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Wren perched on rounded hole of bird box with insect in beak

Wren nest box hole size

What size hole does a Wren house need would be a larger then normal one, whether its in an open fronted style or a large rounded hole.

Wren nest box hole size can be a safe 140mm by 140mm if making or buying a box for the purpose of attracting a Wrens. And while this would correspond to a square open fronted box, it can be made more rectangular. However, to use a nest box using a rounded hole shape, make it one in 45mm or larger.

Seeing as Wrens do use nest boxes, its important then to set one up in your garden with the possibility of attracting them to nest come spring time.

While a bird box intended for Robins would do the trick, so to can a nesting box made for smaller common garden birds. But to go down this route a Wren bird house does not need a perch, as the box shape doesn't require it or ever going to need it.

What it must be of course is to be easily accessible. Rather than accessing the nest box via the entrance hole then - make it a bird box you can open as to clean it out come the end of nesting season.

Nest boxes intended for Wrens require a hole size that reflects what is built in the wild, so a large rounded hole or a wide rectangle or square hole should do it.

But where to place a Wren nest box may be a little more important than an exact hole size, so fix it 2m high off the ground while burying it deep into ivy or a hedgerow.

What a Wren nest box must be then is a wooden box with a wide open front that is the same width of the box; or use a rounded hole like regular bird boxes, but it must be a larger then normal 45mm rounded hole.

Open rectangle shape

To begin with, to know what is the correct size for a nest box intended for use by a Wren, understand the shape can encourage or deter them.

You probably should play it safe with a bird box hole in a rectangular or square shape.

Wren's are known to steel Robin bird boxes, so for them to use a bird box designed for Robins with a large open front, that is a sure fire way to know a large opening is going to be welcomed.

As Wrens are Britains smallest garden birds, they still require a large opening to feel safe to nest - so this wide or square open front can help with that.

Make it a nest box with a large rectangle - or square - bird box entrance hole then to be on the safe side.

Entrance hole of 140mm by 140mm

Its important to know there is no definite nest box hole size that can encourage or deter Wren's - but you can offer a hole size that would satisfy them the most.

I believe a bird box hole size of 140mm by 140mm is the best possible hole size.

It absolutely can be a centimetre or two larger or smaller, but you should be in safe hands if using a square shaped bird box hole.

There's certainly no harm in re-shaping the hole size by making it a little wider, as to create a rectangular entrance hole if that is what you prefer.

As a rule of thumb, the height of the bird box would take up half the size of the bird box height - while the width of the entrance hole would correspond to the full width of the nest box.

Large rounded hole of 45mm

As it happens, a 140mm by 140mm is a safe hole size to attract Wrens, and so to Robins, but a rounded hole shape can be considered.

House Martins use this preferred hole size for their nest box but use a cup design box, so you couldn't really buy a House Martin nest box to accommodate a Wren.

So to so Starlings use a nest box with a 45mm hole size, but their box size could be too big - but it could be an option.

Much like Starlings who use a 45mm, this is probably an entrance hole size you should be shooting for, while a more readily available bird box using a 32mm entrance hole could be an option.

Now it must be said a larger, rounded hole nest box is more difficult to buy, so you'd have to modify the hole size yourself if you need it larger.

Replicate Robin box specifications

If you wish to buy a bird box for a Wren, they would be far and few in terms of availability, but that is only because they are not sold as Wren nest boxes.

Instead, it could be you'd have to buy a bird box for Robins as the full specifications usually replicate the needs for a Wren.

Common Robin nest box hole size would be in the region of 200mm by 200mm, so while a little too large for Wrens - that is not to say they won't give it a go.

In terms of the robin box size or design, so to can this be used by Wrens as they tend to use a wooden bird box intended for a Robin regardless.

To buy a bird box intended for a Robin would be within reason then, but so to buying a nest box for small birds - or at least would be promoted as.

Wren nest box hole size summary

Wrens would happily nest in a bird box with an entrance hole that reflects what they build in nature, so a square, rectangle or rounded hole size would do.

To make it a square Wren nest box hole I would recommend a safe 140mm by 140mm hole size - or a 45mm hole size if its a rounded entrance hole.

Starlings use this bird box hole size but their nest box is far too large, so I would buy a bird box made with a 32mm hole size, which could be suitable for Wrens.

No definite Wren nest box hole size I'm afraid so its a matter of testing different bird boxes with a larger then normal open front or big rounded hole.

Thankfully, nesting boxes promoted for Robins is exactly what you'd need despite the readily available bird box wide open entrance - being a little larger then what is needed.

Instead then go for a Robin bird box that uses a small square or triangular shaped hole which is just what our Wrens need.

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