Where Do Raptors Go In Fall?

On this post I want to share some websites and reference materials, which will give some insight regarding the question: "Where do Raptors go when they migrate south in the fall?"
To Return to our page, you must hit the back button each time. Perhaps, read this through and then visit the sites listed over the course of a few days, because you can become lost in all the info there.

 Not sure yet how the back button thing will work on the phone apps???

Part one to answer the question, Where do Raptors go in Fall? is - they don't all go to the same place in the south.  Some do not even leave the US. Some Come from Canada and extremes in North Alaska, and some leave from just outside your own back door to join the southern movement to "wintering grounds." But these few Web pages and Blog articles give some insights, to how that is being determined and what is known from the data collected at sites like ours.

1. Our first site is a map from Hawk Mountain's website, which is one of the premier count sites of the North East. 
MIGRATION MAP
This map is on their Page called "RAPTORPEDIA," and is a visual of the paths generally taken by raptors in general. 
A paragraph on their page makes this statement:
"In some species of raptors, every individual migrates. In other species, only part of the population migrates and some individuals remain on the breeding grounds. Other species are completely sedentary. Overall, about 45 percent of all raptor populations migrate."

In the eastern flyways, the most famous of the migrants is the Broad-winged Hawk.  For watchers, it is the migration count time which draws the most visitors to our site, and many others, because of the  congregation of the birds as they migrate. They can be seen along the migration path, and particularly at the most southern sites when numbers from the north begin to collide into one funneled area on the Texas border ~ by the hundreds and, up to, by the tens of thousands.  I personally have seen this massing near the Corpus Christi watch on a day when counters recorded over 20,000 in less than an hour. 

The Hawk Mountain Map above, shows Raptor movement. We often discuss migration of birds moving along the 3 major pathways.  The Eastern Coastal Flyway, The Eastern Mountain Flyway, and the Central Flyway. The further west you go the more the kinds of hawks seen may change to  birds we never see east of the Mississippi River. So we often can only discuss Eastern birds.

Notably, this map never mentions the flyways, but rather, breaks their movements into a blood-vein looking pattern of "routes."  Each route is identified by a color, which further identifies it as a Major Route  - Reporting more than 1,000 birds annually, a Minor Route - reporting fewer than 1000 birds annually, or a Possible Route for Peregrines and Osprey, for which there is not enough data. There are also dark orange dots which identify watch sites which report more than 10,000 Raptors annually.  The map also shows the extremes to which some raptors fly in Central and Southern South America.  The concentration of raptors, where the land mass narrows between Veracruz and Costa Rica, can bring in counts of hundreds of thousands of raptors in a day, and the reason why becomes obvious, by seeing virtually all routes merge into this narrow area on the map.  Most raptors do not like to cross large bodies of water, which is also obvious, looking at this map. 

The map was illustrated by Joyce Pendola for Natural History Magazine, with the source given as
Hawks Aloft Worldwide.

Our site definitely fits on the map along the Major Route vein which crosses over us, as our numbers indicate. We have reported over 1,000 hawks a year for 25 years, except for 2 years - 2007 and 2008, (although 08 came extremely close with 913 raptors reported.)   Our 3 best records have recorded over 5200, 5500 and 8600 raptors in those 3 years.  Definitely qualifying our site as a Major Route watch site.

2. Our second site is Hawk Watch International's Page: RAPTOR MIGRATION,  which discusses what we do know and don't understand about migration. It's a sub-page of their Raptor Education page, and one of many on the site, linked to their home page.  In it's own words - "The Hawk Migration Association of North America (HMANA) lists over 1,000 hawk migration sites in North America, and there are websites for many of them where birders can view information on the count totals, weather conditions, site history, and directions to the site."  Social interaction, general education of migration's part in natural ecosystems, the ability to see hawks naturally and up close, and the counts themselves, which help identify the health of raptor populations - are their reasons for being.  They have a variety of opportunities, including studies, research and surveys in addition to it's work with the Hawk Watch counts.

