Pros And Cons Of Using Porches On Purple Martin Housing

[Steve Kroenke]

Pros And Cons Of Using Porches On Purple Martin Housing

To porch or not to porch, that is the question. Nearly all multi-compartment purple martin houses have porches. Many porches are continuous and support multiple compartments on house tiers while others are single porches for specific cavities. Many natural and plastic gourds have porches when srehs are used and many of these cavities do not have them with round holes. No natural woodpecker cavities out west have porches. And purple martins will nest successfully in all these cavity types. So are porches really necessary on purple martin housing? I don’t know if there is truly a correct answer to that question, but we can identify purple martin behaviors that may be influenced either in a good or bad way by using porches on martin housing. But first some historical information and a brief discussion of purple martin morphology…

History

Purple martins never had porches under their nest entrances in woodpecker cavities for thousands of years and don’t in western United States where martins still breed in natural sites. When martins gradually transitioned perhaps hundreds of years ago to natural gourds provided by Native Americans in the Deep South of North America, martin cavities were still porch-less. With the arrival of European settlers in North America, there was a change in the design and type of human supplied cavities for martins. People began offering multi-compartment houses and perhaps at this point porches or perches were added. And currently the vast majority of natural and plastic gourds with round holes do not have porches. So in geological time with 24 hours representing the entire present evolutionary period for purple martins, it could possibly be argued that martins nested in porch-less cavities for more than 23 hours and just a fraction has been in ones with porches. But a lot has happened in the last 100 years or so to purple martin nesting cavities and martins have adapted to the change.

Morphology…Martin Physical Structure

Purple martins possess certain physical characteristics which may have evolved in part over eons as a result of nesting in rustic cavities without porches. These same attributes also relate to the martin’s lifestyle of feeding on flying insects and spending large amounts of time in the sky rather than perching somewhere.

First, purple martins have somewhat stiff tail feathers which are good braces when martins hang vertically on an entrance hole without any kind of underlying support foundation. The tail helps prop the martin against the front of the cavity. Woodpeckers also have such tail feathers. Additionally, stiff tail feathers aid in executing quick turns in the sky when martins hunt flying insects and escape from aerial predators.

Second, martins have short legs with strong feet and sharp nails which are perfect for clinging to rustic surfaces and climbing in and out of woodpecker cavities. Short legs allow the martin to press up against the outer surface of an entrance hole and easily hang there. Martins can also easily climb the coarse surface of the inside of a narrow woodpecker cavity or a natural gourd and cling to it like a chimney swift does inside its nest cavity. Short legs are more appropriate for aerial hunters which spend little time on the ground.

So martins may have evolved stiff tail feathers and short legs with strong feet and sharp nails in part to aid in clinging vertically to natural cavity entrance holes and entering and exiting them. No porch or perch is necessary.

The First Big Change…Multi-compartment Houses With Porches

But change was in the air and purple martins would be presented with an entirely different kind of nesting site from the natural gourd and woodpecker cavity. The European settlers that colonized North America would eventually introduce the multi-compartment martin houses and during that introduction porches were added at some time. Why porches were placed on martin housing no one really knows. Perhaps because many human dwellings or businesses had porches leading up to the front doors then maybe martin houses should have them too. Maybe folks liked to watch martins socializing around their housing and porches outside the nest cavities encouraged this behavior. And since people probably built their martin houses to look somewhat like a human home, then adding porches was perfectly natural.

Purple martins adapted well to porches and have thrived in houses and gourds with these additions under the entrance holes. I have used martin housing with porches and without for all my various personal martin colonies and saw no difference in terms of martin occupancy levels or preferences. But I have seen characteristics, both good and bad, of porched and un-porched martin cavities that relate to and impact specific martin nesting behavior.

Based on many years of observing purple martin behavior relative to housing with or without porches, I have identified a number of pros and cons. In some cases, a pro can also be con and vice versa under certain conditions. Here are my observations and I am sure other folks have seen the same things or more…

Pros

There are many positive reasons to use porches on purple martin housing and each can be correlated with a specific martin nesting behavior.

Porches Greatly Help Martins To Enter Starling Resistant Entrance Holes (srehs)

Starling Resistant Entrance Holes (srehs) are usually horizontally shaped entrances which attempt to deter starlings from entering purple martin housing. These entrances are much smaller in vertical height than the typical two inch or more diameter round holes and focus on greater horizontal length and shape. Most of these entrances are modified variants of the original crescent or half moon design.

The various srehs require purple martins to use different physical actions to enter such entrances than they would with a round hole. Remember: martins evolved in porch-less round holes, not srehs and their bodies are more adapted to entering circular entrances. To enter an elongated sreh requires a martin to engage in some “shape shifting”. The martin must somewhat flatten its body to accommodate the restrictive height, usually around 1 and 3/16 inch, of a sreh; a healthy martin with its wings closed may be normally thicker at its widest girth. The martin may spread out its wings somewhat to aid in flattening of the torso and keep the shoulder areas from interfering with entering the sreh. Some martins even “shoehorn” in a wiggling motion through the sreh. To enter a two inch or more diameter round hole, the martin easily slips in with wings folded at his/her side and no shape shifting action is required.

