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Dave Duit
Joined:16 Mar 2019, 00:42
Location:Nevada, Iowa
Original Join Date:Tue Apr 30, 2013 8:02 am

Post by Dave Duit » 20 May 2019, 08:27

This thread is dedicated to all those interested in purple martins. It was created to educate, entertain and enlighten landlords on everything dealing with martins. Each week, two new facts, figures, findings etc... will be added to the end of the thread in a question / answer format. Simply scroll down to see the latest addition. The on going Q&A will number in the hundreds and span over years. We ask that you don't respond to this particular thread in order to keep it streamlined. Thank you.

268. Why will some martins only eat crushed egg shells or oyster shells from my platform feeder, but not
eat supplemental survival food such as crickets, scrambled eggs or meal worms ?
By nature martins only eat food on the wing or while flying and therefore taking supplemental food from
a platform is "abnormal". Some martins just do not take the food regardless of their hunger. Most
martins will adapt to a platform feeder, but some simply fail to eat. On the other hand, martins will eat
the egg shells for grit because they are forced to get grit "naturally" from the ground along with their
nesting material to build their nest. In short, it is natural to eat grit from the ground and not natural to
eat bugs from the ground. You can try flipping crickets and scrambled eggs into the air for martins
during cold wet weather. It takes time to train martins to take food in this manner.

269. Is an egg or a new hatchling in most danger during cold weather ?
The egg is safer during cold weather due to incubation by the parents.

270. Can female martins determine if an egg is infertile or rotten ?
Martins along with other birds that use their brood patch are able to determine a good or bad egg. The
brood patch on females are used during incubation are so sensitive they can pick up signs of subtle
movement within the egg. If the egg is bad the parents will sometime roll the egg out near the front
of the nest away from the rest of the good eggs. These eggs are typically off color or dirty. If this bad egg
near the front of the entrance is still there a week after the last egg is hatched it is safe for you to
remove this bad egg; otherwise leave the egg alone.

********************* The next section will focus mainly on housing and predators**************************

271. What size compartment should I offer my martins ?
It has been shown that the preferred compartment size is about 7 X 7 X 12 inches in dimension. Large
and deep compartments have created larger clutch counts. If you have a 6 X 6 X 6 compartment it is
highly recommended that you enlarge or replace these compartments. The average adult martin is 7.5
inches long, add 5 to 7 nestling and the parents and imagine the cramped living arrangements for
this martin family. It is also recommended to add venting to your compartments.

272. Besides increased clutch sizes with larger compartments, what are some other benefits of large
compartments ?
Once you have a large clutch, the quality and health of the nestlings is boosted. They now have space to
gain strength is their legs and wing muscles as well as increased air circulation.

273. What size should the entrance hole be ?
Two inches is standard. Most landlords use starling resistant entrance holes. It is a crescent shaped
entrance 1 and 3/16 inches from middle bottom to top middle and 3 inches across at the base and 1/8
to 1/4 inch off the porch floor. Google in starling resistant entrance holes for details. Many holes have
built in anti-wing entrapment. Holes larger than two inches will allow kestrels to enter. Larger holes make
it easier for predators to reach deep into the cavity.

274. Are there other hawks, besides the kestrel, that can get into a two inch entrance hole ?
No. The kestrel, better known as a sparrow hawk is the smallest hawk in the United States.

275. I have 6 inch compartments in my metal house and recently had a great horned owl visit the colony.
How do I protect my martin from the owl when I don't have a lot of money and I need to quickly put up
some protection ?
Any martin colony can have an owl visit regardless of colony size; but when the colony starts getting big
it attracts hawks and owls. During the day when the martins are out hunting for bugs in the afternoon,
quickly secure 2x4 inch wire fencing around the entire house using zip ties. Then cut out one horizontal
wire to make a 4X4 inch square opening; this opening in the fence should be right in front of your metal
house entrances. If you can space the wire fencing a few inches away from the metal house entrance this
is a plus in the design. Once the martins leave for their migration south, you can build a more permanent
style of owl fencing or guards around your metal house. Google images for purple martin owl cages or
guards for examples.

276. Is it possible for a screech owl to enter a 2 and 1/4 inch entrance ?
Not only is it possible it has happened many times to martin landlords. The answer is yes, most definitely.
This is just another reason we suggest crescent starling resistant entrance holes. There are many styles of
STREhs, but the all have one thing in common and that is 1 and 3/16 height from top of crescent to base
of entrance and 1/8th to 1/4 inch off the porch floor. Google images for starling resistant entrance holes
for examples.

277. What size compartment is correct for martins ?
Accepted industry size is a 6 inch cube. When we say "industry" we are really saying manufacturers.
Companies make these small compartments because there is less material involved and therefore less
cost and it can sway the consumer into thinking more compartments equals better. WRONG.
The correct compartment size is actually 10 to 12 inches deep and this is the what you should be
purchasing for your martins. When martins are offered their choice if a 6 inch cube or a large 10 to 12
inch deep compartment, martins choose the larger compartments. Martins instinctively know that a larger
and deeper compartment offers more protection from predators and also produces larger clutch sizes
that are healthier, more virile and stronger nestlings. It allows for less heat stress on humid days due to
increases air circulation.

278. Will larger compartments reduce aggressiveness ?
Yes. If nestlings are confined in a small compartment they will sometimes spill over into adjacent cavities
when heat becomes unbearable. All birds enjoy more space to move around and if this is not available,
living conditions make for an uncomfortable environment.

279. Is there a difference in the aggressiveness of the sexes ?
The Second Year males martin is typically more aggressive than the older males and all females. This is
mainly due to the competition to mate in order to continue their genetic line.

280. Can martins and tree swallows share the same housing ?
No. Being cousins in the swallow family doesn't stop them from fighting. Look up tree swallow protocol
in the link for Chucks Purple Martin Page for details on dealing with tree swallows in martin housing.

281. What is a good height to set my martin house ?
Twelve to fifteen feet is typical. Some landlords have the houses entrance as low as eight feet without
problems. When landlords start to raise housing over 18 feet it may pose problems with the wind. Always
use very sturdy poles when planning your housing set up.