This page itself doesn't tell us where the hawks go, but where to find the data about where the hawks go.  It's one of the major places where data can be found, as it is recorded.  For a number of the early years, Bill reported manually, by "slow mail" (LOL), our records to this site. Now, this year, we have an online report of the 2017 fall data. Jimmy has set it up and records the info primarily from Reports Bill has sent from the team's data. The site which allows you to find a watch and their data is: HawkCount.org.  Our page on this site is: Soddy Daisy Hawk Watch - Tennessee, from which you can access our monthly count data for the year.
HMANA concentrates it's research and resources in the Western US, and actually provides both training and jobs in the field.
3.An interesting article appears on the site: ECOBLOG, entitled The Fall Migration of Raptors.  In this article by Emily Brodsky, a nice discussion of hawks from the Vermont point of view, includes a small map of the flyways, breaking them down into the following: The Atlantic, The Central, The Mississippi, and the Pacific Flyways, also color coded. On this map it is very clear that hawk migration along the Atlantic Flyway, includes hawks which penetrate deep into the southern tip of South America. It doesn't indicate any specific birds. There is  however a lot of good information in this article, including a discussion of how raptors make use of updrafts and thermals, and how far Broad-wings for example fly to reach their southern realms.  She says: "In addition to being a popular place for recreational hawk-watching, Putney Mountain is also an official migration monitoring site.  Because raptor migration is predictable and easy to watch, people have been counting migrating raptors and recording their numbers since 1934, when the first official count site was established at Hawk Mountain Sanctuary in Pennsylvania."

4. An article by Bill Streeter, RAPTOR MIGRATION:AN AUTUMN SPECTACLE, appears on the  Delaware Valley Raptor Center Blog.  It's a great article which actually identifies Falcon Species they see, and breaks down which hawks they expect to see in which months. For them, it may not be uncommon to see 15 species of hawks in a day. He says: "On a good thermal day a hawk can glide 250 miles without having to flap its wings once." Bill also explains that hawks don't necessarily leave due to the cold, but rather due to a need to find the best food sources.  Warmer climes will have active prey, where prey are harder to find in cold weather.  This raptor center has a connection to rehabbers as do many sites.

 You may find  a link on our page to Happinest Rehab, which is dedicated to making sure as many birds are able to make the migration as possible. With help all along the flyways, hundreds to maybe thousands of hawks have a second chance at making that very long trek.

5. UNDERSTANDING HAWK MIGRATION is a page on Onondaga, Ontario's Audubon Society's web page, from Derby Hill Bird Observatory. This page is full of animated information of hawk migration along Lake Ontario.  There are actually maps of the movement of birds showing radar movements recorded to demonstrate the action of birds as they move.  A number of places obtain radar data, and all watch sites are keenly aware of the fact that weather is an extremely important part of Raptor movement. They state something we know to be very true: "Within a season, however, the migration of raptors is strongly dependent on weather conditions. One day can bring phenomenal numbers and the next day can be a disappointment."

 This page discusses the concept in depth and gives a unique perspective on what air currents are involved in the lift required to carry their raptors along. Once again we see raptors skirting the water's edge rather than crossing the main body of water.

Earlier maps helped us see that few raptors follow paths over large bodies of water. And the evidence is definitely visible on radar.  However, they discuss that the winds off the lake seem to push the birds onto shore on most days, and birds have been seen over water on less windy days.  It explains that higher flying birds are the ones that can be seen on radar.  We have often wished we had the benefit of radar on days when we believe the birds are at great heights and we can't see them to count them. Who knows, maybe we have 10,000 raptors every year pass over, but are too high to be seen?

There is also a sequence chart, which is similar to one on our site, which shows the patterns in time sequence, of which birds migrate when.  This map however is unlike ours, in that it is a Spring Migration Timeline! Interesting.  Also interesting, is the number of hawks coming out of Canada! And that is true at most of the northern sites!

I actually wasn't able in this, my first bit of research on the subject, to find specifically which Hawks end up where, except for the info on the first site which gives the info roughly.  I think it is because, there is still so much to learn.  I know there are telemetries on Swallow-tailed kites which are giving great information on their migrations. I love to follow their reports, and often share them on our Facebook page. But extensive telemetry research has not been done on all species of raptors, and information is spotty, or based upon visual reports.  And I  haven't come upon a site or page that has comprehensive info on all of the raptors. There are so many other sites to share, that I am sure there is another blog just waiting to be written on the resources alone.

 But to become more specific more quickly, my research will turn to finding each bird individually, and trying to find results on each one. I also haven't researched the possible hawk watch sites in South America, which may have a data site of their own. I realize many Birders will know that good field guides often include Range maps for N. American, and newest additions will have updated info, usually. But just as I finished this article, I found that Wikipedia offers this information on the first few birds I checked.  When I find more info and have time, of course I will be happy to share it here. In fact I am thinking of putting up a page once I have all the raptors we include in our count charts located.  Hopefully, I can gather that info in total. I already have found one excellent location giving historical information on the history of the knowledge of hawk migration, especially as it related to Panama.  If I just didn't have a greenhouse calling out to me on this the night when my plants can no longer wait...

In the mean time,  the southward drive is still on, and every chance some one can be at Soddy Mountain... we try to add our bit of info to the whole. And as all of you know by now, the only way to do it is to ~
KEEP LOOKING UP!!!!

Cynthia