Feb 23 - getting ready
Days are increasing in length. Spring flowers are off to an early start. Maybe a dragon soon? We're only a couple weeks away from our earliest Common Green Darner observation (March 6).
This got me thinking on what and when. As noted, CGD gets us started, then followed by Variegated Meadowhawk, Fragile Forktail, and Swamp Darner as possibilities in March. Check out the early flight date chart at https://www.ohioodonatasociety.org/species-flight-range-by-early-date
I updated the chart on observations and species count for our season intervals. This is based on all the data.
The peak for both occur in the last 10 days of June - the scales here are adjusted to match the peaks. Interesting that our species count generally outpaces our observations in this charting. I think it holds that the more observations we make, the more species we will see, but there's some wiggle room here. Things ramp up quickly starting in late April, then species hold on a little better in late September.
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I've been wondering about the relationship between the # of species and the # of observations, in total for specific locations, and in this seasonal chart. I'm wondering if there is a complexity that feeds itself:
1) Clearly there is a relationship between the sheer number of observations in a location, and the number of species that have been confirmed in that location. Franklin County is the highest for both (see https://www.ohioodonatasociety.org/county-species-lists).
2) Could it be that observation activity is significantly influenced by human expectation about what they are likely to see? In other words, humans are more willing to spend time looking for odonates when they believe that they will see a lot of them.
Given that there is a limit on the number of species that can be observed, but not a limit on the amount of time that can be spent observing, I suspect that the 2nd dynamic is more significant than the 1st one.
There's a human observation cycle influenced by the expectations of the richness of the experience, and by the expected ease of observation. The graph above smooths out an early spring bump (see the Observation Activity graph on https://www.ohioodonatasociety.org/county-erie). There's an early surge of activity when the first few adults are flying, and then as people get bored seeing the same 1, 2 or 3 species over and over again, they spend less time looking.
Fall species are under-surveyed because it takes more human energy to spend 6 weeks looking at relatively small numbers of the same 2-5 species.
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