What does it mean when we give lots of decimals behind the degrees?

Many of us have GPS devices which give us locations in decimal degrees, but what do all those decimals really signify and can we rely on them? In the image below, Alex Rebelo has set out a series of increasingly accurate data points (using Kenilworth Race Track in Cape Town as his example). 

You can clearly see here the difference between giving two decimal places and three decimal places is about 1km!

Should you ever give 5 decimal places? Unless you are using a survey GPS, the answer is no. 

Most handheld GPS units can get an accuracy of around 6-8m, so giving 4 decimal places is realistic. For most of our purposes (usually mapping frogs), this accuracy level is fine.

Winter is a busy time in the lab. The frogs start calling and it means that we all have to get out into the field. 

For me, nothing is nicer than spending a day than getting up into the mountain and making a recording of moss frogs. 

Here you see a microphone array, errected to conduct spatially explicit capture recapture. See Stevenson et al  for a recent publication on this method.

Stevenson, B. C., Borchers, D. L., Altwegg, R., Swift, R. J., Gillespie, D. M., & Measey, G. J. (2015). A general framework for animal density estimation from acoustic detections across a fixed microphone array. Methods in Ecology and Evolution, 6(1), 38-48.

Welcome to the new blog and news section

We will be bringing you the latest breaking stories from the Measey Lab, and hoping to improve blogging skills.

I've added some stuff in retrospect (below), but will try to keep up to date with some of the events taking place in the lab...

Congratulations to the Lab team who won the ZSSA student pub quiz to the tune of a R500 drinking voucher at the Rat & Parrot, Grahamstown. It was a win with a narrow margin, mostly as André insisted that Rugby was a game originating in Norway! The clue's in the name, André.

Debra Stark, MSc student from the University of Queensland, arrives at the lab to work on acoustic monitoring of Arthroleptella rugosa, a moss frog endemic to the Klein Swartberg.