PURPLE MARTIN WEEKLY QUESTION & ANSWERS PART 4

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Dave Duit
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Joined: 16 Mar 2019, 00:42
Location: Nevada, Iowa
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PURPLE MARTIN WEEKLY QUESTION & ANSWERS PART 4

Post by Dave Duit » 20 May 2019, 08:22

426. Do entrances have to be set facing a particular direction ?
Martins don't care the direction. But for good planning, I suggest facing entrances away from
recurring rain and wind and facing the most open fly zones.

427. Was was the link between the Romans and purple martins ?
The martin was connected to Aphrodite the Goddess of love.

428. How did the sailors of the high seas view the purple martin ?
The purple martin signified good sailing and also good luck.

429. Can you give me a quick overview of martin eggs ?
Eggs are pure white, about 24.5 X 17.5 mm, with an average clutch of 5 and one egg is laid each
day.

430. Can you explain martin egg incubation ?
Incubation lasts about 16 days just after the next to last egg is laid. The female is responsible for
incubation as she is the sex with a brood patch; an area just above the tail on her belly that is
void of feathers.

431. Do all the eggs hatch at the same time ?
All eggs in the nest will hatch within 48 hours.

432. How long is a martins migration and how long does it last ?
Their migration in late summer from Iowa to their wintering grounds in Soa Paulo, Brazil takes
roughly 4-6 weeks and spans up to 5,000 miles.

433. How long does it take for a pair to build a nest ?
After 4-6 weeks of their arrival at their nesting site and once they pair, it will take about 3 weeks
for both male and female to build a nest.

434. Do young pair build mud dams near the entrance or is that designated to older pairs ?
Only an older more experienced pair will attempt a mud dam construction.

435. What is the difference between a martin song and call ?
Songs are longer and more complex than calls. Songs are paired to courtship and mating, while
calls are related to various forms of location and alarms of a predator in the nearby area.

436. Where is the purple martin's non-breeding grounds ?
Brazil is the main area, but they also stay in Colombia, Venezuela, Ecuador, Peru, Bolivia,
Paraguay, Argentina, Brazil, British Guyana, Suriname, and French Guiana.

437. Besides the purple martin, are there other species that have seen a complete traditional
change in their nesting behavior ?
Martins use to make nests in natural cavities and over time became 100% human made housing
users. The other two species are the Chimney Swift and Barn Swallow.

438. What is the distance martins fly on the Gulf of Mexico migratory route ?
Migration across the Gulf is a 500-600 mile trip in non-stop flight.

439. Are the spring and fall migrations the same for martins ?
They don’t take the same route on the spring and fall migration. They don’t take the same paths
from year to year.

440. I think I might have an unhatched egg, what do I do ?
If the egg is more than seven days past the hatch date, and remaining eggs have hatched, it can
be removed.

441. What do I do if new eggs are added to a clutch of eggs that are unhatched ?
You need to wait until hatching is finished; once the babies are at least a week old, only then
can you remove the unhatched egg or eggs.

442. What is an addled egg ?
An egg that is rotten or embryo has died or been destroyed. Martins usually push their bad eggs
out of their nest cup or out onto the porches of the cavity.

443. What is alula ?
A collection of feathers on the first finger located at the bend of the wing. These feathers
are used to reduce turbulence and drag, and to break and steer. Martins have three alula
feathers on each wing.

444. Do I have to put up a predator guard, even if I don't have predators in the area ?
Yes. Just because you haven't seen a predator in your area doesn't mean they are are not there
when you are not looking. All colonies should have predator guards, especially large colonies.
Large colonies are diner bells to hawks, owls, raccoons, cats, etc....

445. I'm trying to start a new colony. I have had martins visit, but they don't stay. Why ?
If the season just started in your area, martins will use your site as a ‘stopovers,’ resting before
flying back to the colony site they nested at last year. They might be from a local area colony
site. Martins are voracious social birds as they will go out visiting other colonies during the day.
Having martins visiting your site is a great sign; it indicates there are martins in the area and
your housing is meeting all the right requirements.

446. When do baby martins open their eyes for the first time ?
Around eight days the baby martins will see their world for the first time.

447. Please explain baby body feathers and the topic of brooding.
Baby martins get their first covering of feathers at 12 days of age. But, they will not be able to
maintain their body temperature without the help of the parents brooding until day 15-20.

448. Do male martin parents have a brood patch ?
Only the female parent has the brood patch on her lower underbelly. The brood patch is a
concentration of blood vessels in a which the mothers own temperature can "heat up" the baby.

