Nest Replacements for Purple Martins
From: Ken Kostka, PMCA, Edinboro, PA
Date: 4/3/01
Time: 10:50:13 AM
There’s a "how to" article (with photos) on nest replacements at http://www.purplemartin.org/update/92nestrep.html I strongly encourage everyone to read this article. Parasites (including fleas, mites, and blowflies) can sometimes become quite numerous in a martin nests. Tests conducted by the PMCA in the late 1980’s showed that only 44% of martin nestlings in parasite-infested nests survived to fledging age, compared to 84% in parasite-free nests.
In 1999, I attracted 1 pair of breeding martins to one of my sites near Pittsburgh, PA, only to find the nestlings dead during the first 7 day nestcheck. They had died at 3-4 days old. This experience was especially distressing since I had been attempting to attract martins to this particular site for over 10 years. The nestlings were covered with what appeared to be blowfly larvae. While I cannot say for sure that blowfly larvae caused their death (since subadults lack breeding experience and can be poor parents), I feel that the parasites contributed significantly to their demise. The pair did not return the following season.
Therefore, I draw your attention to the following passage from the Nest Replacement article: "Although blowflies and other parasites usually don’t become a problem until nestling are about 10 days old, they occasionally cause the death of nestlings that are younger. Few things are sadder for a landlord than finding dead nestlings in a parasite-infested nest during the first 5-7 day nest check, especially if they worked and waited for years to attract martins. Therefore, landlords who have only one or two pairs of breeding martins, and who want to be extra-vigilant in insuring the survival of their colony site, should do nest checks more frequently, such as every 2-3 days, instead of every 5-7 days. Remember, blowfly larvae often hide in the bottom of the nest during the day and won’t be obvious to the landlord when he or she just looks into the nesting cavity. However, gently digging into the nesting material just beneath the nestlings will expose blowfly larvae if they are numerous." Special care must be taken when doing a nest replacement for nestlings that are less than 10 days old. See the article for details.
