Archive for the ‘parasites’ Category

Motivation to Clean Those Purple Martin Houses

Sunday, October 13th, 2013

OK, I know how it is. After the first few years, after your martins leave, you kinda loose the excitement of cleaning out those dirty gourds and house compartments. I guess it is one of the less glamorous aspects of playing landlord to a couple hundred or so odd birds every year. Even though I know better, I find myself again putting off the dirty task. Heck, my birds will be headed back in only a couple of months! What is the big deal, you ask. I know for a fact that there are plenty of folk, good and decent folk, that don’t touch their purple martin houses or gourds from one year to the next. You may be one of those people. You watch from the sidelines and enjoy the view in the spring and come fall you walk away. Nothing wrong with that…unless you want to be taken over!!! Here is my lesson learned from last summer and the reason why I WILL finally get to my gourds this week. I promise!  The bees simply loved the gourds and made quite a nice hive. The paper wasps like to make a home in there also. The solution is simple. After cleaning out the gourds I just cover each gourd with a tall kitchen garbage bag and they sit clean and protected from all sorts of non-purple martin wildlife. You can take all the houses down if you have the garage space or you can plug the entrances with door shields or plugs. Beware, if you use door plugs, look for air vents that you may also have to plug that are large enough to let in creepy crawlies or stinging friends. And if I don’t…well, I deserve what I get!

Why Purple Martin Nestlings Jump

Sunday, June 26th, 2011

Our last blog post touched on one of the reasons that purple martin nestlings jump prematurely out of their nests. Referred to as “jumpers” these youngsters are often doomed. The reason why I,  along with many other South Florida landlords, have seen a huge increase in jumpers this year over previous is our record breaking drought conditions. Dry weather means fewer bugs which means purple martins go hungry and nesting success plummets.

The main reasons that martin landlords encounter jumpers are: parasites, extreme heat and hunger. Drought, though not a specific reason, contributes to low food supply and hunger/malnourishment.

Parasites can torment young inside a nest. Though some have argued that nature should be allowed to take its course, the natural instinct of the Purple Martin (Progne subis, subspecies: subis) has been altered by man.  Before Native Americans created the tradition shift in martins, the nest sites of these birds were tree snags and they nested farther apart. You can read about some of the 1/4 tsp in nesthistory of martins at our parent site: They were much like their West coast cousins, Progne subis, subspecies: hesperia and subspecies: arbicola. The shift not only affected were they nested (tree snags vs man made houses) but the way they nested, as it is believed they were not as colonial in their nesting. That is to say, they were spaced further apart and did not nest in such large groups. The groups of martins nesting in close proximity can create parasite population explosion. We counter this by periodic nest changes and/or the use of a small amount of Sevin. We have a great link to a video on how to do a nest change.

Extreme heat in a nest can  be challenging to combat but if not associated with drought or food shortages, are usually easy to remediate. By making sure all vents are open in nest compartments and gourds, air circulation can be increased which can help lower temps. Many artificial gourds have vents that can opened as an option. For example Troyer gourds have built in mini vent canopies that can be drilled open easily. We recommend drilling these open before the season but a cordless drill can open those up quickly. If those are too small or you want larger vents (more air circulation) than a 1/4 inch threaded PVC elbow (90 degrees) is perfect for the job. It can  be easily installed on any gourd or house for that matter to increase air flow. Just drill a hole large enough to thread the end in and caulk in place. Make sure it points down and, if you want, attach a small piece of screen to cover the opening to allow air in but keep wasps out. The picture shows a modified gourd with elbow in place at the highest point which will push out the hot air as it rises. Know that in Northern climates you may have to plug these vents inn the early spring in times of cold weather to keep your martins warm.

Other tricks folks employ:

Using a frozen gel pack placed in an empty compartment. A frozen bottle of water can be used also.

A secondary shade can also help. Placing a sunshade to keep the sun from beating down on the house surface can decrease temps.