282. How many compartments should beginning landlords start with to attract new martins ?
Eight compartments or gourds is a great start. The initial set up of martin housing can be pricy if you
buy everything new. Some new landlords start out simple and erect used but good quality gourds or
refurbish old metal housing. Always plan ahead for growth in the future. You may buy a 24 rack and only
place eight gourds to start; as your colony grows you can choose to add more for expansion.

283. Will a martin pair nest in a single gourd or compartment ?
The odds are against you if you only place one gourd or compartment. Remember, purple martins are
a species that thrive in colonies or multiple compartments and gourds.

284. If I put up multiple single units, will I attract martins ?
Your chances increase significantly when placing multiple units; either many single gourds or multiple
compartment metal and wooden houses. Keep in mind that location, size of compartments and open fly
zones are just as important when considering your martin housing set up.

285. What is considered a proper martin house ?
A martin house with deep compartments, (12 inches deep), aluminum or wood with slide out trays.

286. Can you give me a list of important features martin housing should include ?
Here is a list:
- 14 to 15 foot steel pole with a sturdy winch able to comfortably lift the housing or gourd rack.
- a functioning ventilation system that opens and closes depending on cold and heat.
- insulated ceilings if you live in the northern state, mainly Minnesota and the Dakotas.
- rain guard porches with 5/8 inch vertical lip to prevent water from entering the nesting compartment.
or a design made to keep the nest dry.
- predator proof with pole baffles and owl guards
- white painted housing keeps it cooler in the hot summer.
- entrance holes no larger than 2 inches in diameter to prevent screech owl entrance. A starling
resistant entrance hole also prevents starlings from entering the nest cavity.
- removable housing for winter storage if possible.
- off center entrances in houses add additional safety.
- easy access compartment portals for weekly inspection of the nest.
- a sparrow door trap should be available to place if needed.

287. I can't decide if I should build a wood or aluminum martin house. Can you offer advice ?
Martins will nest in either wood or aluminum housing. There are pros and cons for both. Aluminum
houses are lighter, more sanitary and require less maintenance, but retain heat on hot days and cold
on cold day. The wooden house can hold a small range of temps in the cavity but will require more
maintenance with minor repairs and paint.

288. I've heard that martins will nest in gourds, is that true ?
Martins will nest in both naturally grown gourds that have been treated and painted white as well as
plastic manufactured gourds. When buying or growing gourds, be sure there is plenty of space inside the
gourd. Both types of gourds will last longer if you store them inside and out of the elements during the

289. Did Native Americans actually provide housing for martins or is this a myth ?
Native Americans rom many different tribes erected natural hollowed out gourds for martins long before
white settlers reach America.

290. Does added ventilation make living conditions better for the martins ?
A well ventilated house increases sanitary conditions, cools the cavity during high temps and reduces
strong smells. All these areas make for a comfortable living for the martins.

291. What benefits can be gained by plugging entrance holes or storing housing inside for the winter ?
It deters sparrows and starlings from claiming a compartment or gourd prior to the martins arrival.
Storing the housing will prolong the life and efficiency of your housing.

292. Should martin houses have subfloors ?
Subfloors are a big plus in the health of your martins. If aids in application of 5% sevin dust if necessary,
helps keep nesting material and floor dry, and helps nestlings stave off hypothermia.

293. Is there a preservative or product that can prolong the life of my naturally grown gourds ?
There is a fungicide called copper sulfate that can be used to treat natural gourds prior to drying and
painting. I suggest you go online to research the steps in preparing natural gourds for use with
martin housing.

294. When is the right time to pick natural gourds to use for martin housing ?
Always wait until the vine has died before picking a gourd. Typically, after a few frosts in the fall, the vine
will die off. If you pick it before the vine dies, the gourd may rot. A fully mature gourd will have thicker
walls than immature gourds. A thin walled gourd is not safe to use for martin housing. A thicker wall aids
in insulation and is less likely to crack during handling.

295. How to I control blowflies in a gourd or compartment ?
You should use the same method for blowflies as that of bird mites. Nest changes when you see blowflies
or mites is a great way to control these parasites. Google purple martin nest changes for parasites and
you will find the necessary steps.

296. Is it safe to replace metal subfloors with wooden subfloors ?
Yes, both subfloors are considered a good practice to keep nestlings safe and dry. If you replace the
metal to wooden subfloors or visa-versa, be sure to do the change prior to the martins arrival in early

297. Is it warmer using wood subfloor as opposed to metal subfloors ?
Wood subfloors have shown through research to provide a warmer condition for martins. Wood is a
natural insulator.

298. Do cavity depressions cut into wood subfloors encourage martins to nest ?
If given a choice between a flat wood surface or a cupped or depression hole near the back of the the
wood subfloor; martins usually choose the wood subfloor with the cavity hole near the back. It provides
an area which offers an excellent place to start their nest.

299. What size hole for a cavity needs to be created on a wooden subfloor ?
Three inch diameter circular hole is the best size. The top edge can be tapered back about a half inch;
a half inch tapered router bit works best for this task. When completed you will have a four inch hole
from the very edge diameter of the hole. If you don't have a half inch router bit, you can utilize a round
file to take off the sharp edge of the three inch hole.

300. What is the best thickness for a wooden subfloor ?
3/4 inch is desired. A thicker subfloor more than 3/4 inch would add unneeded weight, while a thinner
thickness would not allow for the depth of a nesting cavity as mentioned in the previous post.

301. What is the best wood species for building wood subfloors ?
Cedar and redwood are the best. But, green and yellow poplar are two great choices. All four species of
wood are rot resistant. Try to choose light woods and stay clear of heavy woods, like oak and hickory.

302. What is an interior perch ?
Interior perches are attractive to martins, but there are a few requirements before making an interior
perch. A subfloor with a cavity bowl in the back and a 10-12 inch depth compartment is a must. To
make an interior perch:
- take a 3/4 inch thick board and cut it into 1 and 1/4 inch wide strips.
- then, cut 1/4 inch bevel on both sides of one edge.
- next, cut the strips to the width of your compartment.
- now, place the piece six inches forward from the back end of the subfloor and fasten it.
- lastly, fasten a wood doll rod out the same length of the your perch.

