Nest box

Western Bluebird leaving a nest box

A nest box, also spelled nestbox, is a man-made enclosure provided for animals to nest in. Nest boxes are most frequently utilized for birds, in which case they are also called birdhouses, but some mammalian species may also use them. Placing nestboxes or roosting boxes may also be used to help maintain populations of particular species in an area. The nest box was invented by the British conservationist Charles Waterton in the early 19th century to encourage more birdlife on the wildfowl and nature reserve he set up on his estate.

Construction

General construction

Several bird houses

Nest boxes are usually wooden, although the Purple martin will nest in metal. Some boxes are made from a mixture of wood and concrete, called woodcrete.

Nest boxes should be made from untreated wood with an overhanging, sloped roof, a recessed floor, drainage and ventilation holes, a way to access the interior for monitoring and cleaning, and have no outside perches which could assist predators. Boxes may either have an entrance hole or be open-fronted. Some nest boxes can be highly decorated and complex, sometimes mimicking human houses or other structures. They may also contain nest box cameras so that use of, and activity within, the box can be monitored.

Bird nest box construction

Birdhouses in Gramercy Park, New York City, note the use of different diameter entrance holes

One of the most important aspects of a nest box determining the exact bird species that will use it is the diameter of the opening. Most small birds do not like the opening to be too large to prevent other birds from raiding it, so having the size of the opening exactly right increases the chance that the intented specific bird species will use it. For example, in European countries, an opening of 2,5 cm in diameter will attract Poecile palustris, Poecile montanus; an opening of 2,8 cm in diameter will attract Ficedula hypoleuca, and an opening of 3 cm in diameter will attract Parus major, Passer montanus, an opening of 3 cm in diameter will attract Passer domesticus

Another aspect that determines the bird species that will use it is the size of the nest box itself. Different sizes suit different species of birds; for example, very small boxes attract wrens and treecreepers and very large ones may attract ducks and owls. Seasonally removing old nest material and parasites is important if they are to be successfully re-used.

Then, the type of material used is also of importance. Blue Tits, Great Tits and Tree Sparrows have been shown to prefer woodcrete boxes rather than wooden ones. Birds nesting in woodcrete sites had earlier clutches, a shorter incubation period, and more reproductive success, perhaps because the synthetic nests were warmer than their wooden counterparts.

Finally, the placement of the nest box obviously is also an very important aspect. Some birds prefer their nest box to be at a certain altitude at the tree, some birds (as ducks) them to be very low or even at ground level. Also the orientation to the sun is of importance (south facing ones—in northern hemispheres—tend to be warmer than south-facing ones), ...

Bat nest box construction

A typical bat house affixed to a tree trunk

Bat boxes differ from bird nest-boxes in typical design, with the larger opening on the underside of the box, and are more often referred to as roost boxes, although in regards to the rearing of young, they serve the same purpose. Threatened bat species can be locally supported with the provision of appropriately placed bat-boxes. Bats are a means of natural mosquito and insect control in some parts of the world. A single bat can eat 500 to 1,000 mosquitoes per night as well as other insect pests. Directions for making the open bottom bat houses for small and large colonies, as well as locations to purchase them are available on the internet. Bat houses are an ecologically friendly way of controlling mosquitoes as pesticides mostly kill the mosquitoes' predators rather than mosquitoes. Australian Bat Box projects have been running for over 12 years in particular at the Organ Pipes National Park. Currently there are 42 roost boxes using the "Stebbings Design" which have peaked at 280 bats roosting in them. The biggest problem with roosting boxes of any kind is the ongoing maintenance; problems include boxes falling down, wood deteriorating, and pests such as ants, the occasional rat, possums, and spiders.

Other creatures

An unusual case of two wasp nests inside one nest box purposefully set for Boreal Owls.

Nest boxes are marketed not only for birds and bats, but also for butterflies and other mammals, especially arboreal ones such as squirrels and opossums. Depending on the animal, these boxes are used for roosting, breeding, or both. Or, as in the case with butterflies, hibernation.

Wasps may build their nests inside a nest box intended for other animals, and may exclude the intended species.

Birdhouses

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  Typical nest boxes in the UK
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  Multiple nest box and feeding station
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  Holk uppsatt för vetenskaplig studie.
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  Californien.
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  Norway.
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  Nashua River.
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  New Jersey.
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See also

• Biological pest control: birds can help controlling pests in agriculture; section also details the planting of food crops for birds
• Artificial bird nests

External links

• Nest box page from the Royal Society for the Protection of Birds.
• Birds Australia Information Sheet 5: Nestboxes for Natives PDF download
• Rob McDonald, "Birdhouses," Southern Spaces, 12 July 2006. http://southernspaces.org/2006/birdhouses