Protocol - Installing trail cameras for merlin

Aim

• To clarify the procedures to be used for installing trail cameras on merlin nests and at plucking posts.
• These cameras are being used in order to (a) assess prey composition and provisioning rates to merlin chicks, and (b) share footage from active nests with the public.

Equipment list

• Trail Camera
• SD cards (capacity TBD)
• Lithium AA batteries
• Camera support posts
• Camouflaged adhesive tape
• Cable ties/plastic coated wire
• Secateurs/scissors
• Krylon camouflaged paints

Preparation

• At least 8 weeks before the trail cameras are to be deployed, all kit should be programmed and tested (preferably outside) to ensure it is working correctly. Settings should be tested prior to deployment to optimise battery life and storage capacity.
• Trail cameras and ancillary equipment must be camouflaged and taped/painted with appropriate colours to match local vegetation at nest sites.
• Suitable sites to install cameras in all three regions should be considered before deployment is attempted to reduce disturbance of breeding merlin.

Background

• In the North Pennines study area, merlin nests are typically visited three times by a licenced ringer, once to locate the nest, a second visit to determine hatching success and hatch date, and a third visit to ring fledglings. These visits give us the opportunity to install trail cameras at merlin nests without causing more disturbance than in a typical year.

Installation

At nest:

• Suitability of nests for recording video footage (e.g., less dense canopy cover) should be considered before deployment to identify suitable camera sites. This may be considered during the first visit to locate the nest, during the incubating stage.
• The trail camera is to be installed during the second visit the licenced ringer makes to the nest to age chicks and removed after fledging.
• Installation should not be attempted in adverse weather conditions (rain/snow/high winds/fog).
• Two people should be used to set up the camera (the licenced ringer and one person with experience of setting up the equipment prior to deployment on a nest). This will keep time spent at the nest and in the vicinity to an absolute minimum.
• Ideally, the camera needs to be mounted to the support post and disguised with sprigs of heather and other local vegetation, prior to deployment, to reduce time spent at the nest. Ensure dark-coloured zip ties, plastic coated wire, scissors and secateurs are carried for this purpose. Wire can be used to ensure heather does not blow across front of the camera.
• If possible, place the camera on the south side of nest to avoid pointing into direct sunlight.
• The camera head should be secure, and the camera/support post placed in the least intrusive position possible, not blocking the entrance to the nest.
• The camera needs to be positioned about 1.5 m from the centre of the nest cup, looking across into the nest. A slim white stick temporarily pushed into the ground behind the nest, facilitates quick setting of the camera. Do not allow the camera to point upwards as this will leave camera vulnerable to direct sunlight and rain.
• Ensure the camera is firmly fixed and supported to ensure it does not get knocked over by the female or active young.
• Do not allow the camera to sit above the height of the surrounding heather.
• Ensure the memory card is pushed into the recording unit correctly and programmed to record 2-minute videos at the correct picture quality (programming details to be confirmed after testing cameras, optimising for storage capacity and battery life.)
• Trail cameras have an internal screen to check camera positioning and fine-scale adjustments can be made to the camera/heather positioning at the nest.
• The people at the nest should then retreat and watch to ensure the female returns to the nest within at least 45 minutes. If she does not, then go back and remove the trail camera. Then watch again to ensure she returns.
• When the female does return to the nest, keep watch from a distance for a minimum of 1 hour to ensure that she stays at the nest.
• Note: It is important to remember all birds are individuals and will react differently to disturbance. Some birds are known not to tolerate cameras at all. Knowing the individual bird before going to install a camera will allow you to minimise the disturbance and tell if the female is upset in any way. Expertise should be sought to better understand the behaviour of nesting merlin before cameras are deployed so abnormal behaviour can be noted and steps taken if necessary.
• Trail cameras should be removed after young have fledged to avoid further disturbance.
• Upon removing SD cards, each one should be marked with the location ID and date on a piece of masking tape to avoid confusion when accessing data later.

At plucking post:

• Plucking posts should be identified prior to deployment using signs such as white-wash and prey remains.
• Trail cameras are to be installed at identified plucking posts at the same time as deploying trail cameras on merlin nests to limit disturbance to the birds.
• Installation should not be attempted in adverse weather conditions (rain/snow/high winds/fog).
• The plucking post should not be approached for setup or maintenance of trail cameras if there is a merlin at the post. Check from a distance (500 m) to ensure post is empty before approaching.
• Two people should be used to set up the trail camera (one of which should have experience of setting up the equipment prior to deployment). The second person can help test the camera is correctly positioned.
• If possible, place the camera on the south side of plucking post to avoid pointing into direct sunlight.
• The camera needs to be positioned about 1.5 m from the plucking post, looking horizontally where the merlin is expected to pluck prey. Do not allow camera to point upwards as this will leave camera vulnerable to direct sunlight and rain.
• The direction in which the camera faces the post should be determined by assessing prey remains on the ground. Assume the merlin will face the direction where most prey remains fall while plucking and align the camera facing this direction.
• Ensure the camera is firmly fixed to a 50cm (2x2 cm) post, or other suitable post, and supported to ensure it doesn’t get knocked out of position.
• The camera needs to be disguised with sprigs of heather. Ensure dark-coloured zip ties, plastic coated wire, scissors and secateurs are carried for this purpose. Wire can be used to ensure heather does not blow across front of the camera.
• Ensure the post is painted an appropriate colour and disguised with heather to reduce the chances of merlin using the installed post as a perch. The post should not extend above the height of surrounding heather.
• Ensure the memory card is pushed into the recording unit correctly and programmed to record 2-minute videos at the correct picture quality (programming details to be confirmed after testing cameras, optimising for storage capacity and battery life.)
• Trail cameras have a screen to check camera positioning and fine-scale adjustments can be made to the camera/heather positioning on the plucking post.
• Once set up is complete, the trail camera should be left for 2 weeks before removing camera. This should happen at the same time as the camera is removed from the nest.
• Upon removing SD cards, each one should be marked with the location ID and date on a piece of masking tape or to avoid confusion when accessing data later.