Martin Mishaps
Landlord Awareness Can Prevent Accidents

Reprinted from: Purple Martin Update 10(1): 4-5, 10-13

Dr. Thomas Dellinger
James R. Hill, III
Louise Chambers
Ken Kostka
Rebecca Dellinger
Tim Hammonds

This article is a compilation of some of the possible mishaps that can happen in the life of a Purple Martin. Where humans can intervene to increase the safety of the martin, we contributors, as listed above, make comments on what may be done to aid the martin and prevent these mishaps from occurring. While we as landlords can't prevent every accident from befalling our birds, we can “accident-proof” our martin housing and our yards as much as possible, similar to the way parents “child-proof” their homes, so that many accidents can be prevented.


Stuck in Porch Railings

A female Purple Martin that has gotten both of her wings wedged between the porch railings of a Trio Grandpa martin house. This bird would certainly have died if the landlord hadn’t been alert and done a daily walk through his site and found her in distress.

We have seen a few cases of a martin being caught in the porch railing of the Trio TG-12 house (see upper photo on pg. 4). We believe this was caused by two martins fighting, both on their sides, gripped together by their feet, and striking with their wings. On the porch, the bird nearest the railing gets both wings stuck in the railing and cannot release itself. A landlord walk-through and observation would locate the bird stuck in the railing and rescued a bird for the colony site.

At the PMCA we found a young nestling, about 3 to 5 days old, out on the porch, with its head wedged under the railing of the Trio Castle house. Obviously, a nestling this young did not venture out on the porch by itself, but must have been dragged there either accidentally or on purpose, by a parent or an intruder. So perhaps this nestling had already been deemed unhealthy by its parents, but in any case, it was doomed once it was out on the porch. Landlord vigilance might allow a few such youngsters to be saved, especially if they were accidentally dragged from the compartment between the feet of a panicked, fleeing parent, scared off by an approaching human.


Stuck in Entry

A female martin wedged in the keyhole-shaped entrance hole of a Trio Castle. This bird, and the female trapped inside the cavity both would have died had the landlord not been observant and intervened. Both situations shown above were caused by territorial fighting in females.

We once found an ASY-M martin accidentally trapped and dead in the entry of a compartment. The entry was the McEwen-type crescent with a 1-3/16" vertical opening. The dead bird lay in the entry on his side with both wings at the shoulders outside the entry. The body, the head, the tail and feet, along with the primary wing feathers, were inside the entry. Inside the compartment, we also found another dead ASY-M martin. Neither bird appeared to be physically injured. Like in the rail example, above, we believe that the two birds were fighting inside the compartment; the one bird got his wings wedged into the entry such that he could not get loose, and he succumbed. With the first bird stuck and blocking the entry, the second bird, inside the compartment, could not get out and eventually died (see photo on pg. 4 of similar occurrence). Even though we check the grounds around the colony site and look at the outside of the martin houses every day, we failed to discover this situation until it was too late. Obviously, with one bird in the entry and visible from the ground, we might have saved the two birds with more careful observation.

At the PMCA, we have observed over 30 martins crammed into a single cavity during cold weather; the danger here is that if the outermost bird dies, its body may block the entrance hole, trapping the rest of the martins inside where they will die of starvation. Frequent observation trips by the landlord might prevent such fatalities, by removing the dead bird and allowing the others to leave the compartment.


Injuries from Nest Cups or Trays

We know a landlord who used the bottoms of plastic jugs as nest cups. The bottoms were cut to fit the entryways into a Trio Castle house. Unfortunately, some of these nest cups rotated and blocked off the entries. Three martins were inside and could not exit. They died.

To avoid such a loss, landlords modifying houses should make sure that modifications don’t block the entryways. Lightweight nest cups, trays, or inserts should be fastened down so the wind or the birds cannot lift them or get caught behind them.

Another mishap was reported by a landlord with a wooden T-14, equipped with wooden nest trays. A nestling jumped out of the tray as it was being pushed back into the house during a nest check. Unseen by the landlord, the nestling was crushed between the nest tray and the back wall of the compartment. To prevent such accidents, all landlords should cover nestlings with a hand while replacing the nest tray.


Entanglements

Another landlord modified his martin house by using subfloors made from the heavy plastic webbing used to prevent leaves from collecting in the roof gutters on his home. He was greatly saddened to later find a banded martin dead in the nest with its leg caught in the screen. Obviously, a better selection of a smaller web size could have prevented this loss.

Martins have also become caught on pieces of wire or other material used to fasten mesh floors onto metal subfloors. To avoid entanglements of this type, cut off and remove all extra wire, twine, etc., when modifying floor coverings. We have seen a few cases of a baby martin entangled with a fine string pulled tight around its legs. In each case, the string had somehow gotten wrapped several revolutions around a leg, the legs had swelled to a large diameter, and the strings were buried deep within an indentation completely around the leg. Luckily, we found the entanglements in time to save the birds from having their legs amputated by the strings.

