established count with veteran observers. 

Observers must identify migrant raptors accurately at the species level. A conservative target goal is to identify 90% of the migrants positively. Some hawk watches also catalog the age and sex of birds and keep track of color morphs; However, these variables are not currently being used in the RPI analysis; they provide a great deal of additional information.

The monitoring site should always be staffed by at least one qualified observer possessing extensive experience and skill in identifying hawks in flight. Most places have two observers on duty at all times. The number of official observers covering the monitoring site is an essential element of consistency in operating a hawk watch.

Qualified observers have a demonstrated ability to identify all species of raptors passing the monitoring site. The observer should be familiar with the plumages, seasonal timing, and behavior of migrants and demonstrate an ability to record and report data accurately and maintain the quality of the data recorded on site. Fellow birders should respect them as an honest and reliable observer who makes few uncorrected mistakes in identification. They should have a natural or fully-corrected vision.

Qualified observers are primarily “qualified” by their ability to make careful and confident distinctions to the necessary level of detail required by the local count. In some cases, additional observers, apprentices, or other monitoring site participants may be delegated other tasks such as tabulating totals, recording environmental data, entering data in HawkCount, or serving a public greeting and education function at the website while in training as primary observers. Each site needs at least one person in charge as a director, chair, site leader, or president. This person may also be a qualified observer or official counter.

The official counter must fulfill the requirements of the monitoring site protocol. The protocol may specify the conditions under which the count is not conducted, such as bad weather, clearly unfavorable winds, or other conditions, or the presence of other qualified or substitute qualified observer counters at the site.

Official records of each day should record all factors potentially influencing the migration or the observability of the migration.

This should be specified in the local site protocol. Suppose the site is very close to an official meteorological recording station. In that case, these data may be used, but be aware that migration can be profoundly influenced by very localized conditions, so variables such as wind direction and velocity, and precipitation should be recorded site with accurate recording instruments.

Each site viewing location must be considered separately for the data to be used in the Raptor Population Index analysis. If more than one monitoring site is used at a hawk watch, all areas should ideally be staffed simultaneously to obtain complete daily and hourly records from all locations. For many types of analysis, the records of each site must be independent and ensure that migrants are not double-counted. Data from multiple locations should not be aggregated in a single report to be interpreted as coming from a single place but reported as separate monitoring sites.

Without instruments such as rangefinders, vertical beam radars, thermal imagers, or tools such as “ornithodoliths,” these records are subjective. The codes and categories recommended by HMANA only serve the purpose of defining coarse categories. Studies intended to determine the height of flight should use instrumental methods accurately.

The categories for flight height are not intended to replace formal studies using instruments. When counts are made from advantage points such as ridgetops, towers, and tall buildings, it is frequent to record migrants below the height of the observation point. The standard categories can be applied in such cases using a negative sign, e.g., -1, -2, etc.

Visibility is the furthest point that can be observed from the monitoring site. The distance to the point can be established through the use of topographic maps.

Evaluating an observer’s performance is a complex task. It involves the precision and skill to identify migrants, the accuracy and detail of the records taken, and the adequate reporting of the data. Sites should establish the parameters that define a reasonable observer and enforce the use of their data collection protocol at all times.

© Jerry Ligouri

Raptor Resources

Hawk Migration Studies – The Journal of the Hawk Migration Association of North America Hawk Migration Studies is published twice a year. This journal provides regional reports on the migration from across North America and articles on hawks, hawk identification, hawk watching, and more. Hawk Migration Studies is available digitally, for free on our website, with print subscriptions available.

HawkCount – A free guide to hawk-watching sites across North America and an extensive database on the timing, magnitude, and composition of spring and fall migration at each location. The website provides daily reports along with monthly and seasonal summaries for many hawk-watch sites across the continent.

HMANA Newsletter – A bi-monthly email newsletter for HMANA members on hawk migration, hawk watching, HMANA with brief stories on upcoming events and opportunities, and various short news items on hawks, hawk watch sites, and hawk watchers.

