Fen Raft Spider observational study record 009
Location: Carlton Marshes: Dyke 5a, just south of bridge
Date: 23/08/19
Time start: 10.00
Time finish: 11.15
Weather (from BBC weather app):
- General: Sunny and light winds
- Humidity: 74%
- Pressure: 1025
- Temp: 20C
- Temp feels like: 21C
- Wind: 6mph SW
- Cloud cover/sun: Intermittent cloud, mostly sunny
Observational subject:
One nursery web, one adult, two nearby juveniles
Vegetation/macro location:
Web in channel of dyke, on water soldier. Juveniles on water soldier and frogbit
Observations:
10.00: One nursery web containing spiderlings. A banded adult female is on the far (North) side of web -in deep shade and hard to see initially.

10.20: A little movement amongst spiderlings, which seem to be in two groups. The group on the left begins to spread. There is an egg sac to the right of this group with a group of spiderlings immediately beneath it. The guarding female is behind and to the left of the web. She is in the shade and looks very dark in colour in this light.


Mum was very hard to get a good look at. Moving to a different viewpoint to the left, and knocking up the EV compensation to lighten her up, resulted in a better view of her but with overexposure of the surroundings.

Below is a video of the web showing a burst of spiderling activity. The dark flickering to the left and below the adult female is just the playing of light and shadow in the background. My videography skills are in their infancy so bear with me!
10.21.The banded juvenile just north of the web and facing north, sitting on water soldier leaf. It’s in hunting pose, with forelegs on the water meniscus. Body length is estimated at around 5mm.



10.40 The juvenile on the water soldier has moved behind and up the leaf and is now almost hidden from view.
10.55. A second banded juvenile is seen a metre further away, on a frogbit pad. Body length estimated at 5mm long. The first juvenile has returned to the water surface.



No unusual or notable behaviour was noted today. But it’s worth commenting that the juveniles are relatively close together and look almost identical. There is a good possibility that they are siblings who hatched in this location and are growing up there.