Martins are possibly better able to enter the sreh by approaching the entrance in a horizontal profile rather than hanging vertically and lifting themselves up like they would with a round hole. The horizontal approach allows the martin to properly align its wings and flatten its torso to wiggle through the narrow sreh. A porch greatly facilitates this physical maneuver because the martin can first easily position itself horizontally in a non-flying posture at the front of the sreh and then enter. Without a porch, a martin may approach a sreh while flying and then hit the entrance horizontally and squeeze in. Many martins learn to do this, but it can take time. However, variation in size and weight within the martin species may result in some larger martins having problems doing this with ease. Other martins may first hang vertically on the sreh and then lift themselves up and enter. I have watched martins struggle and struggle to enter un-porched crescent Super Gourds for minutes before finally managing to go in; some martins never make it. The slick plastic increases the difficulty of the martin to gain sufficient leverage and traction to slip in or out of the sreh. However, I have observed martins more easily enter un-porched crescent natural gourds because the gourd’s rustic surface on the inside around the entrance provides a good substrate for gripping and forward propulsion.

If martins have to struggle to enter/exit un-porched srehs, the martins can become victims of Accipiter hawks. Every second of delay increases the chances that a Cooper’s or sharp-shinned hawk will successfully capture a martin that is struggling to enter or get out of a sreh. I have seen this predatory activity occur a number of times.

For landlords who use srehs in their housing, porches often greatly help martins to enter the entrances. The porch facilitates the martin’s ability to “shape shift” its torso from a more circular appearance to a somewhat flatten one, spread his/her wings outward, and enter a sreh from a stabilized horizontal profile. Porches and srehs are a perfect combination to aid martins in entering their nest cavities.

Porches Greatly Help Parent Martins To Feed Large Nestlings At Entrance Hole

One of the most important advantages of a porch underneath holes relates to the feeding of large martin nestlings that are clustering around the cavity entrance. This advantage can be applied to all housing and hole design types. As martin nestlings increase in size, they become more mobile inside the nest cavity and will instinctively move toward the entrance to be fed. This is particularly noticeable in cavities with vertically shallow placement of entrance holes where the distance between the entrance and nest is short. This includes houses with entrances cut an inch or less above compartment bottoms and gourds with a similar hole placement. In vertically shallow cavities the martins have limited space to build thick nests and the nests tend to reach the entrance hole. Nestlings can easily crawl to the entrance.

When large nestlings are fighting at the entrance hole of an un-porched cavity to gain an advantage in competing for food, the parent martins may have a hard time clinging in this area and transferring large food items such as dragonflies to their young. Using their feet, the parents may actually grip the heads of nestlings or try to feed them while hovering at the entrance hole. Sometimes the parent martins will drop the dragonflies because the parents are unable to effectively deliver the food directly to a baby because of the number of babies’ heads that are jutting from the entrance. Other times, the dragonfly is not positioned appropriately in the baby’s mouth and he/she is unable to swallow such a large item. The nestling will often drop the dragonfly to the ground. I have seen many dragonflies dropped on the ground underneath my gourd racks because the parent martins were unable to efficiently deliver the food to their large young that clustered around the un-porched entrance holes. This is a terrible wastage of valuable protein, particularly during periods of droughts when dragonflies are less common. I have observed this phenomenon at un-porched sreh and round hole gourd colonies. In the mornings on the ground beneath my gourd racks my yard looked like it was covered with sparkling gems as the wings of fallen dragonflies glistened in the sunlight.

I see fewer dropped dragonflies under my multi-compartment houses with porches and gourds with porches or perches attached near the entrances. In these cases, the parent martins can sit on the porches/perches and deliver dragonflies to any nestlings that are clustered around the entrances rather than try to hang on or hover at the entrance holes while attempting to feed the babies. The porch provides a stable foundation that allows a parent martin to sit in front of the entrance that may be filled with hungry mouths and then more methodically deliver food without having to hold on to an entrance area filled with begging heads! I have observed a parent martin drop a dragonfly on the porch in front of an entrance and then retrieve the prey and feed it to the young.

Porches on houses and gourds with round holes and srehs, greatly minimize the dropping of insects, particularly dragonflies, by parent martins as they deliver food to nestlings clustered at the entrances to their nests. In fact, housing with porches may be more productive in raising better fed youngsters and reduce the wastage of uneaten dragonflies that are dropped to the ground.

Porches Allow Fledglings To More Easily Enter Their Nesting Cavity To Roost

Most of the parent martins in my colonies bring their fledglings back to roost in their nests during the evenings. This roosting behavior can present significant problems for the martins and their young, particularly for recent fledglings which are still learning flying skills. For a few days, fledglings often lack the ability to easily follow their parents back to an un-porched nest cavity, particularly gourds. The fledglings frequently miss the entrance, try to enter other cavities, land on gourd rack crossbars, are attacked by other martins, become separated temporarily from the parents, and exhibit behavioral flying confusion. The parents try and try to guide their babies back to the nest and during the first evening or so this can be a most difficult and stressful time. The recent fledglings often lack the flying coordination skills to easily follow a parent to an un-porched gourd, properly grab the entrance hole, and enter. Additionally, the parents will sometimes hang in front of the entrance rather than quickly enter thereby blocking it and the fledglings can’t always go around or over the parent to reach the hole. In large martin colonies with numerous returning fledglings, the chaos can be overwhelming.