303. Can wood subfloors benefit nestlings and eggs ?
Subfloors with a cavity hollowed out near the back will help secure the eggs in a safe location during
strong winds and storms. The subfloor also keeps the eggs and nestling off the surface of a cold metal
martin house floor.

304. Is a secondary entrance hole inside the cavity needed ?
No. It can hinder nest checks and is not necessary. A twelve inch deep compartment is adequate for
predator protection. But, it is suggested that you add starling resistant entrance holes. Owl guards for
additional protection is a great idea to reduce attacks; especially if you are near a wooded area or
location in which owls visit.

305. I have a wooden house on a hinged pole. How should I do nest checks and what should I do to make
my set up safer for me and the martins?
If you currently have martins in the wooden house, the only way to do a nest check is with a ladder.
Immediately stop using the hinged pole for nest checks. Once the martins have migrated south for the
winter, change your set up to a winch, new pole or telescoping pole to raise and lower the martin house
in the years ahead. Note that this new set up is fine if you plan on using the existing house. If you plan
to put up a new house close by, wait for the martins to become well established in the new house before
removing the old house. Otherwise, if you have an unestablished colony they may become
disoriented and move on to another nesting site.

306. My martin houses are white in color. Is it ok for me to paint the houses blue to make my own house ?
No. Keep the martin houses white. If you change the color the martins may reject their housing upon
their return in the spring. Martin s are creatures of habit and don't like big changes. You can make
improvements like new entrances and owl guards without fear of losing your colony; but color changes
are considered a no no in the martins world.

307. What is the largest wooden martin house in the U.S. ?
I'm not absolutely sure, but the largest I have knowledge of is located in Monroe, Louisiana and is owned
by William Green. It has 690 compartments. The old record was held by George Finney of Winnfield,
Louisiana with 620 compartments.

308. Who has and where is the largest colony in the U.S. ?
Mr. Jerral Johnson of Rainsville, Alabama currently has over 2,000 cavities for martins with more being
installed; he had confirmed 1,067 pairs of nesting martins in July 2013. It is five years later and I assume
there are still over 2,000 cavities and even more pairs of nesting martins. A mathematical
average for nestlings in 2013 data; with 1,067 pair would equal 5,335 nestlings. An interesting note is
that one of our own Iowa Purple Martin Organization members, Tim Millard of Lockridge, Iowa has one of
the largest colonies in Iowa; consisting of nearly 200 cavities.

309. Can I reduce martin aggressiveness by including gourds to my colony ?
To a certain extent, adding gourds to your colony will help reduce aggressiveness. If you add porch
divider to your metal and wood housing, it will have a big impact on cutting down aggressiveness. Some
landlords claim that variety in housing is key to a well functioning colony.

310. Are subflloors a necessity for metal houses ?
Subfloors are a must for metal house cavities. A nestling on a cold metal floor can quickly die from
hypothermia. Metal will absorb the heat from the nestlings body on a cool night. It is recommended to
include subfloors in wooden housing too, like that of a T-14. There are many styles of subfloors sold
online or you can build your own to fit your compartments. Subfloors also allow you to do weekly nest

311. Have there been recent martins that have nested in tree cavities in the United States ?
No. The only documented proof is of a single SY pair in Christmas, Florida in 1993. It was a dead tree
snag of a Sabal Palm tree in the Orlando Wilderness Park. It was an old Pileted woodpecker hole. It should
be noted that this would be an extremely rare happening for a purple martin east of the Missouri River.
The Progne Subis Arboricola purple martin of the forested Orgegon / Washington State up to British
Columbia area are the only species of martins that used tree cavities for nesting.

The following section of questions and answer will focus mainly on Pests and Predators

312. What two predators of the martin have limited their population and growth ?
The English house sparrow and the European starling. Both species are consider an unwanted bird in
the US and it's Eco-system. Both species are aggressive and destructive to all song birds, including the
purple martin. If left unchecked at a colony of martins, these species will quickly outfight a new colony.
Once established, both species will claim the martin housing as their own and are tenacious in
holding their territory. This in tun will force the martins to a place of least resistance and typically the
martins will leave their colony from the pressures of the sparrows and starling. It is the
responsibility of all martin landlords to eliminate sparrows and starling from your colony through
shooting and trapping. Do not attempt to relocate trapped starlings and sparrows as they will return
to your martin colony shortly after their release. You must euthanize these pests.

313. How can I prevent wasps from nesting in my martin gourds and housing ?
The simple fix is to coat the top of the inside gourd with vaseline. The wasps will be unable to secure
their nest to such a surface.

314. I have a nest box set up for tree swallows so they will take up residence in this box instead of my
martin housing or gourds. But, recently the tree swallow nest and eggs were being displaced. What
caused this disturbance for these tree swallows ?
The culprit is a house wren. House wrens will take over a nesting cavity of a tree swallow and place their
own nest and eggs in the cavity and drive off the tree swallows.

315. Is it possible for a snake to climb a steel pole ?
Not only is it possible, it is easy for a snake to slither up a steel pole. A pole guard is a must for snakes,
squirrels and raccoons.

316. If I have a thin pole such as 3/4 inch pipe, that should stop a snake. Right ?
No. A rat snake is a master at climbing small diameter pipes. It should be noted that a 3/4 inch pipe is
probably not strong enough to support a fully loaded gourd rack or house. You need to bring into
account other factors, such as wind and the weight of your housing set up.

317. Are snakes as much of a problem in Iowa as they are in the southern states ?
No. Southern state landlords must deal with snakes more often than landlords in Iowa. But, it still occurs
in Iowa. It is easy to put a predator guard on your pole.

318. Is grease or vaseline on a pole effective in stopping snakes from climbing ?
Grease and vaseline are useless in an attempt to stop snakes from climbing martin poles.

319. Can a large snake get inside a smaller compartment size of 6x6x6 ?
Snakes have the ability to make the most out of every inch available in a small area. When doing nest
checks it is good practice to take a peak inside prior to opening the compartment to check for snakes,
wasps or wing entrapped martins.

