Purple Martins has not been without hazards. An early problem that surfaced was
vandalism. More than 3,000 students attend school on our campus, a few are liable
to create problems.
problem was students shaking the poles out of curiousity or to see the martins
fly, a behavior which can disrupt the nests inside the gourd. Another problem
was students on campus after hours climbing the aluminum poles, resulting in the
collapse of the gourd set.
these problems were solved by the practice of affixing a 10 ft length of PVC electical
conduit pipe, split lengthwise, around the gourd poles and holding the pipe halves
in place with hose clamps.
heavy layer of vaseline is then applied to these pipe halves, discouraging physical
contact by the students while at the same time not ruining clothing in case of
with vandals, the most serious threat to our Purple Martins has been the European
Starling. Starlings are martin-sized birds that resemble a mature male Purple
Martin to the novice observer. The easiest way to distinguish them is by the beak:
Martins have short, dark beaks whereas that of the starling in the breeding season
is long, pointed and yellow.
are not native to this continent, having been introduced from Europe, and martins
have few defenses against them.
threat starlings pose to martins is that they also nest in the same sort of cavities
that appeal to martins and will fight with martins for possession of them. Unfortunately
in such a fight the martin invariably comes out on the losing side. The short,
soft beak of the martin is no match for the long pointed beak of the starling.
Adult martins are frequently killed outright or mortally maimed in fights with
starlings. The martin at right was recovered dead from inside a gourd.
may invade the nest at any time, killing any young or adult martins and breaking
any eggs that may be present.
starling nest can be readily identified as starlings fill the whole cavity with
dried grass and straw whereas a martin nest consists of a flat layer of dried
grass and dead leaves on the bottom of the cavity, leaving the rest of the cavity
open. Starling eggs are robin's-egg blue in color, those of the martin are pale
the starling nest material spilling out of the gourd in the photo at left.
of starlings invaded a gourd, evicted or killed the resident martin pair, built
a nest and laid these six eggs in the space of about eight days.
MUST be controlled in order to keep a viable martin colony. Fortunately an easy
and quite effective way is through the use of Starling Resistant Entry Holes (SREH).
These oddly-shaped entrances capitalize on the fact that a starling usually has
a deeper breastbone and longer legs than does a Purple Martin. The design of these
entrances make it more difficult for starlings to enter.
variety of SREH designs are available, pictured at is a bat-shaped Excluder entrance
and a crescent.
starlings, the House Sparrow is not a native of this continent but was also introduced
from Europe. Unfortunately for the Purple Martin, House Sparrows also nest in
cavities. House Sparrows are small, brown birds common around human habitations.
At right is pictured a male, showing the distinctive black bib.
a House Sparrow is not the threat to an adult martin that a starling is, adult
martins occasionally injured in fights with sparrows.
more serious threat posed by House Sparrows is their habit of entering the nest
while the adult martins are away and destroying the eggs and young.
in possession of a cavity, House Sparrows will rapidly fill the whole cavity with
straw and dead grass, making it impossible for martins to enter. At right is pictured
a female House Sparrow leaving a gourd.
they are smaller than martins, House Sparrows cannot be excluded by the design
of the entrance.
house sparrows, like those few starlings which succeed in entering SREH entrances,
must be trapped and removed.
a variety of traps are available on the market. Pictured here is a Natureline
gourd equipped with a trapdoor entrance. In this case the entrance has been shimmed
down to a size that will admit sparrows but exclude Purple Martins from entering
more thorough discussion of these pests can be found at the
Purple Martin Conservation Association
to martin home