First Nesting Records of the Puerto Rican Nightjar and Antillean Nighthawk in a Montane Forest of Western Puerto Rico /(Primeros registros de anidamiento de Caprimulgus noctitherus Y Chordeiles gundlachii en un bosque montano del oeste de Puerto Rico)


Delannoy, C.A.

Journal of Field Ornithology 76(3): 271-273

2005


J.
Field
Ornithol.
76(3):271-273,
2005
First
nesting
records
of
the
Puerto Rican
Nightjar
and
Antillean
Nighthawk
in
a
montane
forest
of
western
Puerto
Rico
Carlos
A.
Delannoyl
Department
of
Biology,
University
of
Puerto
Rico,
P
0.
Box
9012,
Mayaguez,
Puerto
Rico
00681-9012
Received
4
October
2004;
accepted
10
December
2004
ABSTRACT
I
report
the
first
nesting
records
for
the
Puerto
Rican
Nightjar
(Caprimulgus
noctitherus)
and
Antillean
Nighthawk
(Chordeiles
gundlachiz)
in
Maricao
Forest,
a
montane
rain
forest
of
western
Puerto
Rico.
The
nightjar
nested
in
leaf
litter
at
the
edge
of
a
trail
parallel
to
a
eucalyptus
plantation
(Eucalyptus
robusta),
at
an
elevation
of
620
m.
The
nighthawk
nested
on
rocky
substrate
of
a
trail
in
the
southern
slopes
of
the
forest
at
an
elevation
of
460
m.
These
are
the
highest
elevation
nesting
records
reported
for
these
species
in
Puerto
Rico.
The
nightjar
had
a
clutch
of
two
eggs
and
the
nighthawk
one
egg;
all
eggs
hatched
successfully.
The
nightjar
had
an
incubation
period
of
19
d,
consistent
with
the
18-20
d
previously
reported.
SINOPSIS.
Primeros
registros
de
anidamiento
de
Caprimulgus
noctitherus
y
Chordeiles
gundlachii
en
un
bosque
montano
del
oeste
de
Puerto
Rico
Informo
el
primer
registro
de
anidamiento
para
el
guabairo
(Caprimulgus
noctitherus)
y
el
querequeque
(Chordeiles
gundlachiz)
en
el
bosque
de
Maricao.
Este
es
un
bosque
montano
que
se
encuentra
en
la
parte
oeste
de
Puerto
Rico.
El
guabairo
anido
en
la
hojarasca
al
borde
de
un
trillo
en
el
bosque
paralelo
a
una
plantaciOn
de
Eucalyptus
robusta,
a
una
elevaciOn
de
620
m.
El
querequeque
anido
en
un
sustrato
rocoso
de
un
trillo
en
la
falda
sur
del
bosque
a
una
elevacion
de
460
m.
Estos
dos
registros
constituyen
la
elevacion
mas
alta
en
donde
se
han
informado
a
estas
especies
anidando
en
Puerto
Rico.
El
guabairo
produjo
una
camada
de
dos
huevos
y
el
quequereque
de
uno;
todos
produjeron
polluelos.
El
guabairo
tuvo
un
periodo
de
incubaciOn
de
19
dias
lo
que
es
consistente
con
los
18-20
dias,
previamente
informado.
Key
words:
Antillean
Nighthawk,
caprimulgids,
Maricao
Forest,
nesting,
Puerto
Rican
Nightjar,
Puerto
Rico
The
Puerto
Rican
Nightjar
(Caprimulgus
noctitherus)
and
Antillean
Nighthawk
(Chordei-
les
are
the
only
breeding
caprimul-
gids
in
Puerto
Rico.
The
distribution
of
the
endangered
Puerto
Rican
Nightjar
(hereafter
nightjar)
is
limited
to
coastal
dry
limestone
and
lower
cordillera
forests
of
southwest
Puerto
Rico
(Vilella
and
Zwank
1993;
Oberle
2000).
Approximately
1400-2000
nightjar
pairs
are
es-
timated
to
be
distributed
among
three
main
populations.
These
populations
are
found
in
the
Sustaa-Maricao
Forests,
Guanica
Forest
(east
and
west
of
the
Guanica
Bay)
and
the
Guaya-
nilla-Periuelas
Hills
(Vilella
and
Zwank
1993).
Nightjars
were
detected
for
the
first
time
in
1990
in
the
Parguera
Hills
and
in
1992
in
Si-
erra
Bermeja,
10
and
20
km
west
of
the
western
section
of
the
Guanica
Forest,
respectively
(Vi-
lella
and
Zwank
1993).
The
nightjar
breeding
season
extends
from
February
to
July,
with
a
peak
from
April
through
June
(Vilella
1995).
1
Email:
cadelannoy@yahoo.com
The
Antillean
Nighthawk
(hereafter
night-
hawk)
is
a
seasonal
breeding
resident
and
is
more
widespread
in
Puerto
Rico.
