A DESCRIPTION OF THE FIRST MICRONESIAN HONEYEATER (MYZOMELA RUBRATRA SAFFORDI) NESTS FOUND ON SAIPAN, MARIANA ISLANDS

2006·5.3 MB·English

by  Thalia Sachtleben

n
The Wilson Journal ofOrnithology 118(3):309-315, 2006
A DESCRIPTION OF THE FIRST MICRONESIAN HONEYEATER
1
MYZOMELA RUBRATRA SAFFORDT) NESTS FOUND ON
(
SAIPAN, MARIANA ISLANDS
THALIA SACHTLEBEN,134 JENNIFER L. REIDY,2 AND JULIE A. SAVIDGE
—
ABSTRACT. We provide the first descriptions of Micronesian Honeyeater (Myzomela rubratra saffordi)
nests {n = 7) and nestlings (n = 6) from Saipan in the Mariana Islands. Measured nests ( = 3) averaged 46.7
mm in inner cup diameter, 65.7 mm in outer diameter, 41.3 mm in cup height, and 55.3 mm in external nest
height. We found all nests in two species ofnative trees, 1.47-5.1 m above the ground. Nesting materials were
primarily vine tendrils and Casuarina equisetifolia needles. We also report observations of parental behavior.
Nests, nest placements, and behaviors appeared broadly similar to those reported for this species prior to its
extirpation on Guam, and on other islands in Micronesia. Received2 May 2005, accepted26 January 2006.
The Meliphagidae family (honeyeaters) is though Engbring et al. (1986) found that den-
restricted to the Australo-Papuan region sities were greater on Saipan than on Tinian.
(Mayr 1945). Micronesian Honeyeaters {My- On Saipan, Engbring et al. (1986) counted549
zomela rubratra) occur throughout the high honeyeaters (mean of2.25 birds per station ±
islands (i.e., those of volcanic origin rising 0.14 SE), and estimated the total Micronesian
more than a few meters above sea level) of Honeyeater population at 22,573. In a repeat
Micronesia, with subspecies endemic to Palau survey, the U.S. Fish and Wildlife Service
(M. r. kobayashii), Yap (M. r. kurodai), (1997) counted 316 honeyeaters (mean of 1.30
Chuuk (M. r. major), Pohnpei {M. r. dichro- birds per station ± 0.09 SE; no population
mata), Kosrae (M. r. rubratra), and the Mar- estimate given), indicating a possible decline
iana Islands (M. r. saffordi; Pratt et al. 1987). in the honeyeater population between survey
Within the Mariana Islands, Baker (1951) periods.
found that birds from Guam, Rota, Tinian, and Little research has been published on the
Saipan are similar with respect to morpho- avifauna ofthe Mariana Islands, and many de-
metric measurements, and he does not sepa- tailed aspects oflife histories are unknown for
rate them taxonomically. Micronesian Hon- most native and endemic species (Rodda et al.
eyeaters, along with most other native forest 1998, Mosher and Fancy 2002). This lack of
birds, were extirpated from Guam in the mid- information hampers the development and im-
1980s with the arrival and range expansion of plementation of conservation plans. Despite
the brown treesnake (Boiga irregularis; Sav- interdiction measures, the number of brown
idge 1987, Wiles et al. 2003). Surveys on treesnake sightings on Saipan has increased in
Rota, Tinian, and Saipan (the inhabited islands recent years (Rodda et al. 1998; N. B. Hawley
of the Commonwealth of the Northern Mari-
pers. comm.); although definitive proof is
ana Islands [CNMI]) have indicated that Mi- lacking, 75 plausible brown treesnake sight-
cSraoinpeasniatnhaHnonoenyeRatoetrasoarreTilneisasnn(uPmreatrtouest oaln. oinngsSaainpdan11(Ghraangdg-c2a0p0t4u)redindbircoatwentthrateesannakiens-
A19g7u9o,nR1a9l8p1h, JaenndkiSnsaka1i9831,97C9r,aiJgen1k9i9n6s),aanld- cipient population of snakes is now estab-
lished (Colvin et al. 2005). Thus, information
on the ecology and breeding biology of all
1 Dept, of Fishery and Wildlife Biology, Colorado avian species in the CNMI is urgently needed
State Univ., Fort Collins, CO 80523-1474, USA. so that captive breeding programs can be im-
2Dept, ofFisheries and Wildlife, Univ. ofMissouri, plemented.
