Purple martins are a beloved backyard bird that many people enjoy having nest on their property each spring and summer. However, as the summer starts winding down, it can be confusing to know the right time to take martin houses down for the season. This article will provide tips on identifying when purple martins have finished nesting and how to properly clean and store martin houses after use.
Do Purple Martins Migrate?
Yes, purple martins are migratory birds that fly from their wintering grounds in South America to breeding areas across North America each spring. They typically start arriving back in the United States and Canada in late January or February. Most purple martins migrate back south by late July or August, depending on the region.
Some key facts about purple martin migration:
- They are one of the earliest spring migrants in North America, signaling to many that spring has arrived.
- Adult males arrive at the breeding grounds first to scout out nesting sites, followed by the females 1-2 weeks later.
- Juvenile purple martins leave later in the summer, after they have fledged and learned to fly well.
- Fall migration starts as early as late June in northern areas, extending into August further south.
- They migrate during the day and may form large flocks during migration.
So in summary, purple martins are strongly migratory, leaving their breeding grounds for their South American wintering grounds from mid-summer through early fall, depending on your location.
When Do Purple Martins Leave Their Nesting Sites?
Purple martins start leaving their nesting colonies to migrate south at different times depending on your region:
- In northern areas (Canada, northern U.S. states): late June to mid-July
- Mid-latitude areas: Late July
- Southern areas: August
Some more specific signs that purple martins are getting ready to migrate:
- Increased activity in the morning and evening as martins start roosting together
- Martin numbers around the colony start declining as some birds depart
- Less activity seen around the nests during the daytime
- Nest checks reveal nests that are empty or have dead nestlings
The exact timing can vary by a few weeks in either direction depending on weather conditions each year. Martins may linger longer during a cool summer or leave earlier after a bout of very hot weather. Tracking martin behavior and nesting activity carefully each season is the best way to determine when your local martins have finished nesting.
What About Late Nesting Attempts?
Sometimes purple martins, especially first-year breeders, will start new nests in July or August. However, most nesting attempts that late in summer are not successful since there is not enough time for young to fledge before migration begins.
Martins may lay eggs but often abandon the nest as their urge to migrate takes over. These late nests usually fail and should be removed from housing once most martins have left your site.
How to Know When All Purple Martins Have Departed
Determining when all your purple martins have left for the season takes close observation. Here are some signs that martins have finished nesting and migrated from your site:
- Dramatic decrease in martins around the colony
- No martins seen entering or exiting nest compartments
- No nestlings heard begging for food in the mornings
- No martins roosting on poles or wires near the housing at night
- Only a handful of martins (or none) remain after several days
You may see a straggler martin or two occasionally over the next few weeks. But once the bulk of martins have moved on with no evidence of active nests, you can safely conclude your season is over.
Should I Leave Housing Up if a Few Martins Remain?
Most experts recommend leaving martin housing up for 1-2 weeks after you note the colony has mostly vacated and there is no sign of active nests. A handful of martins may linger behind the migrating flock before eventually moving on.
This straggling behavior is most common in younger birds born that summer. Leaving housing up temporarily allows these stragglers to continue roosting and sheltering while they finish fledging before migrating south.
When to Take Down Empty Martin Houses
Once all breeding and roosting activity has ceased, martin landlords can start taking down empty nest compartments to clean and store for winter. Here are some general guidelines for when to take down martin houses by region:
Region | Time to Take Down |
---|---|
Northern (Canada, Northern U.S.) | Mid July to Early August |
Mid-latitude (Central U.S.) | Late July to Mid August |
Southern (Southern U.S. States) | Mid August to early September |
Again, the specific timing may vary by a week or two each summer. Use the activity at your colony, not just the calendar, to determine when your martins have finished nesting each season.
Can Housing Be Left Up All Winter?