It
is
found
in
open
areas
throughout
the
coast,
foraging
in
towns,
agricultural
fields,
pastures,
and
coastal
to
mid-elevation
limestone
and
cordillera
for-
ests
(Kepler
and
Kepler
1973;
Raffaele
et
al.
1998;
Oberle
2000).
Nighthawks
breed
from
May
to
July
(Raffaele
et
al.
1998).
Here
I
report
first
nesting
records
of
the
nightjar
and
night-
hawk
in
Maricao
Forest
in
western
Puerto
Rico.
On
25
April
2004,
two
field
assistants
found
a
nesting
caprimulgid
with
one
egg
while
con-
ducting
a
point-count
census
of
the
Elfin
Woods
Warbler
(Dendroica
angelae)
along
a
trail
in
the
eastern
section
of
Maricao
Forest
in
west-
ern
Puerto
Rico.
During
a
nest
check
on
7
May
2004,
I
accidentally
flushed
a
male
Puerto
Ri-
can
Nightjar
from
two
eggs
in
leaf
litter
ap-
proximately
40
cm
from
the
trail's
edge.
It
was
a
male
because
only
males
have
a
white
throat
band
and
portion
of
the
outer
tail
feathers
(Raf-
faele
et
al.
1998).
The
nightjar
flushed
from
the
271
272
C.
A.
Delannoy
J.
Field
Ornithol.
Summer
2005
eggs
when
I
approached
to
within
5
m
from
the
nest.
It
flew
silently
to
a
tree
and
perched
on
a
branch
9
m
from
the
eggs.
It
stood
mo-
tionless
and
did
not
return
to
the
eggs
until
15
min
after
I
had
retired
to
a
distance
of
50
m
and
remained
hidden.
The
trail
ran
parallel
to
a
eucalyptus
plantation
and
was
4.6
m
wide
at
the
nesting
site.
Egg
dimensions
were
26.3
mm
X
20.3
mm
and
25.5
mm
X
19.7
mm.
The
eggs
were
buffy-brown
covered
with
numerous
dark
brown
speckles.
I
recorded
longitude
and
latitude
at
the
site
with
a
handheld
Global
Po-
sitioning
System
(Garmin
12
model
GPS)
and
elevation
with
a
Sun
pocket
altimeter.
Nest
lo-
cation
coordinates
were
18°07'N,
66°56'W
and
elevation
was
620
m.
I
visited
the
nightjar
nest
again
on
14
May
2004.
The
male
nightjar
flushed
when
ap-
proached
to
a
distance
of
approximately
1
m.
It
landed
on
the
trail
5
m
away
from
the
eggs
and
engaged
in
a
distraction
display.
The
night-
jar
spread
its
tail
and
wing
feathers,
opened
its
bill,
but
produced
no
vocalization.
Shortly
afterwards
it
flew
again
and
landed
on
the
trail
about
7
m
from
the
eggs.
It
stood
motionless
and
produced
a
soft
"whip"
call
once.
On
closer
inspection
I
noticed
many
egg-tooth
marks
on
the
surface
of
both
eggs,
evidence
that
the
hatching
process
had
begun.
I
walked
away
from
the
nest
and
hid
until
the
male
covered
the
eggs.
An
early
morning
visit
on
15
May
(07:00)
to
the
nesting
site
revealed
two
recently
hatched
cinnamon
downy
nestlings.
I
estimated
a
hatch-
ing
period
of
19
d
(26
April
to
14
May).
I
stood
briefly
in
the
area
and
waited
hidden
un-
til
the
male
covered
and
brooded
the
nestlings.
I
visited
the
nest
site
one
last
time
on
17
May
2004
and
noticed
the
male
nightjar
and
nes-
tlings
had
wandered
away
from
the
edge
of
the
trail
into
the
eucalyptus
plantation.
I
made
no
attempt
to
approach
or
intervene
in
any
way
with
the
adult
and
nestling
nightjars.
My
diurnal
visits
to
the
nest
site
confirmed
the
male
nightjar
was
primarily
responsible
for
parental
duties
during
daylight
hours.
The
male
nightjar
always
incubated
and
brooded
facing
east.
On
20
May
2004,
I
found
an
Antillean
Nighthawk
incubating
one
egg
(28.1
mm
X
27.7
mm)
on
the
rocky
substrate
of
a
trail
in
the
southern
slope
of
the
Maricao
Forest.
Nest
location
coordinates
were
18°08'N,
66°59'W,
and
elevation
was
460
m.
The
nighthawk
flushed
from
the
egg
when
I
was
at
an
approx-
imate
distance
of
8
m.
It
landed
on
the
trail
some
15
m
away
from
the
egg
and
stood
qui-
etly
and
motionless.
I
withdrew
and
remained
hidden
until
the
nighthawk
returned
to
incu-
bate
the
egg.
