Urban Nest Box Services
Peregrine Falcons do not build a nest as we know it like most other species; they can and often do lay eggs on minimal roof top substrate/debris.
Unfortunately in many cases due to bad positioning and usually inexperienced birds they often fail, due either to egg rolling or exposure to weather conditions. Many 1st time attempts often flood out and the eggs are chilled.
This is due to the fact, that the female (Falcon) will create a depression with her breast, to try and contain the eggs on the roof substrate to reduce the chance of the eggs rolling away. As such it means that peregrines can lay just about anywhere on a rooftop/top of a building/structure.
I design, build and install quality peregrine nest boxes made to order and often customised to suit the building/structure in question, but as much depends on positioning as to the design, in many cases if a 'natural' overhang exists I will place a Tray instead of a Nest Box. In all cases, whether a Nest box or Tray is used they will contain 80-100mm of substrate. This allows the Falcon to make a deep depression (known as a scrape) in the substrate to hold the eggs and stop them from rolling.
Peregrine Falcon nest boxes are not small; an adult female peregrine is a Crow sized bird and needs a nest box with enough space for her to lay and hatch the usual 3-4 eggs. The chicks will soon start to move around and once they have become three quarters to fully grown juveniles they will need plenty of room to exercise.
This is very important as fledging peregrines do have a tendency to finish up marooned on the ground if weather conditions are not suitable on the day of their maiden flight. The high success rate I am now able to achieve is largely due to my surveying the structure/area beforehand to determine which areas of a building/structure they use and are comfortable with. A structural positioning survey is essential beforehand for placing a nest box. If arrangements for this have already been made by customers further afield, I also make nest boxes for delivery.
On some occasions the building/structure dictates the direction of the Nest box/Tray but in most cases I will position it to face North through to East, this avoids the predominant Westerly – South Westerly winds nowadays.
When roosting/resting up or incubating peregrines do not like winds/drafts and will seek a sheltered perch out of the wind, this is why direction is important. Nest Boxes could well be ignored by the birds if not placed in a suitable location and facing the right direction.
Another factor that makes positioning of a nest box paramount is that juveniles need a lot of exercise space to build wing strength and muscle. Careful positioning of the nest box, where possible, allows for juveniles to access larger areas to exercise, this also gives them more room and consequently will be better prepared for that all important 1st flight.
In more cases than not I will try to design the nest box so that it allows access to adjoining areas/rooftops on the building/structure.