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 history of martins at our parent site: PurpleMartins-R-Us.com. 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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When do you stop doing nest checks? When the nestlings reach about 23 days old. Some folks say 20 days old, but that seems overly cautious to me. All nest checks are on hold as their are tons of nests ready to fledge any day now. The nests that have fledged (about 8 of them so far) are creating much excitement as they peek into compartments and try to steal food from smaller younger nestlings.

A hawk made a late pass right before dark tonight and I am not sure if he was successful or not. The entire colony flew up in masse and with such an uproar of alarm calls that I am sure some bird was taken. Those early morning and late evening attacks are often quite successful. I will have to stay out later tomorrow and see.

I am not sure when the low hanging gourds are due to fledge soon. It will be interesting to see how the youngsters take to the air without having the advantage of height to get them airborne.

Eggs: 114
Young: 89
Compartments Available:43
Compartments Occupied wit eggs and or young:43

It seems like this is a yearly event. (knock on wood) I hope only once a year is my lot in my landlord life. It could be more, I suppose. It definitely could be worse. So far no lasting effects, other than some worry on my part and some moments of terror on the part of the martins that I had to extricate from the sreh gourds. 2 ASY males, one stuck in the sreh and one within the nest. Gratefully and gently freed. They are so amazing to look at up close.

For those that don’t know, Wing Entrapment is when a purple martin becomes stuck in a SREH. It usually happens when 2 or more martins are fighting over a compartment (nest spot) of any gourd or house with SREH (Starling Resistant Entrance Hole) As one bird tries to leave the nest and is trying to fend off attacks from within the nest from a rival or occupant, the bird gets stuck in the entrance. Basically gets stuck when he turns as he is trying to exit. If not discovered fairly quickly the birds in the nest can die as can the stuck bird. I wonder if vented rooms vs non vented rooms have a better survival time and if the deaths are strictly due to the heat build up in a nest with a plugged entrance? Or is it a dehydration issue? Those that have reported deaths from entrapment usually say that they discovered it either the same day or within a day or two of the event.

You can read about wing entrapment in previous blog posts as well as on our parent website, www.PurpleMartins-R-Us.com. Is wing entrapment a reason to not use SREH? Absolutely not. Wing entrapment remains much less common than the threat of Starlings in an unprotected colony. Of course, you have to weigh the pros and cons in your colony along with your sites individual risk factors for both problems.

I was poking around Twitter last night and came upon a tweet from someone saying that their purple martins had returned and were again starting to build a nest under their eave of the persons home. I had to chuckle since I knew  it was no Purple Martin. As many serious birders will tell you, one of the most important facts in properly identifying a bird is knowing the birds range, behavior and habitat. This person makes a perfect example. Knowing that purple martins do not nest on house eaves makes it easy to correctly I.D this bird as a Barn Swallow. Commonly mistaken by the novice birder, many of the swallow species like Purple Martins, Tree swallows, Barn Swallows can be confusing to some. Add in there Rough Wing Swallows and Violet-Green Swallows and even Bank Swallows, even the experience birders will have to look closely and carefully to distinguish these birds from one another.Heck, I wouldn’t have been able to tell a Rough Wing Swallow from a SY Purple Martin before reading up on it myself.

I found a great little site with some great photo comparisons of these commonly mistaken birds at BirdingIsFun.com which has some great tips to help you quickly tell these apart. As for the person tweeting about the purple martins mud nest under the eave of their home, I don’t think they care. But still it makes me think of how many people are out there convinced they are helping martins who may not be? Every year I hear from well meaning people that place housing and tell me about the bright yellow bills of their purple martins or how their martins will not allow other martins to nest in the house. Inevitably I find out that starlings nesting or Tree Swallows are dominating the house. Not to compare a Starling factory with a pair of Tree Swallows, but both examples show how purple martins can be pushed aside.

I recommend our Purple Martin vs Starling ID page to help those that are new to the world of birding. It is a side by side comparison of Purple Martins and Starlings. Even if you are not new, take a look and be sure…If I had a dollar for every time someone swears they have Martins and come to find out they are not!

Another great resource we recently added to our parent site was the addition of Daniel C. Drew, M.D. page on Tree Swallow/Purple Martin and Bluebird/Purple Martin INTERFERENCE. With his permission we added this page to our site so that new landlords can be more successful in getting purple martins in their Martin housing and Tree Swallows and Bluebirds in their respective housing as well. Though that page is up again, in its original site we both thought that the information contained within it is vital to new landlords that have lots of tree swallows and bluebirds but no luck in attracting Purple Martins to their properly set up site.

