Sunday, August 31, 2008. Crooke's Point- Migrating Species Study

It certainly looks like the Staten Island Dragonfly Atlas is growing a good volunteer base! Thanks to Catherine and Tom for their continued participation, and welcome to Anne! And thanks again to Paul for being such a great group-mentor!

Today's field study at Crooke's Point, Great Kills Park, focused on migrant species, and observing migration behavior. It is commonly known that certain species of dragonflies migrate in spring and fall, but this behavior is greatly understudied. To add data towards the natural history knowledge of dragonfly migration, a sub-project of S.I.D.A., the "Migration Project", will focus on collecting migration data from selected points around Staten Island.

4 members of the Section, including myself, met Mr. Lederer (Paul) at the Education Station where we obtained temporary passes allowing us to drive/park a Crooke's Point. After 15 minutes of chatting about future plans for S.I.D.A. and observations members of the group made this week, we headed out to Crooke's for some field work.

Left: Paul, Anne, Catherine and Tom examine a female Blue Dasher and use field guides to confirm ID, Aug. 31, 2008. Photo by Seth Wollney


The activity was bountiful! The winds weren't blowing in the best direction for migration, so the dragonflies were staging above the dunes, and some bushes. Almost immediately, Paul netted a damselfly in the dune grasses. Although S.I.D.A. is currently not atlasing damselflies, Mr. Lederer is keeping tract of what species are found on the island.

One thing can be said for the "migrant dragonflies", they certainly stay on the wing! With a little study the group was able to learn how to ID the common species. The most abundant species was black saddlebags (Tramea lacerata), with a few common green darner (Anax junius) and wandering glider (Pantala flavescens). A male and female twelve-spotted skimmer (Libellula pulchella), and a handful of blue dasher (Pachydiplax longipennis) were observed. Paul succeeded in netting a female Blue Dasher which the group was able to get study up-close. This is one of the only species whose females are commonly seen encountered in the field.

Above: Paul Lederer, Museum Researcher, showing the group a Blue Dasher, Aug. 31, 2008
Bottom Right: Anne and Catherin examine the dasher before she flies off, Aug. 31, 2008
Photos by Seth Wollney













Before the walk, Tom and I visited the "salt flats" where we observed our first Spot-winged glider (Pantala hymenaea). Paul tells us that about 10% of the Pantala (or gliders) you see on Staten Island are this species, but it's often difficult to seperate it from wandering glider. The only field mark to split the two species is a small spot at the base of the hind wing. Luckily, the individual we observed was perched in some phrags!


**Next Field Study and Walk**

Sunday, September 14, 2008

Get a lot of rest, this will be a long day! The current plan is to start at 8am at the Conference House for the Nature Section walk. Following this walk, S.I.D.A. will meet Mr. Lederer at Sharrot's Pond around 10:30 am. From there we may visit Blue Heron Park, or somewhere else on the south shore.


In other News:

-E-mail inquires can now be sent to statenislanddragonflyatlas@birdingonstatenisland.com
-An official home page for S.I.D.A. is currently in the works!

-Seth Wollney
Section of Natural History
Staten Island Museum