Columbia, MO 65211, USA. We undertook a study to assess nesting suc-
Inst3.C,ur1r5entSWaddrCeoslso:raHdioghADvees.e,rtStEec.ol3o0g0i.calBeRneds,earOcRh cess of common forest passerines in native
97702, USA. and nonnative forests of Saipan. Micronesian
4Corresponding author; e-mail: Honeyeaters were not a target species for this
[email protected] study, as they are reported to be more corn-
309
—
310 THE WILSON JOURNAL OF ORNITHOLOGY • Vol. 118, No. 3, September2006
FIG. 1. Location of Saipan within the Commonwealth of the Northern Mariana Islands, and Saipan study
sites (shaded areas) in which we searched fornests ofnativeforestbirds during 2003 and 2004 to assessnesting
success; Micronesian Honeyeater nests were found atMarpi, As Teo, Kagman, and Laolao Bay. Marpi, AsTeo,
and Kagman study areas were native forest; Cow Town, Bird Island, Obyan, and Naftan were nonnative tan-
gantangan forest; Laolao Bay was mixed native/agriforest. Approximate coordinates (taken at the nearest open
area, generally a road) for study sites were as follows: As Teo 15°11'N, 145°45' E; Bird Island 15° 15'
N, 145°48' E; Cow Town 15° 16' N, 145°49' E; Kagman 15°09'N, 145° 16' E; Laolao Bay 15°09'N, 145°
44' E; Marpi 15° 16' N, 145°47' E; Naftan 15°06' N, 145°44' E; Obyan 15°06' N, 145°43' E. The dotted line
on the location map signifiesthedivisionbetweentheTerritoryofGuamandtheCommonwealthoftheNorthern
Mariana Islands.
mon in coconut plantings, shrubbery and gar- July to November and the dry season from
dens of villages, scrub, coastal strand, and di- December to June. Typhoons may occur at
verse second-growth forest composed of both any time, but are most frequent between Au-
native and introduced trees (Seale 1901, Saf- gust and December (Young 1989, Mueller-
ford 1902, Pratt et al. 1979, Jenkins 1983, Dombois and Fosberg 1998).
Engbring et al. 1986). Over the course of our We focused our study on two forest types
study, however, we incidentally found seven introduced tangantangan Leucaena leuco-
(
Micronesian Honeyeater nests. To our knowl- cephala) forest and native limestone forest.
edge, these are the first nests of this species Most (77%) ofthe forest remaining on Saipan
found on Saipan, although nests have previ- is nonnative (Falanruw et al. 1989), and tan-
ously been found on Guam, and one nest has gantangan forest is estimated to cover 28% of
been found on Rota. Here, we describe nests the island. This tree species grows in dense,
and nestlings from Saipan and compare these near-monocultures on flat lowlands and pla-
descriptions with those from Guam, Rota, and teaus (Craig 1990). Native limestone forest is
other islands in Micronesia from which infor- restricted to cliffs and less accessible areas not
mation is available. easily cultivated (Craig 1989, Stinson and
METHODS Stinson 1994), and is estimated to cover only
— 5-19% of Saipan (Engbring et al. 1986,
Study area. Saipan, located in the western Young 1989). Pisonia grandis and Cynometra
Pacific Ocean (15° 10' N, 145°45' E; Fig. 1), ramiflora dominate the canopy of this forest
encompasses a land area of 123 km2 and is type, and C. ramiflora and Guamia mariannae
,
the second largest island in the Marianas. The are the most common species in the understo-
island has a tropical climate with an annual ry (Craig 1996). Study sites were selected in
mean temperature of28.3° C and mean annual three native, four nonnative, and one mixed
rainfall of200—250 cm. The timing ofthe wet forest (Fig. 1). The mixed forest contained
and dry seasons varies somewhat between common native and agriforest trees, including
years, but the wet season usually extends from coconut Cocos nucifera and mango {Man-
( )
Sachtleben et al. • MICRONESIAN HONEYEATER NESTS ON SAIPAN 31 1
gifera indica). Study areas were delineated by tents contained two eggs or two young. Ini-
transects marked with flagging. tially, we mistook two nests for Bridled
—
Avian surveys. We conducted our study White-eye Zosterops conspicillatus saypani
( )
from April to July 2003 and February to May nests due to their similar size, structure, and
2004. Micronesian Honeyeater nests were placement. However, we noticed that the nests
found while searching line transects according of Micronesian Honeyeaters tended to have
to distance sampling methodology (Buckland thinner walls and deteriorated more rapidly
et al. 2001) or incidentally while moving than Bridled White-eye and Golden White-eye
through the forest to monitor nests of other (Cleptornis marchei) nests, which they oth-
species. When found, each nest was flagged erwise closely resembled.
