PMCA COLONY UPDATE: Fledglings – Plug and String Method

Over the last few days our first nests of the season have fledged and with each nest check we are finding more cavities empty. It’s bittersweet to see the young successfully leave the nest, knowing it’s a sign that our summer with the Purple Martins is coming to an end.

Plugged gourds during a nest check prevent fledgings from leaving the nest before they can properly fly.

Performing nest checks near the end of the season is important to ensure your fledge data is accurate. We continue our 2x weekly nest checks through the entire season until every cavity is empty. The plug and string method allows us to perform nest checks without causing premature fledging- nestlings leaving the nest before they can properly fly.

The plugs with the hanging strings are left in for a few minutes after the housing is raised to allow the nestlings to settle. After enough time has passed, a quick tug on the string removes the plug from the entrance.

Every nest, containing young 22 days or older, is plugged during the entire duration of the nest check and while the house is being raised. A long string tied to the plug allows us to raise the house back to the top of the pole. This gives the young a few minutes to settle and the plug is then pulled out from the entrance.

(Left) A foam pool noodle cut into a half-moon shape to act as a plug. (Right) A long piece of string wrapped around the plug to prevent tangles while not in use.

Applying this technique at your home colony is easy. All you need is; a plug, we use a pool noodle that has been cut into a half-moon shape, scissors, and a spool of string. Simply cut a piece of string that is long enough to reach the ground from your Purple Martin house when it is raised, and tie it to a plug. You can purchase pre-made plugs at PMCA Shop – Entrance Plugs (string not included).

The three young on the NestCam are doing well. Both parents feed the young continuously throughout the day and sleep in the gourd at night. The young were banded on July 19th and could begin fledging on July 27th.

Purple Martin NestCam 2018



PMCA Field Biologist



1 thought on “PMCA COLONY UPDATE: Fledglings – Plug and String Method”

  1. My martins left Alva, Oklahoma in NW Oklahoma on Saturday July 21, 2018. sure is quite in the back yard. All 40 pairs raised a brood. Paul

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