The Purple Martin Society, NA


Glossary of Purple Martin Terms

Purple Martin yawning.  Photo copyright Joe DellingerABCA   American Birding Conservation Association. The ABCA is an organization, founded by Chris J. Slabaugh of Nappanee, IN. The ABCA us a dynamically dedicated group of people actively improving conservation and the environment; promoting and providing better housing and habitat for our beneficial native birds, especially the Purple Martins and the Eastern Bluebirds.

addled     Egg that has rotted and contents are not viable.

adult     Bird that has reached sexual maturity. Though martins can breed by the end of the first year, martins are not considered full fledge adults until they return for their third summer. Bird that has reached sexual maturity. Though martins can breed by the end of the first year, martins are not considered full fledge adults until they return for their third summer.

aerial insectivore      Birds that forage for flying insects.

artificial nests     New technique of providing a man-made nest and installing it into the martin house compartments. Artificial nests are typically made from Styrofoam?and from wood.

asy     Term designating adult Purple Martins. ASY means After Second Year.


baffle, interior     Structure-like wall installed into martin house compartment that both hides martins from outside predators and provides protection and privacy for the martins.

banding     Routine procedure by licensed and permitted banders to place authorized US Fish & Wildlife Service aluminum or plastic bands on the legs of birds' feet. Records are kept of these banded birds so that when the bird is captured, found injured or dead, it can be identified as to where it came from, who banded, etc Bird banding is a universal and indispensable technique for studying the movement, survival and behavior of birds. The North American Bird Banding Program is jointly administered by the United States Department of the Interior and the Canadian Wildlife Service. Their respective banding offices have similar functions and policies and use the same bands, reporting forms and data formats. Joint coordination of the program dates back to 1923.

Barred Owl     A large bird of prey. An owl. A bird that inhabits low laying wetland type habitats. Known predator of Purple Martins.

birds of prey
     Birds that are carnivorous, like hawks, owl, falcons, and eagles.    

breeding season
     Length of time from courtship to fledging of young. In martins, this is approximately 70 days.

brood patch
     Bare spot on breast of female martins. Area of skin that has many blood vessels close to the skin that conduct the female's body heat to the eggs during incubation.


cleat     On martin houses with a rope and pulley system, a piece of metal with an upper and lower project arm to which rope is attached and secured.

     In bad Purple Martin management by landlord, the allowance of House Sparrows or European Starlings nesting in the same house with martins. Typically misconstrued as OK, but is not in the best interest of martins or the interest in general.

contiguous porch
     Porches on martin houses that run completely down the sides, or all sides, connecting multiple compartments. Houses with contiguous porches should have porch dividers. See porch dividers below. 

     Point in the breeding season where the males vie with one another to interest females. May be considered to be time when the pair are seeking a colony site or constructing a nest.

crescent-shaped entrances
     Also called half-moon entrances. Starling-resistant entrances that are cut from a 3" circle. A line is drawn from the top, 1 3/16" down. This half moon is the template and the entrance must be properly installed within one half inch of the porch or floor. These starling resistant entrances were designed by Charles McEwen of Moncton, NB, Canada.


Dawnsong     A martin lure tape. A collaboration of The Purple Martin Conservation Association (PMCA) and Cornel Laboratory of Ornithology. Considered by most to be the one and only lure tape. It is not the typical sounds of martins but special sounds by adult males in the predawn hours at the time of the subadult martin arrivals. It is thought to be a communication between adult males and subadults to encourage the younger birds to nest in the same colonies as the adult males.

     Diatomaceous Earth. Considered to be a biologically safe product to use for typical nest parasites such as fleas, lice and mites. Not good for blowfly maggots. Sprinkle a teaspoon in and around constructed nest. Do not sprinkle under subfloors in martin houses as dust will fly around and birds will breathe it in. DE is a microscopically sharp product that when it comes in contact with small parasites, cut them up, like a birdie vegematic.   

Diamotaceous earth
     See DE above.

     Abbreviation for Dawnsong.


egg dumping

     Includes ovum, yolk and albumen contained within a membrane and a shell of calcium. That from which a young bird hatches.

