My First Sunset Survey

Blog written byLauren Stark

A few years ago, I was the Bat Conservation Trust’s National Bat Monitoring Programme (NBMP) survey intern. I helped identify bats in sound recordings, entered survey results as well as other tasks. Since leaving the role I have become a consultant ecologist and over the summer I frequently carry out a range of bat surveys for infrastructure and development projects across Wales and Southwest England.  

I took part in my first survey in April 2019, carrying out my survey at a local lake in South Wales. It was a slow start, however after a few minutes we were surrounded by multiple species. Although not necessary for the survey, I used a bat detector to help me identify the bat species present. Through the bat detector I heard common and soprano pipistrelles. I also visually identified Daubenton’s bats flying low over the lake. It was great fun.

My site for the NBMP sunset bat survey.(c): Lauren Stark

NBMP and its volunteers

The NBMP has over 2,000 volunteers collecting data through various surveys throughout the year. Some of these surveys allow anyone to get involved, even with no bat survey experience.  The results of these surveys provide the NBMP with important information on:

• Bat population trends in the UK.
• An insight into the state of the environment
• Help in the successful conservation of UK bat species.

How can you get involved?

Anyone can take part in the NBMP sunset/sunrise surveys; no equipment or experience needed.  It is also a perfect opportunity to get together with family/friends and discover bats and other wildlife in your local area. Last year 353 volunteers took part in the surveys. You could be part of the growing number of volunteers. All you need is:

• Someone to join you, if you are surveying away from your house/garden
• Torch (to light your way when you’re walking – please do not shine it at bats!)
• Survey form
• Watc
• Pen or pencil

The survey runs from April to October. You can sit in your garden, go to a local park or watch from your window whether you live in an urban or rural area. Just spend an hour starting from sunset, or an hour before sunrise, and record the number of bats you see in that hour. You do not need to be able to identify the type of bat for this survey, but if you can then please record this as well!

What will you see?

When taking part in these surveys you are most likely to spot five of the more common bat species: common pipistrelle, soprano pipistrelle, noctule, brown long-eared bat, and Daubenton’s bat. Last year the most observed species was the common pipistrelle.

It won’t just be bats that you see as there are lots of other nocturnal animals such foxes, hedgehogs, owls and rabbits that can also be recorded, so keep an eye out for other species too!

If you would like to take part in a sunset/sunrise survey or would like to just learn more visit the Sunset Survey page on the NBMP website!

Bats in the UK

The UK has 18 bat species, 17 of which are known to breed in the UK, which is almost a third of all UK mammal species! Bats are an indicator species; their presence shows that an ecosystem is healthy. A loss in insect populations or poor habitat management can cause a decline in their population. 

Bats are not blind! However, they use echolocation (a series of high-frequency calls) to hunt for their prey in the dark as well as to build up an image of their surroundings. Echolocation calls are too high frequency for humans to hear, however with bat detectors we can. Different species echolocate at different frequencies, which allows us to identify the species from their calls.

You can also tell some species apart by their flight patterns. For example, Daubenton’s bats are distinct in the way they fly, skimming the surface of water to catch insects with their feet. Pipistrelle species on the other hand fly slightly higher twisting and turning in and around trees.

Unfortunately, over the last century bat species numbers have declined dramatically. Causes of this decline include habitat loss, predation (often by cats), and an increase in artificial lighting. Bats and their roosts are protected by law from destruction and disturbance.