Changing nesting material

[Madame WingNut]

Last season, I lost quite a few chicks close to fledging. Weather was extremely hot and I am not sure what happened. If could have been mites or disease.

Should I replace existing nesting material with clean nesting material after the eggs hatch? If so, at what point in development to landlords do this. Last weekend, I counted 67 egg and 1 hatchling in my PUMA rig so they are just hatching out now.

[Scully]

Paula... we do one nest replacement somewhere in the interval from 10 days to 20 days after hatching depending on when we can get to the gourd sets. Some folks do two nest replacements, just be careful of disturbing young birds over 20 days of age.

We use shredded bald cypress bark mulch as replacement material, but I believe pine needle mulch work better if you can get it.

Be aware that this will be a messy and dusty task, and that the nest material you remove may be crawling with mites. Gloves are recommended if you are at all bothered by mites or the thought of them.

Likewise dried bird poop dust, bird dander, dead mite parts and mold spores will all go flying when you are scraping out the old nest. It couldn't hurt to wear a mask to keep yourself from inhaling this dust.

Mike Scully

[Mary Dawnsong]

Hi Paula,

If the problem was mites and if you were doing nest checks, then you would have seen them by the thousands. In the north, the nest parasite likely to do even more damage is martin blowfly larvae. It is easy to miss them unless you are looking for them. Here is more info on nest parasites:
http://www.purplemartin.org/update/Parasites.html

Nest replacements will control both of those parasites -if- you perform them on a regular schedule as a preventative measure. If you wait until your colony is exploding with parasites then it can be very hard to eliminate mites from some types of housing. One reason I use only plastic gourds is because it is easy to completely remove parasites/parasite eggs from them. When I used natural gourds I found it very difficult to control mites with nest replacements during especially bad years.

PMCA recommends nest changes at 10 and 20 days of age and that works very well in my colony. Here are nest replacement instructions:
http://purplemartin.org/update/92nestrep.html

Avoid doing nest replacements before 10 days of age because the tight nest bowl the parents (usually) build is very important for brooding young nestlings. This is especially true here in Michigan where it is often cool at night and even during the day. Without the tight nestbowl, the brood spreads out and it is very difficult for mom to keep them contained under her body. I didn't understand this fully until I installed nest cameras in my gourds. Yet, I have changed younger nestlings when I thought they were at risk from blowfly larvae. The above link has instructions for dealing with the very young.

Do not do nest changes after 21 days of age because the disturbance is very, very likely to cause older nestlings to fledge prematurely. If they try to fly before 26 days of age, they are doomed.

Good luck, Mary

[birdy girl]

Are you supposed to do nest replacements only if mites are present or is it a general rule to replace the nest even if there are no problems present?
Just wondering.

[Mary Dawnsong]

Hi birdy girl,

My post above answers your question (we posted simultaneously).

If you choose to do nest replacements to control parasites, then do them on a regularly scheduled basis. Do NOT wait until you see problems. Even when you don't see any/many mites in the nest, thousands of their eggs can be present. The population of nest mites can explode in just a few days. The idea behind nest replacements is not to throw out mites - it's to throw out the mite eggs before they hatch.

Northern landlords have a serious parasite problem that southern landlords do not have to worry about.
The martin blowfly larvae is a killer. Just look at this photo:
http://purplemartin.org/update/92nestrep.html
Blowfly larvae often hide in the nest during the day and feed on the young during the night. So it can be hard to spot them during routine nest checks. Regular nest replacements keep their numbers well under control, however. I often see blowfly larvae in the bottom of the nesting material when I dump the old nests during scheduled nest replacements.

My best, Mary

[Madame WingNut]

Thank you Mary for a very comprehensive explanation of what I need to do. A couple more questions on materials - do you use wood chips or pine needles? I know cedar chips are not recommended. If I use dry pine needles, should I briefly microwave material first to kill any insect eggs or should that be pretty pest free? The PUMA don't miss their mud nests? Are they fine with the replacement?

[Madame WingNut]

Thank you also Mike. I will do at least one nest change and try for two. Mites don't bother me much. I am monitoring 122 EABL and TRES boxes this spring and the TRES often have mites.

This is my third year hosting PUMA and I am still learning. Last summer the loss of many near-fledging birds was terrible to see. There are many PUMA rigs set up on the island, but most people just stick them up there in the spring and forget about them. I know the importance of monitoring.

[Mary Dawnsong]

Hi Paula,

I really doubt you need to worry about the presence of bird nest parasite eggs on pine needles. If you use pine needles, make sure they are the long, soft kind - not prickly.

This is PMCA's position on cedar shavings, from the archives:
http://purplemartin.org/forumarchives/a ... avings.htm

How important is it to control parasites?
PMCA did a study on nesting success relative to parasite control. This research found that in the North, where both the martin blowfly and nest mite can be very serious parasites, fledge rate almost doubled over a four year period when parasites were controlled:
http://www.purplemartin.org/update/NestSucc.html

My best, Mary