THE OREGON DRAGONFLY AND DAMSELFLY SURVEY
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PACIFIC NORTHWEST DRAGONFLY MIGRATION PROJECT
Images of Sympetrum corruptum, the Variegated Meadowhawk:
male, teneral male, immature female, scans by Dennis Paulson
September 1997 Directed Flights of Dragonflies, A Preliminary Report
Additional 1997 Dragonfly Migration Reports
Aeschna Migration Reported
1998 Dragonfly Migration Reports
1999 Dragonfly Migration Reports
2000 Dragonfly Migration Reports
Video taped observations of mass flights would be invaluable if they can be obtained !!
Last modified 09/08/2001 © Steve Valley, 2001 Visits since 9/23/98
OREGON DRAGONFLY MIGRATION CONTACTS
Please Send Us Your Observations:
Norm Anderson-- Email address: email@example.com
Range Bayer--Project Coordinator Email address: firstname.lastname@example.org
Eric Coombs-- Email address: email@example.com
Terry Morse-- Email address: firstname.lastname@example.org
Dave Pitkin-- Email address: Dave_Pitkin@mail.fws.gov
Steve Valley--Web Master Email address: email@example.com
A PRELIMINARY REPORT
The purpose of this preliminary report is to pull together some of the information
about the recent September 19-21 flights, and to try to put them into perspective with
flights earlier this year in late August and early September and with flights in other
years. However, additional reports from observers are still coming in, weather data have
not yet been compiled, and this preliminary report has been quickly written, so this
report is incomplete.
DO THESE DIRECTED FLIGHTS REPRESENT MIGRATION?
HOW FAR ARE DRAGONFLIES FLYING?
There is no information about how far individual dragonflies fly in these directed
flights; someone needs to research this.
DO EASTERLY WINDS AND WARM TEMPERATURES TRIGGER DIRECTED FLIGHTS?
Many of the flights prior to 1997 were associated with extraordinary warm temperatures
and strong winds from the east during late August and early September. Many of these
flights, including those during 19-21 September 1997, broke up when the wind changed and
began coming out of the north or northwest. However, during 1994-1996 there were days with
these weather conditions without dragonfly directed flights. Also, the Labor Day weekend
flights of 1997 occurred on days without winds from the east.
TIME FRAME OF FLIGHTS
Major directed flights have been noted late August and September, with few flights
after September 10 (Table 2); the range has been from August 29 (1997) through September
21 (1997)(Table 1),
NUMBER OF MAJOR FLIGHTS PER YEAR Major flights (which are defined in legend of Table 1) do not occur every year and prior to 1997, there was at most only one per year. However, in 1997, there have been seven days with major flights (Table 1).
Most flights have been confined to with a mile of the coastline (Table 1), however,
this year's September 20 flight included several independent reports of being up to 5
miles inland, which is very noteworthy.
ESTIMATING DRAGONFLY ABUNDANCE
During 1997, observers have often reported "many," "hundreds,"
"thousands", "scads," or "clouds" of dragonflies.
Unfortunately, these terms are often difficult to interpret because it is uncertain how
these estimates were made or the duration of the observations.
Many of the dragonflies flying during the 1997 flights were not flying strictly south
but were often flying towards the southeast or even east. However, many observers did not
have a compass, so they may not have accurately measured the flight direction. Further,
observers may just assumed that dragonflies were migrating and fall migration is
southward, so they may have assumed that the dragonflies were flying south. Consequently,
the southerly flight direction reported by some observers may have included some flying
towards the southeast, too.
DIRECTED FLIGHT OF OTHER INSECTS Dragonflies have been the focus of observers, but other insects have also sometimes participated in southerly directed flights and may be overlooked. For example on 4-5 September 1991, we observed a southerly flight of Painted Lady butterflies along with dragonflies, and the Painted Ladys made a big spring return flight in 1992 (which was widely publicized in Willamette Valley newspapers), so their flight appears to represent a true migration.
In 1997, a small southerly flight of butterflies was also recorded on September 19 and 20, many of which Terry Morse identified as Red Admirals, which are closely related to Painted Ladys.
We could have easily missed other southerly flights of butterflies or other insects.
. Listing of southerly or easterly flights of dragonflies reported only in Lincoln County. The most thorough observations commenced in 1984.
Table 1.. Listing of southerly or easterly flights of dragonflies reported only in
Lincoln County. The most thorough observations commenced in 1984.
Table 2. Semimonthly timing of Major, Minor, and Possible Minor southerly or easterly
dragonfly flights only in Lincoln County. These data are from Table 1.
19-21 SEPTEMBER 1997 OBSERVATIONS RECEIVED BY 22 SEPTEMBER 1997
More reports are coming in, weather data needs to be added, and distance inland has to
be calculated or estimated, so these observations have not been finalized.
9/19/1997 OBSERVATIONS ARRANGED APPROXIMATELY FROM NORTH TO SOUTH
(Lincoln City at Lighthouse Square just west of HWY 101 near Roads End: about -
mi from the ocean.)
(Newport: address, about - mi from the ocean.)
The following is Terry Morse's report:
"There is a southward flight of butterflies. Most appear to be Red Admirals (Vanessa atalanta) with a small number of unidentified Sulphur butterflies sp.).
"I was actually tipped off by Sympetrum corruptum. Sitting in Subway sandwich shop (2238 N. Coast Hwy [in the Safeway Plaza, which is adjacent to and east of HWY 101]), I noticed occasional dragonflies flying predominantly south between 1000 and 1130 PDT. When I left the store at 1145, I did a 2 minute count. In the first minute I recorded 5 dragonflies flying south; in the second minute, none. I also noticed occasional dark butterflies also flying south.
"As I continued to look, I noticed that there were many more butterflies than dragonflies flying south. It took me awhile to find a good location to do a count (problems with glare from parked automobiles in the Safeway parking lot). I finally wound up on the sidewalk just north of the Fred Meyer parking lot (south side of N. 20th St. [which is adjacent to and east of HWY 101]). Between 1221 and 1226 PDT I counted 23 Red Admirals, between 4 and 5 per minute. Most were flying between 1 and 5 meters up, going higher to clear the Safeway building.
"Walking south on NW Nye St. from 15th to 6th streets, between 1235 and 1245 PDT, I saw only 2 or 3 butterflies passing over, so the flight seems to be concentrated around the highway and east of the highway."
(Newport: Naterlin Community Center [169 SW Coast Highway] adjacent to HWY 101
in central Newport, about - mi from the ocean.)
(Newport: 717 SW 6th, about - mi from the ocean.)
(ocean beach between Thiel Creek and Henderson Creek: less than 0.1 mi from the ocean.)
During a daily walk along the ocean beach during part of 0700-0900 PDT, Sara & Don Brown did not see any dragonfly directed flights. [Range's comment: their walk may have been before it was warm enough for dragonflies to fly, or they may have missed such a low intensity flight.]
Dragonfly directed flight summary for 20 September 1997:
9/20/1997 OBSERVATIONS ARRANGED APPROXIMATELY FROM NORTH TO SOUTH
(South Jetty of Columbia River [Clatsop Co.]: less than 0.2 mi from the ocean.)
At about 1500-1630 PDT, Mary Anne Sohlstrom saw thousands of dragonflies flying south past the observation deck (see Evanich 1990:23 for map) out towards the ocean. It was very warm, probably about 75-80 F, and there was no wind.
(Bayocean Spit [Tillamook Co.]: less than 0.5 mi from the ocean.)
At about 1100-1200 PDT, Mary Anne Sohlstrom saw thousands of dragonflies moving south along Bayocean Spit. There was a huge flock of gulls over the beach that were "hawking" insects out of the air, and some of the dragonflies were flying high enough that the gulls may have been catching them, but there were also other large insects flying. Some of the dragonflies were much larger than the others, but most were small and pretty nondescript. It was very warm, probably about 75-80 F, and there was no wind.
