Acorn certificate student

Bats and “snakes”!

Natasha, one of our first Certificate students this year has been on her placement, here in the Exeter Office, for three weeks now. Here she talks a bit about her experiences and what she’s been up to.

 

A month in the life of an ecologist

Acorn Certificate Course Bats in loft
Natasha and India with brown long-eared bats

Small brown bodies huddle against the rafter. Long ears hang down. Small inquisitive eyes peer in the red torch glow. We get the callipers ready and carefully measure the tragus (the inner part of the ear): 4.3 mm. It’s a brown long-eared bat (Plecotus auritus). Relatively common but an exciting find for our first ever roost visit – up inside an old primary school loft. “It’s not often you find live bats. Usually just the droppings” Colin says. It’s our lucky day!!

 

Back in the office, we map the bat locations, droppings, and potential entrance/exit points. There’s a lot to think about. These maps and notes will inform the next steps: emergence surveys and mitigation options.

Acorn student slow worm
Natasha with the “snake”

A few days later, we are out in a field. Long grass. Brambles and nettles biting at our ankles. We are on a reptile hunt. It’s our second visit to this site and I have high hopes after our first survey with toads and a short-tailed vole. Not the target species we were hoping for… but nonetheless exciting finds for an amateur. Lifting the square black reptile mats slowly, my eyes dart over the ground looking for movement. Nothing. Next mat, nothing. Next mat, “snake” my brain shouts. A legless brown reptile lies curled on the grass, half the length of my arm. Jess comes running over and laughs at my mistake. It’s a pregnant slow-worm (Anguis fragilis). I can’t stop smiling. I found something cool under the mat.

 

Stars shine brightly overhead. It’s 3am and I am waiting in a carpark. Fridays are dawn survey days. Another car pulls up and I clamber in, armed with coffee and lots of layers. 4am. We arrive at the coast and stop in front of a house. Everything is silent. We glide up the path and across the lawn. Two of our team wait out the front, while me and Colin head for the back. Out come our detectors, and right on schedule, we are set up and ready for any incoming bats. The wind whistles and the faint calls of seagulls break the silence. No bats. It’s getting lighter now. A bird swoops past. We look up to see a tawny owl perched on the neighbouring house. My first wild owl in this part of the world. It more than makes up for a bat-free bat survey.

Office time again. Patterns of dots and lines flit across the screen. We are getting our first lesson in Analook. Finding order in the chaos is an art. Slowly but surely, we skim through the sound files. Looking up sonogram patterns and matching the bats. A few thousand more and it’ll be easy. It’s a work in progress but we still have time.

Acorn certificate student bat detector
Natasha setting up a static detector

Natasha has one more week to go on her placement. She is doing really well and has learnt loads in the last three weeks. Next week we have more bat surveys for her to be involved in and lots more reptile work. We haven’t found an actual snake yet, but there’s a few more days to go!

Pipstrelle bat sound analysis

Bat Sound Analysis

What is bat sound analysis?

On every bat survey a detector is used that will record the calls of passing bats. This can be during an emergence survey, to confirm the species of the emerging bat, or during an activity survey, or very often as a static detector, which will record all bat passes over a number of nights. The data is not stored as sound files, such as you might hear through a heterodyne detector, but in a way that produce sonograms. A sonogram is a representation of a sound on a graph.

Each species produces different sounds and all look different when on a graph. Sometimes these differences are extreme, sometimes very subtle. Bat Sound Analysis is the process of looking through these data and seeing what species are on site.

Here at Acorn Ecology we use the software Analook. This is software that is used by many consultancies.

Why learn bat sound analysis?

Much of your time as a Trainee or Assistant Ecologist (and beyond) will be spent analysing sonograms of bats from your survey sites. There can be as many as 3000+ sound files recorded in one night, by one static detector. Multiply this up so that you have two or three detectors on site, for five nights at a time. Then put these out on site on a monthly basis throughout the summer and you suddenly have a LOT of sound files – and that’s just one site! Having the skill to analyse them is a real advantage in what is a very competitive job market.

What do these files look like?

Pipstrelle bat sound analysisHere’s a couple of examples: Pipistrelles at the top, and greater horseshoe below.

GHS bat sound analysis

So if you want to be able to tell your Myotis from your barbastelles, and your horseshoes from your noctules, come on the Acorn Ecology Introduction to Sound Analysis Course!

This course will teach you how to get started with Analook, one of the most common pieces of software. (The fundamentals of the course are easily transferrable to other software packages too).

The course covers:

  • How bats use sound
  • An introduction to using Analook
  • Recognising typical UK bat species sonograms
  • Produce statistics for your report
  • Practice sessions on your own laptop

Much of the course is a practical workshop. We want you to go away feeling confident in your identification skills!

We have expanded this course and we now run a second day, Bat Survey Data: Analysis and Presentation. This course will teach you how to present your data in reports and analyse how bats are using your site. It usually runs the following day from the bat sound analysis course.

Give us a call on 01392 366512 or visit www.ecologytraining.co.uk today for more information.