Porches under the nest holes greatly facilitate the parent martins’ ability to bring their fledglings back to the natal nest for roosting. In my multi-compartment houses with porches, the fledglings could under most cases easily follow their parents back to their nest cavity or an adjacent one to roost. The parents had fewer problems guiding their babies back to the nest as the porch allowed the fledglings to first land in front of the entrance hole and then enter. The fledglings could grab any railing, perch on the porch, and then easily follow their parents into the entrance or go inside independently.

Porches Aid Martins In Watching For Aerial Predators Like Accipiter Hawks And Merlins

When martins are gathered around their housing during the daytime, they can become targets for predation by Accipiter hawks and merlins. Cooper’s and sharp-shinned hawks and merlins will readily attack martins at their nest site, particularly when these raptors can use the element of surprise to catch the martins off guard. Martins need to be vigilant and be ready to bolt from the housing quickly to accelerate and gain altitude.

Porches on martin housing allow martins to sit out in the open where they can more easily observe the surrounding skies for approaching danger. Without a porch, the martin may just have its head protruding from the entrance, particularly with srehs, and not have a more panoramic view of the area. Accipiter hawks can sneak up on the martins and be already inside the colony before the martins are aware of the danger.

Porches Encourage Martins To Socialize Around Their Nest Sites

Purple martins enjoy socializing around their cavities and this behavior includes territorial defense and mate attraction. By sitting on the porch in front of his nest cavity, the male martin can easily intimidate other males and even territory seeking starlings and house sparrows. Just his presence on the porch may be sufficient to keep potential competitors at bay. Should another male martin manage to enter the cavity, a porch will allow the owner of the territory to more easily position himself in front of the entrance and attempt to evict the interloper by pulling him out or going inside to attack.

While perched on the porch, vocalizing male martins can easily advertise their territory to potential mates and then quickly enter when a female flies down to investigate. The porch allows the female to perch near the entrance, pause for a while and check things out rather than go directly to the hole and hang there. Female martins tend to be cautious as they review various males as potential mates and their territories.

As mentioned previously, martins seem to enjoy gathering at their colony site and actively socializing with other martins. Porches encourage martins to remain close to their nesting cavity. Large numbers of martins sitting on porches around their colony intensifies martin socialization behavior and can aid in attracting territory seeking martins. Martins are attracted by others and nothing is more attractive than vocalizing martins socializing around their colony site. Porches (and perches) may greatly increase the attractiveness of housing to territory seeking male martins, particularly SYs. These newly arriving martins are usually somewhat cautious because they don’t have territory and must compete with established dominant males. Porches allow the new males to perch at a distance from the entrance, size things up, and gradually approach rather than go directly to the cavity holes initially.

Porches Assist Martins During Nest Building

Though I build well constructed nests in all my gourds and house compartments, martins will still add some nesting material, particularly leaves. However, if you provide only a partial pre-built nest or allow the martins to solely construct their nests, then a porch underneath the entrance hole helps the martins. The martins can first land on the porch, position themselves in front of the cavity, and then enter with the nesting material in their beaks. Sometimes martins will bring in large or long pieces of nesting material such as twigs or pine needles. Such material may make it difficult for the martins to cling to an entrance and enter without having a porch underneath to provide some support to the martins. Though martins can do it without a porch, particularly with round holes, the porch provides a stable foundation for the martin to land at the entrance prior to entering with nesting material.

Porches Enhance The Human Landlord’s Enjoyment Of His/Her Martins

We humans enjoy watching “our” martins socialize around their colony. I thoroughly like to see large numbers of martins sitting on my house porches. So porches on houses and gourds provide us with an open picture of martins lounging around the colony and socializing. I like that and many “porch sitting” martins greatly increase the personal enjoyment of observing my martin colony.

Cons

Though porches have their beneficial attributes, they also can create problems for purple martins. Here are some of the negative attributes of porches that I have observed over the years. However, some of the disadvantages can be mitigated via appropriate housing modifications.

Porches May Increase Predation Problems

The most negative consequence of using porches on martin housing relates to predation. Natural sites like woodpecker cavities NEVER had porches under entrance holes. A porch underneath an entrance hole can be a “walkway of death and destruction” for martins inside a house or gourd. Great horned and barred owls can easily cling to a porch and grab spooked escaping martins or reach inside unprotected cavities to extract adults and nestlings. Barred owls are cavity nesters and skilled at clinging to sides of trees. Accipiter hawks and merlins will do the same thing. Even the Buteos like red-shouldered and red-tailed hawks and crows can use porches as a means to access nesting martins. I have seen barred owls and Cooper’s hawks sit or hang on porches and drag martins from multi-compartment houses with porches.

However, by installing appropriate predator guards such as wire fencing or dowels in front of the entrance holes and using horizontally or vertically deep cavities or offset holes, the potential predation related problems with using porches are minimized.