I
returned
to
the
nesting
site
on
5
June
2004
and
flushed
the
nighthawk.
The
nighthawk
landed
in
the
trail
floor
12
m
from
its
original
position.
It
engaged
in
a
distraction
display
similar
to
the
one
performed
by
the
nightjar
and
consistent
with
other
caprimulgids
(Gram-
za
1967).
I
found
eggshell
halves
in
the
nesting
site,
typical
of
a
hatching
event.
I
searched
the
area
thoroughly
but
could
not
find
the
nestling.
Maricao
Forest
is
at
the
upper
limit
of
the
nightjar's
distribution
in
Puerto
Rico,
and
hab-
itats
within
this
forest
seem
marginal.
Vilella
and
Zwank
(1993)
determined
that
nightjar
densities
decreased
considerably
with
elevation
in
sampled
areas
of
Susua
and
Maricao
Forests.
Only
two
nightjars
were
heard
in
a
eucalyptus
plantation
in
the
eastern
section
of
the
Maricao
Forest.
The
nightjar's
nesting
site
reported
here
was
at
the
highest
elevation
ever
recorded
and
within
the
same
area
previously
sampled
by
Vi-
lella
and
Zwank
(1993).
The
location
of
the
nightjar
nest
at
the
edge
of
a
eucalyptus
plan-
tation
is
not
unusual.
Some
tree
plantations
within
the
Guanica
forest
are
appropriate
nightjar
nesting
habitat
(Vilella
1995).
The
fact
that
the
male
nightjar
performed
parental
duties
during
the
daylight
hours
is
in
agreement
with
previous
observations.
Vilella
(1995)
reported
that
female
nightjars
never
in-
cubated
during
the
day.
In
fact,
male
nightjars
incubate
considerably
more
(68%)
than
fe-
males,
a
reversal
of
the
incubating
pattern
for
many
caprimulgids.
The
eggs'
appearance
fit
previous
descriptions
(Kepler
and
Kepler
1973;
Vilella
1995).
The
incubation
period
was
19
d,
consistent
with
the
18-20
d
previously
reported
(Vilella
1995).
However,
chicks
hatched
less
than
24
h
apart
in
this
study,
which
differs
from
the
hatching
on
successive
days
reported
by
Vilella
(1995).
Apparently
full
incubation
started
with
the
second
egg.
The
nighthawk
distribution
in
southwestern
Puerto
Rico
extends
from
coastal
up
to
lower
cordilleran
forests
(Kepler
and
Kepler
1973).
The
nighthawk's
nesting
site
reported
in
this
study
is
the
highest
elevation
record
for
this
Vol.
76,
No.
3
Caprimulgids
in
Puerto
Rico
273
species
in
Puerto
Rico
and
the
first
for
the
Ma-
ricao
Forest.
The
nighthawk's
nesting
site
in
gravel
substrate,
a
scrape
in
the
open,
and
clutch
size
of
one
egg
are
consistent
with
pre-
vious
reports
(Kepler
and
Kepler
1973;
Oberle
2000).
ACKNOWLEDGMENTS
I
thank
Hector
Rios,
Alisher
Torres,
Gustavo
Gon-
zalez,
Jose
Vargas,
and
Emmanuel
Sanchez
for
assisting
me
in
the
field.
The
Bird
Life
International
BP
program,
the
Research
Experiences
and
Training
Opportunities
program
(RETO)
of
the
Howard
Hughes
Medical
In-
stitute
and
University
of
Puerto
Rico,
Mayaguez
cam-
pus,
provided
support.
I
am
grateful
to
Francisco
Vilella
and
two
anonymous
reviewers
for
their
advice
and
com-
ments
that
improved
the
manuscript.
LITERATURE
CITED
GRAMZA,
A.
F.
1967.
Responses
of
brooding
nighthawks
to
a
disturbance
stimulus.
Auk
84:
72-86.
KEPLER,
C.
B.
AND
A.
K.
KEPLER.
1973.
The
distribu-
tion
and
ecology
of
the
Puerto
Rican
Whip-poor-
will.
Living
Bird
11:
51-60.
OBERLE,
M.
W
2000.
Puerto
Rico's
birds
in
photo-
graphs.
Editorial
Humanitas,
San
Juan,
PR.
RAFFAELE,
H.,
J.
WILEY,
0.
GARRIDO,
A.
KEITH,
AND
J.
RAFFAELE.
1998.
A
guide
to
the
birds
of
the
West
Indies.
Princeton
University
Press,
Princeton,
NJ.
VILELLA,
E
J.
1995.
Reproductive
ecology
and
behaviour
of
the
Puerto
Rican
Nightjar,
Caprimulgus
nocti-
therus.
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International
5:
349-
366.
,
AND
P.
J.
ZWANK.
1993.
Geographic
distribu-
tion
and
abundance
of
the
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Rican
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