449. Why do purple martins even bother coming up north from South America ?
The Purple Martin is a South American swallow that evolved its migration habit to North America for the long summer days of northern latitudes. The increased hours of daylight each day give martins an advantage in foraging insects. Martins are aerial insectivores, and wouldn't be able to withstand the winter months in most of North America.

450. Several of my martins have been eating on the ground; is that normal ?
Your martins appear to be eating insects off the ground, but they are most likely either eating
grit to aid in their digestion or collecting nest material. Martins are aerial insectivores and are
not ground foragers.

451. Are purple martins, secondary cavity nesters ?
Purple martins historically were secondary cavity nesters. Before people provided man made
martin housing, the martins used woodpecker holes, rock ledges or dead tree cavities. Martins
don't excavate their own cavities; therefore the term secondary cavity nester.

452. Why did the martins move into housing offered by humans ?
Thousands of years ago, man started offering dried hollowed out gourds. Since martins liked this
in comparison to their secondary cavities, plus the decline of natural housing, there was a
behavioral shift in their preference toward man made housing.

453. Can I add housing to my colony during the nesting season ?
As long as it is not modifying existing structures (gourd racks, etc...) It is completely fine to add
a new gourd rack or T14 next to your already established housing.

454. Is there an exact distance between housing set ups ?
No. Each location is unique and the landlord needs to weigh the benefits and disadvantages of
what the area offers. 10-15 feet is fine as long as it can be easily managed for nest checks,
nest changes, walk under checks and end of season cleaning. The main focus should be on open
fly zones and protection from predators.

455. Is the purple martin from South America or North America ?
Avian scientists believe the purple martin is really a South American swallow that over the
years evolved their migration to North America; taking advantage of the long summer days
of the northern latitudes.

456. Where am I most likely to find an urban roost ?
If you are out and about trying to find an urban roost, look for areas bountiful of trees or man-
made structures like bridges and pipes.

457. Is there a wrong time to do nest checks ?
Do not do nest checks when the martins are weather stressed. The only exception during
weather stressed is when there is a wing entrapment or dead bird blocking the entrance.
Never check during the evening or after dark. Never check when weather is bad and the parents
are feeding their babies.

458. What constitutes a reason for doing a nest check ?
Bird mites is the number one reason and most popular reason to do nest checks at least every
10 days or until the babies reach age 20 days,( no nest checks after 20 days because the young
may fledge too early.) Nest check if you see a baby on the ground. Replace him to his rightful
nest if you can; otherwise replace baby to similar aged with the smallest number of nestlings
nest cavity. Check when bad weather has stopped for dead or soaking wet cavities. Check if you
see signs of predation like feathers on the ground near your colony or owl feathers. Check if
your martins are showing behavioral changes such as not wanting to enter their cavities or seem
agitated. When doing nest checks, don't forget to check for capped half egg shell overlapping an
unhatched egg.

459. Can you tell me about purple martins' lungs ?
Martin lungs can best be described as large air sacs. The air sacs are thin walled and extend from
the bronchi of the lungs. A martins lungs take up a large volume of their core upper body. This
increased lung volume helps in respirator efficiency, and decreases body weight for best aerial
maneuvering.

460. How early and late in the day will martins be seen in flight ?
Male martins can be seen in the predawn hours when they sign their dawnsong and in the
evenings as late as a half hour past sunset when feeding young. Martins are somewhat
crepuscular, meaning active in low levels of light.

461. What the heck is an egg tooth ?
A little tough pseudo tooth on the end of the bill that develops in the embryos of all birds. It
aids embryos in breaking out during their hatch from the eggshell. Baby Purple Martins have a
white egg tooth on the upper tip of their beaks. It falls off a few days after hatching.

462. Are martins in danger of blood parasites ?
Not all martins have blood parasites, but it is possible. Haemoproteus prognei is the scientific
name of a microscopic parasite commonly found in the blood of Purple Martins. This is not to be
confused with bird mites that feast on the blood from the outside of the martins body.

463. Do martins eat more prior to their summer and spring migration ?
Martins become hyperphagic prior to their migration from and to Brazil. It is a behavioral
term meaning to eat a lot. Martins become hyperphagic to increase their fat storage for energy
to be used for their long migration.