(southeast of Neskowin [Tillamook Co.] at 8020 Slab Creek Road along the Neskowin Creek Valley: a minimum of 2.4 mi from the ocean [the distance is greater in a line due west].)
At 1330-1350 PDT, Shirley Schwartz saw hundreds of reddish dragonflies flying towards the southeast at her home. They were flying up to 20 ft high, and some were catching insects. There was a slight breeze from the south (?), and the temperature was warm, 75 F. There were also many other insects, including butterflies, flying around. This is the first time that she has seen a dragonfly flight at her home in the seven years that she has lived there, even though she is a good observer.
(Road's End beach north of Lincoln City: less than 0.2 mi from the ocean.)
During 0830-0930 PDT, Eileen Hoog saw many reddish-brown dragonflies flying south up to 15 ft high over the beach.
(Siletz River Valley about 5 mi east of Depoe Bay: about 5 mi from the ocean.)
At 1545 PDT, George Miller saw a narrow band (which he roughly estimated as about 200 ft wide) of small, brownish dragonflies flying in a southerly or southwesterly direction. He estimated that they were flying by at a rate of about 50 per second. None alighted. He had been out walking around and saw none, but then happened to walk into the narrow band and saw them fly by for at least 5-10 minutes. The wind was very still.
(Agate Beach [north Newport] at 54th Street about 1.5 block east of Highway 101: about - mi from the ocean.)
About 1000 PDT, Kathy Malarkey saw some dragonflies flying south, but as it warmed up, there seemed to be more dragonflies flying with some going eastward and some going southward. At about noon, it was very warm (73 F) with a light wind from the east.
(Agate Beach along the beach west of Agate Beach Golf Course: less than 0.2 mi from the ocean.)
At about noon, Jean Madras (sp. ?) saw many dragonflies flying in an unspecified direction.
(Agate Beach at Agate Beach Wayside: less than 0.2 mi from the ocean.)
At about 0930 PDT, Stan Ferguson estimated that about 100 dragonflies per minute across a 20 ft line were flying south. They were about 2 inches long. They seemed to be more numerous at the Parking Lot and less numerous on the beach near the Ocean. It was warm with a wind from the east of about 5 mph.
(Newport at 1107 North Coast Highway [HWY 101]: about - mi from the ocean.)
At 1030 PDT, Laimons Osis saw many dragonflies flying south.
(Newport at Nye Beach: about - mi from the ocean.)
In the late morning, Laimons Osis saw more dragonflies flying south than he did at 1107 North Coast Highway.
(Newport at Lumbermen's Parking lot at 615 North Coast HWY [HWY 101]: about - mi from the ocean.)
At 1122 PDT, Steve Kapillas saw "hundreds and hundreds" of small brownish dragonflies flying south.
(Newport at SW Abbey and SW 11th Streets about a block east of HWY 101: about - mi from the ocean.)
At about noon, Sue Martin saw many brownish dragonflies flying towards the east, but they were not as numerous as when she reported them earlier on ---.
(Coquille Point at east edge of Sallys Bend in Yaquina Bay: about 2.7 mi from the ocean.)
At about 1315 PDT, Bill Tice was travelling westward along North Yaquina Bay Road and started noticing dragonflies flying south at Coquille Point and that they became more numerous as he continued westward into Newport.
LESLIE: were the following dragonflies all flying south or southeast?
(LNG Tank at west edge of Sallys Bend, Yaquina Bay: about 1.9 mi from the ocean.)
Someone reported to Leslie O'Donnell that they saw many dragonflies during 1245-1445. At least some were blue.
(Newport at 717 SW 6th: about - mi from the ocean.)
With unaided eyes looking westward (during 0915-0927, 1107-1115, and 1425 and later PDT observations) or southward (during 1215-1251 PDT observations), I did the following 1-minute counts for an imaginary line of about 50 yards. Dragonflies were flying up to about 30 ft above the ground, but most were within 10 ft of substrate level. I did not see any birds that were trying to catch the low-flying dragonflies.
All the dragonflies seemed uniform in size, were dark or brownish depending upon how the light was shining on them, and looked as if they could have been S. corruptum, but none were conclusively identified.
No butterflies were seen during the 0915-0927 PDT observations; the few noticed seen later were mostly black above.
There were other insects flying up, too, because it was warm.
Codes: House=house west across street, Motel=Hallmark Motel about 1 block west of my apartment.
0915..........0.............0.............0.........House & Motel chimneys indicate wind from east; the sky is completely clear
0920..........0.............4.............0.............Dragonflies pass by in clumps
1107..........0.............10.............2..........Sky clear, wind stronger from east as indicated by House & Motel chimneys.
..............................................................Some dragonflies flying south, some SE, some east, and hard to separate and
..............................................................count ones flying in these slightly different directions, so I lumped them altogether.
1215..........0.............67.............0.............Sky clear; House & Motel chimneys indicate wind from east
At 1425 PDT, the wind had shifted to being from the N/NW, and I saw no dragonflies then, during 1440-1455, or during 1600-1615 PDT.
(Newport at 717 SW 6th Street walking west to ocean: about - mi from the
(Newport [various areas]: about - mi from
Terry Morse wrote:
"Left home [224 NW Brook St.] at 0840 hours. Weather was clear and warm, with a mild breeze of indeterminate direction. Walking through a vacant lot overgrown with weeds at 3rd Street and NW Hurbert St., I saw what I estimate was at least 100 S. corruptum (based on the density of the dragonflies I flushed as I walked through the lot and the overall size of the lot) resting on the ground and low vegetation.
"Walking north along Hurbert, then NW Nye St. to Fred Meyers (20th St. and N. Hwy 101) between 0840 and 0905, I saw 6 S. corruptum clearly flying south 3-5 meters above the ground, numerous others flying lower which may have been flying directionally or perhaps just shifting location due to being disturbed (i.e. it wasn't clear that they had joined the directional flight yet), and quite a few others still on the ground, apparently not yet warmed up enough or motivated enough to fly.
"At 0903 I saw an estimated 100 S. corruptum (probably 200-300) on the ground in a large vacant lot just south of Big Guys Dinner, 1801 N. Coast Hwy. They were easily disturbed, but apparently not yet warmed up enough to fly.
"I was indoors between 0915 and 1120, but could see occasional S. corruptum flying south through a north-facing window.
"Safeway parking lot, 2220 N. Coast Hwy. Did a 5 minute count between 1121 and 1126. Total 68 S. corruptum and 3 Vanessa atalanta (Red Admiral) flying south. Distance above ground estimated 1-15 meters, with most between 2 and 10 meters up.
"SE corner of Fred Meyers parking lot. Did a 6 minute count from 1142 to 1148. 75 S. corruptum and 3 Vanessa atalanta flying south. I was in the open enough to determine that the wind was clearly from the east, perpendicular to the direction of the flight. There were still quite a few dragonflies on the ground in the vacant lot south of Big Guys Diner, and a number flying low to the ground across Hwy 101 obliquely into the wind. It's possible that the low-flying dragonflies and those on the ground were resting. Even though the flight was perpendicular to the wind direction, many of the dragonflies I saw in the open were being buffeted by the wind and did not seem to be having an easy time of it.
"1302: I went back to the vacant lot south of Big Guys Diner to try and catch some dragonflies. This time I brought my wind gauge and compass with me. Wind was from the east, varying from 4-8 mph. Despite the thousands of dragonflies streaming by me, I could not find a good location to conceal myself and ambush them in passing which was not either dangerous or blatantly in violation of private property rights, so I wound up with only 5, 3 male and 2 female S. corruptum. One of the females was caught at 1532, after the flight had ended.
"The flight was clearly over by 1400. Temperature at 1415 was 76 degrees fahrenheit.
