Saturday 15 August 2020

Neighbourhood Odonate Count: Round Two

 A month ago (July 14), I did an odonate count around my neighbourhood (results and comments here), so yesterday (August 14), I decided to do one again, to see how much has changed in a month's time. I followed roughly the same route, and conditions were more or less the same (it was quite windier yesterday though). The biggest difference between the two dates (other than the results) was the change in habitat. One location which was a pond last time was now all dried up, with only a small stream running through. I was actually able to walk across what was once the bottom of the pond! There is some Phragmites management/wetland improvement going on here, so will be interesting to see how that changes over time. On the flip side, a wetland that I was able to easy walk around due to low water levels, has completely flooded because of recent rain. The increased water level resulted in a loss of shorebird habitat, but wasn't completely bad. 

Prior to this count, I had recorded 43 species in my neighbourhood, and that number still stands. I managed to find 26 species on this day (compared to 27 on July 14). The numbers of individuals was also down in comparison to July, with 917 individuals recorded, compared to 1388 individuals last month. This difference in individuals is not entirely surprising however. It can be hypothesized we are past the peak of the odonate season for the neighbourhood. 

Anyways, the results, and some notes. The total from the July 14th count are included in parentheses. 

Broad-winged Damsels (Calopterygidae)
Ebony Jewelwing - 1 (33)
    - one individual in an odd place, zero individuals in the ravine I usually see them, so perhaps they have dispersed? 

Spread-winged Damsels (Lestidae)
Slender Spreadwing - 11 (147)
    - surprisingly low numbers, I wasn't able to access the area where I had the bulk last time, but still way fewer individuals in accessible areas than last time

Narrow-winged Damsels (Coenagrionidae)
Familiar Bluet - 167 (101)
Azure Bluet - 4 (0)
    - recent addition to the neighbourhood list when I found a couple individuals on August 8th. This is a species that is quick to colonize new areas, and I think that perhaps the recent flooding contributed to their arrival. The individuals found on the count were throughout the wetland, indicating they are spreading out. 
Marsh Bluet - 1 (6)
Stream Bluet - 2 (2)
    - pair in copula, as opposed to two males on July 14, indicates breeding
Skimming Bluet - 1 (0)
Orange Bluet - 1 (42)
    - starting to get late, higher water levels resulted in less emergent vegetation for this species to perch on, where they are conspicuous 
Enallgma sp. - 3
Fragile Forktail - 71 (118)
Eastern Forktail - 211 (420)

Darners (Aeshnidae)
Lance-tipped Darner - 1 (0)
Shadow Darner - 1 (0)
Common Green Darner - 46 (14)

Skimmers (Libelluidae)
Halloween Pennant - 2 (0)
    - second record for the neighbourhood, first for location
Eastern Pondhawk - 39 (68)
     - with one location having next to no water, skimmer numbers were down
Widow Skimmer - 46 (25)
    - only one location with this species, making the count excellent
Twelve-spotted Skimmer - 66 (45)
Blue Dasher - 87 (89)
Wandering Glider - 1 (0)
Eastern Amberwing - 23 (57)
Common Whitetail - 47 (80)
White-faced Meadowhawk - 10 (2)
Ruby Meadowhawk - 19 (8)
Band-winged Meadowhawk - 16 (68)
     - no evidence of large numbers like in July, still a few individuals and pairs
Autumn Meadowhawk - 12 (7)
Black Saddlebags - 28 (14)

Total Species: 26 (27)
Total Individuals: 917 (1388)

I once again divided the checklist into the four locations. Quite a striking difference to last time!

Virginia Park
Species: 7 (14)
Individuals: 81 (138)

Northbrook Park (decreased water level)
Species: 18 (24)
Individuals: 244 (620)

Uplands North Wetland (increased water level)
Species: 22 (17)
Individuals: 587 (621)

Uplands Trail
Species: 3 (4)
Individuals: 3 (9)

Misses from the first count:

Emerald Spreadwing - not all that surprising, as I don't normally see this species during the summer. The individual in July was in a part of the wetland that is now inaccessible.
Violet Dancer - I'd consider the individual from the first count accidental.
Tule Bluet - another apparently accidental individual on the first count.
Sedge Sprite - it is late for this species, I checked several areas where they were in July with no luck.
Unicorn Clubtail - late for this species
Dot-tailed Whiteface - this is a seemingly rare species in the neighbourhood, the location where I had an individual in July is now dried up.
Four-spotted Skimmer - uncommon to rare species in Middlesex. The spot I had three in July is now dry. I had one individual at another location on August 8th, but could have just been stopping in.

Other notable misses:

Northern Spreadwing - not sure where this species is this year, have not seen one since July 13th.
Spotted Spreadwing - I have only ever seen one in the neighbourhood (August 4th, 2018), but this is a later season species, so could easily occur, and I just haven't found it (since I was gone for all of August 2019). I have seen several individuals in a park directly to the north of the neighbourhood.

There really weren't all too many surprises. A species I was quite pleased to see was Halloween Pennant, which represents only the second record for the neighbourhood. I am still on the lookout for Calico Pennant!

I was expecting to see more meadowhawks than I did. Numbers of three species (Ruby, White-faced, and Autumn) were up, but Band-winged was down drastically. I suspect that they were done breeding and have since dispersed. 

As mentioned prior, Azure Bluet was a new addition to the list last week. I am hoping this attractive species sticks around and gets a little population going.

I was expecting to see more Wandering Gliders, but still happy I got one.

Unsurprisingly, Common Green Darner and Black Saddlebags numbers were up. These species congregate in numbers before migrating in the fall. The darners were swarming in the evening while feeding. I didn't have much mixed in, save for a Shadow Darner.

Overall, a pretty good day. Any day out looking for odes is a day well spent! I think it was quite interesting to see the contrast between the two dates. I think the biggest surprise was how many species I saw, since I had been expecting quite a few less than in July. I will have to see what I'm up to in mid-September!

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