2023 Dragonfly Survey and Ohio Odonata Society (OOS) Annual Meeting

Following our successful one-day OOS meeting in 2022, we are planning another one-day meeting for 2023:

June 17, 2023
Lowe-Volk Park, 2401 OH-598, Crestline, OH 44827
Crawford County Park District

We will start early with some social time and a business meeting, followed by field trips at area wetlands!

If you are interested in attending, please send email to jlem@woh.rr.com. I will provide details as they emerge.

OK, now officially Spring. Our first full day is complete and we're still waiting on our first adult Odonata observation.

iNaturalist now has 2023 observations as far north as Tennessee and Virginia. Nothing yet for Kentucky or West Virginia.

But it shouldn't be too much longer. I'm dreaming of seeing Common Green Darners, but (of course) missing getting a photo.

Stay tuned and keep an eye on your local wetlands.

Ohio Odonata Data

It has come to my attention that some Ohio Odonata observations in iNaturalist were not in the Ohio Dragonfly Survey project. After some sleuthing and further follow-up there are several instances where observations are not picked up, as follows.

1) When observers are not adding their observations to the project - this happens, and while not optimal, we generally pick things up by using the iNat Curator tool "Find Suitable Observations." But! It seems that there are some exceptions to our processing.

2) Initial wrong ID - an observation gets submitted and the observer isn't sure on the ID or makes the wrong ID. Example, they type in something like "Azure Bluet" and iNat cheerfully plugs in the first Azure Bluet on it's list, Houstonia caerulea - which is a flower, rather than a bug Enallagma aspersum. This observation is located in Ohio, but isn't eligible for the survey because it's not identified as Odonata. Most of these subsequently get the correct ID, but they fall through a crack and don't make it into the survey.

3) "Private" location - it is understood that some locations need to not be made available to the wide world. But, in marking an observation as "private", it can also escape attention to the project Curators. Some my be marked Ohio, some the even more generic United States. Another crack, another fall...

4) iNat user limiting the use of their observations. Some observers prefer a measure of control over their information. Not a problem, other than unless they join the project and add their observations, the data can be locked out of inclusion in the survey. We try to get people to play along, but not always successfully. It's interesting that some of the locked observations are for people that joined the project.

5) We generally want IDs to species for inclusion in the OOS database, but there are both historical records and recent observations that are only at the generic level. This can impact observation counts. A similar situation exists on location data - not everything is located to a county. Better observations make for better data.

6) Along these same lines - we occasionally have iNat users leave the system - and their observations disappear. For better or worse, while we have captured the data and imported to the OOS database, we no longer have an original source to go back to. We treat this similar to historical data that was reported by individuals without a voucher.

What to do? Please add your observations to the project as they are entered into iNaturalist. If you have entered private location observations, please check a couple to see if they're in the project. If you have a photo of an Ode from Ohio and you can't get it to add to the project, check your ID and location - may be there's a discrepancy in your ID of the observation or where it got dropped on the map.

Several Common Green Darners arrived in Greene Co on Mar 6, 2022 marking the earliest Ohio Odonata observations last year. iNaturalist now has reports of adult Dragonflies in Georgia and Alabama. So it won't be long until our 2023 season starts.

Below is a chart of species ranked by early date of adult Odonata observation (Ohio Odonata Society database). 10 or 11 day segments are then charted by span (color band - first to last) and occurrence within the span (noted by asterisk). Where there is a gap in the span, there is no asterisk. The coloration is related to Odonata groups: Darner is red, Skimmer is purple, etc).

This is a reduced version of the whole chart, which has all 173 species and some additional datapoints. A PDF version can be emailed if you are interested - message me with your preferred email address (if I don't have it already).

Now March. It’s possible to see Odonata in March - mostly Common Green Darner. Maybe not right away, but soon. Last year, the flight season set a new early date, by starting on March 6. We've already had some nymph observations for 2023.

Here’s a map of Counties with observations in March. Darker where observations are in the last 5 years. Montgomery and Coshocton have one or two more than the other counties. Notice counties with observations – north to south, east to west. If your county isn’t purple, here’s your chance to get in data!

Many of our earliest sightings are individuals that are migrating on the spring stormfronts. They can drop out of the sky at any wetland, or maybe your backyard.

How are we?