"Contrary to my observations yesterday, when I saw many butterflies and few dragonflies going south, today I saw mostly dragonflies and very few butterflies.
(ocean beach between Thiel Creek and Henderson Creek: less than 0.1 mi from the
Dragonfly directed flight summary for 21 September 1997: NORTHERNMOST EXTENT:
9/21/1997 OBSERVATIONS ARRANGED APPROXIMATELY FROM NORTH TO SOUTH
(Road's End beach north of Lincoln City: less than 0.2 mi from the ocean.)
During 0830-0930 PDT, Eileen Hoog saw many reddish-brown dragonflies flying south up to 15 ft high over the beach.
(Road's End at 7034 NE Neptune Drive: less than 1 mi from the ocean.)
At 1030 PDT, Eileen Hoog noticed that many reddish-brown dragonflies were flying towards the SE; there was no wind that she could detect.
(Newport at the Shilo Inn Coffee Shop [614 SW Elizabeth St.]: less than 0.2 mi from the ocean.)
At 1110 PDT, Jean Weakland saw many dragonflies flying towards the south or southeast.
Evanich, J. E., Jr. 1990. The birder's guide to Oregon.
Portland Audubon Society.
Subject: Sympetrum corruptum
Time: 1015 hours.
Location: vacant lot at intersection of SW 9th Streets and Highway 101, just north of Yaquina Bay Bridge.
Weather: Mostly cloudy (ca. 50% cloud cover); warm; calm.
Details: Walking south on SW 9th Street, I noticed ca. 15-20 _Sympetrum corruptum_ resting on the ground or perched on weeds on a ca. 10 m^2, weed-fringed concrete "pad" at the west edge of the vacant lot in question. I could see more in the larger gravel and dirt area of the lot east of the concrete pad. This is an unusually large aggregation of S. corruptum for Newport, except in the buildup period which seems to precede a directional flight. I also saw one _ S. corruptum_ flying by the life-flight helicopter pad roughly one block north of the vacant lot, and another flying about 1 block south of the lot.
In South Beach, I did not find any in the sandy vegetated area at the north end of the Oregon Coast Aquarium where I noted aggregations prior to last year's and this year's directional flights. I did see one flying outside lab 145 in the east wing of Hatfield Marine Science Center. The only significant number I observed were in the vacant lot at SW 9th and Hwy. 101.
Aside to Steve: Range received reports of a minor flight between about 0700 and 0930 on the next morning, 9 September 1997.
Subject: Re: Dragonfly mass movements
Have you been alerted to the mass flights at the coast this year? I have had 2 phone calls from observers in the Yachats area. I also talked with George Poinar who has a house at Waldport. He has excellent observations for a 4-day period, Aug 29-Sept1. It seems to have been a tremendous flight--like a Hitchcock movie; George said there were so many that he couldnt even get a count per second.
Subject: More S. corruptum than you can
swing a net at!
Left home at 0840 hours. Weather was clear and warm, with a mild breeze of indeterminate direction. Walking through a vacant lot overgrown with weeds at 3rd Street and NW Hurbert St., I saw what I estimate was at least 100 S. corruptum (based on the density of the dragonflies I flushed as I walked through the lot and the overall size of the lot) resting on the ground and low vegetation.
Walking north along Hurbert, then NW Nye St. to Fred Meyers (20th St. and N. Hwy 101) between 0840 and 0905, I saw 6 S. corruptum clearly flying south 3-5 meters above the ground, numerous others flying lower which may have been flying directionally or perhaps just shifting location due to being disturbed (i.e. it wasn't clear that they had joined the directional flight yet), and quite a few others still on the ground, apparently not yet warmed up enough or motivated enough to fly.
At 0903 I saw an estimated 100 S. corruptum (probably 200-300) on the ground in a large vacant lot just south of Big Guys Dinner, 1801 N. Coast Hwy. They were easily disturbed, but apparently not yet warmed up enough to fly.
I was indoors between 0915 and 1120, but could see occasional S. corruptum flying south through a north-facing window.
Safeway parking lot, 2220 N. Coast Hwy. Did a 5 minute count between 1121 and 1126. Total 68 S. corruptum and 3 Vanessa atalanta flying south. Distance above ground estimated 1-15 meters, with most between 2 and 10 meters up.
SE corner of Fred Meyers parking lot. Did a 6 minute count from 1142 to 1148. 75 S. corruptum and 3 Vanessa atalanta flying south. I was in the open enough to determine that the wind was clearly from the east, perpendicular to the direction of the flight. There were still quite a few dragonflies on the ground in the vacant lot south of Big Guys Diner, and a number flying low to the ground across Hwy 101 obliquely into the wind. It's possible that the low-flying dragonflies and those on the ground were resting. Even though the flight was perpendicular to the wind direction, many of the dragonflies I saw in the open were being buffeted by the wind and did not seem to be having an easy time of it.
1302: I went back to the vacant lot south of Big Guys Diner to try and catch some dragonflies. This time I brought my wind gauge and compass with me. Wind was from the east, varying from 4-8 mph. Despite the thousands of dragonflies streaming by me, I could not find a good location to conceal myself and ambush them in passing which was not either dangerous or blatantly in violation of private property rights, so I wound up with only 5, 3 males and 2 females. One of the females was caught at 1532, after the flight had ended.
The flight was clearly over by 1400. Temperature at 1415 was 76 degrees fahrenheit.
Contrary to my observations yesterday, when I saw many butterflies and few dragonflies going south, today I saw mostly dragonflies and very few butterflies.
Subject: Dragonflys in Waldport
My husband and I took a short trip to visit friends in Waldport on Sat night. We ended up staying near Yachats on the beach. Early this morning (Sunday Sept 21) we went beach combing and noticed thousands of Dragonflies! I even had one land on the front of my t-shirt and hang around with me for 30 mins. At first I thought that the dragonfly had landed and died....
This dragonfly had a reddish orange body and I noticed its wings were pretty tattered. I got home and decided to do some research on the net and found your web site.
I have some questions that I hope you can answer for me:
Do Dragonflies migrate?
(Nearly all of the ones we saw today looked like adults.)
Is there a specific time of year that Dragonflies swarm?
Perhaps the warm weather today had a key?
How can I identify the one that landed on my shirt?
Hope you can help with these questions or recommend some sites!
Meanwhile I will be stopping by the library....
The reason I'm writing is to ask about a fantastic dragonfly display I witnessed last Friday, Sept 19th. I was a the South Jetty at the mouth of the Columbia River in Oregon. Along the northside of the jetty were 1000's of dragonflies coming in from the ocean (I assume from Washington) traveling along the jetty eastward than southward on the beaches. They didn't fly very high, but sure were difficult to catch. I was finally successful at catching several and determined they were Sympetrum corruptum Variegated Meadowhawks. (Thanks to your key and photos). As far as I could see they were all or mostly dull in color, no bright red individuals as in your scanned image.
Is this species truly migrating? From where to where? Was this unusual? It was a constant stream for the 5 hours I was there, with at least 100 in my immediate vicinity at all times.
Subject: Re: Aehsna migration
I was mostly just north of Newport, @ Moolack Beach, Saturday the 20th, from ~9-12. It was warm and clear, with at most a light breeze until ~1030-1100, when the breeze became stronger. The migration was almost soley composed of *Aeschna* spp., although there were a few ?*Sympetrum* mixed in. Lacking a net, I wasn't able to get specimens. They were flying ~2-3 m off the ground, heading due south along the beach and just inland (very abundant along the west side of 101 in Newport proper). I made several counts of the individuals passing my point of view on the beach, averaging ~30-40 per minute. While at a restaurant in northern Newport, there were at least 10 in my field of view at any time. Could the buildings have been concentrating them? After noon, I travelled down to just south of Waldport. I noticed abundant *Aeschna* most of the way down, although I seemed to lose them along the beach south of Waldport - perhaps the lack of beach cliffs in that area led to them moving further inland?