320. Is it true that a raccoon can climb a round metal pole ?
Yes. Raccoons are exceptional climbers and this is the reason a pole baffle is a great idea to prevent
raccoons, snakes, squirrels, etc...

321. Can a sparrow hawk, better known as a kestrel breach a 2 1/4 inch entrance ?
Yes. But they can't get in a 2 inch hole, or better a starling resistant entrance hole.

322. Would a kestrel actually build a nest in a martin compartment ?
It is possible if the compartment is at least 6X6X6. Take measures to ensure that a kestrel nest is not
built in a martin cavity.

323. Will a bluejay interfere with martins ?
They won't make a nest in the cavity, but there have been observations of bluejays snatching unattended
baby martins that have strayed on the porch and are too young to fly, or may reach into a shorter depth
compartment to try to pull a young one out.

324. Can I shoot a jay if he is around my colony ?
No, It is against the law. But, you an prevent the problem of jays trying to pull out babies by providing
deep compartment cavities.

325. Will great horned owls kill martins ?
Great horned owls are a major predator of martins. GHOs will usually hang out in nearby trees and wait
dusk to make their move to predate martins.

326. Will a bright light in my lawn near my martin colony deter owls ?
It makes no difference to the owl if there is a light or not. The best way to discourage owls is to use owl
guards or owl cages.

327. Why is a 2 inch hole bad news when it relates to great horned owls?
A 2 inch hole allows the GHO to reach into the cavity with their long feet and extend their talons to grasp
the martins.

328. What other methods will the great horned owl use in predation of martins ?
Owls will fly silently toward the martin gourd or house, then slam against the martin housing. This in turn
alarms the martins which causes them to exit the cavity. At this time, the owl will either grab the martin
as it exits to try to catch the martin within the first few feet of their exit.

329. What can be done to reduce the success of a great horned owl predation ?
Always have 12 inch deep compartments and 5 inch wide porches. If possible, include ultra modern slide
out trays. These trays provide additional safety with a built in interior perch and tapered cavity. Adding
owl guards or an owl fence surrounding the housing would be a welcome sight for the martins, but not
for the owl.

330. Can a screech owl breech a 2 inch hole ?
Yes. That is why we recommend less than a 2 inch hole. It is preferred that all landlords utilize the
crescent shaped entrance, better know as the starling resistant entrance hole or SREH. There are many
varieties of SREH to choose from and all work well in deterring starlings, screech owls, etc...

331. I noticed my martins getting pset when a crow flew over their housing; are crows a threat ?
This is usually the fish crow that is the culprit. The common crow is slower and larger in size but no
threat to martins. The martins may throw a tantrum when a crow is near, but the fish crow is the only
problem for martins.

332. Are fish crows found in the midwest and how should they be dealt with in relation to martins ?
Fish crows live mostly on the ocean coast line and southern states and therefore won't be seen in the
midwest. Those living on the coast and southern states can manage fish crows the same way we deal
with great horned owls; owl guards and owl cages.

333. Do martins and tree swallows migrate together ?
Yes. Many sightings of these two species have been recorded. There is no problem within the two species
during migration, but competition for nest cavities may occur once they reach their nesting grounds.

334. Will martins chase away a much bigger predator such as a hawk, owl or crow from their colony ?
Martins are very protective of their eggs and young. Early in our history, farmers took advantage of this
trait to aid in the protection of their own chicken flocks. The larger your colony is, the more likely the
martins will take chase after a predator. They will also swoop down on squirrels and cats that happen to
pass by the colony.

335. How does a small martin deal with a large predator such s an owl or hawk ?
By giving out an alarm call they quickly recruit large numbers of other martins to chase the predator. In
addition to the group gang up on the predator, other species will join in on the chase. There is
advantages in numbers.

336. When is a hawk most likely to attack ?
Anytime during the day is the simple answer. Attack times are unpredictable. They will not attack at

337. Will house sparrows pierce or damage a martin egg ?
Yes. They will peck a hole in the martin egg. They will also remove eggs from nests, toss them out.
Sparrows are probably the number one problem for martins. Do not allow martins to exist near your
martin housing. Trapping and shooting are the best methods of eliminating sparrow. Sparrow nest
removal will sometimes enrage the sparrow and they can go on a killing spree. Sparrow nest removal
before martins lay their eggs is an option, but ultimately; killing the sparrow is best. Never try to trap
and relocate a sparrow.

338. Will a sparrow claim an already occupied compartment or gourd and build a nest on top of the martin
nest and or eggs ?
This happens all the time and is not uncommon. They will build a nest even if an adjacent compartment
is empty. ASY adult martins will put up a good fight and is typically on guard, but they need your help
as a landlord in eliminating sparrows. SY martins are not as vigilant.

339. What does a sparrow nest look like inside of a martin gourd or cavity ?
House sparrow nests are a mess of grass, rootlets, weeds, string, straw, hay stems all bunched together
with a small hole leading to the center of the mess and lined with feather in the back of the tunnel hole.
The nest usually fills up the entire cavity from floor to top of roof.

340. Will a starling damage or destroy martin eggs ?
Most definitely. Starlings are very aggressive and kill adult as well as baby martins and destroy eggs. An
example of how fast they work on creating death in a martin colony: in six hours one starling entered five
nests and tossed out or pierced 20 eggs. Starlings' beaks are tough and pointed and they will use this
weapon of peck adult and young martins to their death. NEVER allow starling to stay at your colony. Both,
starlings and house sparrow MUST be destroyed at your colony, through trapping and euthanasia or via
shooting. Traps must be monitored at all times and never left unattended in case you accidentally trap a
martin or any other species. If you trap a good bird, release it immediately.

341. Will starlings and house sparrows through out young martins ?
These nasty enemies will remove baby martins by any means necessary. They will routinely fight adults to
gain access to the cavity and then either kill the babies or simply through them out to the the ground.
Both house sparrows and starlings will stop at nothing to claim a martin cavity regardless if it occupied or

342. Are male house sparrows more aggressive than the females ?
Over many years it has been observed that the male will make attacks on martins but the females are
much less aggressive. A female will perch herself on a porch or in an entrance and block martins from
accessing their own cavity. The male house sparrow is malicious and often murderous around nesting
season. Male house sparrows will often try to kill adult female martins while they are trying to
incubate their eggs.

