Roostwatch JE

Roostwatch JE

Welcome to Roostwatch JE! 

Find out more about the wildlife around your home and garden by taking part in Roostwatch JE.

You can do this by looking out for signs that bats might be using spaces around your home and garden or outbuildings while enjoying the summer evenings, looking for bats as they emerge to feed for the night.  

Why take part in Roostwatch JE?

Bats are fascinating animals. The only true flying mammal, 18 species of bat have been recorded in Jersey, some of which are known to be breeding locally.  

Bats and humans have lived in tandem for many tens of thousands of years, and provide humans with a plethora of benefits, from the pollination over 500 plant species to producing guano in their dropping, a highly effective fertiliser to the consumption of insect pests, decreasing the needs for pesticides. For example, a common pipistrelle can eat up to 3000 insects a night, mostly midges and mosquitoes! 

Bats are protected internationally through Multilateral Environmental Agreements, and locally under the Jersey Wildlife Law (2021). Protecting and monitoring bats is becoming increasingly pertinent, as bats are subject to an expanding number of threats, varying from climate change, light pollution, decreasing insect numbers, and loss of roosting sites.  

Roostwatch JE aims to increase our knowledge of the places bats in Jersey choose to use for resting and breeding. This information will help us to learn more about these fascinating creatures and will help us to assess their conservation status in Jersey.  

How to get involved

Bats are such quiet house guests, most of us have no idea they are living close by. To find where bats hangout we need to look out for a few clues; 

  • Look around the outside of buildings, garages, barns or outbuildings you have access to.  
  • Look for gaps where bats might squeeze in (e.g., under roof tiles, behind cladding, fascia boards etc). 
  • Look for holes in trees, e.g., woodpecker holes, cracks in branches or lifted bark. 
  • Look on the ground, windowsills, and walls for droppings, and look for dark stains just below a gap where bat roosts may be present.  
  • If you are going into an open space like a barn or attic, keep an eye out for piles of droppings and insect wings on the floor. 

Remember bats are protected by law from disturbance, so don’t go searching for bats themselves, keep light and noise to a minimum if you are heading into a loft space and withdraw if you see any signs of presence.

Bat droppings

Bat droppings are small and look similar to mice droppings. The ‘crumble test’ can be used to tell them apart. Roll the dropping in a piece of tissue, in-between your finger and thumb, if it disintegrates to a dust, it is a bat dropping. The droppings are made of insect parts and are generally dry and odourless. They can have a glittery look when crushed.  

Places to keep an eye out for bat droppings include windowsills, attics, balconies, virtually anywhere close to an entry point (a point of access into a bat roost). 

How to Roostwatch

One of best ways to discover if a building, bat box or tree has active bat roosts is to sit back on a clear evening at dusk and watch. It is a wonderful way to enjoy a warm summer evening and contribute to science at the same time!  

Set aside an hour or two on a nice summers evening. 15 minutes before sunset, find a good spot with an unobstructed view where you think bats might be flying in and out of their roost then sit back, relax, and watch until it gets too dark to see the roost site or bats. 

Try and pick a spot that is far enough away from the bat roost that you do not disturb or agitate them, but you still have a view of them flying in and out of their roost. As much as possible, try and count them as they leave, but also make a note of any that return. Although it may be tempting to use a torch or light to get a better view, please don’t as bats need the cover of darkness to feel safe. 

Take photos of where the bats are flying in and out of, even if the bats are not in the photo.


Submit your sighting record Roostwatch.JE form



General advice and information guide: Roostwatch guide

Places and signs to look for bat roosts: Looking for bat roosts

Bat dropping identification guide: Bat dropping identification guide

Bat Conservation Trust & Mammal Next Door guide to How trees are important to bats

Click here to see videos of bats emerging from a selection of different roosts

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Pipistrellus pipistrellus © Miranda Collett
Pipistrelle dropping under a roost entrance