That's about all I can think of to say. If you have questions or need clarification, just let me know.
Subject: S. corruptum influx and (very) minor flight (Long)
Date: Fri, 28 Aug 1998
Greetings all. 28 August 1998. Newport, Oregon. Weather clear, calm, and moderately warm (probably ca. 60 degrees F). Because I heard on the radio that the temperature in Newport was supposed to reach the high 60s or low 70s today (conditions associated in the past with mass flights or appearances of S. corruptum, I checked a number of brushy locations for the species on my normal rounds.
Between 0857 and 1917 hours, I made a quick reconnaissance of the hedges at the north end of a supermarket parking lot (JC Market at Highway 101 and Olive Street) and two overgrown vacant lots between NW 12th and 15th streets and Highway 101 in Newport. Between the three locations, I counted 8 S. corruptum. Since these were very brief forays (ca. 1-2 minutes through each field) just to see how many dragonflies I could flush, there were doubtless many more in both vacant lots, but not in the hedges in the JC Market parking lot.
At 0923 hours I noticed 2 S. corruptum flying roughly SE (I judged the direction of flight from the position of the sun, assuming it to be approximately eastward; didn't have my compass with me) across the Fred Meyer parking lot at NW 21st Street and Highway 101. At 0933, I saw 1 S. corruptum in apparently undirected flight around a parking lot just south of the Fred Meyer store. This individual first flew east, then north.
At 0937 hours I walked south along Highway 101 past the two vacant lots I had investigated earlier. Several S. corruptum flew up from the vegetation at the edge of one lot adjacent to the sidewalk. I did not have to walk through the lot to notice the dragonflies.
At 0945 hours, I stopped at a restaurant at the northwest corner of NW 12th Street and Highway 101 for breakfast. Through the window of the restaurant, facing east, I noticed occasional S. corruptum flying more or less south through the parking lot of a restaurant across the street on the east side of Highway 101. My naked eye attention was initially caught by the red flashing of their wings in the sunlight. Thereafter, I watched them with 8x binoculars through the restaurant window. I did not make any effort to measure the rate of passage of the dragonflies, since I could not see well enough to be sure I wasn't missing many. I did estimate that the rate was less than 1/minute, however.
I left the restaurant and returned to Fred Meyer's to buy a stopwatch. Walking south from Fred Meyer (NW 21st St. and Hwy. 101) to Olive Street and Hwy. 101 (ca. 20 blocks) between 1110 and 1145 hours, I was overtaken by or otherwise observed 5 S. corruptum flying more or less south (approximately parallel to Hwy. 101) on the east side of 101. I saw none flying in other directions. In a 5 minute timed observation at the McIvar's Landing parking lot (northeast corner of NE 12th St. and Hwy. 101) beginning at 1127 hours, I counted 2 S. corruptum flying more or less south, and none flying other directions. I counted dragonflies crossing a sight line ca. 70 meters long perpendicular to the direction of flight, facing east on the east side of Hwy. 101. These two dragonflies are included in the total of 5 I observed flying south between 1110 and 1145 hours. The temperature reading on the Bank of America thermometer at the southwest corner of Olive St. and Hwy. 101 read 61 degrees F at 1145 hours.
Continuing south on side streets parallel to Hwy. 101 (both east and west of the highway) from Olive Street (Hwy. 20) and SW Bayley St., 1 block north of Yaquina Bay Bridge, between 1200 and 1218 hours, I observed no S. corruptum flying. Visibility along my route was limited by buildings and trees, so I could easily have missed them. I did see 1 S. corruptum on the grass at SW 10th St., just north of Bayley St.
At 1239 hours, I left my home on SW 10th St. just north of Bayley and walked south across Yaquina Bay Bridge to Hatfield Marine Science Center. My purpose was to check the scrub at the northwest corner of the Oregon Coast Aquarium parking lot in South Beach, where I have often seen aggregations of S. corruptum during influxes and mass flights. I saw no S. corruptum flying, and only 1 S. corruptum perched on a plant stem at the north end of the OCA parking lot. The northwest corner of the lot has become a "dump station" for dogs belonging to visitors to the Aquarium. The vegetation appeared heavily trampled compared to the way I remember it being last year. Perhaps the area is less attractive to S. corruptum than it was in previous years. I did see 1 Aeshna [probably palmata -- thoracic stripes green; abdominal spots relatively large], hawking for insects above the scrub (generally within 1 meter of the ground) in the northwest corner of the parking lot, as well as several Woodland Skippers (Ochlodes sylvanoides).
Continuing east to the Hatfield Marine Science Center staff entrance on SW 25th Street, I flushed 1 S. corruptum from the ground, and may have seen one flying approximately southeast (not positive it was an S. corruptum). Sky still clear. Weather according to the NOAA weather display in the HMSC mailroom: air temp. 60 degrees F; wind WSW 7 mph, gusting to 10 mph.
Walking south along the HMSC nature trail between 1338 and 1409 hours, I flushed 3 S. corruptum from the trailside vegetation. One, which I got a prolonged look at, was a mature (red) male. I saw no S. corruptum in flight. I did see 1 unid. Aeshna flying, and a male Libellula forensis landed on a Himalayan Blackberry bush at the far south end of the trail.
Just west of the HMSC staff entrance, on SW 25th St., I saw one S. corruptum flying more or less south across SW 25th St., approximately 4 meters above the ground, just above the level of the surrounding vegetation. Returning home by the same route I took to HMSC, between 1414 and 1441 hours, I saw no S. corruptum.
Discussion: The weather report for the Oregon Coast this morning called for temperatures between 65 and 75 degrees. Though normally vigilant for signs of S. corruptum, I did make a special effort to check two vacant lots where I had previously noticed S. corruptum congregating prior to and during mass flights because the weather conditions favored an influx and/or flight of S. corruptum. Though I check these lots from time to time anyway, my special trip to them based on the weather report may have biased my observations. I can't be certain that S. corruptum wasn't present in these fields earlier in the week. I did check the parking lot at Oregon Coast Aquarium for S. corruptum at 1208 hours yesterday (27 August 98) and saw none. This would be more meaningful if I had seen many there today, but I didn't.
Modest Sympetrum corruptum flight, 27 August 1999
Terry Morse firstname.lastname@example.org 935 SW 10th Street #6 Newport, Oregon 97365 Phone: 541-265-8434
There was a modest directional flight of Sympetrum corruptum through Newport this morning. I first noticed
dragonflies heading south at 09:57, while looking out the window of a restaurant at 12th St. and N. Highway 101
in Newport. Looking out the window, I counted 9 dragonflies flying south in a 5 minute period (1.8 per minute).
Bearing of the flight was 165 degrees, essentially south. Most of the dragonflies seemed to be between 2 and 5
meters above the ground, though a few passed by at 10 meters above the ground. Sky was overcast. Wind
speed 2 meters above the ground in the restaurant parking lot was essentially zero. I didn't have a thermometer,
but the temperature was moderately cool, probably in the mid 50's Fahrenheit.
To get a more accurate flight rate, I did a 15 minute count between 10:19 and 10:34 in the restaurant parking
lot, facing east and counting dragonflies as they crossed my line of sight (length of line ca. 20 meters, the width
of the restaurant parking lot). Although I could see them approaching from the north, I didn't count dragonflies
which crossed the line behind me; only those I could see passing in front of me. This was, in part, because the
dragonflies' flight paths were erratic, frequently reversing direction and heading north for 5 to 10 meters before
turning back and flying south. I did my best not to double count dragonflies which crossed my line of sight flying
south, reversed direction and headed north, then flew back across the line going south.