-------photo by OakleyOriginals on Flickr

Even a misting system has been used by many with success. Just makes sure the water does not go into compartments which would lead to wet nests. Also the misters should only run intermittently in the hottest part of the day so that the water can dry off. The evaporation is what cools. Don’t let the misters run at night or continuously. Our Free Purple Martin House Plans page has instructions available on how to make a mister system for your martin houses.

Hunger is a difficult problem and the debate is heated on how much humans should intervene on this. Though supplemental feeding is often done in early spring cold snaps for returning adults, one should strongly weigh the consequences of feeding purple martin nestlings. Remember that if you have several nests that are doing poorly from lack of food, the parents are suffering also. If there is a long term problem, supplemental feeding is a very short term solution. Read our Emergencies page for first responder care of purple martins.

What other problems lead to Purple Martin nestling Jumpers? Let us know what you think.

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Drought and Heat Takes a Heavy Toll

Saturday, June 25th, 2011

Time after time, this season, I have received calls from landlords concerning dead purple martin nestlings. I myself have found several jumpers this season. Jumpers are nestlings that are far too young to fledge but jump out of their nests for whatever reason. Usually extreme heat, hunger or parasites are the culprits that lead a martin nestling to such a desperate act. I liken it to people trapped in a high rise that is ablaze. The victims jump to their death to escape the fire.

purple martin feederThis year South Florida is suffering from record drought conditions. In droughts flying bugs are significantly decreased leading to catastrophic food shortages. Nothing but rain can re-establish the equilibrium of the food chain. Since our weather is usually fair, our population of purple martins is not familiar with supplemental feedings. In some emergency situations like extreme cold, purple martins can be trained to accept food from an elevated tray or Bed & Breakfast type feeder. Unfortunately, when the weather is fair enough to fly and catch some bugs, the birds will just forage longer and farther from the nest. So training them to accept feedings is extremely difficult. To see a video of supplemental feeding of purple martins click here.

In the usual activity of a purple martin nest you will see some of the nestlings at the entrance waiting to be fed while others are sitting in the back of the nest resting. As the ones in front are continuously fed and get full they turn around and retreat to the back of the nest to sleep, digest and grow. The nestlings that were resting and digesting then get hungry again and come back to the front of the nest to take their place at the entrance to wait for a mouthful of bugs. The nestlings are in a continual carousel of being fed, keeping the parents busy feeding a nest full of an average of 5. But when the nestlings are not getting enough food then they all cluster at the front. So these “jumpers” can actually be accidentally pushed out by the jostling of the babies at the entrance for food.

Martin nestlings that jump due to starvation are usually doomed as the accompanying dehydration is far more deadly than the martin keelhunger. Since all purple martin nestlings water intake comes from the insects that the parents bring, in cases like this the jumpers are all very dehydrated. Not wanting to sound like a pessimist, there is not much that can be done. Feeding a dehydrated and malnourished nestling can cause it to just die faster. Looking at the jumper you can often see clues as to how well fed they are or are not. A pronounced keel (breast bone) shows lack of muscle development from chronic malnourishment. Dry, flaky skin is a sign of dehydration. A  wildlife rehabilitator would also look for signs such as skin turgor or “tenting” of the skin as a sign. Emergency injections under the skin would then be given BEFORE any feedings would be attempted. Water or other liquids can aspirate and kill birds quickly if given by mouth. This article on Hydration of Purple Martins can answer some questions and prevent more harm from being done while a rehabilitator is contacted. If their are other nestlings in the nest sometimes the weaker nestlings “jumping” can increase the survival rate of the nestlings left in the nest. If the jumpers can be hydrated then fed by a rehabilitator, they can often be reintroduced into the nest when the are approaching 21 days old before they fledge. Nest checks become increasingly important to know the age of the nestlings. As lowering housing may sometimes cause fledglings to prematurely fledge out of fright.

Though we provide housing for these wonderful birds, one can’t feel responsible for acts of nature such as drought. We help as best we can and give them a chance to survive. Next year they will return and hopefully with better weather conditions. We learn from our experiences and the next season will bring another chance at life.

Look out for our next entry on some of the other causes of “jumpers”.

