Common Habits Of

The Purple Martin

Purple Martins are a very interesting bird species. Their habits around the colony have been studied for years and if not understood, can be very disconcerting to the 'novice landlord' or 'landlord to be' trying to attract them. Many myths have been passed down through the ages about these birds from people who themselves didn't fully understand them, thus making it even harder for the novice to understand them. Let's look at a few of the daily routines of martins and maybe some of this will make understanding their daily habits and activities a little easier. Just remember, individual pairs may vary, and their individual actions may also vary as well. If you see something happening in your colony that you don't understand, pay attention to what's going on, make notes and then, if you can't figure it out, discuss it with an expert. There are also many very experienced landlords around. Get to know them. They may even be able to help.

On this page I'll attempt to describe some of the activities that happen under normal circumstances on a daily basis in and around a purple martin colony. And again, remember, even though this bird species is very friendly towards humans, we're still dealing with nature and wild creatures, so anything is possible at anytime. They still exibit all the wild traits that all wild birds have and will at times follow these natural instincts and leave us wondering what in the world they're doing. Sometimes the only things we can do are 'Look, Listen, and try and Learn'.


Understanding The Different Birds

It's early spring, the sun is getting higher in the sky and the weather is warming.  For the prospective martin landlord, anticipation is running high. We have our housing up and have followed all the rules we were suppose to. Now all we need is for some martins to arrive at our house. 

Before all this happens, and to understand the migration, you have to first understand the different stages of the birds.  

First, purple martins are what is called sexually dimorphic.  This means the males and females have different plumages.  However, there is another kink to be thrown in.  Purple martins also display what is called delayed plumage maturation.  This means that the mature birds are the ones that show the true colors and not the young birds.

Now, we have to understand that there are 'three different stages' of birds.

The first are HY (Hatching Year) birds. These are birds that have just hatched and are in their first year of life. Obviously, these birds are fresh out of the nest, are just learning to fly and have not made any migration trips.  Sexual identification of these birds is practically impossible, even if sitting side by side.

Next, there are SY (Second Year) birds. These are birds that were born last summer, have made one trip south, are returning and are in their second calendar year of life. These birds have not yet nested and still contain the sub adult plumage.  Although difficult for the beginner, sexual identification is possible after a little study of the species.

Finally, there are the ASY (After Second Year) birds. These are birds that have made at least two trips south, have molted away their immature feathers, have obtained their adult plumage and are in at least their third calendar year of life. These are birds that have had a chance to nest at least once, possibly more.  Sexual identification of these birds is very easy because of the mature males' total black cloak of feathers.  This is the bird where the species gets its name because of it's purple hue that comes from the black feathers when the sun shines on them.  The females will have a nice even mottled pattern to their breast feathers and are easily told from the immature birds..

To help distinguish the ages, look at the pictures here.


Chronological Colony Life

Usually the first birds to return are the older ASY birds. These birds are often established in a site somewhere and, if successful with nesting last season, will usually return to that site to do their nesting each year. This is known as 'site fidelity'. Since they have successfully raised young at that site before, they feel safe enough to return to that same site to do it again. Although not always, the older males are usually the ones to arrive first. These early arrivals are usually known as 'scouts'. Because of the nature of martins to show up at a site for a period of time, then disappear for days, it was once thought that these birds arrived first to check the site out and then returned for the rest of the flock, but this 'longtime myth' has been proven wrong. Scouts are nothing more than the first birds to arrive for the spring migration and the other birds simply arrive when they are ready.

Once these early birds arrive, they set about getting to know the area again and simply lounge around until more birds arrive. This is why you may see them for a short while and then they disappear for long periods of time, even days. They are in no hurry to do anything. Martins are superb fliers and spend many hours on the wing finding food or just plain enjoying life.

Once the females start arriving, the males begin selecting as many adjacent compartments in the site as they can successfully defend.  (Known as 'male porch domination').  This is done with the intent of possibly attracting more than one female to mate with. They then seek out the females, attempting to court them and persuade them to set up house keeping with them. Again, the females have just arrived and are in no hurry to settle down. This is when the males are most vocal, chasing after and courting the females, insisting that they investigate the cavities that they have claimed.  An interesting point here, females don't pick the first male that comes along.  Instead, they investigate the cavities each has chosen and if they like the cavity, then they will stay with the male that owns that cavity.  This is another reason why it's advantageous for a male to acquire and defend more than one cavity.  Often, if they survive the migration, the same pairs will mate each year providing he has the same good cavity. Once she's made her decision, the pair will strengthen their bonds, the male following her everywhere she goes, protecting her from other males while at the same time, trying to attract more females to his other cavities if he possesses them.

