(DRAFT) - Taxonomy
Species FINCH, LAYSAN
Species Id ESIS101041
Date 14 MAR 96
TAXONOMY
NAME - FINCH, LAYSAN
OTHER COMMON NAMES - FINCH, LAYSAN; FINCHBILL, LAYSAN; FINCH-BILL, LAYSAN; CANARY, LAYSAN; FINCH, LAYSAN and YELLOW; HONEYCREEPER
ELEMENT CODE -
CATEGORY - Birds
PHYLUM AND SUBPHYLUM - CHORDATA,
CLASS AND SUBCLASS - AVES,
ORDER AND SUBORDER - PASSERIFORMES,
FAMILY AND SUBFAMILY - FRINGILLIDAE,
GENUS AND SUBGENUS - TELESPYZA,
SPECIES AND SSP - CANTANS,
SCIENTIFIC NAME - TELESPYZA CANTANS
AUTHORITY -
TAXONOMY REFERENCES -
COMMENTS ON TAXONOMY -
Laysan Finch
Telespyza cantans Wilson, 1890
KINGDOM: Animal GROUP: Bird
PHYLUM: Chordata CLASS: Aves
ORDER: Passeriformes FAMILY: Fringillidae
An adult male Laysan finch (Telespyza cantans Wilson, 1890) has a
bright yellow head, throat, and breast; the lower back and rump is
greyish-brown; the abdomen is whitish, and the neck has a grey
"collar." An adult female retains dark streaking on the yellowish
crown and some steaking on the flanks; females also have a grey
collar, yellowish throat and breast, and dark brown spots on the back
(01,04).
In both sexes, birds take three years to reach adult plumage (01,
05). In general, in the molt sequence, the amount of yellow increases
with age in both sexes, and males gradually lose their spots. Second
year and adult females are similar; second year males may also appear
similar to second year and adult females (01,03). However, with
experience, it is possible to age and sex the birds with a high degree
of accuracy according to plumage characters (01,19).
In addition to sexual dichromatism, there is also some sexual
Taxonomy - 1 (DRAFT) - Taxonomy
Species FINCH, LAYSAN
Species Id ESIS101041
Date 14 MAR 96
dimorphism. Males are slightly longer in wing and tail measurements
than females (01), and bill dimensions and weights are greater (19).
The weights of twelve captive Laysan finches (of both sexes)
ranged from 24.4 to 37.9 grams, with a mean of 32.8 grams +/- 3.6 SD
(07). Data taken in 1985 show that the mean weight of 123 adult male
Laysan finches was 34.7 +/- 2.57 and the mean weight of 90 adult
females was 31.38 +/- 2.66 (19).
The Laysan finch (Telespyza cantans) was described by Wilson in
1890 (02). It is now widely acknowledged that he incorrectly
indentified the bird as being from Midway Island (01,03,08,10,11,52)
when it was, in fact, from "Moller" or Laysan Island. Wilson
described the finch from a captive bird (10,15) which he obtained in
Honolulu; he apparently was told that the original source of his
specimen was Midway.
To further complicate matters, the type specimen was not an adult
male. Thus, when Rothschild received an adult male Laysan finch from
his collector in Hawai`i, he described it as a different species, the
"yellow Laysan finch" (Telespiza flavissima) (11,04,10,12). Within a
few short years, Rothschild recognized that his "yellow Laysan finch"
was, in fact, just an adult male of Wilson's Telespyza cantans
(04,11). (Bryan (12) mistakenly wrote that T. flavissima was a female
specimen of T. cantans.)
Rothschild and others have used the spelling Telespiza (06,11),
whereas Wilson's original spelling was Telespyza (02). Both spellings
have since been used, although the latter is correct (01,08). Besides
"Laysan finch," common names for T. cantans which are found in the
literature are: Laysan finchbill (03,18), Laysan finch-bill (Western
Hemisphere Convention Annex, 1967), Laysan canary (10), yellow Laysan
finch (11), and honeycreeper (50 CFR 17.11). The scientific name
Psittirostra cantans cantans was then applied by some authors (03,
13,14).
In some older literature, the Laysan finch (as well as the Nihoa
finch, Telespyza ultima) have been placed in the genus Psittirostra
(01,03,13,14,52), which includes another heavy-billed honeycreeper,
the 'O'u (Psittirostra psittacea). Some authors consider the Laysan
finch (T. cantans) and the Nihoa finch (T. ultima) to be conspecific
races (i.e., T. cantans cantans and T. cantans ultima), but Banks and
Laybourne found sufficient differences between them to recommend
classification as distinct species, based on age and sexual dimorphism
plumage sequence, size differences, and color differences (01,08).