This erratic flight was curious, since there was no wind to speak of which might buffet them. In previous years,
where we have observed fairly stiff head- or cross-winds buffeting the flyers, there might be brief reversals of
direction, but nothing like the meters-long reversals I saw today. Perhaps strong winds provide a cue or
incentive for the dragonflies to maintain directional flight that was lacking in the relatively windless conditions.
I counted 22 dragonflies in 15 minutes (1.47 dragonflies per minute) flying south, and 1 which flew north across
my line of sight. I didn't see the latter return south.
Because the flight was very uneven, I did another 15 minute count between 11:15 and 11:30, this time breaking
the count down by minute to estimate the variance of the flight rate. In 15 minutes, I again counted 22
dragonflies flying south (1.47 per minute), and 7 flying north. At least 4 of the 7 appeared to reverse direction
and continue flying south. After the 15 minute count, I watched 5 dragonflies which turned from flying south to
flying north. All five reversed direction and flew back south after flying 5 to 10 meters north. I think this was a
truly southward flight, despite the many dragonflies seen going north.
The minute by minute breakdown of the 15 minute count is as follows:
mean = 1.47 per minute +/- 1.36 (s.d.); n = 15 ; total = 22 dragonflies
At 11:31, I began walking north from 12th and N. Highway 101 to Yaquina Head, at the north end of Newport.
Between 11:31 and 12:28, when I arrived at the Yaquina Head interpretive center, I saw no dragonflies along
Highway 101. I doubt that the flight stopped so abruptly, so it may be that the dragonflies were joining 101 from
either east or west just north of 12th Street. I've noticed such localization in previous years, with numerous
dragonflies flying toward 101 from the west at around 12th St. (as observed on Nye Street, 1 block west of
101), but relatively few seen on Nye south of around 8th Street. Perhaps topography influences the flight.
I should add one observation. In previous years, there has been a sudden, noticeable
increase in the number of
Anax Junius, Common Green Darner
10,000+ seen in a loose feeding group ~1 mile long by (all we could see)
1/4 mile wide at 9:30 a.m. Most appeared to be
females (or young males?) moving down the S.E. side of Mt. Shasta at
~4,000 ft elevation, above and east of town of
the next day only ONE was seen in the exact same area at the same time
Maybe this was migratory?
308 Bloomfield Rd.
Sebastopol, CA 95472
Subject: Re: 9/8/99 Morning Flight of Dragonflies in Lincoln Co.
Carol DeLancey wrote:
At 7:45 a.m. on Wednesday, September 8, I observed a dragonfly directed flight through Yachats. My house is located one block north of the Yachats River and three blocks east of the actual ocean shore. It was a very warm morning, with an east wind. The dragonflies were traveling in a southerly direction; but they may have been funneled in that direction by the surrounding ridges. It wasn't until I did an Internet search at work that I realized I should have done a count. Having seen past migrations, I would categorize this one as fairly dense but possible localized. Once I drove north of Yachats, I saw no more dragonflies. Of course, this could simply mean that the insects were flying just east of Highway 101, which would make sense as my house is also located just east of the highway. I plan to tell my volunteers about it and raise some awareness locally. Perhaps that will spawn additional observations. If you have any further information not currently on your web site that I could share with my volunteers, please forward it to me at the address listed below.
There is magic in the air!
Carol L. DeLancey
Volunteer Services Oregon Coast Aquarium
(541) 867-3474 ext. 5316
Your report is very helpful because I have received several reports this morning of a flight before 9:30 AM at the HMSC. Ethan Clemmons pointed it out to Bob Olson, who estimated flight rates of about 20-50/minute flying towards the southeast. Bob said they were reddish and looked like the ones he has seen in directed flights in past years. At the time of the flight, the wind was mild and from the east. At 9:30 the flight stopped, and somewhere at about that time, the wind shifted to out of the south. I have also heard a report that there were about 200/minute flying south last night (9/7), but I am trying to follow up and verify that report. I am sending your report to Steve and Terry for their interest. Again, thanks for your report! It helps piece together what this phenomenon is and when it occurs!
PO Box 1467,
Newport, Oregon 97365 USA
On Wed, 8 Sep 1999, JANET LAMBERSON wrote:
Subject: Sympetrum corruptum
Subject: Re: Sympetrum corruptum flight,
8 September 1999
I'll add a little to Terry's post:
I arrived at the Newport airport at 0700 the morning of Sept. 8. A gentle breeze was blowing from the east/northeast; it seemed to be less than 5 mph most of the time. At approx. 0728, I was standing near our aircraft on the tarmac near the fixed base operations west of the runway, preparing to depart for a pelican survey. A Sympetrum corruptum flew past me approx. 2 m above ground level, heading south. A second Sympetrum corruptum followed on the same course and altitude less than 10 seconds later. I was facing west, toward the FBO buildings when I saw these first two dragonflies. I then spun around to face east, so I could look out across the wide expanse of taxiways and runway toward the dark woods approx. 400 meters to the east. The sun was just rising in the east, and provided excellent backlighting for the dragonflies, which showed up very well against the dark trees. It appeared that dragonflies were flying up from the grasses in the wide mowed corridors on either side of the runway, and immediately flying south. Most of the dragonflies appeared to be less than 5 meters above the ground as they were flying. I believe the mowed grassy corridors are >100 meters wide, and extend the length of the runway (5400'). I couldn't see whether dragonflies were rising along the entire runway length, but they were rising along the entire length I could see, which I'd estimate at about 1500'. Unfortunately, we had to load up and leave at that point, so I could not calculate a good flight rate. As we taxied out onto the runway at about 0740, the number of dragonflies emerging from the grass had increased dramatically -- thousands of dragonflies were flying south over the grass bordering the runway, all brightly backlit by the rising sun. Based on the large 6000/minute directional flight I witnessed on Cascade Head on 8/31/97, it appeared that the flight rate was at least 1000/minute over the grass along the east side of the runway. I didn't see many dragonflies over the runway as we rolled north on takeoff; they seemed to be staying over the grasses. We flew south along the coast to Cape Arago at 1500', then descended to 150' and flew north to Newport at that altitude along the surf line, surveying for brown pelicans. We did not encounter any dragonflies on either leg of our flight.
Subject: Re: Coastal Dragonfly Flight
Subject: RE: Sympetrum corruptum
directional flights on the Oregon coast, USA
I was on a butterfly field trip on August 29 to a locality high in the mountains, Corral Pass, just NE of Mt Rainier, but west of the Cascades divide. We saw a fair migration of Sympetrum corruptum occurring there, with individuals passing at the rate of about 1 per minute, all headed south.
So much we don't know!
There was a very strong movement of dragonflies this afternoon at Ft Stevens. Wind was NNE at 14.5km according to the weather service. The direction of movement was to the south approximately perpenducular to the direction of the wind. I was at parking lot C from 1400hr to 1510hr and did 1 minute counts at parking lot A from 1520hr to 1540hr. Those individuals that I saw well (including two good studies on perched individuals through a spotting scope) appeared to be Variegated Meadowhawks (Sympetrum corruptum). Average count per minute was 47.6 with a range of 7 to 84 per minute (median was also 47) in twelve counts. There were also quite a few darners in the area. Those that allowed close study appeared to be Paddle-tailed Darners (Aeshna palmata). These showed NO directional preferences.
Subject: Dragonfly movement at SJCR
Thanks for your posting about the flight today--great information! In Newport, I was out and about at 1:45-2:30 PM this (9/11) afternoon and did not see any dragonfly activity. There was a strong wind from a northerly direction, but it was not a cold wind. These flights can be local, so records of these flights and locations without flights at the same time are informative.