(c) 2011

Blowfly Mystery Update

Monday, August 31st, 2009

In a recent post I wrote about a strange case of apparent Blowfly infestations in ADULT purple martins. You can read about it HERE.

The latest issue of “Feathers and Friends” had an interesting interview with Willie Conley, a well known and prominent  purple martin landlord in Indiana. Some excerpts of the article follow:

“Willie… hosts around 250 pairs annually. This year he had 251 pair. …He first had this problem with this parasitic infestation back in 2004 already, but this year was exceptionally bad. This year Willie treated around 70 martins in his own colony that were infested, and they all survived. Though he did find 2 untreated martins that had died of the sickness.

An infested martin starts growing a big pink bubble right at its under tail coverts. In this bubble there are tiny little holes in which there are up to four white little white maggots per hole. Usually just two. Willie has found as many as 23 maggots in ONE martin. These maggots grow bigger and bigger until the martin dies.

Willie saved a dead martin that died of this parasitic infestation to see what the maggots would do. He put the (dead) martin in a sealed jar. The maggots turned into white pupal cases (cocoons) , which later turned to a dark brownish color.”

courtesy of Feathers and Friends

After a couple of weeks this is what had emerged.

(The house fly on the left is for size reference)

According to Dr.Terry L. Whitworth, Owner and Operator, Whitworth Pest Solutions, Inc., and Washington State University Adjunct Professor in Entomology; these photos are Sarcophagidae -flesh flies. They normally only feed on dead nestlings, though occasionally they can infest living tissue, usually via a wound or injury.

Dr.Whitworth brings up an important point though. That since these maggots were from a bird that was found dead that these flesh flies could have deposited the larvae on the dead bird and not necessarily have been the cause of death. Really the only way to be sure is to examine the larvae that are directly removed from the living bird.

So we are left with more questions and still have a mystery. If you have any information that may help us is solving the riddle, please let us know. You can contact us at susan(at)purplemartins-r-us(dot)com or use the contact us page to the right.

The American Bird Conservation Association / Feathers and Friends can be contacted via phone at (260) 768-8095 x:5 Subscription rates are  $18 for 1 year. Tell them Susan from PurpleMartins-R-Us sent you!

Blow Fly Infestations- What a BOT it?

Tuesday, August 11th, 2009

I thought being in the South that I was safe from Blow Flies (Protocalliphora sialia) but alas after talking to a few folks and doing some research I am sure I have experienced a more sinister type of Blow Fly here at my colony.

A few weeks ago I posted about a nestling that had some sort of “lump” or cyst on its abdomen. The nestling died soon thereafter. Since then I have been doing a little digging into what it actually was. When I found the dead nestling it was quite apparent that the mass had opened and since I saw no other injuries or obvious issues with the nestling, that very well may be what killed the bird.

This led me on a quest to find out what may have been the cause.  At first I thought they were Bot Flies. What is a Bot fly? Well, in short it is an insect that’s larvae lives as a parasite within the tissues of a living organism. Horses commonly get them as do other mammals. I have since come to learn that there is a type of subcutaneous BlowFly (Trypocalliphora braueri) or a type of Housefly (Philornis sp) that may be to blame.

I realized it wasn’t just me when I was reading my latest issue of “Feathers and Friends” (a magazine published by “The American Bird Conservation Association”) I read about several landlords reporting birds with “bubbles” that are “caused by an insect that laid eggs there and the eggs hatch into little worms” When I read this, It sure sounded like a BotFly.

I spoke with Mr.Terry Whitworth, PhD, who is the Adjunct Professor of Entomology for Washington State University. A portion of his email to me was as follows, ” There are two possible culprits in Florida, one is Trypocalliphora braueri, a subcutaneous blow fly. The other is Philornis, a Muscidae (a type of house fly) that occurs in Florida. By the time the larva comes to the surface where the bump can be seen the damage is done. Removing it or killing it at that point will not change things much for the nestlings. Neither pest is always lethal, it depends on the number of larvae that develop and where they burrow. I once took 25 mature Trypocalliphora larvae off a nestling junco and it survived long enough to fledge.”