The Convention on Nature Protection and Wildlife Preservation in
the Western Hemisphere Annex for the U.S. (1970) lists both the Laysan
and Nihoa finches under the species designation Psittirostra cantans.
Early taxonomists were uncertain about the closest relatives of
the endemic Hawaiian honeycreepers (51). Laysan finches, along with
the other Hawaiian honeycreepers, were formerly considered to be in a
separate family, the Drepanididae, but are now considered to be a
unique subfamily, the Drepanidinae, under the family Fringillidae (08,
14). Raikow's detailed work (16,17) on Hawaiian honeycreeper hind
limb and pectoral appendage myology (including the Laysan finch)
confirmed that the closest relatives are the fringillids.
Listing of specimen location have been compiled by Ely and Clapp
(15) and, more recently, by Banko (20). Banko listed 217 specimens
Taxonomy - 2 (DRAFT) - Taxonomy
Species FINCH, LAYSAN
Species Id ESIS101041
Date 14 MAR 96
at 20 locations. He reports that the type specimen is held at the
American Museum of Natural History in New York.
Photos of plates of Laysan finches occur in the following
citations: (02,03,06,11,14,21,22,52).
Taxonomy - 3 (DRAFT) - Status
Species FINCH, LAYSAN
Species Id ESIS101041
Date 14 MAR 96
STATUS
Coded Status
E: Federal Endangered
COMMENTS ON STATUS -
U.S. STATUSES AND LAWS:
The Laysan finch (Telespyza cantans) has been designated an
Endangered species pursuant to the Endangered Species Act of 1973
(50 CFR 17.11; P.L. 93-205, 87 Stat. 884; 16 U.S.C. 1531-1540), as
amended. The species has this status wherever found including the
State of Hawai`i.
This species is protected by the Lacey Act (P.L. 97-79, as
amended; 16 U.S.C. 3371 et seq.) which makes it unlawful to import,
export, transport, sell, receive, acquire, or purchase any wild animal
(alive or dead including parts, products, eggs, or offspring):
(1) in interstate or foreign commerce if taken, possessed,
transported or sold in violation of any State law or
regulation, or foreign law; or
(2) if taken or possessed in violation of any U.S. law,
treaty, or regulation or in violation of Indian tribal law.
It is also unlawful to possess any wild animal (alive or dead
including parts, products, eggs, and offspring) within the U.S.
territorial or special maritime jurisdiction (as defined in
18 U.S.C. 7) that is taken, possessed, transported, or sold in
violation of any State law or regulation, foreign law, or Indian
tribal law.
RESPONSIBLE FEDERAL AGENCIES:
USFWS -Responsible for the management/recovery, listing, and
law enforcement/protection of this species.
All Federal agencies have responsibility to ensure that any
action authorized, funded, or carried out by that agency is not likely
to jeopardize the continued existence of the species or result in the
destruction or adverse modification of Critical Habitat (50 CFR 402),
and to utilize their authorities to carry out programs for the
conservation of the species.
STATE STATUSES AND LAWS:
STATE: Hawai`i
DESIGNATED STATUS: Endangered
ADMINISTRATIVE AGENCY: Department of Land and Natural Resources
STATE STATUTE: Hawai'i Revised Statutes, Chapter 195D.
INTERNATIONAL STATUSES, TREATIES, AND AGREEMENTS:
Status - 1 (DRAFT) - Status
Species FINCH, LAYSAN
Species Id ESIS101041
Date 14 MAR 96
The Laysan finch is listed by the U.S. as Psittirostra cantans in
the Convention on Nature Protection and Wildlife Preservation in the
Western Hemisphere Annex (1970).
ECONOMIC STATUSES:
None.
