Steve's Herpetological Blog

An insight into the life of Steve, his research and the many books he reads

#SciFri

#SciFri: What torches do I use during amphibian surveys?

One of the conversations that will probably come up this weekend at the Herpetofauna Workers Meeting in Sheffield regards what torches we should be using when conduction amphibian surveys. At this time of the year, as we enter the amphibian breeding season, I am often asked what sort of torches and other equipment I use when out surveying amphibians by torchlight. There are a number of industry standard such as Clulite Clubman, which is without fail one of the best torches for surveying for amphibian on the market. However, Clulites are typically quite large, cumbersome and expensive. Most people surveying for amphibians within the UK and Ireland (and perhaps further afield too) are volunteers and may not necessarily have £125 to spend on a torch. Therefore, I am going to introduce you to some cheaper alternatives that do just as good a job. I have used them since 2013 and they are still going strong – all of the amphibian-related publications and research I have conducted since have utilised at least one of these torches at some point. One of the things I think is important from the start it point out that lumens and candlelight are not comparable units of measurement, and that the sellers of the products I have listed below may slightly overstate the power of their torches where they have conflated these two.

A large carpet of common frog (Rana temporaria) spawn illuminated by one of the CREE LED torches linked below, highlighting how bright they are and how wide an area they illuminate on their widest setting.

When it comes to handheld torches, I like something that is compact, can easily fit in a pocket or your bag and doesn’t take up too much space. This is one of the reasons why I moved away from using Clulites, although I have used them multiple times when conducting toad patrols with the Cambridgeshire and Peterborough Amphibian and Reptile Group. I therefore explored a few different options with my colleague Mark Goodman, until we found the winning formula. The torch from our experience that has the perfect balance of brightness, battery life, use and durability is a generic CREE LED torch. This may not look like much but it performs extremely well for the price, which is one of the most attractive features. The torch is also waterproof, can be used underwater for extended periods of time, and the beam can be focused to a single point. This is extremely useful when ponds may be slightly turbid or you want to point out your observations to others in the group you are surveying with.

A male and female great crested newt (Triturus cristatus) in the act of courtship, note the glare artifact that is caused holding CREE LED torches at too high an angle in relation to the surface of the water when conduction amphibian surveys

Following the philosophy that switching to your sidearm is quicker than reloading, I always carry two just in case. If you’re worried about running out of power when in the field, then you can always purchase one of the torches with additional batteries just in case. Depending on the purpose of your surveys, you may not want a bright white light, you may want a red light instead. Don’t worry, the torch gods have you covered as you can get one of these versatile little torches with a red CREE LED as well! These are perfect for when you’re trying to reduce your impact on amphibians while undertaking your surveys. One thing that I should warn you about is that the bright white light of the torches doesn’t cut through turbid water as well as the more warm yellow light that a Clulite produces. This hasn’t yet been an issue but if you’re switching from a Clulite to a CREE LED torch, then you may need to slightly later your technique to make the most out of the torch.

My colleague Mark Goodman using one of the head torches linked below while swabbing a common midwife toad (Alytes obstetricans) that is being held by Liam Smith.

Another piece of important equipment to consider is a headtorch. Headtorches provide directed light, which for helping to illuminate the area ahead of you, when you’re recording data or aiding in reducing the risk of tripping etc. Again, there are some standard headtorches that seem to be used in ecology – mainly those produced by Petzl. I have tried these and unfortunately, they don’t seem to last very long given the abuse of being out in the rain or being used for extended periods of time, before they die. Therefore, I have been using a CREE LED headtorch for a very long time now – with this one being the first one I bought and still use (this is the one Mark is using above). I have also experimented with a headtorch which is very much like the handheld torches I use, whereby the light can be focused to a single point (this is the one I am using below). These again are quite versatile and I carry one as my back-up, or lend it out when someone else joins me and they don’t have a suitable headtorch. It is probably worth mentioning here now that I have used all of the torches listed above in other countries too, such as Malaysia, Tanzania, Singapore and the United States. All are still going strong!

A photo of me using the second headtorch linked above back back in early 2017 while undertaking an amphibian survey in Cambridge. Note that the headtorch has been turned off here to ensure the sheet I was writing on was visible.

Hopefully, that information and those links I have provided give you a little something to think about. The final consideration that you need to make is how you’re going to power them. All of the torches above use 18650 batteries, which was another consideration in their purchase – a common power source across them all. Ten years ago, 18650 batteries were quite expensive but thankfully because they are used in a number of vapes, their price has come down. What I would recommend is that you buy some additional ones, such as these, to use for when the ones in the torches inevitably die after a long evening of use. The charger I use for my batteries is the Nitecore I4 V2, which quickly charges a whole range of batteries, not just 18650s. This is the newer model of a Nitecore charger that Mark and I first experimented with over a decade ago with, which he purchased from Maplin (which probably ages these tests as Maplin went into administration in 2018). Make sure your spare batteries are kept somewhere secure and dry when you are in the field, and you should have issues when it comes to changing them should you need to. Something again to be aware of is sellers overstating the capacity of batteries, they’ll typically have 2,300 to 3,600 mAh at 3.7 volts.

My Nitecore I4 V2 charging some 18650 batteries ahead of an amphibian survey. Note I have added my initials to the batteries to help distinguish them from my colleagues.

The professional ecologists reading this may be a little confused, assuming that I used all of the ‘proper’ tools that they are used to. Amphibian surveys have always been a hobby of mine and so I have sought out ways to do things as effectively as possible on a budget. Seeing as these solutions have worked and stood the test of time, I haven’t really felt the need to change them or update my equipment. The only things I have done in recent times is to buy some additional batteries to replace some that I bought many years ago that have come to the end of their functional life. Therefore, if you’re just starting out and you’re not undertaking surveys as part of your paid work then I would recommend everything listed above as it has enabled me to make a difference for more than a decade now! If anyone reading this has been in the field with me, none of the above information will be new. However, for those of you that haven’t I hope it was useful and best of luck surveying amphibians! If you have any questions or comments, please leave them below.

Please note: Not all of the products listed above may match those in the photos, unfortunately different sellers produce near identical products today compared to a few years ago so I have tried my best to match these where possible. Thanks!

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