About 4 to 6 weeks after the ASY birds have arrived, the SY birds will begin filtering in. These are the birds that were born the previous year and have not yet nested or even selected a site. Since they are not already established in a 'site', they begin looking for a place to start a home. These are the birds that are usually attracted to new sites to start new colonies. Upon first arriving in an area, they also are in no hurry to start nest building or egg laying. They instead, flirt around the different homes they find, investigating all available ones until they find something that they consider interesting.  This is why it's imperative that new potential landlords make their sites as appealing as possible.
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One unusual thing the established males do is attempt to attract other males to the site. This is done with hopes of breeding with any females that they in turn may attract. (This is known as forced pair copulation). This is especially done with the SY birds, since they have not nested yet and may not know how to defend their females. All the time they are doing this, they are trying to defend all the holes in their immediate territory for more possible females. If the young males do decide to stay, they in turn will try to attract other females. This is one of the most active times around the site and a lot of noisy chattering, fluttering and squabbling will take place.  Plus, it's one of the ways a site will grow.

After a few weeks of lounging around, the older birds will settle down and nest building will start.  Sometimes this nest building begins even before the SY birds begin arriving and thus, makes the year last longer for the landlord.  Nesting may be spread out as much as a month or two because of the different ages of the birds. Both birds will make nesting material gathering flights, but it is usually the female that ends up doing most of the work, refining the nest to her liking. The male will usually make flights with her to hurry her on and to also protect her from other males while she is on the ground. This is when she is most vulnerable against the forced pair copulation from other males. This nest building usually lasts from about 3 days to 2 weeks for each pair. The material they gather may vary from grasses, pine needles, (pine straw), sticks, small stones, mud and fresh green leaves. Even things such as gum wrappers and cigarette butts may be found. On smaller compartments, the mud is usually used to make a dam in the front of the nest leading up to the entrance hole. Most of the time, these mud dams are built in the smaller nesting compartments and is thought to be protection from the elements. Mud is seldom used in the larger gourds and deeper compartments.  The reason for the green leaves is not actually known, but they are believed to keep the eggs moist and usually cover the eggs with them when they leave to forage for food. The birds will replenish these leaves from time to time.

In the back of this nest, the female makes a small depression or bowl, and when nest building is complete, it's here she will place, depending on her age, anywhere from 2 to 7 soft white eggs. The SY pair will usually lay smaller clutches of about 3 or 4 eggs while the ASY pair will often lay 4 or 6 and sometimes even 7 if the compartment is large enough.

Not surprisingly there is a second factor that will sometimes dictate how many eggs are laid. If the nesting cavity is larger in size, such as a 7" x 7" x 10" cavity or a 10" diameter gourd versus a 6" x 6" x 6" nesting cavity, the average number of eggs laid will surprisingly increase in number. Apparently, with the extra room, they will lay more eggs. It's very common for mature birds to lay 7 eggs if there is room for them to do so, however there also has to be abundant food available to feed the young.

Once egg laying begins, eggs are laid at the rate of one per day, usually in the morning around daylight or shortly after. This is how a landlord, doing nest checks at 4 or 5 day intervals and keeping good records, can tell when egg laying started and thus approximate when hatching will begin. Actual incubation begins with the laying of the next to the last egg. The incubation stage of the nesting period will last for about 16 to 18 days with the female doing most of the incubation. During this period, the males will simply sit around or fly off to gallivant on the breezes of the day.

At the end of this incubation period, all the eggs will hatch within a day or two of each other. Young martins are born featherless, a term known as Altricial. (Birds born with feathers are known as Precocial). Once all young are hatched, the brooding stage begins and will last for about 28 to 30 days after which time the young will fledge. This is probably the busiest time for the adult martins, having to gather enough food to keep the young fed. Trip after trip has to be made to supply the ever hungry, growing fledglings with enough food so they will grow into birds that are ready to fly within one months time. About a week to 10 days before the young fledge, they can be seen poking their heads out of the compartment entrance hole, taking stock of the neighborhood while waiting for the parent birds to return with more food. This is an anxious time in the colony. Predator attacks become more prevalent when there are a lot of young present. It's a must to have predator guards in place during incubation and brooding times. Many predators would love to get at the eggs or young martins and make a meal of them.  This is an especially good time for the landlord to make daily walk-unders in his colony, checking out the ground and making sure that all is good in his martin housing. 