464. Are martins stealers of nest material or food ?
Sorry to say that martins are notorious kleptoparasites. Parent martins will steal nesting material
from a nearby neighbor at the drop of a hat given the opportunity. Why go seek out nest material
when it is so convenient to just step next door and grab material. Another form of
kleptoparasitism is when older pre fledged martins standing on the outside porch will steal food
brought back by neighboring parents intended for their own youngsters.

465. What is mate guarding ?
It is when the male partner will guard his female partner during her fertile time to ensure he is
the only male to copulate. At the time period of nest building and the egg laying time, he will
mate guard her every move. He will accompany her to the egg shell tray or the ground when
seeking out nest material.

466. What is mobbing behavior ?
This occurs when the colony of martins vocally and physically harass any predators in the area
to drive it away from the colony. Mobbing can take place in mass by the martins and usually
includes dive bombing the predator. Martins will chase hawks from behind so as to not become
the hunted. Cats and squirrels are relentlessly dive bombed until driven from the area.

467. Do martins have an oil gland used for preening ?
Like many birds, the martin does in fact have an oil gland. It is located above the tail and near
the base of the rump. This gland secretes an oily liquid through a duct in which the martin can
press in order to force out the oil. This gland is also known as the uropygial and preen gland and
the oil once spread on the outside of the feathers during preening will aid in insulation, water
proofing and in keeping the feathers soft and flexible. When the bright sun hits the martins
feathers it in turn manufactures vitamin D; which is eventually absorbed into the skin to deter
the chances of getting avian rickets.

468. Will martins renest after a failed nest ?
A replacement clutch after a failed first nest or its eggs will sometimes cause a second attempt.
When a nesting attempt fails after the young have hatched, a renest is unlikely.

469. Are martins single clutch birds ?
Typically martins have only one brood of nestlings per season. In the southern states there have
been a few recorded second clutches due to longer breeding season possibilities.

470. Can you tell me about how martins sleep ?
During the breeding season, martins sleep inside their nesting cavity with the head turned,
resting on their back with the bill slightly tucked under their shoulder feathers. In the late
summer at the tail end of the breeding season and during their winter months in Brazil, martins
sleep outside in the open on tree branches and on oil refineries' pipes in South America.

471. How are martins' voice boxes rated in relation to other song birds ?
The purple martin voice box appears to be above average in the song bird world. Their syrinx
or voice box which is positioned where the trachea and split of the bronchi tubes meet. Martins
have a superior capability to create a variety of vocalizations due tot heir extremely developed
syrinx.

472. I want to put up a new replacement house; can you give me some insight on what I need to do ?
Replacement housing should be replaced over a two year period. Martins have strong site
fidelity; by drastically changing housing from one season to the next might be detrimental to the
colony. If the replacement house is identical, erect it in the same location, it is best solution to
put up the new housing near the old for an entire season. Don't replace or eliminate the old
house until some of the martins accept and breed in the new house. Landlords with many active
housing systems can replace a house between seasons without risk of colony abandonment.

473. Is there a list of "to do" at the end of each season after all your colony has migrated south ?
Every landlord has a different routine on caring for their martin set up at the end of the season.
There are different opinions but there are a few "to do" that every responsible landlord should
abide by. First, keep your housing in good condition and make repairs as needed; such as winch
cable replacements, painting of T-14s, replace old cracked weathered gourds, lubricate winch
mechanisms and or cables, cover the entrance holes or plug them to discourage sparrows from
entering during the winter or early spring prior to martins arriving. A few other tasks that
landlords do, but have varying opinions are as follows: Clean out all cavities with 10% bleach
solution, (9 parts water to 1 part bleach), rinse thoroughly, dry, sprinkle inside with a little 5%
sevin and store for the winter. Collect clean soft white pine needles for early spring pre-nest
material. Send in your end of year tallies to the PMCA. Make sure to order supplement crickets
and crushed egg shells prior to the martins arrival in spring. Make improvement plans and ideas
for the next season.

474. What four things can I do to stop owls from attacking my martins ?
Owls hunt at night and listen for martins to make small noises inside their cavities. Therefore,
it is important to take measures to protect your colony from this predator. Here are four tactics
to discourage owl predation: Placement of housing in an open setting with large fly zones.
Install wire cages and or house mounted guards. Be sure to have deep cavities and or tunnel
turns to decrease the success rate of the owl attack. Include decoys to reduce chances of hawks
attacking perching martins.

475. Which three states have seen the most decline in the purple martin population ?
Minnesota, Michigan and Wisconsin. For the past 42 years the martin population has been stable
and it is amazing that in some southern states there has been a slight increase. But, song bird
populations nationwide have been in decline.

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