343. How many clutches will a house sparrow typically raise in a year ?
Three clutches per year and they multiple fast. They are so prevalent because they are persistent,
adaptive and successful as a species.

344. Will house sparrows cause problems for other native birds ?
Virtually any cavity dwelling native bird will and can be harassed, killed, annoyed or compete with by
these messy, disease carrying pests. They are a non native species that cause endless headaches for
many species of birds including the purple martin.

345. Is the House Sparrow a native bird ?
No. They are a native bird also known as a weaver finch. They were introduced into the U.S. from Europe.
They originated from Eurasia and North Africa and have been introduced on ever continent of the earth
and most islands. They are a threat to many nesting bird species.

346. Is the European Starling a native bird ?
No. They were introduced from Europe. The starling reproduced and spread at an alarming rate across
the U.S. They are an aggressive bird that will congregate in enormous roosts numbering in the
thousands. They are hard to drive away and consumer many insect. They are a threat to nesting native
species because they compete for nesting cavities and reduce available food sources for other birds.

347. What year was the house sparrow introduced into the USA ?
1859 was the beginning of the sparrow in the USA. Ever since that year, all native birds living in the US
have had troubles with sparrows.

348. What year was the European Starling introduced into the USA ?
Early 1890's, at central park in New York City. And over 130 years later we are regreting their
introduction into the US. Conservationists are much wiser now and have a better understanding of
the problems that species other than native cause.

349. Will a cat refuse to eat a starling ?
Yes. The starling gives off a foul smell to the cat.

350. Are sparrows and starling disease carriers ?
It has been shown that both are carriers to 35 different types of lice, mites, fleas and diseases. This not
only affects other birds, but livestock as well.

351. If a starling or sparrow is shot on top of a martin house and doesn't fall off, will martins remove the
dead starling or sparrow ?
Yes. Martins will drag the dead starling or sparrow from the house if you don't do it for them. Keep in
mind that it is probably safer to trap them instead of shooting near your martin colony; a
stray pellet or BB may hit a martin. Pellets and BB will go through a metal house if the aim is off and kill
a martin inside the cavity. Perch wires are an ideal place to kill sparrows and starlings if there are no
martins close by.

352. What color is a starling egg ?
A pale blue. The starling eggs will be found in clutches of four to six eggs and positioned in a nest made
of weed stems, twigs, grass, straw and other available trash lined with finer plant materials and feathers.

353. What are the colors of house sparrow eggs ?
White and speckled with brown and black. They lay in the middle of a tunnel lined with feathers which is
completely engulfed in a huge mass of grass, weed stems, hay, paper strips and anything else they can
try to make a nest.

354. Is the English House Sparrow a protected species ?
No. It is not protected and not a native species the the US. We recommend eliminating sparrows from
colony area. Trapping and euthanasia or shooting is encouraged. Please do not kill (Chipping
sparrows) song sparrows or finches; they are harmless to martins.

355. Is the European Starling a protected species ?
No. It is not a native species of the Americas and it is not protected.

356. I can't bring myself to kill an English House Sparrow or European Starling. If I catch one in a trap can I
release it 10 miles away from my martins ?
No one wants these pest birds in their yard. The proper and humane method is to dispose of them

357. How long will a house sparrow survive in a trap ?
8 to 24 hours if not given water an food. Stress is what kills the house sparrow in a trap.

358. How early will house sparrows start making a nest in a martin compartment ?
As soon as it starts warming up in early spring. Several weeks before the martin scout are to arrive in
your area. Do not allow house sparrows to become entrenched in nest building before your martins

359. Do starlings sometimes toss out martin nesting material when attempting to take over a martin
cavity ?
Yes. This is a behavior common to starlings. They also do the same to other starling nests in the area.

360. Have you ever seen a house finch make a nest in a martin gourd or cavity ?
House finches are adaptive nd open to making their nest in a martin cavity; but it is not their normal
behavior in nest building. They are harmless to martins.

361. How soon will a house finch nest in a martin cavity ?
The same time as an English house sparrow; which is a few weeks before the martin scouts are due to

362. Will a finch be as destructive as a house sparrow ?
No comparison. There has never been a witnessed incident of a finch killing a martin. They are also
unlike the starling in that they do not throw out the nesting material of a martin. Finches are 100%
harmless to purple martins.

363. Can do describe the appearance of a House Finch ?
Slightly smaller than a house sparrow, but their tail is a little longer. The male is streaked brown with a
red breast, forehead and rump. The female is absent of the red coloring and looks similar to a purple
finch, but finer streaks an no contrasting stripes on the face. Their sound is warm and clear sort of
warble and musical.

364. Can you tell me about House Finch eggs and their nest ?
House Finch eggs are smaller than a English House sparrows eggs. The eggs are pale blue and lightly
spotted with black. Their nest is a well kept cup made of grasses. Nests can be found in flower pots,
bushes, thickets, natural cavities and inside or outside ledges.

365. Is the House Finch a native bird ?
In the west yes, in the east no. They occur naturally from Texas to Nebraska and west to the Pacific coast.

366. Can you explain how the House Finch got to the eastern states ?
They were introduced. The eastern population have descended from caged birds and released near New
York City in the 1940's. In the early years after their release they had a difficult time surviving around the
Long Island area. They were helped along by spreading to suburban areas and the widening interest by
people of other native birds. House finches quickly adapted to the available winter bird feeders and thus
expanded westward; and now cover most of the United States.

367. What will happen if a house finch has established a nest in a martin cavity when the martins arrive ?
There are two parts to this answer. The house finch will readily give up their nest cavity to the rightful
purple martin. They are not persistent or destructive like house sparrows. Secondly, and good news is
finches normally have already raised their first clutch for the summer by the time martins arrive. So, if
you happen to have a finch take up house in one of your martin cavities; consider them a a squatter on
free rent from you until the martins come back.

368. Do house finches peck holes in martin eggs or through out nestlings ?
No. Finches are unlike sparrows in this behavior. House finches have an unusual child like behavior in
which they are observed tagging behind martins in their daily routines. It is believed that house finches
are simply curious about the martins; this is completely harmless to the martins.