Unfortunately, martins, particularly fledglings that are returning to roost in the evenings, will often sleep on exposed house porches and gourd racks. Dowel guards may do little to prevent owls from predating martins in these situations though a wire cage enclosed around a house or gourd rack could help keep these predators at a distance. When martins are lined up or crouched down on porches at night or early morning, owls can easily see the martins, swoop in and score a kill. I have often heard the death rattle of roosting adult and fledgling martins being grabbed off house porches and then seen a huge barred or great horned owl flying away from our colonies with a screaming martin in the owl’s talons. It is horrifying and I often find myself trembling after one of these nocturnal terrorist attacks! Our martin colonies are partially illuminated by security lights and it is easy to see an owl flying through the colony or perched on the housing.

During the early morning hours when male martins are dawn singing, the males may come out and sit on porches to vocalize or just remain silent. This is suicide if a barred or great horned owl is stalking the colony site and predating martins. I have watched these huge owls swoop right into our colonies and grab male martins off porches! Fortunately most males seem to leave the colony site and vocalize high in the sky where they are safe from the night terrorists.

In my opinion, the predation issue is possibly the major con with using porches on martin housing. There are some other possible disadvantages, but these do not rise to the same level of negativity. Here they are…

Porches Can Sometimes Allow Starlings To Enter Srehs

Starlings are larger than martins and have much longer legs. Starlings are muscular birds and can wiggle into a variety of entrances if they can use their powerful legs as pushing devices. Martins are slender with short legs. Both starlings and martins vary somewhat in size within their species.

The most effective srehs that deter starlings but allow martins to enter may be ones that are either flush with the porch or are no more than about ¼ inch above it. This placement of srehs helps to defeat the starling’s ability to use its long powerful legs effectively to push forward. The starling must crouch down almost on his/her belly in front of the sreh and this position may help to reduce the starling’s ability to use its legs to push through. If the sreh is higher than ¼ inch above the porch then a small starling, particularly a female, may be able to use its legs for greater leverage in forcing him/herself through. I have watched a few starlings enter standard crescent entrances in Trio aluminum houses where the entrance is around ½ inch above the porch. Crescents cut lower down, particularly flush with the entrance, have been starling proof from what I have observed in our satellite martin colonies. However, most srehs probably deter the majority of starlings independent of the distance the entrance is placed from any outside porch.

Porches May Encourage Young To Prematurely Venture Out

In cavities with vertically shallow entrance hole placement, martins will build their nests up to the hole. As the martin nestlings become older, they will move to the entrance hole to fight for their share of the food. Having a porch directly under the entrance will sometimes encourage nestlings to venture out on the porch prematurely, particularly as the larger young cluster in this area and fight for food. Once the nestling is on the porch, he/she may be attacked by other martins, particularly SY males, and knocked from the porch. Or the youngster may lose its balance and prematurely fledge in the absence of its parents; these babies are often doomed.

This “wandering porch behavior” by the nestlings also relates to the predation issues previously discussed. Nestlings sitting on porches are easy prey for hawks or crows which will often perch in an obscure place near a martin colony and look for opportunities. I have seen Cooper’s hawks fly right up to a house that had nestlings on the porches in front of their nest holes and grab these vulnerable babies. Even red-shouldered hawks will do this.

Continuous Porches May Encourage Male Martin Nest Domination Behavior

Many male martins may exhibit a territorial defense behavior called nest domination. Males do this to possibly reduce intra-specific competition with other males for potential mates, provide females with a variety of nesting choices, and exert their territorial drives that exist in most songbirds. Continuous porches that connect multiple compartments tend exacerbate this nest domination behavior as the males can move along the porch and defend numerous cavities.

However, by using separate porches for certain housing designs like T-14s and porch dividers on traditional square or rectangular houses like the Trios and Trendsetters, nest domination behavior can often be minimized. Also, porches on gourds are not impacted by martin nest domination behavior as there is only one cavity involved.

Porches Can Aid House Sparrows In Better Defending Nest Cavities From Martins

While porches allow martins to sit in front of their cavities and offer resistance to competitors like starlings and house sparrows, sparrows in particular can use the same strategy against martins.

Srehs will stop most starlings but not house sparrows. So sparrows can try to usurp cavities in houses and gourds with or without porches. Sparrows will often sit on a porch in front of a house compartment or gourd and defend it against martins. Martins are larger than sparrows, aggressive and have a wide but soft weak flat bill. However, the martin’s weak bill is no match for the heavy crushing finch like beak of the sparrow in head on battles. Sparrows can face martins in head on beak to beak confrontations on porches and the sparrows nearly always prevail.

On porch-less housing such as gourds, martins can use their very aggressive fighting abilities in close quarter conflicts with sparrows inside the cavities. Martins tend to win these battles as sparrows are often reluctant to fight larger birds inside the nests. In numerous conflicts I have observed between martins and sparrows inside nest cavities, the martins won most. In beak to beak confrontations on porches between martins and sparrows, the sparrows were usually victorious.

Porches That Are Flush With Entrances May Allow Rainwater To Intrude Into The Nest Cavity

Porches that are flush with an entrance hole or close to it may allow rainwater to splash or seep inside the nest cavity. This is a not major problem and can be mitigated to a point with nest trays, elevated sub-floors, rain canopies/roofs or when using some gourd types such as Troyer Horizontals, drilling drainage holes under the neck area. Also if the porch is pointed slightly downward from the entrance hole, a lot of the rainwater will drain off.