Subject: Dragonfly Flight in Progress
At this moment (9:45 AM on Sept. 12), there is a directed dragonfly flight near the Lincoln County Coast. "Hundreds" per minute have been estimated flying south in Yachats along HWY 101 by Jim Bowers, about 30-50/minute in south Newport near HWY 101 by Terry Morse, and up to 25/minute near the beach in southwest Newport by myself. Based on compass readings, most of the Newport dragonflies appear to be heading towards the southeast, with some flying eastward. At 8:30, temperature was 70 F with 20 mph winds from the east; these are the weather conditions that are correlated with big flights during September and early October. Based on past experience, this flight will end when the wind stops being from the east.
Subject: Sympetrum corruptum
flight at Newport, 12 Sep 1999
11 September 1999. While walking to work from the vicinity of Yaquina Bay Bridge in Newport to Yaquina Head Outstanding Natural Area (YHONA) at the north end of Newport, I encountered a modest number of Sympetrum corruptum on the ground or perched in low vegetation. "A modest number," while qualitative, is considerably more than I normally see while walking around Newport, that being none. A sudden increase in the number of S. corruptum on the ground seems to precede a mass flight by one to several days. At 1021 hours, I saw one S. corruptum on a bush in the JC Market parking lot, 107 N. Highway 101. The sky was clear, temperature 60 degrees F, the wind calm. I also saw one S. corruptum flying approximately east or northeast across Hwy. 101 at about 6th Street. I saw none at the vacant lot south of Big Guy's Diner, 1801 N. Hwy. 101, which is where I usually see the largest number. At 1043 hours, I saw a moderate number of S. corruptum on the lawn between Hwy. 101 and the Wal-Mart parking lot at 25th St. and N. Hwy 101. I saw no indication of a flight in progress. In an unrelated but interesting note, there was a large emergence of winged termites at YHONA in the early evening (between at least 1930 and 2030 hours, probably longer). 12 September 1999. At 0830 hours, I woke up and saw large numbers of S. corruptum streaming past the window of my apartment. Clearly, a significant flight was in progress. After calling Range Bayer, I went outside to try and estimate the flight rate. At around 0840, I counted 112 S. corruptum flying south across an observation line perpendicular to the direction of flight in a period of 3 minutes (37.3 per minute). My location was the corner of Bay St. and SW 10th St., 2 blocks north of Yaquina Bay Bridge and 2 blocks east of Hwy. 101. Length of the line was approximately 40 meters, and I was facing east. I observed dragonflies flying from approx. 3 inches above the ground to as much as 10 meters or more up, though most I could see were within ca. 5 meters of the ground. At 0903, I counted 137 S. corruptum in 5 minutes (27.4 per minute) flying south across a different observation line, about half a block south of Bay St. on SW 10th St. The bearing of the flight was ca. 162 degrees (relative to true north), slightly east of south. This is a rough approximation, since my view of the final vanishing point of the dragonflies was blocked by buildings, and the flight path was somewhat erratic as the dragonflies maneuvered around obstacles and over the buildings. Length of line was again approximately 40 meters, also facing east. Height above the ground still ca. 3 inches to 10+ meters. I also saw one larger dragonfly, possibly an Aeshna sp., during the count. Since it was backlit, I can't be sure it was an Aeshna. 1004 hours. Walking to work along Hwy 101. Temperature according to the Bank of America thermometer at the intersection of Hwys. 101 and 20 was 73 degrees F. The wind was from the east (bearing approximately 115 degrees, somewhat shifting), gusting to about 9 mph as measured with a handheld Dwyer wind meter. The flight bearing was approximately 173 degrees (again, relative to true north). Here, in the JC Market parking lot (107 N. Hwy 101), I had an unobstructed view south and could get a more accurate vanishing point direction than in my earlier observation. I didn't have time to take a count, but S. corruptum were flying steadily past me. 1040 hours, vacant lot south of Big Guy's Diner, 1801 N. Hwy 101. S. corruptum flying, but I didn't see any perched or on the ground. Only Woodland Skippers (Ochlodes sylvanoides). 1110 hours. Lighthouse Rd. and Hwy 101 in north Newport. S. corruptum still flying steadily south. Between N. 25th St. and Lighthouse drive, I saw dragonflies flying east across the highway wherever there was a break in the woods on the west side of Hwy. 101(i.e., wherever a road intersected the highway, creating a break in the trees), but almost none flying above the level of the tall trees lining the road between breaks. Turning west onto Lighthouse Rd., I entered Yaquina Head ONA. At 1119 hours, I saw substantial numbers of S. corruptum flying east (bearing 110 degrees) into the wind along the south side of the headland, where the road down to Quarry Cove intersects Lighthouse Drive (this is perhaps 1/4 mile out from Hwy 101, still near the base of the headland). Many S. corruptum were "stacked up" in the lee of a ca. 10 meter tall spruce at the intersection of Quarry Cove road and Lighthouse Drive (SE corner), before continuing east into the wind. Dragonflies were sparse along Lighthouse Drive west of Quarry Cove road, though I did see 1 flying approximately south at the entrance to the Interpretive Center parking lot, more than halfway to the tip of the headland. 1215 hours. Now by Yaquina Head Lighthouse at the tip of the headland, I saw large numbers of S. corruptum flying east past the lighthouse. I counted 40 in 5 minutes (8 per minute) along a 15 meter observation line, between ground level and ca. 3 meters above ground, facing south on the south side of the lighthouse. It was difficult to see the lower-flying dragonflies against the background vegetation, so this is doubtless an undercount. I also saw 3 orange dragonflies, probably Red Admirals (Vanessa atalanta) or ladies (V. cardui or V. anabella) flying east among the dragonflies. (During the course of the afternoon, I got a close enough look at some of the butterflies to determine that both Red Admirals and ladies of either or both species were included in the flight. I'm also reasonably certain I saw at least one fritillary or crescentspot flying east during the afternoon). Cabbage White (Artogeia rapae) and unidentified sulphur butterflies (Coliadinae) were nectaring on plants near the lighthouse, but did not appear to be participating in the flight. S. corruptum were also flying on the north side of the headland past the lighthouse. At 1253 hours, I did a 1 minute count (the most I could manage before someone would interrupt and ask what I was counting) of dragonflies passing north of the lighthouse, looking over the edge of the cliff toward the ocean along a 5 meter line (the cliff is somewhat sloping here, not precipitous), to a height of ca. 3 meters above the level of the slope. Counted 31 S. corruptum (31 per minute) and no butterflies. At 1355 hours, I did a 5 minute count of S. corruptum flying east on the north side of the tip of the headland at the same location, the observation deck west of the lighthouse. Counted 216 S. corruptum (43.2 per minute) and 4-5 orange butterflies (none very dark, so probably ladies rather than Red Admirals). The wind is still from the east (heading 110 degrees), 5 mph gusting to 10-11 mph, the dragonflies flying more or less into the wind. Details of the observation line are the same as for the 1253 count. At 1413, I did a 5 minute count at the northeast end of the lighthouse parking lot, on the north side of the BLM field office, facing north. Counted 51 S. corruptum (10.2 per minute) and 1 lady. My observation line (actually a plane) was approximately 15 meters long, extending to approximately 3 meters above the ground. Shade temperature beside the field office was 88 degrees F, extremely high for Newport. At 1428, standing on the observation deck west of the lighthouse, I looked west out to sea with 7x, 25 binoculars and saw large numbers of S. corruptum over the ocean. Clearly, the dragonflies were flying from above the ocean east towards the mainland past the lighthouse, as logic suggested. Elevation at the base of the lighthouse is ca. 86 feet above mean sea level, and I was looking straight out to sea from that elevation. At 1434, I found a red (fully mature) male S. corruptum atop the vegetated island in the middle of the lighthouse parking lot, perched on the tip of a seaside plantain (Plantago maritima) in obelisk position, facing away from the sun, the tip of its abdomen pointed approximately toward the sun. At 1548 hours, S. corruptum were still flying past the entrance to the Interpretive Center parking lot, but the flight seemed to have tapered off (but not stopped) by the lighthouse. I did see 2 Red Admirals flying east over the lighthouse parking lot, but few dragonflies. Looking out over the ocean with binoculars, I failed to observe any dense aggregations of dragonflies. At 1615 hours, there were still goodly numbers of S. corruptum flying east on the south side of the headland at Quarry Cove, less than halfway to the tip of the headland. The wind was very calm here due to the sheltered location. At 1630 hours, there was still a sparse flight occurring by the lighthouse. At 1648 hours, I returned to Quarry Cove and counted 59 S. corruptum flying east in 5 minutes (11.8 per minute) along an observation line approximately 25 meters long and 3-4 meters high. I also saw 1 Red Admiral flying east, but not during the count. Between 1700 and 1905, I was working indoors and unable to observe any flight, so I couldn't tell when the flight actually stopped. By 1905 hours, however, a heavy fog had blown over the headland on a south wind, and I saw no more dragonflies. 13 September 1999. Yaquina Head. Afternoon. Weather is foggy, cool, and calm. During the course of the afternoon, I saw 2 S. corruptum flying from brushy vegetation on the south side of the headland, but no evidence of any mass directional flight. Another exciting flight on the Oregon coast!
