Different sizes for the same species ?

[Chkm8]

Went to buy some nest boxes today. Apart from the round versus rectangular there are numerous variations in depth which vary by several inches top to bottom. All carry the RSPB label but is there any preference anyone has noticed eg: a minimum depth from entrance to base as some even with the RSPB label appear very shallow.

John.

[KnockerNorton]

Hole-nesting birds generally prefer deeper boxes, I use at least 15cm from the hole to the floor. They will use shallower boxes, especially where they haven't got much choice, but they'll take a deeper hole if they can. It's a predation thing - deeper holes prevent predators reaching in and grabbing out the female/young/eggs.

[Chkm8]

Thanks for the info. I have 2 of the shallower ones and apart from roosting have not been used in 2yrs.

John.

Hole-nesting birds generally prefer deeper boxes, I use at least 15cm from the hole to the floor. They will use shallower boxes, especially where they haven't got much choice, but they'll take a deeper hole if they can. It's a predation thing - deeper holes prevent predators reaching in and grabbing out the female/young/eggs.

[jurek]

Hi,

It is better to use deep nest boxes. Otherwise cat etc. can easily pull out young birds.