It is generally not recommended to leave martin housing up over winter when no birds are nesting. Once vacant, nest compartments left up will likely attract non-native and pest bird species looking for roosting sites. Starlings, house sparrows, and other competitors may move in and be difficult to evict come spring.
In addition, martin houses left up all winter will accumulate more dirt, nesting debris, insects, and damage from weathering. This makes spring cleaning more difficult. Take down all compartments and poles if possible once martins have migrated.
How to Clean Out Used Martin Houses
End-of-season house cleaning is important for maintaining healthy, sanitary martin housing each year. Follow these steps when taking down and cleaning nest compartments:
- Use caution when removing nests, as they often contain live parasites.
- Discard all old nesting material and droppings. Do not compost.
- Thoroughly scrub all interior and exterior housing surfaces with soap and water.
- Rinse well and allow to completely dry before storing for winter.
- Apply a disinfectant or sanitizing spray after cleaning.
- Seal any openings in housing greater than 1/4-inch.
Be sure to use rubber gloves and a respirator or dust mask to avoid direct contact with debris, droppings, or parasites.
Can Nest Compartments Be Left Up for Winter?
It is best practice to fully disassemble martin housing each fall for proper cleaning and maintenance. However, some landlords prefer leaving actual nest compartments or gourds intact and fastened over winter.
If nests will be left up, be sure to:
- Completely empty and scrub out all compartments.
- Seal openings and holes.
- Perform maintenance like repainting or re-securing.
Nest access holes can be left open or sealed with wood covers. Capping holes may provide extra assurance compartments will not be accessed over winter.
Where to Store Martin Houses in Winter
Purple martin landlords must find a safe place to store empty housing during cold-weather months when birds are away. Some tips for winter storage:
- Bring Indoors: Dismantled martin houses can be stored in a garage, shed, basement, or similar. This protects them from weathering.
- Weatherproof Container: Sealed plastic totes or covered trash cans work well to store components.
- Hang Houses: Some landlords hang gourds or wooden compartments under sheds or porches for storage.
- Rodent-proof: Take measures to prevent mice or squirrels from accessing stored compartments.
Make sure all housing is completely dry before placing in enclosed storage containers to prevent mold or mildew growth.
Off-season Maintenance
The off-season is a good time to perform any needed maintenance on your martin housing. Tasks might include:
- Repairing leaks
- Replacing old gourds
- Reinforcing or replacing pole systems
- Installing new predator guards
- Adding fresh paint or protective coatings
- Assembling new compartments
Take advantage of the time when housing is down to make any required upgrades to your system. Proper storage and maintenance will help ensure many more seasons of enjoyment from your martin housing.
When to Put Purple Martin Houses Back Up
Once winter is over, martin landlords eagerly await the return of their birds! Follow these tips for the timing of when to put martin housing back up:
- Early spring is best, from late February through March.
- Aim to have housing up 1-2 weeks before martins return to your area.
- In northern regions, have houses up by mid-March at the latest.
- Housing can go up earlier in southern regions, as early as February.
- Check regional Purple Martin Society websites for specific guidance on housing-up dates.
Displaying housing too early risks attracting starlings and sparrows. But having nests ready and waiting for returning scouts is key. Housing must be up in time for the first arrivals.
Preparing Housing for Spring
When getting ready to put martin houses back up, be sure to:
- Install cleaned compartments on freshly painted poles.
- Make any needed repairs.
- Secure new suet/guard cages if using.
- Have mealworms available.
- Plan when to trap for unwanted birds.
With housing up and ready, you can eagerly await those first scouting martins of spring!
Conclusion
Knowing the right time to take down martin housing takes careful observation of the birds’ behavior each season. Watch for decreased activity, vacant nests, and night roosts shifting away from the site. When all signs point to martins having migrated, housing can come down for cleaning and off-season storage.
Plan to have freshly cleaned compartments back up in early spring, ready for martins to begin the nesting cycle again. Follow this annual cycle of housing up and down, and you’ll provide many seasons of enjoyable martin nesting at your site.