—
and assigned a unique nest identification num- Nest composition and structure. Only
ber. Nest contents were visually checked and three nests were accessible and in adequate
described at 3-day intervals, using a mirror on condition for measurement. Cup heights were
a telescoping pole if necessary. We did not 39, 40, and 45 mm (mean = 41.3 mm), and
mm
handle nest contents while nests were still ac- nest heights were 41, 50, and 75 (mean
tive; thus, no egg measurements were made, = 55.3 mm). Internal diameters were 43, 47,
and we visually estimated nestling character- and 50 mm (mean = 46.7 mm), and external
istics by using a millimeter ruler for compar- diameters were 55, 69, and 73 mm (mean =
ison. 65.7 mm). Nests were composed of vine ten-
After each nesting attempt was completed, drils and Casuarina equisetifolia needles (Fig.
we measured the nest’s height, distance from 2), and part of a leaf skeleton from a native
trunk, and number and diameter of supporting Pandanus sp. was entwined around the outer
branch(es). Tree species and tree height were base of one nest.
—
also recorded. We used a clinometer to mea- Nest placement. Micronesian Honeyeater
sure nest and tree heights (unless these could nests were located at various distances from
be measured directly with a steel measuring roads (i.e., from <25 to >100 m). Four nests
tape), a steel measuring tape to measure dis- were placed in Guamia mariannae and three
tance from the trunk, and a millimeter ruler to were placed in a Psychotria (genera compris-
measure diameters ofsupporting branches. We ing more than one species in CNMI, and
also estimated the distance between the nest which we could not identify to species level,
and the nearest road in 25-m categories (<25, are listed herein only to the genus level). Nest
26-50, 51-75, 76-100, and >100 m). Nests (and tree) heights in G. mariannae were 1.5
m m m
were collected if possible and measured with (5.6 m), 3 (5 m), 3.5 (6 m), and 5.1
m
a millimeter ruler, after which they were la- (not obtained), and in Psychotria they were
beled and given to the CNMI Division ofFish 1.5 m (2 m), 1.7 m (2.3 m), and 3.8 m (8 m).
and Wildlife on Saipan. Nests were placed 83-184 cm from the trunk
in G. mariannae and 0-103 cm from the trunk
RESULTS
in Psychotria generally near the outer edge of
We discovered seven honeyeater nests on the tree (Fig.,2). The number of nest support
31 May 2003, and on 17 February, 9 March, branches varied from two to five in both tree
12 March, 7 April, 9 April, and 26 April 2004. species, and support branch diameter ranged
Two nests contained eggs, two contained nest- from 1.5 to 9.7 mm in G. mariannae and from
mm
lings, and two were empty when located. The 1.5 to 2.5 in Psychotria.
—
female was sitting on one nest and was not Egg description. Although four monitored
disturbed; in this case the nest contents were nests each contained two eggs, we had a clear
not determined when the nest was discovered. view of the eggs only in the nest found on 26
No adults were in attendance at three nests April 2004. The eggs were creamy white and
upon initial discovery. Four nests failed (three marked with two distinct rings of brown
during incubation and one at an undetermined speckles, one ring near the broad end and the
nesting stage), and three fledged young. Four other near the narrow end of the egg.
—
nests were located in mixed forest, and one Nestling description. Of the three nests
nest was located in each of the three native from which young fledged successfully, we
sites. All six nests in which we observed con- found two during the nestling stage and one
312 THE WILSON JOURNAL OF ORNITHOLOGY • Vol. 118, No. 3, September2006
FIG. 2. Micronesian Honeyeater (Myzomela rubratra saffordi) nest photographed on Saipan, Mariana Is-
lands, 19 April 2004, showing its placement at the outer end ofthe branch.
