We also have an interesting article from Stephen Powles who has been doing some camera trapping of otters.

Transcription

1 Summer 2013 Hello and welcome to the Summer 2013 newsletter. Summer is finally here and it s time for the June otter survey. If you are an otter spotter, you will find your survey forms attached/enclosed with this newsletter. If you ever run out of survey forms for your otter surveying, just a reminder that you can download the survey form from our website You can also use the website to send in records of any other wildlife you may see whilst out and about. Thank you to those who attended our otter spotter training day at Yarner wood in March and to those of you who have taken on a new site. In this newsletter you will find some of the answers to the tricky questions you asked us on the training day which James Williams, otter expert has kindly answered for you. We also have an interesting article from Stephen Powles who has been doing some camera trapping of otters. Thank you for continuing to survey for otters and for sending in your records. Best Wishes Caroline Caroline Jones Devon Biodiversity Records Centre cjones@devonwildlifetrust.org

2 Otter spotter training day on 9th March Photo: Alex Sams DBRC held our annual otter spotter meeting and training day on the 9th March at Yarner wood Nature reserve on Dartmoor. The training was very well received. Feedback from people who attended the event has been excellent and everyone seemed to enjoy the day. The morning was a classroom session led by Ellie and Caroline from DBRC about otter ecology, recording otters and the work of DBRC. Albert Knott from Yarner wood nature reserve also talked about the work he would like to do to record otters in the Bovey Valley woodlands. In the afternoon we went out into the Bovey Valley and surveyed 3 stretches along the River Bovey where we found recent signs of otter activity. Twenty three people attended the event, a mixture of existing and new otter spotters as well as 4 students from Hungary! Twelve of those who attended have taken on new operation otter sites to survey. Some of the volunteers are going to help Albert with his study at Yarner wood. Thank you to everyone who attended the day and to Albert and the volunteers at Yarner wood who helped to make the day a success.

3 Your questions, answered!.. James Williams Attendees of the otter spotter training day asked us so many questions, we had to consult an expert to get the answers to some of them. So here they are, courtesy of James Williams, otter expert in true James Williams style: Q. How far can otters smell spraint? A. Scent varies according to weather and atmosphere, so the distance will vary too, but it would be a very bad scenting night if the pong could not cross a British river! Q. How long do otters smell the spraint for? E.g. even when its old? A. Some of the scent remains for ages, but it has a half-life component which means that they can date it for freshness. No reaction much to stale news! Q. How long after they have eaten do otters leave spraint? A. Sometimes about 4 hrs. They have a rapid throughput from a very high metabolic rate. Q How long after they have eaten do otters leave anal jelly? Do otters only produce anal jelly when they can't spraint, or can they produce it at the same time as spraint? A. Nobody knows whether AJ just happens when there is an accumulation to get rid of, or whether an otter can decide to give this rock a shot of AJ rather than a spraint. Q. We know that competing males fight each other but how do males compete with other males for territory in terms of spraint e.g.- would they spraint in the same area as one otter has already sprainted to signal they are there? A. Boundaries can get marked by both contenders. But spraint is not only aggressive/defensive. Family bonding and partner seeking also come into it. Thank you James for answering these questions! An Evening of Otters, Devon Mammal Group (DMG) 7pm, Thursday 24th October 2013 White Hart Hotel, South Street, Exeter, EX1 1EE If you would like to hear more from James Williams and other otter experts, Devon Mammal group are organising an event in October called An Evening of Otters. There will be 4 specialist speakers looking at different perspectives on otters: Dr Paul Chanin will discuss the implications of the 5th English otter survey and James Williams from Somerset Otter Group will discuss their detailed studies evaluating the number of otters on a catchment; Mary Rose Lane will discuss the challenging issues of otters and fisheries and Miriam Darlington will talk about her extraordinary year s search for the wild otter from Devon and further afield. There will also be an update on DMG otter projects. Otter books will be on sale. Please note there will be a pit stop and drink re-fuelling session between speakers 2 & for DMG members, 3 for non members. Booking essential, please contact Sue Smallshire on or suesmalls@btinternet.com to book.