A fairly common question is 'how are we doing?' There are different ways to consider. From the data, we can look at the combinations of county and species. To date, we have 6,671 combinations of the 88 Ohio counties and the possible 173 species. This number grows as County Records are established. We can compare this cumulative number to individual years, or perhaps more enlightening in a multi-year accumulation. A 5-year look smooths the curves. The chart shows the most recent 20 years. In beige is cumulative co|sp value - as theoretical maximum growing year by year (scale is on the left). The aqua is the 5 year value (left scale). The red line is the percent of the theoretical max accounted for in the 5 year running accumulation (scale is on the right). Note that prior to the start of the statewide survey, the percent observed was in the teens. We are now over 75% - meaning three quarters of the documented co|sp pairs are being recorded in the recent 5 year period. This helps answer the question - better, and pretty good.

Survey Target Counties for 2023

Last season (2022) saw progress based on published goals. See the 2022 journal articles March 04, March 12, July 13 and the January 04, 2023 journal for description and progress. We moved the needle considerably on observations, less so on species.

Goals are good. Looking at county data provides a view on where we need more attention (#observations, #species, comparison to historical, comparison to adjacent counties). The map of counties, below, highlights these target counties. The darker the color, the greater the need. Four counties are at the top of the needs list - Van Wert, Hardin, Noble, and Brown. Everything highlighted needs more species. Finding new species requires people looking.

If your county is blank, good job. Keep it up and maybe venture to one of the green counties.

An extra bit (the +'s) helps see relative need compared to 2022. Each + sign indicates the multiple of the 2022 observations we need in 2023 to keep relative pace to the overall survey. Back to our priority targets - Van Wert was the 2022 low for observations (52), and one of the 4 counties that had just a single observer. Van Wert is also on the low side in total observations (649). If we pick a target of getting to 1,000 observations, we need 7 times the 2022 observation count. 1,000 observations for every county may be ambitious, but again, goals are good.

More to come.

Odo Info Update

New species distribution maps and flight charts are ready, as a combination graphic (map and chart). See the Comet Darner example below.

For those of you that get the Ohio Odonata Newsletter, these combo's were included in the Feb edition. If you didn't get the newsletter, but would like to, send me an email. Similarly, there is a zip archive of the individual 173 files, this can also be emailed.

My email is jlem@woh.rr.com

Slaty Skimmer

The January 5 Journal elicited some observations and a question regarding Slaty Skimmer from jheiser. This got me thinking a bit (I do read all the comments!) The first Ohio Slaty Skimmer was observed in 1896 (Osburn, Erie Co), so it been around for a while, albeit in low numbers few and far between.

This began to change to change in the 1990's when we started to see a few every year. The big increase began in 2017 with the start of the statewide survey.

Maps below are changes through time. The dark shading is for the defined time period, light would be the previous period. White means no records.

Here's where we start, looking at data prior to 1950. This would be about 60 years of data. These early years probably represent vagrant individuals.

Next up is the period from 1950 to 1989, this would be the years when voucher numbers increased. Data from about 40 years.

Next is data from the first Statewide Survey, the 10 years of the 1990s.

Next, the early 2000's. Note the southern counties - artifact or the arrival of resident populations?

Next, the new Statewide Survey gets started and look at the breakout. 42 new County Records. Big increases on the numbers being reported.

Now the most recent 3 years, continuing the increase in range and numbers. We now have Slaty Skimmers in 86 Ohio Counties (just missing Seneca and Jefferson). Nearly half the total records have arrived in the last 3 years.

The final map highlighting Slaty counties with larger survey numbers - each diamond represent 50+ observations (1 diamond means something in the 50-99 range, 6 diamond means over 300).

Charting All the Data by Day

Here's a couple charts updated with the 2022 additions. Compare previous in the Feb 10 Journal.

First the total observations

This looks similar to last year, just with an adjusted scale (increase).

Jun 24 now busiest day with 2,401 observations, up by nearly 500 from last year's high of 1,921 on Jun 23.

The span of days with over 1,000 observations per day has expanded, now May 29 to Aug 15 (79 days). Last year's range was Jun 11 to Jul 20 (40 days).

Now the Species by Day

This chart is very similar to a year ago, you have to look pretty close to find differences.

The Species top day is Jun 23 with 113, followed closely by Jun 14 with 112, and Jun 15 with 111.

Jun dominates with 23 days over 100 species. We did add to the previous total, where a year ago Jun had 15 days with 100 or more species. Jul is the only other month with 100 species days at 3.