during the incubation stage. Micronesian Hon- beginning to erupt from the back pins, and 1-
eyeater nestlings are altricial and closely re- to 2-mm head pins were visible on day 10-
dseevmeblloepBrreiddlpeidnWfheaitthee-rse.yeBenceastulsiengnsesutnltiilngthdee-y 1131-.1B4o,thwhneesntltihnegsofblseedrgveedrpwraemsat1urmelfyroonmdtahye
velopment was variable, each nest is treated nest. One nestling was captured and returned
separately. to the nest, but the second could not be relo-
The 2003 nest contained eggs when found, cated and was left to the adults who remained
and the two nestlings were first seen at day nearby and were agitated. At this time, the
0-1 following hatching. At this age they were nestlings were estimated at 5.5 cm in length,
estimated to be approximately 2 cm in length, but they were not yet fully feathered. Red
had dark pink skin, and were downy on their feathers, 1 mm in length, had erupted on the
wings and backs. On day 3-4, the nestlings back, gray feathers had erupted on the head,
had grown to 3—3.5 cm in length, were still and 8-mm tail pins did not yet have erupted
covered with down, and their skin color was feathers. The breast was bare. On day 14-15,
dark pink/purple. They appeared well fed, as the remaining nestling’s wing feathers had
they had large, rounded stomachs. At day 6- turned dark gray, and it fledged at day 15—16.
7, when their eyes were beginning to open, The second nest that fledged young was
the nestlings were 4-4.5 cm long, with wing found on 12 March 2004. On that date, the
mm
pins approximately 5 in length and back two nestlings were already approximately 4
pins beginning to erupt. Theirheads were cov- cm in length, their eyes were open, and they
ered in long down. On day 7-8, the chicks had 2-mm long downy feathers erupting from
were still 4-4.5 cm long, their wing and back the pins on their wings, backs, and heads. On
mm
pins were 8 and 2 (respectively) long, 15 March, only one nestling remained. This
their bills were beginning to curve, and their nestling fledged prematurely on 18 March
head pins still had not erupted. Underlying when the observer approached to ~3 m from
skin color, which lightened progressively the nest. The nestling fluttered away, but it
throughout nestling development, was pale could not fly and was captured and returned
pink by this stage. At day 9-10, the wing pins to the nest. We estimated the nestling to be
were 10 mm in length and tail and head pins 4-4.5 cm long and it did not appear fully
had erupted 1 mm. Tan brown feathers had feathered. The erupted feathers were mostly
erupted from the wing pins, red feathers were black, with small red patches of feathers ap-
n )
Sachtleben et al. • MICRONESIAN HONEYEATER NESTS ON SAIPAN 313
pearing on the head and back. By 22 March, measurements of nests we found on Saipan
when the final nest check was performed, this fall within these ranges. In contrast, the av-
nestling had fledged. erage outer height of 18 nests found on Chuuk
On 9 April 2004, we found the last suc- was 20 mm, considerably shorter than nests
cessful nest by observing the female bringing from Guam and Saipan, although the average
food to her two nestlings. The nestlings were external diameter was similar (50 mm; Brandt
estimated at 3-3.5 cm in length and were al- 1962). Our nest heights are also similar to
ready developing pin feathers. On 13 April, those reported from other islands, varying
the nestlings were ~4 cm long, covered with from 1.2 to 4.6 m (Hartert 1898, Seale 1901,
long, black pins from which feathers had Yamashina 1932, Mayr 1945, Brandt 1962,
erupted, and their eyes were open. Three days Jenkins 1983; N. Drahos pers. comm., C. C.
later, the nestlings were 4-4.5 cm long and Kessler unpubl. data).
theirbills were visible overthe rim ofthe nest. Similar to our descriptions of nests found
They were black all over with no red feathers on Saipan, nests from Guam, Rota, Chuuk,
visible. By 19 April, the nestlings had fledged. and Palau have been variously described as
—
Parental behavior. Only females were ob- “loosely constructed,” “fragile,” “frail,”
served incubating (n = 5 nest checks) or “not heavily made,” and having see-through
brooding nestlings (n — 1 nest check). How- sides (Brandt 1962, Pratt et al. 1980, Jenkins
ever, one or both members of the pair were 1983; C. C. Kessler unpubl. data). In addition,
often observed close to the nest. When ob- they were found placed among the outer
served, the adult(s) were always very agitated. branches of the trees in which they were con-
Typically, one or both adults would feign in- structed (Seale 1901, Brandt 1962, Pratt et al.
jury, fluttering about low to the ground and 1980, Jenkins 1983). Unlike the nests we
drooping one wing. Ifonly one adult was pre- found on Saipan, however, those on other is-
sent, this behavior was sometimes accompa- lands tended to be found in open locations,
nied by scolding; if both adults were present, such as the edges of clearings or the outer
one adult would often feign injury while the perimeters offorests (Brandt 1962, Pratt et al.