Hawkwatching in the Americas – Edited by Keith Bildstein and Daniel Klem Jr. (Kempton, PA: Hawk Migration Association of North America, 2001, 277 pp.). This book consists of 24 peer-reviewed papers presented at the 25th-anniversary meeting of the Hawk Migration Association North America (HMANA) in June 2000. Intended primarily for the experienced hawk watcher, it should be of interest to anyone with interest in bird migration per se, with essential papers on full-season hawk watches in coastal Texas, raptor migration through Mesoamerica (Veracruz), aging eagles at hawk watches, and using Doppler weather radar to study hawk migration.

The State of North America’s Birds of Prey – By the Raptor Population Index (2008) is the first continental report on the population status of North America’s migratory birds of prey. Written by 22 of the hemisphere’s best-known raptor migration specialists, the 426-page book includes a brief history of raptor conservation in North America, the principles and methods for the use of migration counts to determine population trends, regional overviews of trends in migration counts, a report on the conservation status of 20 species of birds of prey, and more. This book can be purchased online from Buteo Books.

Additional Recommended Books on Raptors

  • Bird! An Exploration of Hawkwatching. Brian M. Wargo. BMW Publications (2016). “Bird!” is an existential exploration of nature through the guise of hawk watching. In his first book about this esoteric subject, Brian M. Wargo, a physical and social science educator, taps into the universality of Homo sapiens’ longing to connect to the biotic world.
  • Birds of Prey: Hawks, Eagles, Falcons, and Vultures of North America. Pete Dunne with Kevin T. Karlson. Houghton Mifflin Harcourt (2017).
  • Birds of Prey of the East: A Field Guide. Brian K. Wheeler. Princeton University Press (2018). It uses hundreds of artist’s illustrations by Wheeler to illustrate plumage differences for all eastern raptors, including both genders and various ages, morphs, and types.
  • Birds of Prey of the West: A Field Guide. Brian K. Wheeler. Princeton University Press (2018).
  • The Crossley ID Guide: Raptors. Richard Crossley, Jerry Liguori, and Brian L. Sullivan. Princeton University Press (2013). In typical Crossley style has roughly 5-10 individual hawk photos (“cutouts”) of a species dropped into an appropriate background photo on each page, illustrating different ages, morphs, or genders in flight and perched. The images work well, and the text is well written.
  • A Field Guide to Hawks of North America (Peterson Field Guide Series), Second Edition. William S. Clark and Brian K. Wheeler. Houghton Mifflin Harcourt (2001). The only accurate “field” guide to North American hawks. The text by Bill Clark and Brian Wheeler is comprehensive, and the detailed illustrations by Brian Wheeler show how the hawks look when seen close up, perched, and in flight.
  • Hawks at a Distance: Identification of Migrant Raptors. Jerry Liguori. Princeton University Press (2011). A follow-on to the 2005 book, including hundreds of small images for identifying hawks when they are very far away.
  • Hawks from Every Angle: How to Identify Raptors in FlightJerry Liguori. Princeton University Press (2005). A superb guide with 339 color photos of hawks in flight. This book emphasizes critical characteristics for identification and discusses confusing species.
  • Hawks in Flight, Second Edition. David Sibley, Pete Dunne, and Clay Sutton. Houghton Mifflin Harcourt (2012). A classic. Pete Dunne’s exquisite prose evokes vivid images of the hawks as you usually see them in the field. Excellent line drawings by Sibley and black-and-white photographs by Sutton make this book very helpful. It covers many more species (23) seen in North America and provides more detailed discussions of subtle differences in shape and behavior.
  • Hawks on High: Everyday Miracles in a Hawk Ridge Season. Phil Fitzpatrick. Savage Press (2019). A collection of 70 poems was composed over two years—drawings by Penny Perry.
  • Hawks on the wing: A Video Guide to Identifying Eastern North American Raptors. Josh Haas. A video guide featuring Eastern raptors, teaching viewers flight ID through the use of video and audio commentary; including multiple species on screen side-by-side.
  • A Photographic Guide to North American Raptors. William S. Clark and Brian K. Wheeler. Princeton University Press (2003). This book contains several hundred relatively large full-color photographs of 43 species of North American hawks. Complementing Field Guide to Hawks of North America, it provides superb pictures of the various plumages of each species, including 46 images of Red-tailed Hawk alone!
  • Raptors of Eastern North America: The Wheeler Guides. Brian K. Wheeler. Princeton University Press (2007).


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