Subject: 1949 Reference to S.
corruptum flight in Oregon
In reading over the sections on S. corruptum in Corbet's new book, Dragonflies, Behavior and Ecology of Odonata, I came across a reference to a mass flight in Oregon which I had not previously seen: Macy, R.W. 1949. On a Migration of Tarnetrum corruptum (Hagen) (Odonata) in Western Oregon. Canadian Entomologist 81: 50-51 (Feb. 1949). Range Bayer got a copy of the article via ILL. It is noteworthy that the flight occurred well inland (6 miles southwest of McMinnville, Oregon) and the flight direction was westward. It is also notable that the flight appeared to occur in horizontal (vs. temporal) "bands" or "waves," as we have noticed on the Oregon coast. There is still considerable mystery surrounding the coastal flights, but this suggests the possibility that the S. corruptum we see on the coast could be coming across the Coast Range from the Willamette Valley. The date of the flight was 29 August 1949.
2000 Dragonfly Migration E-mail Reports
Subject: odonate migration
Just a note to record a neat migration event. My wife and I went for a hike on the slopes of Mt. Adams, in the South Cascades of Washington state, on 25 August. We hiked from 4600' - 5800' through subalpine forest. In just about every small clearing we flushed one or more Sympetrum corruptum. I'm sure there must have been many more of them, as we saw only those that we flushed because they were perched near the trail. After flushing, they perched from the ground to well up in the trees. I looked at about a half-dozen of them at close range, and all were in immature coloration, as would be expected. This of course is one of our two prominent dragonfly migrants on the Pacific coast (Anax junius is the other), but this is only the second time I've seen them high in the Cascades in the fall, although I suppose it's an annual event. While resting in a large meadow at 5800', I actually saw two of them fly by at treetop level at high speed, heading directly south, and one that I flushed from the ground flew straight up and over the treetops (the trees were about 15 m tall), again heading south. I had seen exactly the same sort of thing several years ago at about the same elevation in the North Cascades, near the Canadian border. There must be an awful lot of them to the north of us, although many in the mountains may come from the interior of Washington, where they emerge in large numbers in August from shallow lakes and ponds in arid country. As far as we know, they are heading at least as far south as central California, >1000 km away.
Subject: Re: odonate migration
On the heels of Dennis's report, we have had a minor influx of Sympetrum corruptum into Newport, on the central Oregon coast, USA, today (29 August 2000). Typically, S. corruptum is absent from Newport most of the year. I begin seeing small numbers in late July or early August. Late in August or early in September there will be a sudden increase in numbers, sometimes quite dramatic. A few days to a week or so later, we witness a mass directional (migratory) flight headed south or southeast. Some years the flights are quite large, some years barely observable. There may be more than 1 flight per year. Most seem to last 1 day, but multi-day flights have been observed. This year, I have not seen any S. corruptum before today, which may be because I have had little time to actively search for them. However, Mike Patterson has been observing them in low numbers at Neawanna Ecological Observatory at Seaside, on the northern Oregon coast, since late June: http://columbia-pacific.interrain.org/ahscience/neawanna/insect01.html#neaw Today (29 August 2000), between 09h00 and 09h25 Pacific Daylight Time (PDT), I saw 2 S. corruptum in a 25 minute walk from 935 SW 10th St., just north of Yaquina Bay Bridge, to the corner of Highway 101 and NW 11th St. in Newport, a distance of approximately 1.5 miles. Typically, I would see none in this distance. At 11h37 PDT, I did a 27 minute walk-through of a vacant lot at Highway 101 north of NW 15th St. where I frequently look for S. corruptum. On previous (albeit more cursory) walk-throughs this year, I have not seen any S. corruptum. Today, I observed 4: 3 through close-focusing binoculars, 1 in hand. One seen through binoculars was a male with some red coloration, though perhaps not as much as a fully mature male; 2 were of indeterminate sex, with immature/female coloration (yellow ground color). The one I caught and released was a male with some red coloration, perhaps somewhat less red than the male I saw through binocs. Given the difference between seeing one close-up and the other through binoculars, this is uncertain. Abdomen length of the caught male was ca. 28 mm. Approximately 5 minutes of the 27 minute walk-through was spent stalking and netting the 1 dragonfly I caught, so effective search time was probably closer to 20 minutes. Weather around 09h00 today was clear and warm, with a mild north breeze (guesstimated at 2-3 mph). A heavy fog bank appeared to be hanging over the beaches, but the sky at Highway 101 (perhaps 0.5 miles inland) was clear. I took more precise readings with a Brunton Sherpa pocket weather instrument and a Silva compass corrected for magnetic declination following my search of the vacant lot. The sky was clear above, but overcast to the north. Wind was from true north, average 8 mph (averaged over a 60 second period), maximum 13 mph. Air temperature was approximately 71 degrees F. Besides the 4 dragonflies, Woodland Skippers (Ochlodes sylvanoides) were numerous in the lot, as well as acridid and possibly tettigoniid grasshoppers. I saw 1 sand wasp (Sphecidae: Bembicini) and 1 spider wasp (Pompilidae). I likely would have seen more species had I not been concentrating on dragonflies. Stay tuned for further developments.
Report Date: 13 September 2000
Subject: Dragonflies at SJCR (South Jetty of
Reprints of 4 Published Accounts of Migratory Flight by Sympetrum corruptum
On a Migration of Tarnetrum corruptum (Hagen) (Odonata) in Western Oregon
By Ralph W. Macy
Reed College, Portland, Oregon
On the warm afternoon of August 19, 1948, as I was walking through a wheat stubble-field on my farm located six miles southwest of McMinnville, Oregon, I became aware that I was in the midst of a dragonfly migration. I could see them all about me for a radius of perhaps seventy-five feet which was about the limit of my vision for an insect of this size. When first seen there was a considerable number passing toward the west with from thirty-five to fifty of the insects visible at any given moment but after about five minutes they began to thin out until only a few were visible. I then walked south for two hundred feet at which place another heavy concentration was encountered. After a short interval these thinned to a few stragglers. Thinking that the migration was about over I retraced my steps only to meet with another wave. It soon became apparent that the migration was taking place over a wide front and that the insects tended to fly in groups over the valley floor.
To the east, from which the dragonflies were coming, the nearest water is the South Yamhill River, about two miles distant, but there is no reason to believe that this stream was their point of origin. Except for several rivers these migrants could have crossed some fifty miles of dry fields before reaching this area which lies at the edge of the foothills of the Coast Mountains.