other scolded. We observed injury-feigning 1980; C. C. Kessler unpubl. data). Reported
behavior on 9 of 26 nest visits and scolding nesting materials are diverse and include fine
during 5 of 26; this behavior was observed roots and fibers, grasses, leaves, ferns, weed
only at nests containing nestlings. Microne- stems, and pieces ofcoconut bast (Mayr 1945,
sian Honeyeaters appeared very intolerant of Baker 1951, Brandt 1962). As on Saipan, Ca-
disturbance at the nest during the incubation suarina equisetifolia needles were included in
stage, as each time the incubating female was nests found on Guam.
flushed from the nest during a nest check ( The chief difference between our observa-
= 3), the nest had failed by the next visit. tions and those ofother authors in the Mariana
Islands is the suite of tree species used for
DISCUSSION
nesting. On Saipan, nests were placed in Psy-
Prior to our study, nests of Micronesian chotria and Guamia mariannae (trees native
Honeyeaters had been found on Guam (Har- to the Mariana Islands), whereas nests on
tert 1898, Seale 1901, Yamashina 1932, Jen- Guam were placed in Pithecellobium dulce,
kins 1983; N. Drahos pers. comm.), Rota (C. Casuarina equisetifolia Delonix regia and
, ,
C. Kessler unpubl. data), Kosrae and Pohnpei Bruguiera gymnorrhiza, only two of which
(Baker 1951), Chuuk (Baker 1951, Brandt (C. equisetifolia and B. gymnorrhiza are in-
1962), Palau (Pratt et al. 1980), and in the digenous to the Mariana Islands (Raulerson
southwest Pacific region (Mayr 1945). The and Rinehart 1991). On Rota, the nest was
amount of information provided varies by found in nonnative Acacia confusa. This dif-
source. Nest measurements are variable, with ference is likely a reflection of other authors
the following ranges reported from Guam: cup working primarily in habitats that were dif-
height 25-50 mm, outer height 50-120 mm, ferent from those in which we worked (only
internal diameter 25-60 mm, and external di- one ofour study areas comprised mixed native
mm
ameter 35-80 (Hartert 1898, Seale 1901, and exotic forest), rather than differences in
Jenkins 1983; N. Drahos pers. comm.). The honeyeater habitat use among islands.
314 THE WILSON JOURNAL OF ORNITHOLOGY • Vol. 118, No. 3, September2006
All reported clutch sizes are of one or two Parental distraction displays of Micronesian
eggs, although a nest found on Palau con- Honeyeaters on Saipan appear to be the same
tained three nestlings (Pratt et al. 1980). Two- as those ofbirds on Guam and Rota, although
to three-egg clutches are characteristic of the on Guam and Rota only females have been
Meliphagidae family (Mayr 1945). Microne- reported to feign injury (Stophlet 1946, Jen-
sian Honeyeater eggs from Saipan, Guam, kins 1983; N. Drahos pers. comm.).
Rota, and Chuuk all had a base color ofwhite, Three of the seven nests we found on Sai-
off-white, or cream, generally with rufous- pan were in native limestone forest, which has
brown speckling, although Yamashina (1932) not previously been reported as preferred hab-
described the speckling as gray and dark yel- itat for the Micronesian Honeyeater; the spe-
low-brown. The speckling may be concentrat- cies has been considered more common in co-
ed at the broader end (Hartert 1898, Seale conut plantings, shrubbery and gardens ofvil-
1901, Brandt 1962, Jenkins 1983), near the lages, and diverse second-growth forest. Sim-
narrow end (Yamashina 1932), near both ends ilarly, Cardinal Honeyeaters (Myzomela
(this study), or may be scattered over the cardinalis) in Samoa are most abundant in vil-
whole egg (Brandt 1962). lage habitats (Freifeld 1999), and Orange-
We found no comparative descriptions of breasted Honeyeaters (Myzomelajugularis) in
nestlings or data on their age at fledging. Fiji are most abundant in coconut plantations
However, several authors have described (Steadman and Franklin 2000). This under-
fledgling Micronesian Honeyeaters from scores the importance of obtaining ecological
Guam. Seale (1901:57) reported that “. . . the information forall native species to furtherthe
young are olive brown above, yellowish on development of conservation plans. Some of
the under parts, washed with red on the sides the habitats in which Micronesian Honeyeat-
of the fore breast and back; bill dark, yellow- ers are reportedly common, such as backyard
ish on the base of lower mandible; feet and gardens, would appear unsuitable as nesting
iris dark.” N. Drahos (pers. comm.) described habitat, given this species’ apparent intoler-
a pair of fledgling Micronesian Honeyeaters
ance of disturbance at the nest and the likeli-
recently out of the nest. The female was hood of disturbance in these areas.
