Starting Public Sites
Martin colonies located in public sites, such as parks, waterfronts, schools, museums, or gardens can be a great way to showcase this enigmatic species to the public, as well as attract more attention to a property. Martins are fun to watch and easy to study. In this area of the country, purple martins rely on humans to provide housing for them. Putting up a colony can help make your organization look more eco-friendly. However, there are some considerations to starting and maintaining a public colony site:
1. Confirm that you have the correct habitat for a martin colony. Do not erect housing near trees or in an area that will be impossible to manage, inaccessible to designated nest monitors, or in an area prone to vandalism. (See Resources for more info on proper habitat)
2. Decide who is going to fund and maintain the colony and make sure they have proper training on martin identification and nest checks.
Who is going to pay for the equipment initially, and who will pay for any repair parts that may be needed? Who will be the designated nest monitor(s)? Are all of the staff informed as to who will be monitoring the colony so that there are no misunderstandings? In addition, many well-meaning public sites have hosted bluebirds, tree swallows, house sparrows, or starlings when they thought they had martins. Make sure that you, the staff, or the volunteers take the time to educate themselves.
3. Choose quality equipment when setting up.
Don't be tempted to buy the cheapest setup you can find. In this case, you get what you pay for. If the pole is unable to be raised and lowered or the compartments can't be opened, it will make management difficult and a chore. Round holes will make battling starlings an issue. Gourds can be more attractive to martins than a plastic house. Do your research and buy the best equipment you can afford.
4. Educate yourself on the proper management of a martin colony. Properly managed martin colonies last longer and raise more and healthier young than unmanaged colonies.(See nest check guide)
5. Be willing to control invasive species when they show up.
This is a very important issue, and is often not considered by staff or volunteers. You must NOT allow English house sparrows or European starlings to nest in your public colony site. These two invasive species can kill our native martins as well as throw out their eggs or young. They do NOT get along with martins, and will keep you from having a healthy colony, or even from getting one established. For more information on these two species and why they must be controlled, see this page from the PMCA and read the PDFs at the bottom of this page. A well-managed public site (free of starlings or house sparrows) is a good example of environmental stewardship for the public. If local rules/regulations at your particular site do not permit the control of any species (even non-native invasive ones), then you may want to reconsider starting a martin colony there.
USDA National Invasive Species Information Center - European Starling
Global Invasive Species Database - English House Sparrow
6. Do not allow any other native species to take over the martin housing.
If native species such as bluebirds or tree swallows attempt to nest in the martin housing before martins move in, temporarily close off the martin housing and put up a separate house for the native species in question. Do not reopen the martin housing until the competing native species has laid at least 1 egg in a separate nest box. For more information, see this page.
7. Take care of the equipment to prolong its useful life, and take security precautions.
Make sure cables and winches are in good working order. Don't allow poles to become rusted together. Replace broken ropes or rusted parts. Put the housing away in the off-season, or cover it, if possible. Clean out the housing at the end of the season to reduce mite populations and to keep the housing looking its best. Take precautions to prevent the public from being able to lower the housing without permission. Consider putting locks on winches or removing the handles, when the colony managers are not present, but make sure your colony manager or nest monitor has a key!
8. Consider putting up educational signage to advertise your healthy colony site.
Informed staff and members of the public will get more out of the experience of having a martin colony onsite if they understand the biology of the species, and are more likely to be respectful of the space around the colony site.
If you already run a public site, please join the Facebook group entitled Public or Nonprofit Purple Martin Colony Management!
Controlling English House Sparrows and European Starlings Humanely
English House Sparrow Myths
Nest ID for Cavity Nesters