A deep ditch bordered by clumps of willows lay directly across the path of the insects and within twenty to fifty feet of this they began to rise in order to clear the shrubbery. Otherwise they flew at a height ranging from two to ten feet above ground with a few travelling higher. Their average speed was estimated to be from four to five miles per hour as long as the breeze into which they were flying remained gentle.
As far to the north as a quarter of a mile the migration continued but with fewer participants perhaps due to the fact that this region was on a hillside some two or three hundred feet above the valley. As a heavy sea breeze began to surge from the west the speed of the flight was somewhat slowed and the insects in some instances came to within several inches of the ground but in no case did a single one turn back, alight, nor deviate from a westerly course. Near the top of the hill these insects were passing at the rate of seven per minute over a fifty foot front.
At the height of the migration, when first observed at 2 p.m., the temperature was approximately 80°F whereas by four o'clock it had become considerably cooler but the migration continued unabated. Unfortunately I was unable to continue my observation for several days thereafter so that the duration of the flight is unknown. On the night of September 4, a single specimen of the migrant came to the lighted window of the house on the farm and was caught. This suggests the interesting possibility of night flight, also observed at times in butterfly migrations, but it is also quite possible that the dragonfly had been aroused from a nearby resting place. Careful search in the vicinity on the following days did not reveal any additional specimens.
Because the migrants were abundant during the migration and without exception were flying in one direction at a moderate speed it appeared that many might be taken in a few minutes. However this turned out to be an illusion, for all but two of the insects managed to elude me during an hour of determined effort with the net. One of the two which I captured was very kindly identified by Dr. E. M. Walker of the Royal Ontario Museum of Zoology in Toronto as Tarnetrum corruptum (Hagen), until recently placed in the genus Sympetrum. Dr. Walker commented that the species has the reputation of being a wanderer.
Another dragonfly, determined by Dr. Walker as Sympetrum pallipes (Hagen), was rather common in the vicinity of the migration but its flight behaviour was entirely different for after flying about at random for a few minutes it always stopped to perch whereas the migrant flew steadily in one direction and not one ever alighted.
Original citation data: Macy, Ralph W. 1949. On a migration of Tarnetrum corruptum (Hagen) (Odonata) in Western Oregon. Canadian Entomologist 81: 50-51.
Reprinted by permission of the Entomological Society of Canada
Migration of the dragonfly, Tarnetrum corruptum (Hagen).
Mr. P. E. Turner, Jr., reported on a small libellulid dragonfly, Tarnetrum corruptum ( Hagen), which began a 3-evening migration over the San Francisco Bay area on 24 September 1963, and which was most numerous on the third evening. Mr. Bryan Furman collected a sample of twenty-seven specimens on 24 September in Kensington, Contra Costa County; these were badly tattered, but the live, migrating individuals were not tattered. The migrants seem to have been at least one day old, because the sample specimens had their full coloration. The sample included ten males, fifteen females, and two individuals whose sexes could not be determined. The dragonflies were flying eastward with a light westerly breeze on these warm evenings, and passed over Kensington between 17:50 and 19:50 PDT on 24 September, crossing the Lake Drive ridge at their apparently normal flight altitude of ten to twenty feet. This seems to be the first record of a migration by this genus, although a number of migrations by the closely related genus Sympetrum, excluding S. corruptum (Hagen), have been recorded.
The direction of the breeze indicates that the dragonflies were probably migrating from lakes and ponds in Marin County. Dr. Philip Corbet (A Biology of Dragonflies, Quadrangle Books, Inc., Chicago, 1963) has pointed out that odonate populations scatter after emergence and assemble before mating, and that migration can take place because of unfavorable seasonal temperatures, predation on tenerals by matures, long maiden flights, overpopulation, and threatened loss of temporary habitats; the latter three of these causes seem to offer the most plausible explanations for this particular migration.
I wish to thank Dr. D. P. Furman for the weather and migration data and for the specimens collected by Mr. B. Furman, whom I also thank for collecting the specimens.
[- C. S. koehler, Secretary, Pacific Coast Entomological Society]
Original citation data: Koehler, C. S. 1965. Migration of the dragonfly, Tarnetrum corruptum (Hagen). Pan-Pacific Entomologist 41(1): 66-67.
Reprinted by permission of the Pacific Coast Entomological Society
Mass movement of Tarnetrum corruptum (Odonata : Libellulidae).
The observation of a unidirectional mass movement of the dragonfly Tarnetrum corruptum (Hagen) (Libellulidae) was particularly notable since it was an almost exact repetition of a movement observed by B. Furman and reported by Turner (1965, Pan-Pac. Entomol., 41: 66-67).
On 25 September 1970 between 17:30 and 18:00 PDT in University Village, Albany, Alameda County, California, individuals of Tarnetrum corruptum were flying due east across a 50-foot front at a rate of four per minute. Most individuals flew about four feet above the ground, but some flew as high as 20 feet. At the time there was a light easterly wind of about five miles per hour. During the period the dragonflies were moving across a front which extended at least from Albany to University Avenue in Berkeley.
No individuals were noted on the days before or after the event, although all were unseasonably hot.
The first observation alluded to above, the only other recorded mass movement of this species, took place on 24-26 September 1963 at nearby Kensington (two air miles distant). Then, the individuals were noted flying in the same direction at the same time of day.
Taken together these two observations reflect an event of at least periodic recurrence or are highly coincidental.
Paul A. Opler, University of California, Berkeley 94720.
Original citation data:
Opler, Paul A. 1971. Mass movement of Tarnetrum corruptum (Odonata : Libellulidae). Pan-Pacific Entomologist 47(3): 223.
Reprinted by permission of the Pacific Coast Entomological Society
Mass movement of Sympetrum corruotum [sic] (Hagen) (Odonata: Libellulidae) in central California.
The observations of unidirectional mass movements of the dragonfly Sympetrum corruptum (Hagen) have been reported in the Kensington-Albany-Berkeley area in central California in recent years in notes by Turner (1965, Pan-Pac. Entomol., 41: 66-67) and Opler (1971, Pan-Pac. Entomol., 47: 223). In these references the species corruptum was assigned to the genus Tarnetrum. Turner suggested that these dragonflies were "probably migrating from lakes and ponds in Marin County.''
Records of a flight of Sympetrum corruptum in the fall of 1969 in Marin County are presented. On 11 October 1969 at 17:15 hours, Daylight Saving time, while traveling north on Dais Road, just south of the intersection of Sequoia Valley Road and Muir Woods Road (which is in an area west of the city of Mill Valley), hundreds of dragonflies were observed flying uphill and eastward. It was possible to look westward, with the sunlight shimmering on their wings, where they could be seen for a distance of more than a hundred yards - it was a mignificent [sic] sight and flight. At the road level the dragonflies flew from about 4 to 25 feet in height. Looking west and downhill some were flying one hundred and more feet above the dried grassy fields. Rarely a specimen was observed to settle on some vegetation. The flight was continuing at 17:40 hours when I had to leave. The afternoon was warm with only the lightest breeze. A continuation of their flight in an easterly direction would have brought them into the areas where Turner and Opler had reported their flights in other years.
Sympetrum corruptum is a species with a very wide distribution. It occurs from Canada to Honduras and is also known from Asia. The single female specimen, collected at the time of the observed flight, was confirmed as belonging to this species by Dr. D. R. Paulson of the University of Washington, in April 1970. Dr. Paulson reported that he and other Odonata specialists now prefer to include corruptum in the genus Sympetrum Newman.
Paul H. Arnaud, Jr., California Academy of Sciences, San Francisco.
Original citation data:
Arnaud, P. H. 1972. Mass movement of Sympetrum corruotum [sic] (Hagen) (Odonata: Libellulidae) in central California. Pan-Pacific Entomologist 48(1): 75-76.
Reprinted by permission of the Pacific Coast Entomological Society
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