Frequently asked questions
Below are some typical questions about monitoring nest boxes. Please click on a question link below to go directly to the answer. If you have a technical issue about entering your data, please click here instead.
When shall I start monitoring my nest box?
When should I stop monitoring my nest box?
There's nothing nesting in my nest box - should I record the fact that it's empty?
The nest in my nest box has been abandoned - should I still record it?
The female does not leave the nest box when I look inside - should I move her to see the nest contents?
My nest box contains an empty or abandoned nest - should I clean it out?
I've seen birds going into my nest box but there is no nest - what is happening?
Birds started building a nest in my box but have not laid eggs - is this unusual?
My nest box has fallen down with a live nest in it - what should I do?
Predators are trying to get into my nest box - what should I do?
The young have left my nestbox and are now on the ground in my garden - should I rescue them?
How do I safely monitor an open nest?
How do I record young feather length?
You can start monitoring your nestbox as soon as you put it up. Different species of birds begin breeding at different times, so you should refer to the species pages to find out when birds are likely to start showing an interest in your box.
Some species of birds (e.g. House Sparrow, Starling, Robin, Spotted Flycatcher and very occasionally Great Tit) will nest more than once during the breeding season and birds whose nests have failed early in the season may attempt to breed again. Birds will often use nest boxes that have already been nested in, so whether it has been used already or not, please carry on monitoring your box just in case any new occupants take up residence, at least until the end of August.
Yes please! Once you have registered your nest box please ensure you send us your observations over the season, even if you saw no activity at all - we're interested in finding out which boxes have been occupied, so that we can understand why this should be. For how to record details about an empty box, please see here.
Definitely. A record of an abandoned or destroyed nest is every bit as important as a record of a successful one as it helps us to work out what proportion of nests actually manage to fledge chicks.
During the incubation period, the female (and, in some species, also the male) will spend most of her time sitting on the eggs and may be there when you look in the box. If you encounter an adult bird sitting tight on the nest, simply leave it alone and carefully replace the lid. The birds do leave every hour or so to feed, so if you visit the box a bit later you might be able to count the eggs or chicks. If you can watch your box from a distance, you could even wait until you see the incubating bird leave. It doesn't matter if you can't record the contents of the nest at every visit.
Please leave the nest box alone until the end of the breeding season, even if it contains an abandoned nest and dead eggs and/or chicks. It is actually illegal to clean out nest boxes during the breeding season, from 1st February to 31st July, in case active nests are inadvertently disturbed.
Birds may explore prospective nest sites at the beginning of the season - even if they do not use the box for nesting, they may roost in it or simply feed on any invertebrates they find inside.
There can be quite a delay between the birds finishing the nest and the female laying the first egg. Occasionally, birds will build a nest but then decide to move to a different site, abandoning it before it has even been used. We're very keen to know how often this happens, so please record your visits even if no eggs have been laid in the nest.
If the nest has fallen on to the ground, approach the nest and quickly hang it back up again, making sure that it is secure enough to prevent it falling again. If the nestbox is damaged but easily repaired, try to mend it on the spot. If any nest contents have fallen out of the box, carefully place them back inside. If you have to replace eggs or chicks, make sure you place them right inside the cup of the nest, not at the edge. On the other hand, if the nest has fallen and the young have left the nestbox and look almost ready to fly, it is best just to leave them - do not attempt to catch them and put them back in.
There are various things you can do to a nestbox to help protect it from predators. However, if you do see a predator actually attacking your nestbox, it is best to let nature take its course. If you attempt to catch the predator or frighten it away, you may end up scaring the nesting birds away yourself and so do more harm than good.
It is common for newly fledged birds to appear on the ground or out in the open immediately after leaving the nest and unfortunately this is the time when they are most vulnerable to predators. However, the best thing to do is to let nature take its course. The parents will usually be close by and will still be feeding the young birds. If you attempt to catch the birds or move them along, you will scare both them and the adults. If you are concerned about cats stalking the birds, see if there are any measures you can take to deter cats from entering your garden right from the start of the breeding season.
It is perfectly safe to monitor nests both in boxes and natural sites. Scientific studies have shown that, so long as observers follow the NRS Code of Conduct, making regular visits to a nest does not increase the probability of it failing. For instructions on monitoring an open nest, please see here.
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