/ Purple Martin     Purple Martin adult egg clutches are 5-7 eggs with an uncommon 8-clutch occasionally. Subadult martin pairs typically lay 3-5 egg clutches. Eggs are spherical in shape, or long spherical in shape. The size is 24.5 x 17.5 mm. The egg color is white with a slight gloss. Eggs are laid, one per day by the female. Incubation begins with the "next to the last egg that is laid" so that all eggs hatch within the same time period. Incubation is from 15-17 days. Since females have the brood patch, the females can only incubate the eggs. The males can only insulate the eggs while the female is out feeding for herself.

  A specialized structure on the upper beak of a bird embryo in which the soon to be hatched bird uses to chip away at the center area of the egg hemispheres to release itself from the confines of the egg. The eggtooth structure falls off within a few days of hatching. 

English House Sparrows
     A non-native bird species to this continent from Europe. A tenacious nest-site competitor of Purple Martins and many other cavity nesting birds. Male is brown with conspicuous dark brown bib. Female is lighter brown and pedestrianly colored. These sparrows are one of the main reasons for the decline of martin and other native birds in the last fifty years.

European Starlings
     A non-native species from Europe. A strong nest-site competitor with a fierce long yellow beak, hence, the nickname, needlebeak. Considered to be, along with House Sparrows, a main reason for the decline in Purple Martins. Birds  have long legs, bright yellow beaks and are brightly marked and speckled in wintertime.

    Outer tough exterior of insects. Many times, exoskeletons are found inside the nesting chambers


fecal sac     Excrement by young birds that is gleaned from the nests by the parents, flown a distance from the nest and dropped. In early stages, parents may ingest these as there is much nutrient that passes right though very young nestlings. This is a time, that the parents do not have much time to forage for themselves but only for their young.

Federal Migratory Bird Treat Act
   This important law protects all common wild birds found in the US, except the House Sparrow, European Starling, feral pigeon and resident game birds in season.

     The act of leaving the nest by nestlings. First wing.

     A bird that has recently left the nest but still depends on its parents for food.

forced-pair copulations


gizzard      Strong muscle of the stomach that digests food of birds. Usually contains small stones or grit ingested by birds to aid the gizzard in its digestive process.

     A strong walled, or thick skinned plant with a large cavity. Related to pumpkins and squash. Usually, irregular in shape. Hollow Calabash or other bottle gourds have been traditionally used as bird houses for Purple Martins, wrens, etc. In martins, must be large, 11" diameter and thick skinned.

gourd, natural
     See gourd above.

gourd, plastic
     Manufactured synthetic gourd, made from special plastic with a lot of UV inhibitors. Today's plastic gourds have large cavities, snap out front, rain canopies and access holes for landlords to monitor the martins inside.

Great Horned Owl
    Large bird of prey and owl. Considered to be by many martin landlord, the #1 predator of Purple Martins. A lean, mean predator machine! Owls are protected by law.

     Coarse particles, like sand, pebbles, eggshells, etc, that birds pick up and is deposited in the gizzard to help aid in the digestion in the gizzard.

ground-climbing predator
     Animals that have the agility to climb both metal and wooden martin poles in search of food. These are raccoons, opossums, cats, squirrels, and snakes.

ground-climbing predator guard
     Structure attached to either the martin house or martin house pole to prevent the advancement and subsequent access by ground climbing predators such as raccoons, opossums, cats, squirrels, and snakes. Types are stovepipe baffles and 40" inverted cones.

H - I - J - K - L

house     Man-supplied structure, made of metal, wood or plastic that will give shelter to nesting martins.

insectivorous     Description of birds that eat diets of insects.

     Young bird that is no longer under the care of its parents and on its own but has not molted its juvenile plumage.

Kleptoparasitism is the stealing of food or nesting material by one animal from another.

kleptoparasitism of nesting materials
     The behavior of stealing another bird's, or pair's, nesting materials. Usually stolen while the other bird is away from the nest. Common behavior in both adults and subadults that are short on time to build their nests.

