As a Bluebird nest box Monitor, you are responsible to MBTCS to care for your trail, and when you are no longer willing or able to help us, to let us know you are turnig your boxes back to us to re- assign to an able person!
Bluebirds usually raise two clutches of young in a typical year.  And you should clean out your boxes between nestings.

Bluebird nest box monitors and bluebird banders should take particular note when they are cleaning out nests from their boxes. Use caution when cleaning the boxes.  Your health may be at stake.  But it’s not the bluebirds we have to fear; it’s deer mice who may have made a nest in a box and not one of our feathered friends!

When cleaning out a bluebird box make sure you stand upwind.  Also wear gloves, and a face mask is a suggested recommendation.  After removing the old nest, whether bird or mice nest, clean the interior and spray the walls, ceiling and floor with a 10% bleach solution.

A mouse nest is something of particular concern.  Deer mice, one of our most common rodents, may carry the hantavirus, which can produce HPS (Hantavirus pulmonary syndrome.)  HPS can be a very severe condition and in a few cases has been fatal. 

The danger to you comes from being in contact with the urine, feces, or waste of infected mice.  It is possible to breathe in dust particles of this infected material!

This virus can result in flu-like symptoms in humans before it develops into something more serious.  According to the Canadian Lung Association (

“Symptoms usually appear about two to three weeks after being exposed to the virus. These early symptoms include:

  • fever
  • muscle aches (especially in large muscles like the thighs, hips, back and shoulders)
  • feeling very tired

Some people may also feel dizzy, get headaches and have stomach pain, diarrhea and/or vomiting.

If you develop any of these symptoms you should seek medical help.  While there is no specific cure, the earlier the treatment for HPS the better the chances of recovery. Developing HPS is not common.  It is a rare condition.  But having said that there have been at least 24 cases of HPS on the prairies during the past 20 years and over that period there have been 7 associated deaths.

“Deer mice surveys for hantavirus were done in Alberta around a decade ago. Between four and 23 per cent of mice were positive. There was no correlation between the number of mice and the number of human cases.”

This report is not meant to scare you; it is designed to remind you to take appropriate precautions when cleaning out your bird boxes.  If you are using the latest bluebird boxes on your trail, at year’s end it’s best to leave your box floor down (or open) so that nothing (no mice) can enter the box over winter and develop a nest.  Then at the start of next year before your bluebirds arrive, replace the floor to its usual position.

By the way, when you use rubber gloves to help clean out boxes make sure you disinfect the gloves after they are used.  That means spraying them with a 10% bleach solution too … before you clean out the next box.

Good luck with your birds.