mouse gray with a faintly rusty-red chin, her Overall, we found that Micronesian Hon-
bill was black with a yellow stripe on its edge eyeaters on Saipan have nesting requirements
aanndd thheer teoypesofanhderfebeiltlwwearseybelalclko.wHatetrheepobratseed, and behaviors similar to those on Guam prior
to their extirpation. Information on the nesting
that the male was similar, but the middle of
requirements of Micronesian Honeyeaters on
the back, chin, and lower half of the head
Saipan should aid in the establishment of ef-
were faintly cardinal red. Other authors’ de-
fective captive breeding programs forthis spe-
hscernispitvieo.nsTahreeresimairlearsaevletrhaolughdislessismiclaormiptriee-s cies, and for future re-establishment on Guam
among our descriptions of nestlings from dif- and Saipan (if necessary) once brown tree-
snakes have been controlled or eradicated.
ferent nests, and between our descriptions of
nestlings and those of other authors. The for-
ACKNOWLEDGMENTS
mer may be explained by factors that could
affect nestling development, including the
This studywasfundedbytheU.S. FishandWildlife
number of nestlings present in the nest (thus, Service (USFWS) Region 1 Office, Portland, Oregon.
whether provisioning must be shared), breed- We extend special thanks to the USFWS Marianas
ing experience or foraging ability of the Team, in particular H. B. Freifeld and A. P Marshall;
adults, or food availability in different study the Commonwealth of the Northern Mariana Islands
areas. The latter presumably is explained by DivisionofFish andWildlife, especiallyJ. B. deCruz,
continued plumage development after fledg- L. Williams, S. Kremer, and N. B. Hawley; J. Quitano
ing. Although our sample size included only for allowing us access to As Teo; N. Johnson and S.
Mosher for helpful field information; and S. Hopken
two nests, Micronesian Honeyeater nestlings fortranslating the Yamashina (1932) paper. We appre-
seem apt to leap from the nest before they are ciate the constructive comments madeonearlierdrafts
fully ready to fledge, which, under undis- ofthe manuscript by J. B. de Cruz, A. B. Franklin, R.
turbed conditions, seems to be at 15-16 days. A. Hufbauer, R. J. Craig, andtwoanonymousreferees.
Sachtleben et al. • MICRONESIAN HONEYEATER NESTS ON SAIPAN 315
LITERATURE CITED etation of the tropical Pacific Islands. Springer-
Verlag, New York.
Baker, R. H. 1951. The avifauna of Micronesia: its Pratt, H. D., P. L. Bruner, and D. G. Berrett. 1979.
origin, evolution, and distribution. University of America’s unknown avifauna: the birds of the
Kansas Museum ofNatural History, Lawrence. Mariana Islands. American Birds 33:227-235.
Brandt, J. H. 1962. Nests and eggs ofthe birdsofthe Pratt, H. D., P. L. Bruner, andD. G. Berrett. 1987.
Truk Islands. Condor 64:416-437. A field guide to the birds ofHawaii and the trop-
Buckland, S. T., D. R. Anderson, K. P. Burnham, J. ical Pacific. Princeton University Press, Princeton,
L. Laake, D. L. Borchers, andL. Thomas. 2001. New Jersey.
Introduction to distance sampling: estimating Pratt, H. D., J. Engbring, P. L. Bruner, and D. G.
abundance ofbiological populations. Oxford Uni- Berrett. 1980. Notes on the taxonomy, natural
versity Press, Oxford, United Kingdom. history, and status of the resident birds of Palau.
Colvin, B. A., M. W. Fall, L. A. Fitzgerald, andL. Condor 82:117-131.
L. Loop. 2005. Review ofbrown treesnake prob- Ralph, C. J. and H. F. Sakai. 1979. Forest bird and
lems and control programs: reportofobservations fruitbatpopulations and theirconservation in Mi-
and recommendations. Report to the Office ofIn- cronesia: notes on a survey. ‘Elepaio 40:21-26.
sular Affairs, Honolulu, Hawaii. Raulerson, L. and A. Rinehart. 1991. Trees and
Craig, R. J. 1989. Observations on the foraging ecol- shrubs of the Northern Mariana Islands. Coastal
ogy and social behaviorofthe BridledWhite-eye. Resources Management, Saipan, Northern Mari-
Condor 91:187-192. ana Islands.