Overall Porches On Purple Martin Housing Do Far More Good Than Harm

There are a number of pros and cons relative to using porches on purple martin houses and gourds with srehs and round holes. Though martins never had porches in the past and still don’t for many gourds with round holes, porches provide many advantages. If you are using srehs in your martin colony, then properly placed porches tend to help martins enter these holes. If you are using round holes or srehs, porches greatly minimize the dropping of large insect prey such as dragonflies by parent martins as they feed their young clustered around the entrance. Porches also help parent martins successfully lead their recent fledglings back to their natal nests and enter them at roosting time. These major positive attributes of porches are sufficient reasons to use them on any type of martin housing with either round holes or srehs. The main negative aspect of porches relates to predation issues and even here appropriate guards can be installed on housing and deep cavities can be used to minimize this adverse possibility though may not stop it.

Steve Kroenke

[James Strickland FL]

Steve, I pose a question to you. As in nature if the enviroment is changed, so will the aninmals within that enviroment will change. As you talked about the short legs and the strenght of the legs and the strong tail. Do you think that over time the martins may change their structure of their bodies to accommodate for these changes due to not having to use them any more? We see it in humans as as humans have had products made to make their lives easier, we have as humans become fatter.

[Tim Mangan-Kansas]

Steve:

As usual, very interesting and informative article. For me, having porches offers an element of additional enjoyment in watching my martins. All of my gourds I will be offering this season are the new Troyer tunneled horizontal gourds with porches.

One of the most interesting cycles of the martin season is when the scouts first arrive and they are trying to attract a female to my site. As you have described, I have witnessed many times how the male will swoop down, enter a particular gourd and start vocalizing to a female still flying around the colony site. The male will be positioned just inside the gourd opening, often with just his head sticking out of the entrance hole and vocalizing trying to get the female to come down and check out the potential nest site. The female will land on the porch which gives her the opportunity to check out the inside of the gourd without actually going in. I really enjoy watching this stage of the nesting cycle.

Last season, I had several ASY males who would just sit on the porch while the female was sitting on eggs. To some, this is nothing more than a martin perched on a porch. To me, it brings out the fidelity of the male to his mate and his loyalty in protecting the nest and his mate while she is incubating the eggs.

Just prior to fledging, a lot of my young will come out on the porch to check out their new surroundings. Again, I enjoy watching them as they take in all the activity around the colony. It also gives me a better opportunity to watch them take off on their maiden flight.

Until last year, I had never seen a starling at my site. As far as porches having negative issues regarding predators, I totally agree with everything you stated. However, it was because of the porch, I was able to eliminate this pair of starlings from my colony. I found that the starlings, when landing on the porch to enter one of my gourds, hesitated for a second or two before going into the gourd. This second or two allowed me to take aim and get a good shot off to rid my site of this predator.

There are dangers to having porches but, to date, I have not had a problem with owls. I did have several hawk attacks at my colony last season, all unsuccessful, that I witnessed. Until such time as I have a predator problem, due to having porches, I will continue using them. For now, the added viewing enjoyment of having porch's outweighs the disadvantages of having them.

Great article.

Tim

[Guest]

I agree with all about porches and for all the same reasons.

I have found the following to be the case with my setup of porches attached to a 45 degree tail prop,this puts the porch about 3 inches below the entrance and the parents do feed from this porch as the young start making their trek to the entrance.

The ramp/tail prop is slick while the porch has traction. I have modified clinger entrances by rounding the sides and putting just a slight belly in the bottom of the entrance.This gives them a little more wing room/breast room. The PM's either basically fly straight in or when sitting/perching on the porch they just seem to hop right up and in with very little effort as opposed to a factory clinger. I have seen them cling with one foot at the entrance and the other foot on the ramp for support while feeding as well.

I have witnessed starlings trying to enter this modified clinger but with the slick ramp they just can't seem to be able to get a push off. I also have relativly larger rain hoods which also get in the way of the starlings head and shoulders when and if he tries to cling.This was in 2007.

I will be using this arrangment on all of my 24 gourds this year,2008.

[John Miller]

Great overview Steve

I use mostly porched gourds and tunnel entrances, but I do use a few unporched naturals with crescents cut directly in them. Martins enter these well because as you noted they can grip the natural gourd. Even slightly oversized, I have not seen starlings enter unporched crescents in natural gourds. However, in my small sample size of a dozen gourds, I observe better breeding success in porched gourds with nestlings sometimes jumping early from the unporched -- maybe getting pushed out -- especially in gourds where the unporched entrance may be too low. Pros and cons, as you have said.

John

[geezer]

Steve, Great post as usual.

My question concerns whether porches shoud be placed INSIDE and OUTSIDE on gourds.

Mary Dawnsong believes that the inside porch allows the PM's to essentially hide below the inside porch in case of hawk or owl attack.