Whether they be Blowflies, Houseflies or Botflies, whatever you call them, these nasty bugs can kill! Though not the same bug they are somewhat related. Some infest by way of laying their eggs or larvae into living tissue. Others crawl up through the nests and suck blood only to drop into the nest to grow then repeat the process. Getting larger and needing more blood each time. Usually a “Northern” plight, Blow flies can be controlled via nest changes as Sevin has NO affect on the larvae. A pair of forceps or tweezers can be used to pull these nasty things off of the nestlings. Once the Blowfly larvae are done feeding and growing in larval stages they form a pupal case in which they remain, dormant, until they are ready to emerge as an adult. Something like a caterpillar forming a cocoon before it emerges as a butterfly.

The typical BlowFly, can exsanguinate a nestling when present in large enough numbers but if caught early are controllable. These other guys (Philornis, Trypocalliphora and Botflies) however spell bigger trouble.

You think I am dreaming this all up? Read this article by The University of Northern British Columbia. (Be warned, if you don’t like bug pictures…don’t click) Basically it explains how death can result several ways. The Bot larvae move around and migrate in the soft tissue and can kill the bird, the wound itself can become infected and kill the bird, the Bot larvae will feed on the tissue and weaken the bird to the point of death, the Bot can damage the wings and thus, “produce an obvious awkwardness in locomotion, which may render them more susceptible to predation.” (that is a direct quote) In short the damage is severe and serious.

And talk about BiZzArRe? There is even a species of Bot Fly that lays its eggs on mosquitoes.When the mosquito bites the eggs are transferred. What does that mean? That means look out! Humans can get it too! Still don’t believe me? Just Google it. But that is another story.

What can be done about these subcutaneous (under the skin) Flies? Unfortunately, nest changes may not be helpful as once the adult Fly lays the eggs/larvae they crawl onto the bird and burrow into the skin. Another options is pretty gruesome and may not be legal. Also, it may cause more problems than it solves. Now, I could explain how the skin is cleaned with an antiseptic such as betadine prior to making a small incision from which the Bot Larvae is removed with a pair of forceps or tweezers but I wouldn’t want anyone with paranoia cutting holes in a purple martin with a wart. And legally, I think I could get in trouble for telling people to perform surgery on a federally protected bird without some sort of Veterinary license. All of this may be a mute point as once the larvae are large enough to cause the visible lump, the damage to the birds soft tissue is done. As puts it, “They develop under the skin of some birds.The bird has died after…maggots have consumed much of its muscle tissues. Once their host is dead, the larvae leave it to pupate…”

In humans, the true Bot Fly wound (which is open so the larvae can breathe) could be covered with petroleum jelly or some other occlusive salve so that the larvae will emerge on its own, seeking air to breathe, after a day or so. I think that on a bird this course of treatment would not be successful. How could you place a dressing on a bird? We have the issue of a pretty dirty living environment (a nest) talk about infection!  So, basically the wisest course of action would be to take the bird to a wildlife rehabber.

Of course we also have the problem of not really being sure which one of these 3 flies is the true culprit. Perhaps it is a combination of the 3, maybe some other. In order to find the true source of this problem I urge all that may witness this to photograph any lumps you may see on your nestlings and monitor them. Of course you can email them to me at the “Contact Us” section.

It is important to stress that with the classic and somewhat common Blow Fly infestations, that nest changes are by far the easiest and best treatment. Elevated subfloors help and nest trays make cleaning your purple martin bird houses super easy. Pulling off any Blow Fly larvae that are latched on to the nestlings with tweezers. For those of you that have questions regarding nest changes, this short video may help you overcome any trepidations that you may have.


If you want to learn more about Blow Flies or help with blowfly research go to for some interesting facts.

The American Bird Conservation Association / Feathers and Friends can be contacted via phone at (260) 768-8095 x:5 Subscription rates are  $18 for 1 year. Tell them Susan from PurpleMartins-R-Us sent you!

©2009 S.Halpin /