Since all birds don't start nesting at the same time, this activity period will be spread out over about 4 to 8 weeks. Some compartments will be busy while others will not. But, once eggs are hatched and young are present, the activity level for that nest increases greatly. Regular nest checks by the "Landlord" will keep him/her fully informed as to the condition of the site and the young in it.

At about three days before the young fledge, they are about the same size or even larger than the adults. At this time, they're probably too heavy to make that first successful flight. The parent birds seem to know this and will stop feeding them. This causes the young to lose some weight, thus enabling those first crucial flights to be successful. The parent birds can be seen trying to encourage the young to come out of the compartments and fly. With enough observation, a landlord might even catch sight of a parent actually pulling a young one out of the entrance hole, trying to get them to take that first leap.

Upon exiting the nest, the young will take off with much excitement. The parents will often chase and harass the young, screaming at them, seemingly scaring them into flight. This first flight is a critical one. They have to learn to fly, and they have to learn to fly well, quickly. Their life depends on it. There are many predators that are waiting on the young and they have to be able to fly very well in order to evade these predators.

Once fledged, the young will practice flying, landing and taking off again, returning to the site occasionally for a rest and they may even spend a night or two in the compartment, but they will not stay long. For about a week, the young will practice flying while still begging for food from the parent birds. Often, they can be seen on nearby power lines or open trees, begging for food from the parents and waiting for the parents to feed them. But, as nature will have it, all good things must come to an end and the young have to start feeding themselves. They will now have to put their practice flights to use. They will start hanging out with the adult birds, learning how to feed themselves and beginning to enjoy the start of their lives, investigating everything that is around them. They will visit any and all houses that they find in the area, making mental notes of the area where they were born. Although the majority of these young will not return to the site of their birth, most will usually stay within a 25 to 50 mile radius. This is nature's way of keeping inbreeding at a minimum. This is why your housing should be left up until the birds have gone for the summer. These practice flights of other young will include investigating your house and just maybe they'll return to your house next year.

After a couple of weeks of this, the entire flock will now start gathering in 'communal staging areas'. This is an area where birds from the general area will gather, readying themselves for the long and arduous flight south to their wintering quarters in South America. The groups will be small at first, but as more birds hatch and join in, they will grow in size. Although not always, these gatherings are usually around areas where there is fresh water present. They need to drink, and water usually harbors thousands of insects, something they need to gain the energy that is required to make the long trip south. Except for a few late nesting pairs, it's at this time that the small individual sites will become void of birds. This is a sad time for the landlord. Their birds are leaving for another long winter. But, we as landlords shouldn't be sad. This is what our hard fought efforts were all about. To attract birds, have them successfully raise young, and then watch them fly away into the sunset. A cycle that is repeated year after year at site after site.

It's now late summer, the sun is retreating lower in the sky, the weather is getting cooler, anticipation of fall and winter is running high. It is now time to take the housing down, clean it out and fix any and all problems with it. Might even need to paint a gourd or two. We've done everything we were told to do and we successfully fledged some baby martins. Now, all we have to do is wait for spring to do it all over again, and that's just around the corner.


Some questions and some possible answers...most are common occurrences around a purple martin colony.


I've been told that I shouldn't bother the birds during nesting or they will leave...

Not so.  That was your mother's way of telling you to leave the birds alone when you were a child, otherwise, not knowing any better, we would have disrupted the nest.  However, it's a proven fact that when regular nest checks are done on a purple martin colony, more and healthier young are produced than at one that has been left to its own accord. The landlord that is involved has a much better handle on the activities or problems that may arise in the colony. With these regular nest checks, good records are able to be kept, and the landlord is then able to give immediate attention to problems and correct them before anything detrimental happens to the site. Landlords that are out, around and under their housing every day will get to be known by their birds and the birds will quickly begin to trust them. Soon, their presence is practically ignored as the martins go about their daily activities. Contrary to common belief, the martins will not mind at all if you temporarily invade their nests. In fact, if done right, after some time, some of them won't even get off the nest but will stay there and ride the housing down and then back up. This is the ultimate trust from your birds.

How often should I do my nest checks?