What is your feeling on this issue?

geezer

[James Strickland FL]

Sorry Steve I have a question. How far from the round hole do you place the pourch? Thanks for the info

[Steve Kroenke]

Hey James,

Evolution is a relatively slow process for many species but can be quicker with bacteria and viruses!

As environments change, animals must adapt to these changes or possibly become extinct. Natural selection helps to “weed out” the less fit and the stronger members of the species survive and pass on their genes for future generations.

Purple martins can adapt to changes in their housing and have clearly done this over thousands of years. Changes to martin physiology takes MUCH longer and we probably won’t be around to see it! Physical changes may result from genetic mutations which in turn prove to be favorable relative to survival rates. Natural selection comes into play. These changes are then passed on because the impacted individuals have greater survival rates and produce more offspring to continue the traits.

Since there will probably be a variety of entrance holes offered to martins, including various srehs and rounds, and different kinds of housing, I don’t know how this scenario will ultimate impact martin leg and tail structure way in the future. Also, martins are birds that spend a lot of time in flight, so the current leg and tail structure still relates to that aspect of martin biology/behavior. So the short legs and stiff tail feathers could still be functional.

We humans can impact the breeding behavior of martins and even see changes immediately as martins adapt to new housing designs and entrance holes. Impacting the morphology of purple martins by changing their physical structure is far more complicated and uncertain.

But it is fascinating to think about what a martin will physically look like thousands or millions of years from now if this species survives that long! The human species may not be around to see any of this! Many astronomers believe there is “monster asteroid” roaring through the universe and this cosmic killer will eventually have its fatal impact with the earth. That may end the reign of Homo sapiens just like a huge asteroid may have ended the world of the dinosaurs some 65 million years ago.

Regarding the placement of the porch below a round hole...

I usually place a porch about an inch below the round hole. You can vary this and I have placed holes lower down. However, on my Troyer Horizontals, the hole will be placed almost flush with the porch because of the spacing available at the front of the Troyer tunnel.

Steve

Tim

Thank you Tim for sharing your observations and insights regarding porches on martin housing.

This season I watched the confusion and stress of numerous parent martins as they tried to bring their babies back to roost in my un-porched gourds. It was total chaos at times and many youngsters never got in their nests. The martins that nested in my houses had a much easier time. Over at Bob’s colony where he has replaced most of his gourds with houses with porches, the parent martins were able to lead their babies back to roost with much less confusion and problems.

For many years, I would never have considered using porches on my round hole gourds. Martins are successful in them, but the two main issues relating to feeding the young and bringing them back to roost have convinced me of the advantages of porches.

I hope you continue having great success with porches and even if you experience some predation issues, you still may be able to resolve or minimize the problem with owl guards and selective on site guarding during the critical early morning time.

I am glad the porch helped with ridding your site of the starlings. The porch was both a pro and con. The porch probably helped the starlings to enter the crescent, but then proved to the starlings downfall when their hesitation allowed the Grim Reaper to harvest his reward!

As soon as get my Troyer Horizontals with porches on the racks, I will post pictures of them. I am also using Sunset Inn Trendsetter houses on multi-purpose poles with Troyer gourds. I will post some photos of this set-up, too.

Martin time is approaching and it will be exciting for you with your new Troyer Horizontals with tunnels and porches.

Steve

Hey Dick,

I enjoy reading about all your modifications and your enthusiasm to try different designs! Experimentation is the key to creating successful designs and products.

Your observations confirm that martins will use porches underneath an entrance to easily feed their babies that are clustered around the hole.

The distance between the porch and the sreh can sometimes influence a starling’s ability to enter the hole. We had starlings breach Trio crescent entrances at two of our satellite colonies. The distance between the bottom of the entrance and floor appeared to be a little over ¼ inch. We have never had starlings enter any of Bob’s crescent entrances that are flush with the floor or around ¼ inch.

At one site, the male starling seemed to never enter the crescent while the female did so with ease. Bob shot both and brought the female home for me to “study”. She was smaller than normal and even her beak was short. She almost looked like some kind of mutation. This is scary! If more “smaller” starlings are breeding, then these may soon be able to enter more of the srehs. We use only crescents at our satellite martin colonies because we can’t monitor them constantly and starlings are more common in the urban/suburban areas.

Starlings are intelligent and persistent birds. I hope your modified clingers continue to keep the starlings out. One thing to look for. Starlings will fly directly to a round hole and enter it without clinging. Since you have made some changes to the clinger and possibly increased the size just a tad, a smaller starling may be able to fly directly to the hole and wiggle in. Just something to think about.

Thanks for sharing all your ideas with us on the Forum!

Steve

Hey John,

When Bob used a lot of natural gourds, some of his crescents were slightly larger than “normal”. Martins entered them relatively easily and we never saw any starlings do so. The martins could much more easily the naturals with crescents than the plastic Super Gourds.

I have seen the same problems as you with holes cut too low down on gourds. The babies often cluster around the entrances and it is so easy for them to be pushed out by their siblings as they fight to get the best position for feeding. In this case, a porch could be a plus if the baby could get back inside before being knocked off or prematurely fledging.

On my vertically deep woodpecker gourds, the babies tend to stay deep down inside the nesting chamber until they are closer to fledging. Then they tend to cluster more near the entrance.

