Calvert County (MD) Dragonflies and Damselflies: Part Four -Dragonfly Family Petaluridae

A series of journal notes going forward will be a closer look at the various families of dragonflies and the species within that can be found in Calvert County, Maryland.

Family: Petaluridae (Petaltail)
The following are notes from the book “Natural History of DelMarVa Dragonflies and Damselflies” by Hal White:
1) The Petaluridae family of dragonflies was the dominant group of dragonflies at the time of the dinosaurs.
2) Today, there is only one species, Gray Petaltail/Tachopteryx thoreyi, within this family in eastern North America.
3) The Gray Petaltail is one of only eleven species worldwide within this family.
4) It has only been observed on the DelMarVa peninsula once and that was over 70 years ago.

The Gray Petaltail is listed on the Maryland Department of Natural Resources (DNR) S3 watchlist. According to the DNR “List of Rare, Threatened, & Endangered Animals in Maryland, S3 has the following meaning:
S3 = Vulnerable / Watchlist — At moderate risk of extinction or extirpation due to a fairly restricted range, relatively few populations or occurrences, recent and widespread declines, threats, or other factors. Typically occurring in 21-80 populations.

Below is a comparison of two occurrence databases for the southern Maryland counties:
iNaturalist research grade observations:​ Calvert = 8​ St. Marys = 0​​ Charles = 1
MD Biodiversity (i.e., Richard Orr):​ Calvert – present St. Marys – present​ Charles - present

A closer examination of the Calvert County iNaturalist observations (as of January, 2020) reveals the following:
1) Six of the eight Calvert County observations were made in Calvert Cliffs State Park (CCSP) and 4 of those 6 were made on a single day (12 June 2016) within a three hour span.
2) The other two CCSP observations were made on 02 June 2018 and 23 June 2019.
3) The remaining two Calvert County observations were made on the same day (18 June 2019); the specific location within the county not listed.
4) The date of the Charles County observation was 11 June 2019.

Moral of the story: June appears to be the month to keep an eye out for the Gray Petaltail.

Anotado por rosalie-rick rosalie-rick, febrero 06, jueves 18:02

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