Small surveillance cameras have never been cheaper, so why not spy on the great tits in your garden?
As the bird box season in southern England kicks off late February/early March, you need to start to plan NOW for the 2013 season!
Why do it?Although you won't get the kind of quality pictures we see on BBC programs like Springwatch (http://www.bbc.co.uk/springwatch), installing a cheap camera in your garden bird box will give you a special insight into the lives of some of your little feathered friends. Following the process of nest building, egg laying, feeding the chicks and finally fledging, can be a rewarding experience for young and old alike.
Basic configurationThe kind of camera normally used for bird boxes produces a composite video output designed for use with a television. In fact, if you still have an old analogue TV, this will make an ideal monitor.
Some cameras also include a microphone. The added dimension of sound is a great benefit, so choose this type where possible.
As there is very little light inside a bird box, most cameras used for this purpose include infrared lights (IR). Invisible to the birds, this light can be used day and night without problems, although it does give you a slightly weird grey-scale image. If the natural light level does rise during the day, the camera may automatically switch off the IR lights giving you either a monochrome or a colour image, depending upon your camera type. But once again, the shades or colours will look a little strange because the camera is so sensitive to IR light (I may discuss this future in a future post).
Buying a camera (or even a box with camera)You can now buy bird nesting boxes complete with camera kits from garden centres and on-line suppliers like this:-
But if you want to DIY, its usually best to start with the camera and then build a box. The reason I say that is because you need to consider the image area and the camera mounting arrangement first.
The camera shown below is a suitable (and cheap) colour camera available from Maplin:-
To focus, slacken the locking screw on the lens mount, and rotate the lens until the image is sharp.
Size Matters!The smaller garden birds (e.g. blue tits) tend to select nest boxes with relatively small openings. Presumably this reduces the risk of larger birds and other predators raiding the nest. However, birds such as the robin prefer to nest in open fronted boxes, even though this leaves them rather exposed.
Sometimes garden birds choose weird places to nest such as watering cans and traffic cones. But its best to follow sensible box designs when building your own to improve success rates.
Design GuideThere are plenty of designs available on the internet, so rather than providing a detailed design, here are a few design considerations.
This is a short list of birds with box opening sizes:-
- 25mm blue tit
- 28mm great tit, blue tit
- 32mm sparrow
- open robin
If this is your first and only bird box, I'd recommend a box with a 28mm entrance hole, as this is likely to attract blue tits or great tits.
These are the two species that commonly (and readily) occupy nest boxes, and you want to give yourself the best possible chance of success if you are only putting up one box.
Ten Quick Design Tips
- If you are using natural wood, this should be at least 15mm thick (a wooden fence gravel board is a good choice). If using exterior grade ply-wood it can be thinner.
- The floor dimensions should be a minimum of 110mm x 110mm. Its better to be narrow and deep so the birds can move to the back of the box, further away from the entrance hole and any danger.
- The access hole should be 28mm diameter.
- The access hole should be approx 125mm above the height of the floor.
- As the nest will probably be 50-70mm high, the camera needs to be high enough to capture the required view. This will also depend upon the focal length of the lens used/supplied with the camera. Also remember that the camera should be focused to where you expect the birds to be after the nest is built (i.e. not focused on the box floor).
- It is usually best to position the camera so that the entrance hole is not visible. This is because the light coming in through the hole will be bright, while the nest will appear too dark.
- The box should not be air-tight, but must protect the camera from water. So pay attention to the roof design, and maybe cover it with roof felt if required.
- The simplest place to mount the camera is usually directly above, mounted on the back wall. However, this gives the least interesting pictures. If your box is big enough, try mounting the camera above the entrance hole (at least 30mm clear above the hole) and direct it at an angle towards the back of the box (remember to focus where the "action" will be after nest construction).
- The camera has to be connected to a long cable, so either: 1) allow the connectors to be housed inside the box, or 2) protect the connectors externally (e.g. box, sealed plastic bag, I've even used an old water bottle).
- Fitting a hinged lid to your bird box is unnecessary. Its better to screw it down with a couple of brass screws. These won't rust, so it should be easy to quickly remove the lid to clear spider webs or re-align the camera.
Now! Where should I put the box?The first consideration is cable length. If your camera came with 20m or 30m of cable, you must allow for this, and some of this length will be consumed by the path between bird box and TV. Extending this cable may introduce noise, as the cable supplied is usually low quality. So if your cable is not going to be long enough, it may be better to buy a better quality [longer] length to replace the original cable.
Try to find a location where the box can be mounted about 2m above the ground, with the entrance hole facing out towards reasonably clear space (i.e. don't bury the box in a bush, or face it towards a wall or fence that is just a few feet away!). If you can see the box from your house (especially from the comfort of a easy chair) so much the better, as you will be able to witness the birds behaviour both inside and outside the box.
If you have bird feeders (and if you don't, you should have) do NOT put your bird box nearby. I'd suggest that the box should be 10m away. If this is not possible, then at least face the box away from the feeders. Maybe move the feeders if this is easier, at least during February to June.
If possible, avoid easy access for cats, as they seem to be the biggest single reason for avian loss of life! Ultrasonic cat deterrents do work on young cats with good hearing (and young people). Old cats with bad hearing don't bother to harass birds.
Some articles are very specific about bird box orientation (e.g. "don't face it due south as it will get too hot!"). But we have had success with boxes pointing roughly north, south, east & west. In the spring, the sun is lower in the sky but relatively weak. As spring turns to summer the sun gradually moves over-head at midday. So a south facing box gets the benefit of the sun during the cooler months earlier in the season, while in summer the sun is too high to shine directly through the entrance hole and cook the chicks.
Nest boxes can get very hot by the end of May/early June for any orientation where the box is not shaded for most of the day. So the branch of an over-hanging tree can provide some relief.
Watching and WaitingDon't sit in front of your TV for hours on end, waiting for a bird to turn up. It will drive you crazy!
- Turn your TV on for a few minutes each day during March. What you are looking for are signs that something has been in your box. I usually put a few bits of dried grass in the box as an indicator. You quickly get used to the pattern, so its easy to see if its been disturbed.
- If your camera has sound, you may be able to connect it to a simple amplifier (like the cheap active speakers available for computers) and leave this on with the volume turned up. This acts like an audible alarm, as you will hear anything moving on or in the box.
- DO NOT put food in your box to tempt visitors in.
- If you have a cold spell (especially if it snows from December to March) you may get over-night boarders!
- Potential couples should be visiting your box during March and April. If nest building has not begun by the end of April, you have probably been unlucky...try again next year!
Your Garden Birds May Not Have Read This!Surprising at it may seem, not all garden birds have internet access, so they may not have read this post. One of the great pleasures in watching garden birds is witnessing unusual behaviour.
All the "rules" listed in this post are there to be broken. They are just offered to you with the hope that you will be successful, and this will encourage you a put up more nest boxes, and maybe experiment a little.
May the force of Bill Oddie be with you! http://www.billoddie.com/