Steve

Hey Geezer,

I have never used any kind of inside porch on a gourd, so can’t comment from experience relative to predation issues. However, I can share some of my thoughts on the subject.

A porch on the inside of a gourd is essentially an extension of the outside one with the entrance hole area dividing the two. If the gourd does not have any nesting material in it or not enough to reach the level of the inside porch, then I believe martins could “huddle” under an inside porch if they would do it. Of course, this all depends on how much vertical depth is between the inside porch and the gourd bottom. Many gourds have relatively shallow vertical depth between the entrance holes and the bottoms so that limited room is provided for martins to hide in. If you have built a nest in the gourd that is level with the inside porch or the martins have done or if the nest is close to the same level, then I don’t believe the inside porch offers much protection. The martins would not be able to “get under the porch” that has nesting material between it and the gourd bottom. The martins would probably instinctively just get as far from the entrance as possible, usually toward the back of the gourd. There would probably need to be around 2 inches or more of space between the inside porch and the nesting material for a martin to easily slip up under the porch. And even then, maybe only one or two martins could do this at a time. Would martins instinctively do this or would they tend to move to the back of the gourd area? Also, an inside porch does NOT restrict visibility from the outside to the inside. Owls have fantastic nocturnal vision and can see inside gourds and house compartments with direct line views to the nesting chamber. A flat inside porch would not block this view. A hawk could probably see inside during the daytime.

Inside porches are probably designed to assist martins in exiting gourds with srehs rather function as anti-predator barriers. The martins can hop on the porch and exit the sreh in a horizontal profile. I don’t necessarily believe inside porches are absolutely necessary for martins to exit gourds with srehs, but they probably help. I have seen martins exit crescent Super Gourds without any kind of porches. I would not arbitrarily use inside porches on any of my gourds with round holes.

I believe inside porches should be used mainly on gourds with srehs to assist martins in exiting the nest rather than as any kind of predator guard.

Just some of my ramblings!

Steve

[James Strickland FL]

Steve thanks for where to put the porches. As for your hypothesis I would have to agree. I know that it takes thousands of years for a animal to change and I was just wondering if the any change had happen to the Purple Martin over these years. As for human being here, I would have to agree with you on how long humans will be here. I think that we will be impacted and the human race will be destroyed. But animals are surviors and life will go on and evolution has show that. Hopefully it is after you and I have let.

[Kelly Applegate~MN]

Here is an example of evolutionary change in martins:
Let's say ALL entrances in the entire martins breeding range is set at 1 3/16". The only birds that would be able to breed would be the ones that squeeze through, excluding the larger birds. These larger birds will eventually die off in time leaving only their smaller cousins that were able to breed. Eventually the gene for larger martins disappears through several generations of offspring and the martin population is now smaller on average than before. It's all about genetic traits being passed down to the next generation that gives them an edge to survive and reproduce.

[Steven Spencer]

Great article, Steve! I wondered when you were going to get off the deer stand and finish it! I think porches help solve a few of the problems we have created since the martin "behavioral shift" occurred. First of all, man has introduces a foreign competitor, the starling, so now we have to have sreh's with porches to aid the martins enter. Secondly, when martins originally nested as isolated pairs in dead trees, the fledglings would not have the distractions of numerous compartments and harassing adults when returning for the evening. There would be less confusion at an isolated nest. Porches would help the fledglings hit their spot, hopefully, on the first try. Third, adult martins feeding young could "cling" to a dead tree much easier than the side of a slick painted gourd or house. Instead of just "hanging" by their top claws on a gourd or house they could have "grabbed" the side of the dead tree, enabling better food transfer. Sort of like a bluebird parent grabbing the hole and side of the cedar bird house when feeding young.

There are a few negatives like you mentioned, but I also think the advantages outweigh the disadvantages.

[Steve Kroenke]

Hey Steven,

We haven't been doing much deer hunting so far. Been so warm over here and the deer are just not moving around much. I did get a nice 7 point buck the other day! We have been eating venison!

Humans have significantly changed the breeding biology/behavior of purple martins. Some good and some bad. Your points about martins nesting in woodpecker cavities and alone or perhaps small groups are well taken. I have seen martin fledglings land at the base of a pine tree and "crawl" up the trunk using their strong feet and sharp nails to propel them upward. The rustic tree bark provides the perfact substrate for climbing. So parent martins could easily cling to the side of a dead tree near the entrance hole and feed their young.

Porches do far more good than harm even though they are not necessary on cavities with round holes. I am in the process now of installing perches on many of my natural gourds that maximize vertical/horizontal depth. These perches will help the parent martins to better feed their large young. I will not porch all my gourds this season, but hope to do so after the 2008 season.

Our good friends Al and Ursula Scott have a huge super colony located about 6 miles northwest of us. In 2007 their second season out here, they attracted probably over 150 pairs of martins. They use quality housing like Lone Stars, Trendsetters, Super Gourds, Trios and Troyer Horizontals. They use round holes in their colony but are this year adding tunnels and porches to all their gourds. Ursula and I talk a lot about our colonies and we believe the porches will greatly assist the parent martins relative to feeding young and bringing fledglings back to roost. I plan to write an article about Al and Ursula's outstanding super martin colony and post photos of their site on the Forum. They have a great location.