Once a week is probably fine to start with during the nest building stage, but as egg laying begins, every 4 or 5 days will give the landlord a much better handle on what is going on in the colony and will enable him/her to quickly correct any problems that may arise. Don't need to over do it but it's good to know how nest building is going, if and when the first eggs are laid, when the first babies hatch, are nest parasites a problem, etc. Because of the time schedules associated with nesting, approximations can be made as to when the young should fledge. Also, good record keeping is a must. You can make your own sheets or get some that are already made up for you, it doesn't matter.  But keeping accurate records helps tremendously in keeping track of all the things that are going on in your colony.

My birds are sitting on my house. Suddenly, one will they take off, screaming at and chasing other martins. What is going on here?

These are usually males that are trying to attract other birds to your site. This is good for you. They're actually trying to increase the size of your colony and that's what the whole thing is all about. The males are usually the vocal ones of the species and are the chatterboxes of the groups. It's their loud vocalizations that draw other birds to the site. Once they spot another potential 'site mate', they take off after it, calling loudly to get its attention and to try and attract it to come down to the site and join them. Sometimes it might be other males, and sometimes, it might be females with the hopes of nesting.

Note: This activity, although ongoing throughout the day, is usually most prevalent during the nest building stages. 

 There is also another thing that you might notice.  In the very early morning hours of pre-dawn, male martins will sit out on their housing and sing their song to try and attract other martins to the site.  (They will also do this from very high in the early dawn sky).  This is known as 'dawn singing'.  Their calls seem to carry further on the early morning air.  Cassette tapes and CD's have been made of these vocalizations for landlords to play with the intentions of attracting martins to their sites.

Help, I'm being buzzed by my birds...they fly off the housing to buzz very close to my head while chirping very loudly.

If you're being buzzed by your birds, (a term known as strafing), it's because you're not spending enough time with them. This often happens when birds start nesting and the landlord doesn't pay them any attention. If you as a landlord don't spend any time with them, they are not having any human contact and therefore, are viewing you as a stranger or intruder and thus are buzzing you to protect their area. This is a very common activity around martin sites and will happen every year, especially with new birds that have arrived at your site or when there are young in the nests. But, the birds are harmless to humans and no harm will come to you because of it.

The solution: Spend more time in and around your colony, doing walk-unders, and talking to your birds. (No I'm not joking. They actually get to know you and your voice). They will soon become used to you being around and the buzzing will stop. (And no, I can't guarantee your neighbors or family won't have you committed for talking to your birds).

My birds are fighting. How do I stop it?

You don't. Fighting in a purple martin colony is a common occurrence and you will witness it all the time. They will very often fight all the way down to the ground. Remember, they are fighting for a reason. They have laid claim to an area and they consider it their territory, therefore, if invaded by another bird, will fight for it. Maybe they are both after the same gourd or even the same female. They will also do the same with Sparrows and Starlings, two of the martins worst competitors.

My birds are here in the early morning and late evenings, but nowhere to be seen during the day. Where do they go?

This is very common around a purple martin colony. Martins eat insects. Also, martins are superb fliers and spend many hours on the wing. They can easily spend 4 or 5 hours a day on the wing in search of insects for food or just plain enjoying the thermals. Since martins eat only insects, they will range far and wide to get them and may have to spend long periods looking for them. Once fed, they will return to the site and sit and preen themselves. They are just enjoying life, so don't fret, it's what they do.

The SY birds are bothering the young ones that have just fledged. What can be done?

Nothing. This is another common occurrence in a martin colony. Often, in a colony, there are bachelor males that are not able to attract females and are known as 'floaters'. Although not always, these are usually SY males. These birds will often harass the young to try and drive them from the area. It all has to do with competition. For nests. For food. With the young driven off, there is less competition, thus living is easier.

I did a nest check and found 4 dead babies in one of the nests. What happened?

There are a number of things that could be the problem here. Inspect the babies. Do they seem to be in good condition? If so, then something could have happened to the parents and the babies ended up starving to death. Although not always, the death of one parent will often make the other one abandon the nest, and thus the young parish.

Do the young have peck marks all over their heads and bodies? If so, then you have problems with pest birds such as Starlings or Sparrows invading your nest and killing your young. These birds are very aggressive nesting competitors and will often destroy the eggs or kill the young or parents. If this is the problem, then an aggressive trapping program should be set in place to rid your site of them.

You may have seen 'floater' martins around the site. It has been thought in the past that these birds do harm to the unfledged young, but there is no documented cases where these birds will harm young. Yes, they will chase and harass flying fledglings, but that is because of the competition for nesting sites. They are trying to drive the young from the area so there will be less competition for nests next year. They have never been known to harm young that are still in the nest.