369. Do I need to worry about house wrens making a nest in a martin cavity ?
It is unlikely that a wren will make a nest in a martin cavity; but is has happened on very rare cases.

370. Will a wren cause problems for martins ?
On occasion they have been known to pierce eggs and throw them out.

371. What should I do if a wren problem arises ?
Put up a nesting box for wrens well away from your martin colony. This will probably stop the wrens
interference with your martins.

372. Can I eliminate wrens like I do to sparrows and starlings ?
No. House wrens are a protected species and they do eat huge amounts of insects, spiders and small

373. Why did all of my martins suddenly disperse from their cavities and roost in near by trees; only to
return and flutter around the entrances ?
A snake in the cavity will stop martins from re-entering their cavity. A second possibility would be a
very serious mite infestation with many young dead inside the cavities. The snake should be immediately
removed and a baffle attached to the pole or a good cleaning out of the mites and treatment should take

374. A cooper's hawk caught a sub adult male yesterday and made another attack today. What should I do?
Cooper's hawks are birds of prey and he is doing what comes natural. Twelve inch deep compartments
can aid in giving the martins a sense of security while on their housing or inside the cavity. But, once the
martin leaves it's porch it is not safe. If your martin housing is too far from your own residence the hawk
will feel bolder and more likely to attack. Next season, set up new housing closer to your own
residence. If possible, cut down any trees near your martin set up to allow for a more open area. Hawks
sometimes hang out is nearby trees and wait for opportune moments to make their attack. By taking
these steps, the older martins in the colony can see the hawks earlier and sound an alarm, giving the
colony increased time to avoid the hawks. Martins can see an incoming hawk as far away as 2,000 feet.

375. Should I be concerned about bubble bees near my martin colony ?
Single bumble bees will not be cause for alarm. But, an unkept, neglected colony set up with old
sparrow nest may be inviting to bumble bees to set up a nest of their own. If this happens it could cause
problems for the martins.

376. If a starling kills a leader inside a compartment, will the whole colony collapse ?
No. The mate may leave this compartment, but the colony will not leave.

377. I thought I had eliminated every starling in my martin colony, only to find a clutch of starling eggs in
one of the compartments. How is this possible ?
Starlings can be very elusive and their tactics shrewd when avoiding martin landlords. They can find ways
around avoiding detection. They have a tendency to keep a low profile and read the landlords moves. You
may think that there are no starlings around and as soon as you go inside your own home, they return.
The best method to ensure their eradication is to do weekly nest checks, looking for starling eggs and

378. I set a sparrow trap on a compartment with sparrow eggs. When I caught the male sparrow in the
compartment, I removed the male sparrow and disposed it. I noticed the eggs were gone when removing
the old sparrow nest. Where did the eggs go ?
Male sparrows will eat their own eggs for nourishment when they see no way out. They also eat the eggs
to cover any indication that there was a sparrow in the compartment. It is their way of trying to protect
his own species.

379. I moved to a new location and the area was loaded with sparrows. So I eliminated every sparrow within
sight by shooting and trapping. The next year I had my new martin housing set up and amazingly was
able to attract a beginning colony. The problem is there are still sparrows showing up, just not as many.
How can I ensure that that no sparrows will be present ?
There is no possible way to eliminate every single sparrow unless you spend every waking moment of
every day shooting and trapping. The few sparrows that remain are probably very wary of any movement
made on your part and will be the toughest to shoot or trap. They are wise and will avoid you at all cost.

380. When a raccoon attacks a colony, will the martin colony leave ?
It is possible depending on the size of your colony. A raccoon is unlike other predators, in that they are
on the housing for a longer time during the attack. This would cause much more stress on the colony
and therefore increase the chances of colony abandonment. It is best to take precautionary steps prior
to an attack or raid by installing a baffle on your pole.

381. I have been told it is not wise to shoot sparrows and starling off my martin houses. Why ?
You are playing the laws of average. Eventually your aim will be off or you don't take the time to
concentrate on the shot. This will lead to you accidentally shooting the house. The shot may pass through
the compartment and strike an unseen mother martin sitting on her nest. Wait until the sparrow or starl-
ing lands on a wire perch or nearby tree to make the shot. Some landlords carry the gun out near the pest
but not take a shot; this allows for the pest to get comfy with your presence. In time you will be able to
approach the pest for a closer and improved success rate of making a good kill shot while avoiding the
chance of accidentally hitting a martin.

382. I thought I eliminated every sparrow from my site. But, after I returned from work there were a few
hanging around. What can I do ?
It is time to invest in a live sparrow trap. Read the instruction that come with the trap. Have someone
monitor the trap in case you accidentally trap a species other than a sparrow or starling. Other birds
need to be released immediately.

383. When blackbilled magpies land on my martin porches during breeding season, the baby martins come
to the entrance thinking their parents are there to feed them an insect. But, the magpies quickly grab the
baby martin and fly away. This is terrible, what can I do to stop the magpies from murdering my babies ?
Fastening wire cloth netting on the outside lip of the porches with smaller openings in the netting will
most likely eliminate the magpies. It will still allow martins to enter, but restrict larger magpies. Larger
magpies are usually the ones picking off baby martins. This is more of an issue in Canada.

384. If I hung a dead starling under my martin housing, will that keep other starlings away ?
This is not advised. It will attract hungry kestrels and nasty blowfies as it is unsanitary.

385. Have you ever seen a chimney swift steal a dragonflies from a martin in flight ?
It is rare to see a swift attempt to steal a dragonfly from a martin in flight. I doubt that on this rare
event that a swift would be successful.

386. Will ospreys living close to my colony interfere ?
Osprey forage only on fish. There will be no interference to your martins.

387. What does the term " crepuscular" mean when is relates to owls ?
Owls are definitely predators of martins. The term "crepuscular" is defined as dusk to dawn feeders.
Owls will look for roosting martins as well as martins in their cavities during this time period. Always
provide either 12 inch deep compartments or an owl cage or combination for owl protection.

