Journal archives for December 2021

December 25, 2021

A Small Swamp Survey

After just about walking off from this swamp, rather than just leaving things at my normal "only recording species' presence," I thought I'd take a slightly more scientific approach and bisect it, recording every damselfly and dragonfly. Normally for these sorts of activities you'd record weather but I can only estimate temperature from memory, remembering it was quite cool, only around 16°C, with some light to moderate wind gusts, but most importantly it was sunny.

I walked from the far side through the middle of the 50m wide swamp. Water depth was 5cm at most. I recorded:

  • 5 Slender Ringtail (Austrolestes analis)
  • 4 Ancient Greenling (Hemiphlebia mirabilis)
  • 3 Aurora Bluetail (Ischnura aurora)
  • 1 spider
  • 1 fly

view observations

I couldn't find a name for this swamp. The old (no longer working) governement mapping system might have had more names but the new one doesn't have a name for this one.

See also the Big Swamp Survey a little later in the morning.

Posted on December 25, 2021 09:54 AM by reiner reiner | 2 comments | Leave a comment

Big Swamp Survey

Having surveyed a small swamp earlier in the morning I decided to also survey the nearby Big Swamp (so named) in a similar, repeatable manner. This was mainly for Odonata (dragonflies and damselflies), particularly for the generally rare Ancient Greenling (Hemiphlebia mirabilis). This swamp is ephemeral and dries out over summer most seasons (apart from the artificially deepened dam). It is also significant as the only known breeding site for the Common Glider (Tramea loewii) dragonfly in Victoria as I observed one emerging there ten years ago.

The temperature was about 20°C–22°C with light to moderate wind gusts and sunny. Water depth was generally to about 10cm but deeper around the area of the dam in the east where I started. I bisected the swamp roughly in an east–west direction across about 300m of the swamp and recorded all insects I disturbed:

  • 41 Ancient Greenling (Hemiphlebia mirabilis)
  • 14 Slender Ringtail (Austrolestes analis)
  • 5 Wandering Ringtail (Austrolestes leda)
  • 3 Aurora Bluetail (Ischnura aurora)
  • 3 Blue-spotted Hawker (Adversaeschna brevistyla)
  • 2 flies
  • 1 moth

view observations

A significant number of the Austrolestes were newly emerged and all the Adversaeschna brevistyla seen had emerged that morning (a few more of these could not be photographed/recorded as they flew away).

Posted on December 25, 2021 08:33 PM by reiner reiner | 1 comment | Leave a comment