Another landlord reported finding a dead adult martin, entangled in a rubber band that it must have carried into the nest. The bird was entangled in such a way that it could not fly and starved to death before the landlord found it. This kind of mishap could only be prevented by luck and by doing frequent nest checks. Purple Martins are notorious for bringing in a variety of unusual, man-made nesting materials, some more suitable than others. Landlords can provide safe materials, as listed elsewhere in this article, and they can also remove any potentially hazardous materials as soon as they notice them in any nest during weekly nest checks.


Roll-Outs and Fall-Outs

A 12-day-old nestling martin that has fallen from its nest. A landlord that keeps accurate records will know which nest to return this “fallout” to.

Just about every year, we find baby martins (from about 7-14 days of age) out of their cavities, on the ground or on the porches. Out of the nest in this manner, these young birds will die or be taken by predators in short order. Our speculation is that these youngsters had been crawling around inside their nests and had tumbled out the entrance hole because the nest was built too high, bringing the nesting material to the lower edge of the entry hole. When landlords find these conditions, we suggest that some of the material be removed, lowering the top level of the nest at the entry to 1/2" below the entry hole.

Later in the nesting season, birds nearer fledging age often end up on the ground several days before they are developmentally capable of flight. Heat, hunger, overcrowding, parasites, and accidents all account for these. Again, babies on the ground are doomed (see photo on pg. 13). Landlords who keep accurate records should return these birds to their rightful cavities. When in doubt, place them in a nest with young the same age, or, as a last resort, place them off the ground in specially-designed fallout shelters.


Bare Floors

A 13-day-old nestling with “splayed leg syndrome.” Nestlings raised on slippery metal house floors (or on smooth, flat nest trays that have lost their nest material) sometimes develop leg defects because the substrate doesn’t have enough friction for them to keep their legs underneath them — their legs keep slipping out to their sides — and the legs grow with a permanent deformity. Nestlings with this condition are doomed.

Some nests are built with (or end up with) only a thin layer of nesting material (or none at all) covering the floor. As a result, eggs and young often end up on bare floors. Slick, bare metal floors are a menace to young birds. The bare metal will sap body heat from the nestlings, weakening or killing them. If the baby birds manage to survive, and the floor is slick, then sometimes the nestling develops splayed legs and cannot exist in the wild with the deformity.

The best prevention for splayed-leg development is to maintain an adequate amount of nest material, by adding pine needles or cedar shavings, or by adding a piece of plastic mesh (plastic canvas from a craft supply store, for instance) to cover the floors. Leg splay has been seen in smooth floored wooden houses as well, so nest trays should offer a textured material whenever possible (see photo on pg. 11).


Medical Trouble

We occasionally find adult martins down on the ground that are injured, sick, starving, or exhausted. We always get these birds quickly to a licensed rehabilitator who has the knowledge, skill, and materials to diagnose the problem and get the birds back flying. These are the kinds of mishaps that the landlord may not be able to prevent, but frequent walk-throughs of the colony site may allow impaired birds to be rescued before they die from exposure, starvation, or are found by a cat or other predator. At the same time, we urge landlords not to try to rehabilitate martins themselves. Despite good intentions, we know of many home rehab efforts that turned into tragedies for the martins due to the landlord’s lack of knowledge about the nutritional and physical needs of martins.


Vulnerability on the Ground

Two road-killed Purple Martins. These birds were likely killed as they landed on the road or berm to pick up nest material or grit.

During nest building, Purple Martins land on the ground to gather nesting material. They also land on the ground to look for grit. Although martins are proficient fliers, they are subject to several dangers when standing on the ground. Feral and household cats take a huge toll of such martins by hiding and stealthfully leaping out to take them before they can get airborne. Martins on the ground are also in greater danger from hawks suddenly coming onto them or springing out from hiding in a nearby tree.

To reduce the danger to martins gathering material from the ground, landlords should provide a shallow elevated pan with pine needles, coarse straw or coarse grass stems cut into 6 to 8-inch lengths for nest material, as well as crushed eggshells or oystershells for grit. Place these elevated platforms at a distance from bushes or trees that could provide concealment for predators. Landlords can also supply man-made mud puddles by filling an upside-down garbage can lid full of mud and mounting it on a post.

Martins will also gather nest material and grit from the edge of roads, and as such, are in danger of being hit by cars (see photo on pg. 11). If you have ever seen your martins landing on or near the road, sweeping up and removing material from the street, or offering them nest material and grit nearer their housing, will help them avoid a potential collision with a car.