4 Otter spotters needed at Yarner wood Albert Knott Natural England are asking for volunteers to help with surveying for otters across East Dartmoor National Nature Reserve near Bovey Tracey. The aim will be to cover as much of the reserve as possible looking for signs of otter up the river Bovey and its tributaries and other wet woodland habitats with the aim of trying to demine and their potential use of communication corridors between watercourse. If you are interested please contact or as it will help the two students covering the area over the summer months. Yarner wood nature reserve Camera Trapping of Otters Some Tips (Part 1) Stephen Powles Spraint surveys, as done by, are an excellent technique for detecting the presence or absence of otters. If whole river systems are surveyed on the same day,

5 spraint surveys may also give an idea of the likely number of territories. If the survey is completed on one day and repeated 24hrs later to check for fresh spraints, the results are likely to be more meaningful. The Somerset Otter Group organises an annual Two-Day Event (see ) to estimate the number of otter territories in Somerset. In addition, foot prints will give some idea of the size of the otter and the likely direction of travel. For animals that are elusive and largely nocturnal, as is the case with most of Devon s otters, camera traps are a new and useful study method. Downloading the SD cards is exciting and becomes quite addictive! Using camera traps can be challenging in any species but, in the case of otters, the aquatic environment, their excellent insulation and their rapid movement increases the challenge considerably. Having spent over three years using numerous camera traps of various makes and models this is intended to be the first of a number of articles in which I will be passing on some tips to help anyone looking to use camera traps in general and for otters in particular. Are all camera traps the same? No, far from it! Important considerations are: 1. Does it detect otters? Most importantly it appears that some simply do not detect otters! Admittedly I have only tested one of each but neither my Prostalk PC3000 nor HCO ScoutGuard SG550V has succeeded in detecting an otter. 2. Is it fast enough to photograph an otter? A major limitation is trigger speed. This is the speed at which a camera takes a picture (or video) after an animal has been detected. With an otter often spending only a few seconds at a spraint site, a trigger time of more than 5 seconds will often fail to get an image of the otter. Reconyx cameras have very fast trigger speeds (fractions of a second)and Bushnell cameras (less than one second) are also relatively quick. Cameras using conventional flash to illuminate at night, rather than LEDs, are very slow but do have the advantage of producing a colour picture. Moultrie D50 3. How long do the batteries last? Some only last a few days; others (such as the Bushnell or Reconyx) may last for many weeks or months. 4. Do you want video clips as well as still images? Not all cameras will record video at night (e.g. most of those using flash will not).

6 5. Interval between still images. Whilst videos are great to watch they are slow to look through, use more battery power and can soon fill a SD card. For survey work it is often easier to set the camera to take still images. Most cameras will take three or four images in quick succession which is usually enough to show which direction the otter is travelling but the interval between the images needs to be not much more than one second. Some are very slow (e.g. eight seconds for the Spypoint IR-7). 6. Does it need to be covert / black? The more expensive models have LEDs that are not visible to the naked eye (of humans!). This does not appear to be a big issue with otters although some appear to be aware when the camera switches on. 7. Price. Some are under 100, most are and some are over 400. It is very difficult to recommend any one camera but of the ones I have used, the Bushnell range is a good compromise. The Reconyx are excellent but expensive and do not take video (although they take an infinite number of still images in quick succession). The Spypoint IR-7 is less expensive, takes reasonable video but has along interval between still images. My next article will give tips on where and how to site camera traps and some tips as to how to avoid losing them in a flood! I would very much welcome hearing of your experiences using camera traps ( s.w.powles@btinternet.com ), especially as to which ones have and have not worked well for you. Many thanks to Ambios ( ) and Devon Mammal Group ( ) for helping with my work. Otter spotter Danny Jarvis On the subject of camera traps, otter spotter Danny Jarvis and his partner Vandela have a camera set up outside their house on the River Lyn near Lynton and have some fantastic photos and footage of otters, mink, otter spraint and salmon eaten by otters! Check out their website Half-eaten salmon on rock outside Danny and Vandela s house!