     You and I! The devotees who not only put up martin houses to attract martins, but those who manage well and keep good records of their colonies.

lure tape
     A tape, or cd, designed to attract martins to a new colony site. Dawnsong is a martin lure tape.male porch domination      A behavior in adult males whereas the adult males do not allow other birds to nest next to them on contiguous floors. Behavior where the adult males guard the compartments next to them but also all along the contiguous porch. Occasionally, adult males, and some females, will guard an entire martin house and keep all martins from nesting in the same house. Porch dividers are very important in preventing such behavior.


martins     A type of swallow.

mate guarding
     Behavior by males whereas the males stand guard their fertile females everywhere they go to thwart off advances of other males in order to insure their paternity.

     To go to another place. The routine of travel for birds from their breeding grounds to their wintering ground and vice versa. Usually done in order to find adequate supplies of foods.



montaine martins


Nature Society, The

Nature Society News, The

neo-tropical migrants

nestling crossovers
  The act of nestlings venturing out, or crossing over, to a different compartment than their own natal compartment. Crossovers can endanger nestlings. Many older nestlings enter a compartment, not their natal cavity, and commandeer food from younger nestlings. Younger nestlings may die from their food being confiscated by older nestlings while, many times, these older nestlings (unfledged birds) are unable to find their way back to their own natal compartments. They may "wander" along the contiguous porches only to either be knocked off (by unattached and/or first year males) or fall off the house and become doomed on the ground.
nestling wanderings
  The act of nestlings as they roam the porches before they fledge.


nest replacements


nest-site competition

nest-site competitors

non-native species


oology    The scientific study of bird eggs. Bird eggs sizes are sized in millimeters, the standard in oology. In measurements, the length is given first, then the width. In order to measure eggs accurately, calipers are used. Purple Martin eggs are typically 24.5 x 17.5mm




     Abbreviation for porch dividers. See porch dividers below.

   The breaking, or chipping, action by the bird embryo to release itself from the egg confines. This chipping is done by a specialized "eggtooth" on the end of the upper beak of the embryo. The eggtooth structure falls off within a few days of hatching. 


     Purple Martin conservation organization, founded by James R. Hill, III.
PMCA considered to be the research base from which much PM information comes from.


porch dividers
  Partitions placed between compartments on a long, contiguous porch to prevent Male Porch Domination by adult males and nestling wandering or crossovers. Partitions can raise the residency rate in PM houses from the typical 50-65% to 75-100%.


predator guards


premature fledging

Progne arboricola

Progne hesperia

Progne subis





rain canopy

rat snakes

roost (n)
According to Terres Encyclopedia of North American Birds:

Roost: Term for place for flocks of blackbirds, starlings, robins, and other species sleep together in trees, shrubbery, or reeds and other upright grasses in marshes.

A roost, in PM terms, is an enroute migratory habitat whereas martins will roost, rest, and feed for a period of time on their northern/southern migration. Martins are known to roost in the city parks of São Paulo, Brazil while on their wintering grounds. On the North American continent, we have found many roosts in the last ten years. The first and largest is at the Lake Ponchartrain Bridge between Metairie and Mandeville, LA. There are two distinct martin flocks that roost underneath the Lake Ponchartrain Bridge: the south flock on the Metairie side (thought to be mostly migrants) and the north flock (thought to be mostly local birds) six miles from the north end of the bridge.

Other known large roosting areas are under many bridges along the Gulf, like the one at Biloxy, MS and Dauphin Island, AL, in Mobile Bay. There have also been roosts on the I-45 bridge leading to Galveston Island and State Highway 147 over Sam Rayburn Reservoir and State Highway 21 between Milam, Texas and Many, LA. A few short years ago, an important roost was discovered at Lake Murray, SC, NW of Columbia, SC.

Other roosts have been discovered at Presque Isle State Park on Lake Erie in Erie, PA, Corpus Christi, TX,downtown in the city of Chicago at Montrose (staging) and Belmont Harbors (roosting) on Lake Michigan, in  Texas in Wichita, Lewisville, and Arlington.

roost (v)

rope and pulley


S & S Controller


scout arrival date

Scout Report, The

sexual maturity

similar birds (to martins)


slot-shaped entrances







starling-resistant entrances

stovepipe baffle


subadult arrival date





telescoping poles


Top-Guard Animal Barrier

Trio Houses



U - V - W - X - Y - Z

Update, The PMCA PM


wintering ground

Zook PM Elevator

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Photo copyright Joe Dellinger