Wind Damage

The strong winds associated with summer thunderstorms often blow housing over, especially housing mounted on inadequate poles, those with lots of wind resistance to their design, houses mounted on poles that are too tall, or houses mounted on sectional poles held together with threaded pipe joints.

We know of several cases where strong winds or tornados have blown active martin houses to the ground, spilling the eggs and young onto the ground (see photo on pg. 13). If the landlord will restore the housing to the best of their ability as soon as possible after the storm, the martins will do their best to carry on, feeding young, incubating eggs, and replacing lost eggs or young in many cases. Landlords should make sure to maintain the original compass orientation of all cavities, since this is how martins locate the correct cavity. The birds will accept a shorter pole if necessary; the most important thing is to get the housing back up quickly, so feeding and incubation can be resumed.

At the PMCA, we commonly lower our martin housing with the approach of severe, daytime, thunderstorms, especially if the local weather station warns of strong winds. Make sure the lowered housing is locked into the same compass direction as in the raised position and that the wind can’t rotate it. During approaching storms, Purple Martins will quickly enter lowered housing. If need be, you can leave active martin housing lowered overnight during or after storms, but DO NOT physically lower active martin housing during the night; this will cause birds to panic and fly out, leaving their eggs and young unincubated and unbrooded all night long.


Rotated Houses

To prevent misorientation of martin housing after lowering a telescoping pole for a nest check, mark alignment notches on all joints first. Improper compass orientation of active housing can have disastrous results.

Houses that twist in the wind can rotate far enough that the martins get disoriented and can’t find their way back to the correct nest. Telescoping poles should have alignment marks added with a permanent marker or paint to help the landlord orient the house correctly after nest checks (see photo on pg. 12). Housing systems that operate with a winch or lanyard may need to have a locking pin and notch added at the top of the pole. Landlords also need to make sure that their poles and ground sockets fit correctly for the same reason.


Choked on Insects

A 10-day-old nestling martin that has choked to death on a dragonfly that has apparently bitten onto the inside of its esophagus, preventing swallowing.

We have seen cases of nestling martins that were fed large cicadas or dragonflies by their parents that the babies could not swallow or spit out. As a result, the nestlings choked to death (see photo on pg. 13). At the PMCA, we once attempted to remove a large dragonfly from a choking nestling. Removal caused massive hemorrhaging of the bird’s throat, evidence, we believe, that the half-dead dragonfly had bitten onto the esophagus of the nestling, preventing swallowing. There is very little a landlord can do about this rare phenomenon. It is due to inexperienced parents not properly crushing the heads of the prey they deliver.


Other Martin Mishaps

When landlords repaint their gourds, or clean the nests out of them between seasons, they must make sure the drainage holes don’t get plugged with paint or dried mud. Five of the 7 drainage holes in this natural gourd are plugged with elastomeric paint.

A nestling martin whose developing plumage was compromised by being raised in a mud bath, caused by a gourd with plugged drainage holes.


A natural gourd that has had its front torn off by a Great Horned Owl in search of a meal. This Ohio landlord did not have his gourd rack protected by owl guards.

A Trio Castle that has had its easy-open, flip-up doors opened or pulled off by a Great Horned Owl out for a meal. This house needs to be equipped with an owl guard.


A natural gourd that has been taken over by a nest of paper wasps. Landlords can prevent this by coating the ceilings of nest cavities with petroleum jelly.

A black rat snake descending a martin pole after having a nocturnal meal of martin egg and young. All martin housing needs to be equipped with pole guards.


This diligent landlord is removing a male House Sparrow from a SD-1 (Spare-o-door) trap, installed in a Trio Castle compartment. House Sparrows should not be allowed to nest anywhere on a landlord’s property as they will break martin eggs, peck and kill martin babies, clog martin housing with their nests, and prevent colonization of new sites through territorial aggression.

A martin nestling that has the pinching head capsule of a flying ant attached to its beak. Landlords should carefully remove these.


A mite-covered landlord’s hand after touching a house covered with dispersing nest mites. Landlords can control nest parasites with nest changes. Should mite infestations occur, landlords can wipe down the inside and outside walls of their housing with an alcohol soaked rag.

Purple Martins often succumb to bad weather. Landlords can assist starving martins by providing them with live crickets or mealworms.


We hope that the mishaps mentioned in this article, and the dangers shown in the accompanying photos, will help landlords be more vigilant in their efforts to help martins.


Copyright 2001 by Purple Martin Conservation Association. All Rights Reserved.

Our members benefit from 4 issues annually, packed full of helpful and fascinating information like the article above. You can become a member and support the work of the PMCA by making a tax-deductable donation.

JOIN US TODAY!