I hope to soon to have my Trendsetter Sunset Inns and tunnelized Troyer Horizontals with porches. As soon as I get some of the set-ups ready, I will post photos on the Forum. I am real excited about the Sunset Inns and Troyer Horizontals combination on multi-purpose poles.

I hope you can come over in 2008 and visit our martin colonies again.

Steve

[Guest]

Hi Steve:
As a newcomer to the "Martin World", ( 1/2 a season last year), I'd like to compliment you on a geat posting. It's packed with info that I'd think is most helpful for the newcomers in particular. The other postings from various people replying to yours I also got a lot out of.
My situation (location) is going to be particularily challenging for the upcoming season as I'm on 5 acres of property 20 minutes east of Winnipeg but 3 1/2 acres is solid bush. I have 2 martin houses newly set up, one being a Coates aluminum and one which I just put up near the end of the season which is a Buskas House. I believe I've positioned them as best I can after clearing out a lot of trees etc.
I'd love to send you some photos for your opinion if you wouldn't mind.
Thanks again for a most interesting read.
Doug T

[Steve Kroenke]

Hey Doug,

I am glad you enjoyed the article and I hope you have a great purple martin season in 2008.

Yes, you can send me some photos of your set-up. Here is my email address: [email protected]

You may even want to post some photos on the Forum so other folks can review and offer their comments.

While martins prefer open colony sites, martins will nest in areas that may seem not that ideal relative to tree encroachment issues. Key factors such as martin population dynamics of a specific area come into play. If you have several good open flyways to the housing where martins can fly nearly level to their nests, then that will improve chances of attracting martins to less than ideal sites. Too many trees nearby can increase predation problems from Accipiter hawks. These hawks will use stealth to ambush the martins around their nests.

Looking forward to seeing your photos.

Steve

[geezer]

Steve,

Here are a few thoughts on the vertical distance from the entrance to the porch:

1. The consensus choice is FLUSH with the entrance. The only downside is that Rain Water may get into the nest chamber and the nest may get wet. However, Starlings are not able to get in.

2. If the porch is placed between 1/4" and 1/2" below the entrance, then Starlings may be able to enter (no matter what type of entrance holes you have).

3. The 3rd approach is the DICKLAXT method...place the horizontal portion of the porch at a large distance below the entrance. The Purple Martins still have a place to land, but the starlings cannot get in.

Is #3 a new approach to the porch problem?

geezer

[Guest]

Geezer,I don't know if others have tried this before me but I thought about this last year and winessed a starling being unsucessful at ebntering because he could not get a foothold to push himeself in. I don't know if it is the answer but I saw it work once so have changed all of my 24 gourds over for 2008,time will tell. I think an added feature that may deter a starling is the closeness of tghe rain hood in thatb it gets in there way in the initial cling position seeiong that they are a bit larger than a PM IMHO only.

dick

[geezer]

Dick, Thanks for the reply.

Someone should manufacture a DICKLAXT PORCH MODIFICATION, that can be easily screwed onto gourds.

Please keep us all informed about your success in the forthcoming season.

geezer

[James Strickland FL]

This weekend I was working on my natural gourds and was thinking of a good porch to use on them and looked at my crescent gourds with pouches and they have the metal one on them. I took one of them off and cut it in half and it was perfect for the natural gourds. The pouches are the metal ones that are sold at PMCA shopping. So if your looking for a good porch buy them and mod them for your gourds.

[Steve Kroenke]

Geezer/Dick,

The only potential problem I see with having the porch farther down from the sreh deals with the ease of martins entering the entrance. Of course, the vertical depth is the issue here. How much is too much? From what I have seen with standard crescent entrances, martins have an easier time entering these holes if the porch is either flush or close to the bottom of the hole. This hole placement allows the martin to assume a horizontal profile and then enter. If you use enlarged srehs or perhaps the clinger, then the porch placement probably is not as critical to help the martins enter. The martins can either lift themselves up from a vertical posture and enter or just fly directly to the hole and enter horizontally while in flight. Just some of my thoughts.

Steve

James,

Thanks for the comment about the metal porches sold by the PMCA. We have used some porches made from trim coil, which is a vinyl covered aluminum, and the martins did fine with them.

Steve

[geezer]

Hey Steve,

Nice article on BlueBirds. BTW, I finished painting my wood bluebird house yesterday. In the past I have used the BlueBird SuperGourd, but wanted to go more traditional this year. There are many Bluebirds in my area also....many of them fledged on my property. Three of my neighbors in the area, will allow me to place bluebirds houses out this year. Sort of a mini bluebird trail.

I have thought about what you said about "flush porches", and the potential wet nest problem. The 12 THG's with tunnels will be OK....the water will drain from the tunnel before reaching the nesting compartment, but the SuperGourds could be a problem.

I have a large amount of dead dried cattails from around the pond. I propose to use them to build a sub-floor covered with hardware cloth to allow the water to drain away harmlessly. (BTW, the cattails are the PM's favorite nesting material)

Also "tipping" the SG's slightly forward should help to drain the water away from the gourd.

geezer