Spiders and Bats

October 2019 has been a fine month for watching the diversity of wildlife along the river, conditions changing from day to day. Our temperate climate here allows for frequent changes which other countries don't have. A continental climate means summer is summer and winter is winter, with predictable weather most of the time, although climate change may be affecting this. 

Rivers flowing through a landscape can have a very local effect and provide habitat for more species of wildlife than other regions. 

Insects are a key to this. What have spiders and bats in common? They prey on insects which are very often most numerous in riverine environments. Spiders and bats often go unnoticed until conditions change, and their presence becomes more visible:

A spiders web on a misty morning 22nd October 2019

This web was laden with water-droplets, until they evaporated in the sun.

Another web on the same morning quite close to the ground

and the river bank.

Bats forage when light-levels are low, spending the daylight hours roosting in darkness hidden away unnoticed by creatures which might otherwise prey on them.

Here the huge old oaks along the river provide excellent roosts, with old branches providing cavities in the bark where there is space for bats to squeeze in and hang onto the rough surfaces. 

 An old oak on the edge of the river at the end of an important bat flyway.

As soon as light levels fall, bats fly out of their roosts mostly in old oaks 

some distance from the river and make their way along a hedge

and trees down to the old oak where they immediately start to catch aerial

insects over the river surface and in the trees above. They move on along the river, catching insects as they go, as the vegetation on the banks forms a directional guide for them to follow. When they have finished for the night they usually follow the same route back to their day roosts. They do not fly in strong winds or driving rain, so mature vegetation and trees provide shelter and enable them to continue foraging.