Fen Raft Spider behavioural study record 004

 

Location:                                           Carlton Marshes: Dyke 5b, 8m South of bridge

Date:                                                   16.07.19

Time start:                                        14.00

Time finish:                                      15.45

Weather (from BBC weather app):

• General:                  Sunny intervals and light winds. Feeling very warm.
• Humidity:               58%
• Pressure:                 1018 mb
• Temp:                       21C
• Temp feels like:      25C
• Wind:                       N, 6mph
• Cloud cover/sun:    V sunny with occasional cloud cover

Observational subject:

2 Balls of spiderlings in a nursery web with egg sac, adult beneath

 

Vegetation/macro location:

Web and spiderlings about 30cm above water surface in water soldier about 1m from east bank. Adult sitting on frogbit on water surface immediately beneath web.

Observations:

14.00. Dark unbanded adult female present

Initially 2 balls of spiderlings seen in web. Little activity at this time.

 

14.20. Adult has moved away from me to next frogbit pad. Can only see back of abdomen and spinnarets. Contrasting light and obscuring leaf cover prevent photo.

14.40 has turned around and is facing me

15.00. Spiderlings have coalesced into a lens shape roughly facing the direction of the sunlight

15.40. Spiderlings noted to be very active in full sun

 

Lens formation and increased activity consistent with increased exposure to warmth from sunlight. Suggests active basking behaviour in spiderlings. No active movement of adult into sunlight does not support active basking behaviour in this individual during this study.

14.45 End.