 |
| Participating hawk watch sites in 2013 and 2014. |
In 2013, HMANA partnered with the
Migratory Dragonfly Partnership (MDP), a group dedicated to the long-term study
of dragonfly migration in North America, to formally incorporate daily
dragonfly observations and counts into the fall monitoring protocols of
participating hawk watch sites.
HMANA partnered with MDP again in 2014 to continue monitoring efforts and help increase our understanding of dragonfly migration. After just two years, some interesting trends are coming to light. Thank you to the Xerces Society for analyzing the data and summarizing the findings. You can read the full 2013 and 2014 reports online at http://www.hmana.org/migratory-dragonfly-partnership/.
By the end of the 2014 migration
season, over 1,300 individual species records had been collected from 40
hawk watch monitors at 19 participating observatories.
|
|
 |
Number of dragonflies counted flying past 19 hawk watch sites
in eastern North America in 2013 and 2014.
|
Fall migration in eastern North
America begins near the end of August and can continue into October, although
numbers are usually highest in September while migration on the west coast
begins about two weeks later. Within that span, some days see enormous spikes
in the number of passing dragonflies while others have no activity at all.
Migration intensity may vary from year to year; two pulses in 2014 occurred
early in September, but peak numbers were seen later in 2013.
In 2014, Lighthouse Point in CT
experienced the highest one-day migration pulse of almost 6,000 dragonflies on
7 September, and Hawk Ridge, MN and Illinois Beach, IL both witnessed
peak dragonfly numbers (>6000) on 2 September. The two Midwestern
strongholds of Hawk Ridge and Illinois Beach were also champions in
overall reporting, with 151 and 95 observations submitted, respectively.
Because dragonflies skirt coastlines, preferring not to fly out over open
water, raptor monitors at these Great Lakes sites are ideally placed to
witness large groups of migrants funneling past observation sites.
Attention Spring Sites!
Based on the success of this
partnership, HMANA is excited to continue participating in the MDP in 2015.We
are looking to broaden efforts at hawk watch sites, not only throughout
western reaches of North America,
but also gathering information about northward
spring migration for
dragonflies. How much you or your spring site would like to be involved is
completely up to you.
If you’re interested in
participating, please contact Julie Brown (brown@hmana.org) for more
details. For more information, monitoring guidelines and protocol,
please visit http://www.hmana.org/migratory-dragonfly-partnership/.
And thank
you to all participating hawk watch sites and individuals for making the
Migration Dragonfly Partnership such a success!
Ah, but at some hawk-count sites, it's simply impossible to count migratory dragonflies and do anything -- and I do mean "anything" -- else. In my two falls at Smith Point, TX, there were numerous times at which 6000 dragonflies were visible at once. Since I was being paid (if we can use that term loosely) to count migrant raptors, there was just no way, despite my interest, to count dragons.
ReplyDeleteTony: We understand and that is just the way it has to be. I think the Xerces people would still be interested in an estimate and the species, if identifiable, as they are just getting started with their own migration monitoring. We will help them as we can, but for HMANA, the raptors take precedence.
ReplyDelete