388. Can a mockingbird that perches on my martin housing hinder my chances of starting a colony ?
Mockingbirds are not a threat to martins and they will not make a nest in your martin housing. If they
spend an excessive time perching on your housing, consider moving your housing. Mockingbirds are a
species known to be pertinacious, stubborn and unyielding to their birds and can hinder your chances of
becoming a new landlord.

389. Eliminating sparrows is desirable and encouraged. When I eliminated the sparrows they remaining few
made nests elsewhere. But, in time some sparrows tried to come back to my martin housing. When they
returned, so did some martins. I'm confused, why would martins show up once the sparrows started to
show up ?
This is common behavior for martins. When the sparrows and martins both try to establish at the martin
housing at the same time; each species is trying to promote and spread their own kind. When the
sparrows arrive, the martins inherent competitiveness kicks in and visa versa. The simple answer is to go
above and beyond in your quest to eliminate all sparrow from the area.

390. Do starlings migrate ?
Most starlings do not migrate. They congregate in large flocks and once the spring arrives they start
competing with the newly arriving song birds for nest cavities.

391. A snake got into my lower metal house cavity and killed the babies. I got rid of the snake and cleaned
out the compartment. The compartment of babies above that cavity had babies and were untouched, but
were not feed the day of the killing. But after the cleaning the parents started feeding the babies. Can
martins smell snakes ?
Martin sensory smell is very poor. The issue of parents returning to feed the young was not that they
couldn't smell the snake, rather the fact that you cleaned out the cavity below and the parents could see
that the snake was no longer present and therefore safe for a return.

392. Would a paper wasp nest found in a martin compartment be a call for concern ?
Yes. When doing your weekly nest checks you should physically remove the wasp nest. Do not use a spray
on the wasp nest because it could be harmful to martins, especially nestlings. Adult martins do catch and
eat wasps while in flight. But, within a confined space like their nest compartment they are unable to
catch wasps. Wasps could easily sting martins in a cavity. If a wasp nest is already made in a cavity;
martins will not make a nest in that compartment.

393. Is it true that a landlord in Illinois lost all of his 100 pair of resident martins in a two year period ?
This actually happened to an Illinois landlord. The reason he lost his entire colony in two years was due to
a combination of events: Extended periods of cold and rain, raccoon and snake attacks, continued hawk
predation, and a massive parasite infestation. This was an unusual happening of multiple events. By
practicing a best landlord management program, this landlord would have easily avoided this disaster.
These practices include: 12 inch deep compartments, supplement feeding, proper parasite control and
nest changes in infested cavities, predator pole guards, wide open spaces, and weekly colony
monitoring. Even with all of these practices, it is common to lose a few martins each year.

394. I continue to eliminate starlings and they just keep showing up. Why is this happening ?
Areas heavy with livestock have a higher concentration of these pests. Starlings are one of the most
prolific species in the world, numbering over 200 million. There are only around 5-6 million martins.
Keep up the good work and continue disposing of the starlings.

395. Are parasites a problem for martins ?
In small quantities, martins can withstand bird mites. But, I suggest doing a nest change if bird mites
are seen on your weekly nest checks. Please refer to steps of a nest change earlier in this thread. It
involves remove the nestlings up until twenty days of age from the infested nest, placing them in a
safe bucket, removing the old nest, replacing cavity with fresh soft white pine needles, (use of 5% sevin
dust shake into pine needles optional) and then replacing nestlings back into middle of new nest. Do one
nest at a time if multiple nests are infested. If blowflies are present, remove them from the nest, same as
with dust mites and pull off blowflies if they are attached to nestlings. Buffalo gnats can be treated with
cotton balls soaked in absorbing junior with excess liquid squeezed out and placed inside cavity and or
applying absorbing junior around the entrances. Always be gentle with the nestlings.

396. What is diatomaceous earth and should I use it to control parasites in the nest ?
Diatomaceous earth is fossilized diatoms and is a powdery, very abrasive substance. It should NOT be
used in any bird nests to control parasites. It can become airbourne when martins move around in a nest
releasing these fine particles. This dust can be inhaled by the martins, causing great irritation in the birds
lungs and lead to death or severe health problems. DO NOT USED (DE) for parasite control.

397. Can I use 1/2 inch square pieces of "no pest" strip placed under a subfloor to combat parasites that
enter the nest ?
No. Even though birds have a terrible sense of smell, the vapors can still effect the martins lungs and
therefore should NOT be used as a form of parasite control. "No Pest" strips are coated with a pesticide
and is not safe for birds in general.

398. When do the pests blowflies start making their rounds in bird houses ?
Blowflies can start occupying nest compartments as early as an hour before dawn. Blowflies can kill
nestlings with heavy infestations. Blowflies are not as common in the upper midwest as they are in the
southern states.

399. Will bird mites disperse from one compartment to the others nearby ?
Yes. It is common for mites to infest one compartment, only to find nestlings in a nearby compartment.
If mites are found, quickly do a nest change or rid the compartment of these parasites. If left unchanged,
the mite eggs and larva can stay dormant until heat from other nests revive and attract them in masses.
It is important to do weekly nest checks for mites and deal with them promptly to stop their spread in a

400. What is Avian Pox and can martins acquire this disease ?
Avian Pox is a mosquito borne viral disease. Purple martins can acquire avian pox, especially the nestlings
since they are not covered with feathers in their early stage of life. Manifestations of the disease can be
seen as wart like lesions on the head around their bills. I can cause blindness and or death. It is not
transferable to humans or other animals, only to other birds. Martins do eat mosquitoes, but can't be
infected by eating a mosquito carrying the viral disease. They acquire the disease through being bite.

401. When I did my last nest check I noticed hundreds of tiny white worms covering the bottom of the nest
floor. What are these little miniature maggots ?
These tiny energetic maggots are actually flea larva. You should quickly remove them by scraping out the
compartment and then completely and thoroughly clean the cavity, including the nest tray. Once you have
completely and immaculately cleaned this cavity, replace the cavity with soft white pine needles and a
teaspoon of 5% sevin dust and shake it down into the nests floor. Do not allow sevin dust to touch the
martin's skin as it is an irritant. A clean house is a happy house.