Craig, R. J. 1990. Foragingbehaviorand microhabitat Rodda, G. H., E. W. Campbell, and S. R. Derrick-
use of two species of white-eyes (Zosteropidae) son. 1998. Avian conservation research in the
on Saipan, Micronesia. Auk 107:500-505. Mariana Islands, western Pacific Ocean. Pages
Craig, R. J. 1996. Seasonal population surveys and 367-381 in Avian conservation: research and
natural history ofa Micronesian bird community. management (J. M. Marzluff and R. Sallabanks,
Wilson Bulletin 108:246-267. Eds.). Island Press, Washington, D.C.
Engbring, J.,F. L. Ramsey,andV. L.Wildman. 1986. Safford, W. E. 1902. The birds of th—e Marianne Is-
Micronesian forest bird survey, 1982: Saipan, Ti- lands and their vernacular names I. Osprey 1:
nian, Agiguan, and Rota. U.S. Fish and Wildlife 39-70.
Service, Honolulu, Hawaii. Savidge, J. A. 1987. Extinctionofan islandforestavi-
Falanruw, M. C., T. G. Cole, and A. H. Ambacher. fauna by an introduced snake. Ecology 68:660-
1989. Vegetation survey ofRota, Tinian, and Sai- 668.
pan, Commonwealth of the Northern Mariana Is- Seale, A. 1901. Report ofa mission to Guam, part I.
lands. Resource Bulletin PSW-27, USDA Forest Avifauna. Bernice P. Bishop Museum Occasional
Service, Pacific Southwest Forest and Range Ex- Papers 1:17-60.
periment Station, Berkeley, California. Steadman, D. W. and J. Franklin. 2000. A prelimi-
Freifeld, H. B. 1999. Habitat relationships of forest nary survey of landbirds on Lakeba, Lau Group,
birds on Tutuila Island, American Samoa. Journal Fiji. Emu 100:227-235.
ofBiogeography 26:1191-1213. Stinson, C. M. and D. W. Stinson. 1994. Nest sites,
Gragg, J. E. 2004. Rodent reduction for enhanced clutch size and incubation behavior in the Golden
White-eye. Journal of Field Ornithology 65:65-
control of brown treesnakes (Boiga irregularis).
M.Sc. thesis, Colorado State University, FortCol- Stoph69l.et,J.J. 1946. BirdsofGuam. Auk65:534-540.
Hartleirnst., E. 1898. On the birds of the Marianne Is- U.S.eFsitshbiardndsuWrivledy,liSfaeipSaenr,viCcNe.MI1:997N.igDhrtaifntga1l9e97Refoerd-
lands. Novitates Zoologicae V:51-69.
Jenkins, J. M. 1983. The native forest birds ofGuam. WFiasrhblaenrd(AWiclrdolciefpehaSelruvsicleu,scHioninao)lualsus,esHsamweaniti..U.S.
Ornithological Monographs, no. 31. Wiles, G. J., J. Bart, R. E. Beck, Jr., and C. F.
Jenkins, J. M. and C. Aguon. 1981. Status of candi- Aguon. 2003. Impacts of the brown tree snake:
date endangered bird species on Saipan, Tinian patterns of decline and species persistence in
and Rota ofthe Mariana Islands. Micronesica 17: Guam’s avifauna. ConservationBiology 17:1350-
184-186.
1360.
Mayr, E. 1945. Birds of the southwest Pacific. Mac- Yamashina, Y. 1932. On a collection of birds’ eggs
Millan Co., New York. from Micronesia. Tori 7:393-413.
Mosher, S. M. and S. G. Fancy. 2002. Descriptionof Young, F. J. 1989. Soil survey ofthe islands ofAgui-
nests, eggs, and nestlings of the endangered jan, Rota, Saipan, and Tinian, Commonwealth of
Nightingale Reed-Warbleron Saipan, Micronesia. the Northern MarianaIslands. U.S. Departmentof
Wilson Bulletin 114:1-10. Agriculture, Soil Conservation Service, Washing-
Mueller-Dombois, D. and F. R. Fosberg. 1998. Veg- ton, D.C.