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A Pulley System for Large Nest Boxes

Photo © Jane Thompson/Macaulay Library

by Robyn Bailey (Project Leader), based on material by NestWatcher Lee Pauser

Lowering The Box

Lowering The Box

A Santa Clara County (California) Park's employee demonstrates how to lower a Barn Owl box using the pulley system. At this height, the box would be easy to clean.

Problem: Large boxes on tall poles

Many people would love to erect nest boxes for Barn Owls, American Kestrels, Wood Ducks, and other large cavity-nesting birds, but find that there isn’t an easy way to clean and maintain them once they’re ten feet up on a pole. I don’t know about you, but I don’t love climbing ladders propped against trees or poles on uneven terrain. Moreover, it’s usually not possible to drive right up to a box and unload your ladder, so the ladder must be carried afield on foot. In discussing this problem with Lee Pauser, a long-time NestWatcher and nest box enthusiast, he shared with me his pulley system that solves the “ladder problem” for about $25-30.

Lee’s plan for the pulley system is thoughtfully laid out and intended for a somewhat handy person with access to specialized tools. You may want to engage the help of a builder if needed. While that might add to the cost initially, think of the years of ladder-toting that you will be spared!

Pulley System Masthead

Pulley System Masthead

The heart of the pulley system is the masthead, made from garage door components and plastic plumbing parts.

Solution: The Pulley System

At a minimum, you will need to access your nest boxes once a year to clean and refresh the nesting material. Birds such as Barn Owls, American Kestrels, and Wood Ducks do not bring nesting material to the nest, so your initial deployment should include wood shavings as nesting material. Thereafter, these materials can be cleaned out and refreshed after each nesting season. You may also find unhatched eggs or deceased nestlings that should be removed from the box. This is much easier to do three feet off the ground than ten feet high on a ladder. For routine nest box checking, use a ground-based solution rather than raising and lowering the box to monitor for NestWatch.

These videos demonstrate lowering and raising the nest box. Note that this can be done by one steady-handed person.

Tips for Success

  • The design is intended for boxes weighing around 25 lbs. Some boxes can weigh up to 75 lbs, and may not be suitable for the components used in this design. Because this pulley system has not been tested for much heavier boxes, we suggest you replace the ABS (plastic) components with metal ones if your box weighs more than 50 lbs.
  • Use a 2″ diameter galvanized metal pole in a 12′ length to mount your pulley system. Sink 3′ of the pole into the ground with cement so that the pole’s final height is 9′. If you are concerned about vandalism and/or curiosity, you could increase the pole height to 16′ for more protection.
  • If you have multiple boxes, you can attach a winch temporarily so that one winch is not needed per box. This would reduce cost. If you only plan to service one box, then you can leave the winch installed on the pole.
  • Although the pole itself is a predator deterrent, snakes and raccoons might still be able to climb to the box. Although no setup can be 100% predator proof, you might wish to fashion a detachable predator guard that can come off when the box is cleaned.

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8 responses to “A Pulley System for Large Nest Boxes”

  1. Charles Smith says:

    A specific parts list would be helpful

  2. Jeff Scott says:

    This is an interesting design but the weight of the box is sitting on the cable all the time. It would be nice to devise a break or stop for the box or pipe clamps to sit on.

    Have you had any issues with cable failure?

  3. Lee Pauser says:

    One Barn Owl nest box with the cable system has been installed for over a year, and functions perfectly. The cables used are those used for garage doors which weigh much more than the nest box. I’ve never had a garage door cable break.

  4. Michael Hyatt says:

    Awesome! I have all parts and attempting to start this project. I decided to use just cable on the winch. Only BIG question how to cut slots in the PVC. How did Lee attempt this?
    Thank you!

    • Lee Pauser says:

      Since I wanted to make several mastheads, I made a jig to ease the task. The jig is made of ¾” plywood and consists of a bottom, one end and 2 sides into which the 4-3/4” length of 2” ABS pipe snugly fits. (I wish I could include a photo.) I drilled two 3/8” holes into each side of the jig exactly where the holes for the 4-1/2” bolts (pulley axel) are to be. I then inserted the 2” ABS pipe, drilled 2 holes into the sided of the pipe, and inserted the axel bolt to hold the pipe in place. After carefully measuring on my table saw where the slots are to be cut, I set the saw’s blade height to cut through the jig’s bottom and ABS pipe. Be careful not to cut more than 3-1/4”. The narrow stub can be broken off to finish the slot.

      Hope this helps…

      • Lee says:

        I should also have said that the open end of the jig will be where the slots are cut from. Also cut one slot at a time, and flip the ABS pipe over to cut the other slot.

  5. Z. Levi says:

    It seems like this design might allow the box to move radially with strong winds. I worry that this might cause nesting owls to abandon the box. To minimize the box rotating about the pole, I’m considering using a square metal post and welding up a mount to secure to the box. That said, I could be over-engineering this. Have you observed any issues with box rotation scaring the owls off?

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Cornell Lab of Ornithology

Cornell Lab of Ornithology