402. I found 21 babies dead in the compartments, so I removed them and scrubbed down the cavities. The
parents only flew by once, so I closed the entrances for a day or two. Did I do the right thing ?
Removing the dead babies and cleaning out the compartments was the correct thing to do. But, you
should not close the entrances. In closing the entrances, you shut your parents off from re-nesting
attempts. Now, you may have to start all over again in getting martins to colonize your location next

403. I had a baby fall out of its nest so I returned it to the nest. I found it again on the ground, so I placed
nestling in my fallout shelter. The parents were feeding it in the fallout shelter, but it continued to be
found on the ground and eventually died. Why did it die ? Did other martins feed it something deadly ?
In a few more days it would have fledged successfully.
You did everything right and it was not your fault. The nestling was originally pushed out if its nest due
to sibling competition for incoming food, and being the weakest runt. Nature can be harsh and it is
simply the rule or nature. The other martins did not feed it anything bad, interior nest parasites may have
driven it out and or it was beyond ability to survive.

404. Could you break down the average times for a martin pairs clutch size, incubation time, nestling time
and number of nestings per season ?
Clutch average is 5, incubation period is 15-18 days, nestling time is 28 days and only one nesting per
season. These are averages and can vary from one nest to the next.

405. What was the biggest martin colony back in the days of 1988 ?
We have long past the days of what was considered a huge colony. Back in 1988, Robert L Gross from
Grandview, Indiana had 361 pairs. Today there are colonies that easily pass this number.

406. What percent of all banded martins are reported ?
Less than one-half of 1% are reported.

407. How much of a nestlings food is converted toward energy and growth ?
One-third of their food is dedicated to their energy and growth requirements. In comparison, mammals
are one-tenth.

408. What percent of a martins lungs make up their total body ?
Martins lungs take up 20% of their total body. In comparison, a human's is only 5%.

409. What is a martins resting and flight breathe rate ?
At rest a martin breathes 30 times per minute, In flight, the energy expended requires up to 450 times
per minute.

410. What is the body temperature of a martin ?
107degrees. Birds in general range from 100 to 112 degrees.

411. Do martins show albinism ?
Albinism has been seen in martins. Albinism is the lack of pigmentation.

412. Is the blowfly found in the martin species ?
Yes. Along with 138 other species.

413. Are starlings and sparrow carriers on mites, lice, fleas and disease ?
Yes. To be specific, 35 different kinds.

414. Are martins feathers good insulation ?
Birds generally have feathers that adapt best to their particular environment. Martins feathers
endure a range of temperatures from Canada in their breeding months to that of Brazil in the
our winter months.

415. Of all the species in North America, which one has been managed by man the longest ?
You guessed it, the purple martin.

416. Is the martin the only species east of the Rocky Mountains that is completely dependent on
people for their nesting site ?
Yes. There are other bird species in which there is human intervention and interaction; but the
purple martin (Progne Subis subis) is in our hands.

417. There are around 9,000 different species of birds worldwide and about 800 in North America.
Are there different species of martins in the world ?
There are several species of martins, with three major species in the United States. In the US,
we have the eastern purple martin that we see in Iowa, the hesperia in the desert southwest
and the arboricola in the pacific northwest. The other species that can be found in other area to
the south of the US include the elegans, tapera, chalybea, cryptoleuca. These species can be
seen on my online video titled, "purple martin life by Dave Duit". at the 2:20 time.

418. I know starlings have been called flying rats. So, how many of these flying rats exist ?
It has been estimated around 200 million starlings in North America. In comparison, there are
about 7 million purple martins.

419. What is the exact scientific classification of a Progne Subis (Purple Martin) ?
Scientific Classification
Kingdom Animalia
Phylum Chordata
Class Aves
Order Passeriformes
Family Hirundinidae
Genus Progne
Species Progne Subis

420. What other names have been used for the purple martin ?
House martin, gourd martin, western martin, black martin, purple gem, (Spanish: Golondrina
Purpúrea ), (French: Hirondelle noire).

421. Where can I find a list of all the Iowa ASY and SY martin reports by date, town and name ?
Under the " Iowa Purple Martin Discussion " in the forum, click on " 2019 ASY scout & SY subbies
arrival reports for Iowa" thread. Each year will have all reports listed and is updated daily.

422. Are there more males than females with the martin species ?
Males very slightly outnumber females; both asy and sy.

423. What is Project Martin Watch by the PMCA ?
"This project is one of the most involved, but most important Citizen-Science projects under our leadership. Project MartinWatch is a program of regular and frequent nest monitoring, beginning with nest-building and lasting through the fledging of the last nestling. It provides data ranging from housing, cavity-type, and size; as well as ranges of nest-initiation dates, clutch-sizes, and ultimately nesting, hatching, and fledging success. Project MartinWatch is a long-enough established and powerful-enough dataset that many of our outside research collaborators find value in it and are interested in partnering with us in order to link their objectives to this dataset. The fact that this program encourages regular monitoring has the added benefit of allowing the participant to observe problems occurring in the colony as they begin to occur, and intervene before the problem reaches irreversible levels." (Copyright PMCA.ORG) Purple Martin Conservation Association.

424. What is the PMCA's Citizen Science ?
"Citizen-Science involves the contribution of data or observations from the public to an organization that has a scientific interest in collecting the particular data for study.
There is probably not a better subject for Citizen-Science participation than our very own Purple Martin! The eastern race’s habit of only nesting in man-made housing and in proximity to humans, coupled with the level of attention and management we give to the bird; lends well to using enthusiasts to gather and provide the PMCA valuable data. In fact, our gathering of data through Citizen-Science dates back to 1995 with the initiation of our Project MartinWatch and now includes three other projects. " (Copyright PMCA.ORG) Purple Martin Conservation Association.

425. I'm planning to erect another martin house in my existing colony. How far apart should they be
placed ?
There is no exact figure; but they should be far enough apart for martins to easily exit and
enter their cavity and enough room for you to safely do nest checks. Fifteen feet or more.

Dave Duit
Joined:16 Mar 2019, 00:42
Location:Nevada, Iowa
Original Join Date:Tue Apr 30, 2013 8:02 am


Post by Dave Duit » 15 Jun 2021, 13:19

just bumping

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