So what do you use to put in those martin houses and gourds? Many of the available choices that some folks may use work great, some are a bad idea.

Good

Typically the most commonly used prenest material is Pine Straw. Pine straw is just pine needles. It may differ in length and color depending on what kind of pine tree the needles are from but usually pine needles from Longleaf pine, Slash pine or White pine.

Leaves can also be quite water repellent. It really depends on the leaf. Oak are good. Small and flat they are safe.

Corn Fodder which is dried cut up corn stalks

Bad

Grass clippings are a bad choice. First, the grass absorbs water. This in itself is bad enough but then it can mat down and become compacted to the point where water will not easily penetrate. Making your gourd a pool of death.

cedar shavings, though easy to find at any petstore and quite cheap, are not a good choice. They absorb water and stay wet. If you ever use shavings in a cage for a rabbit or hamster, you know! Though I have used it in a pinch, you should try to avoid it.

The most important thing to remember is that American’s have been altering the nature of purple martins for hundreds or perhaps thousands of years. Since martins have lost the instinct to nest in a natural cavity, we have a responsibility to care for these birds as part of our heritage as American’s…whether Native American, North American or United States of ‘American’.

Finally, the martins are getting down to business. Though they may still be having minor squabbles on who lives where, the bringing in of nest material is a sure sign that nesting, egg laying and an onslaught of ASY purple martins are not to far away.

If you are a new purple martin landlord it is vital to play your purple martin dawnsong. Decoys should be up and though some folks report that the purple martins sometimes seem to attack decoys others don’t mind at all.

If you use artificial (plastic) purple martin gourds it is imperative that you place nesting materiel inside the gourds. The slick plastic can make it virtually impossible for the martin to exit the gourd which will leave them trapped inside. So for safety alone, placing nest materiel in the gourd is an important part of being prepared for the arrival of your martins. Of course an added bonus is that it keeps the gourd warm and ready for them when they arrive after a transcontinental migration. Purple martins won’t bring in nest materiel so they can have a warm comfy place to sleep but I am sure it is a welcome feeling for them when they do return.

morning vocalization

Naples has just reported the first SY (subadult) Purple Martin of the season on 2/19 so I predict that nesting will be beginning at anytime, here in Florida.Keep playing that purple martin dawnsong and be ready for more birds, all wannabe landlords. Don’t give up!

The last few nights I have seen birds get turned away as night falls. I can almost swear (if I was the swearing type) that more than 2 birds are going into the same gourds. It seems several pairs are co-habitating at any given time. I have witnessed at least 4 birds enter a gourd last night and tonight, and unless these odd birds out are kicked out of the gourds after I go in, they must have stayed the night. I can assume it is not all to friendly in the gourd as I can see the gourd shaking a bit for a few minutes. I am torn as I consider putting up more housing, but then I remind myself that as many gourds or martin houses I put up, the birds would fill them. And do I really want a super colony? Well, actually that would be cool but between kids and tball and piano lessons and all the other “stuff” I would not be able to do them justice. Basically I wouldn’t be able to watch out for my birds the way I want. So until my kids are a bit older and can help with some of the purple martin things, the colony can stay as it is…well, maybe a few more gourds!

I will have to rededicate myself to trying to recruit others into this hobby that I love so much. I have considered having an “open yard” and invite locals to see my colony but the logistics has me confused. Do I do it now early in the season or wait till babies are being fed, do it in the morning or wait till dusk and watch them gather in their big flock before zooming in for the night? Would I rent a Porto-let or open my house to strangers? hmmmm

The colony activity here in West Palm Beach has certainly kicked up a notch. The male purple martins are even heard singing while still in there gourds. I opened up the other gourd rack and filled them with pine straw. Artificial gourds should be filled with a few handfuls of pine straw to prevent them being unable to exit the slick plastic gourds. Even with the black traction strip in my Troyer Horizontal Gourds, they can be difficult, if not impossible to exit. So make sure you place some nesting material in those gourds. I know “some” ultra conservative birders may scoff at giving purple martins this help. They see it as unnecessary interference. But that thinking is flawed. It has nothing to do with altering nature but more to do with preventing a birds death by our hand.

The Purple Martin colonycam is up and averaging about 90% up-time.