If the young seem to be unharmed, check the nesting material. Are there things such as chicken mites or blowfly larva in it? If so, then there is a good chance that they may have killed the young. These parasites feed on the young birds, and if the infestation is very bad, then they can drain a young bird of enough blood to cause it to die. Sometimes, if the infestation is bad enough, the young will jump from the nest rather than die from the incessant biting from these pests. This is a common problem in the south where the insects like the warm weather.

I found a single dead baby martin on the ground near the house. What happened?

Again, there are a couple of different things that could have happened. One, if the baby bird looks in good physical condition, then the parent birds must have noticed something wrong with it and removed it from the nest. This is a common occurrence. Nature has a way of insuring survival of the fittest, and when parent birds of all kinds feel there is something wrong with a young one, they will remove the potential problem leaving the remaining ones to grow healthier and stronger.  No, freshly born baby martins will not exit the gourd or housing compartment on their own.  They are ejected somehow.

If the young bird has peck marks, then it is the work of the Starlings or Sparrows again. Set up an aggressive trapping program to remove them. And don't just relocate them, or they will return the next day. Destroy them so they are gone for good.  These are non-native birds and need to be controlled or they will quickly take over a martin colony, driving the martins away.

My young have fledged, but are not interested in staying in my housing. Why Not?

The nesting period is the most dangerous time for birds. The building of nests, the laying of eggs, constant flights to the nests to feed the young. All this commotion attracts the attention of predators. The longer the young are in the nests, the more susceptible they are to attack from these predators. For instance, snakes and raccoons can smell the young in the nest, and make every effort to get to them. Also, the young in the nest make a lot of noise that can attract other prey birds such as owls, therefore it's in their best interest to vacate the site as soon as they are able.. Once out, the young are more susceptible to flying predators such as acipitor hawks. This is why the have to learn to fly very well, very quickly. Once out of the nest, they might return for one or two nights, but soon join the adults roosting in trees or on power lines, practicing flying and readying themselves for the long flight south. They will still fly overhead, but will not stay in the housing anymore.

I had 4 nesting pairs that raised 12 young. Does that mean that I will have 20 birds return next year?

No! There are a number of factors to be considered here. The death rate on migrating martins can be high at times. Storms, predators, age, exhaustion from the migration flight, lack of food. All factors that may ultimately end in death.
Also, nature has devised other plans for the young. Although born in one site, most do not return and seek out this same site the following year. They instead return to the general area, say a 25 or 50 mile radius, and then start searching for a place in which to nest. This is one of natures ways of preventing inbreeding. Although sad for us, this is good for the species in general. It's a natural way for the species as a whole to build immunities that will ward off infectious diseases that could annihilate entire flocks if allowed to propagate. It has been shown through testing and banding that only about 1 in 5 will return to the same site that they were fledged from. Sad, maybe, but look at it this way. While your fledglings will leave your site to go to other sites, other fledglings from other sites will come to yours.

My birds are all gone. Is there anything I should do to my site?

Although not immediate, this is a good time to take the housing down and clean it out. Now, some say that it is not necessary to clean out old nests, and there have been tests done that show that the martins will readily return to old nests, but I like to clean mine out and here are my reasons. Old nesting material will harbor parasite larvae that feed on young martins. I like to remove them by destroying the old nests. Also, since I use gourds, I like to remove the old nesting because it will hold moisture, and that will hasten the decaying of gourds. Even though I've treated them to last longer, I just like the idea of putting up a nice clean gourd each spring. Once I have things ready to go up, I can place new nesting material in the cavities. (Pine straw in my case). The birds accept this material just as well as the old nests from last year and I feel more comfortable.

If your housing does not raise and lower VERTICALLY then this should also be fixed. Housing that tips to get at it should be replaced with or reworked to housing that will raise and lower with the house in the upright position. This will then allow you to do nest checks on a regular basis without dumping eggs or young out of the house.

Another thing that can be done is to fix any potential problems with the site such as loose housing or frayed ropes or cables. If your housing is of the kind that does not allow access to the compartments for nest checks, then now is a good time to update the housing so this can be accomplished. If you have gourds, then you can add access holes to them to allow you to get into them for nest maintenance. If they need painting, then a touch up here and there may be in order. Remember, the more you can do for your birds, the larger the broods will be and the larger your colony will grow.