Calhoun (1948) experimented, on the Ohio State University campus,
with simple nesting substrata for attracting Mourning Doves, and he
found a rather high degree of utilization. The substrata consisted
of flattened, cone-shaped platforms made of heavy-weight roofing
paper. Some of these substrata were still in place during 1950, and a
large percentage were being used as nesting platforms by doves. This
observation suggested that Mourning Doves might nest on platforms
which, with slight modification, could be converted into traps.
Two types of combination nesting substrata and trap platforms were
tested during 1951-1953 on the Ohio State University campus. One
of these consisted of a short board placed in a tree in a horizontal
position. Three small sticks, arranged in the form of a triangle, were
nailed to the surface of the board. This was done to give the platform
a more natural appearance and to prevent the nest from being dis-
lodged by the wind. The entire top of the trap was removable, and
only the bases were placed in likely Mourning Dove nesting sites.
None of the nine substrata of th, is type was used for nesting. The
second type platform was similar to the first except that most of its
length was covered with an arch of poultry netting. The two ends
which formed the trap were removable. Fifteen of these open-end
cages were erected during 1951 for use by nesting doves. Of the 15,
six were occupied by doves, and three were destroyed in land-clearing
operations soon after erection. The six pairs nesting on the substrata
represented about half of the pairs of doves known to be nesting in
the immediate area. In 1952 eight of these substrata were erected and
four were used by nesting doves; during 1953 ten were erected and
six were used. Each of these counts cover separate substrata and do
not include renestings on the same substrata; although from one to
three pairs used the same substrata for a second nesting attempt
each year.
The top and 'sides of the cage were made of one-inch mesh poultry
netting reinforced at the ends with number nine-gauge smooth steel
wire. The arch of wire was permanently attached to the base board.
The removable ends were also made of poultry netting reinforced
with the heavier wire. The ends were attached to the open-end cage
with small springs. In order to hold the hinged door firmly in place,
the double base of the end holding the trap mechanism was fitted over
and under the end of the piece of wood forming the nesting substratum.
When the trap was in operation, the door was closed with a light
spring. It was held open by a heavy wire fitted with a notch, the
latter of which engaged a small staple driven into the removable base
which held the door in place. With the treadle in a slightly elevated
position, the trigger fitted under the prop near the notch. Slight down-
ward pressure on the treadle disengaged the prop and permitted the
door to close. The sensitivity of the trigger was adjusted by changing
the depth and angle of the notch in the prop. The entire assembly was
painted black.
Frame-a9 ,Steel Wire
All Wood- I"Thick
Doves were fledged in 19 of the 23 nests located on substrata
during the period 1951-1953. This represents a nesting success of
82.6 per cent. The four unsuccessful nests suffered the following fates:
No. 1 was destroyed by land-clearing operations; No. 2, a nest estab-
lished during March in which only one egg was laid, was deserted
before incubation had begun; No. 3, the week-old young perished
during a heavy snowstorm; and No. 4, the eggs disappeared from the
nest. James P. Mackey, Jr. (unpublished field notes), studying Mourn-
ing Doves on the Ohio State University campus in 1952, determined that
33 (64.7 per cent) of 51 nests were successful. It should be noted that
the nesting success drops to 62.2 per cent when the six nests on the
substrata are not included in the calculation. Mackey indicated that
wind was a major factor in the destruction of nests in 1952. The loss
from wind is largely averted when the doves place their nests on
these substrata.
Swank (1952) recently developed a pull-string trap for the capture
of nesting Mourning Doves, and he was successful in taking 94 birds.
The Mourning Dove normally does not enter a nesting trap readily,
and when a pull-string trap is used the operator may have a long
wait before the bird enters the trap. Also, it is sometimes impossible
for the operator to station himself in such a position that he has an
unobstructed view of the nest, and good visibility is imperative when
a pull-string trap is used. Accordingly, it seemed desirablb to investi-
gate the feasibility of using an automatic trap. Although the sample
was relatively small, the automatic trat was used with notable success
in 1951. Of the six pairs of doves nesting on the substrata, all but
one bird were .captured.
The trap described herein seems to be quite versatile, and it can
be operated either automatically or manually. If it is desired to have
a pull-'string trap, the prop holding the door ajar may be placed against
the staple on which the treadle hinges. By attaching a string at the
site of the notch in the prop and threading the string through the top
of the cage, a tripping device can be extended to a point of vantage
and the trap operated manually.
Trapping operations were carried on when the nestlings were between
three and eight days of age. At night the door of the trap was propped
open without the trigger engaging the treadle. If a bird were sitting
on the nest the following morning, the prop under the door was pushed
from its resting place with a forked stick. The brooding bird was thus
captured, and the trap was set for the second bird.
Where studies are conducted on nesting doves, it is sometimed '
desirable to nest-trap all of the adult doves in a chosen area. Of course,
it cannot be expected that all of these birds can be induced to place
their nests on the substrata. Accordingly, tests were made as to the
feasibility of moving nests onto substrata. Again the sample was
admittedly small, but all efforts at moving nests were attended with a
high degree of success. Twelve birds were trapped on the six nests
that were moved onto substrata.
A total of 23 adult doves were trapped. Four of these birds sustained
.slight injuries on the bends of the wings, and this was the on apparent
damage imposed by the trapping operations. The captive birds often
fluttered about in the trap immediately after the door was released,
but they soon quieted down and brooded the nestlings. The author
made no attempt to trap the nesting doves during 1952 and 1953.
Preliminary results indicate that this substratum may have value
for reducing nesting losses, but it must be tested under diverse situa-
tions before it can be unconditionally recommended. The trapping of
adult birds on their nests always carries with it potential hazards, but
such. hazards need not be augmented by the u.se of an automatic trap for
the Mourning Dove if appropriate precautions are exercised. In at least
some instances, an automatic trap is preferable to a pull-string trap.
The marked success .attending the limited operation of this combination
substratum and automatic trap for nesting Mourning Doves suggests
that its utility should be given further test by wildlife biologists.
LITERATURE CITED
CALUOUr, Jor B.
!948 Utilization of Artificial Nesting Substrate ly Doves and Robins. Jour-
nal of Wildlife Management, 12: 136-142.
SWANK, WENDELL G.
1952 Trapping and Marking of Adult Nesting Doves. Journal of Wildlife
.Management, 16: 87-90.
Ohio Cooperative V/ildli/e Research Unit, Department o/Zoology and Entomology,
Ohio State University, Columbus 10, Ohio.