One unique activity that many landowners support in the Chesapeake Bay watershed is housing and protecting native Purple Martins. You’ve probably seen landscapes with beautiful Purple Martin houses or gourds hanging from poles. 

Purple Martins are almost completely dependent on human-made houses.  For over 30 years, we’ve installed Purple Martin nesting structures in appropriate habitat, maintained their homes, and monitored Purple Martin colonies for martin landlords around the Eastern Shore.  See our short Purple Martin video. 

Our team monitors Purple Martin colonies, records data on eggs and chicks, and oversees successful fledging. Data is collected during nesting season and reported yearly to individual landlords.  We also report the combined results in our newsletter, Habitat Works.  Last season, 1,560 Purple Martin Chicks fledged from 79 houses and 60 gourds.    

Unfortunately, Purple Martins are experiencing a population decline due to several factors, including habitat loss, competition with non-native species, weather, predators such as snakes and owls, and human activities. 

Purple Martins’ diet is entirely flying insects. When we have a great deal of rain and cooler temperatures, there are fewer flying insects to provide food to help them survive the cold nights. Purple Martins deplete their fat stores while traveling from South America to their breeding grounds (the Bay region) and need to consume insects upon their return. They love the Bay’s healthy wetlands and insect-rich meadows.  

Furthermore, predators are a problem. One year, we saw an increase in nighttime owl attacks on the Purple Martin colonies. In response, we install owl guards on all our martin nesting structures to prevent such attacks. We also control non-native English House Sparrows that try to take over the houses, destroy the eggs, and kill the chicks and adult birds.  

Finally, insecticide use in areas surrounding the Purple Martin colonies is harmful to Martins. Treated insects can move to an area that has feeding Martins. Insecticides can travel up the food chain and poison Martins and other insectivores. 

CWH continues to monitor and manage Purple Martin colonies in hopes that they grow and thrive. If you are interested in installing a Purple Martin house or need help with maintenance and monitoring, email us at info@cheswildlife.org. Also, tune into watch our Purple Martin Live cam at Barnstable Hill Farm.