67/03/11:32 FR 04001/ - Original listing
69/03/08:34 FR 05034/05035 - Republished list
70/08/25:35 FR 13519/13520 - Proposed relisting
70/10/13:35 FR 16047/16048 - Final ruling on previous list
74/01/04:39 FR 01171/01178 - Updated list
76/09/30:41 FR 43340/43358 - Updated list
76/10/27:41 FR 47180/47198 - Updated list to correct errors
77/07/14:42 FR 36420/36431 - Updated list
78/12/11:43 FR 58030/58048 - Updated list
79/05/21:44 FR 29565/29577 - Five year review
80/05/20:45 FR 33768/33781 - Updated list
83/07/27:48 FR 34182/34196 - Updated list
85/07/22:50 FR 29901/29909 - Five year review
Status - 2 HABITAT ASSOCIATIONS
HABITAT - TERRESTRIAL
TERRESTRIAL
COASTAL
LAND USE -
Mixed Rangeland
Lakes
Beaches
Sandy Areas other than Beaches
NATIONAL WETLAND INVENTORY CODES
NWI NWICLS NWIMOD NWISPEC
Riverine, intermittent RB1
Marine, intertidal BB2
Marine, intertidal BB1
Marine, intertidal
COMMENTS ON HABITAT ASSOCIATIONS -
The Laysan finch is endemic to the coral sand island of Laysan
in the Northwestern Hawaiian Islands (NWHI). Laysan Island itself is
part of the Hawaiian Islands National Wildlife Refuge (HINWR). The
finch also presently occurs outside of its historic range on several
islets at Pearl and Hermes Reef, an atoll northwest of Laysan also
in the HINWR, where they were introduced in 1967 by the U.S. Fish and
Wildlife Service (03). The Northwestern Hawaiian Islands Passerine
Recovery Plan (03) lists the present essential habitat for the Laysan
finch as: "All land area to the mean lower low water line on Laysan
Island (approximately 407 ha. (1,005 acres)). All land area on all
islands (nine) of Pearl and Hermes Reef to the mean lower low water
line (approximately 34 ha. (84 acres)."
The finch habitat at both Laysan Island and Pearl and Hermes Reef
encompasses all of the islands' plant associations, except that barren
flats or beach areas occupied only by Nama sandwicensis are reported
to be used infrequently by the finches (03,49). On Laysan, finches
seem especially associated with Scaevola and the bunchgrass Eragrostis
(03,08,15,21,22,26), although all plant associations are commonly
utilized for feeding, nesting, or cover (49). On Pearl and Hermes
Reef, finches have been reported to utilize Eragrostis, Solanum,
Tribulus, and Brassica (03,13,19).
Kramer (31) also reported that many finches, especially males,
entered empty shearwater burrows.
Five (32) or seven (33) plant associations have been described
for Laysan Island; these associations cover approximately 187 ha.
(463 acres) of the island (03). Approximately one-fifth of the
interior of Laysan is covered by a salt water lake (identified as
intertidal marine Nat. Wetlands Inventory type M2 in the keywords).
The major vegetation components on Laysan Island are the
following species: Boerhavia diffusa, Cenchrus echinatus, Sicyos sp.,
Conyza bonariensis, Cynodon dactylon, Cyperus laevigatus,
Eragrostis variabilis, Fimbristylis pycnocephala, Heliotropium
curassavicum, Ipomoea indica, Ipomoea pes-caprae, Nama sandwicensis,
Pluchea indica, Portulaca spp., Scaevola taccada, Sesuvium
portulacastrum, and Tribulus cisoides (03,33).
The vegetation components on some of the Pearl and Hermes Reef
islets include the following species: Sesuvium portulacastrum,
Eragrostis variabilis, Lepturus repens, Setaria verticillata,
Habitat Associations - 1 Boerhavia diffusa, Lepidium bidentatum, Tribulus cistoides, Solanum
nelsoni, Sicyos hispidus, Scaevola taccada, Cynodon dactylon, Brassica
campestris, Cornopus didymus, and Tournefortia argentea (03,19,50).
During the breeding season, clumps of Eragrostis seem to be
especially important as nesting sites (03,05,06,10,11,13,15,49). For
a more complete picture of habitat utilization, refer to the
narrative field "N-Biology" in the sections on Food Habits and
Reproductive Site Requirements. Laysan finches have also been seen
entering seabird burrows, but it is unclear what they might be getting
or doing there (39); possibly they are looking for invertebrates or
preying on eggs. Another possibility is that they are eating and/or
searching for edible roots, such as Boerhavia, which seems to be an
attractive food item. These roots are frequently exposed by seabird
burrow digging (49).
After a rain on Laysan Island, Laysan finches have been seen to
probe the bases of the Eragrostis clumps, presumably for fresh water
(03). At other times Sincock and Kridler saw them drink from the lake
(03); it should be noted that although the overall lake is hypersaline
the finches were probably taking water from some of the several fresh
water springs that border and feed the lake. In 1986, finches were
observed apparently drinking water from the lake next to the east side
"blowout;" this area is known to be fed by fresh water seep(s) (49).
If any of the plant associations (or on Laysan, the lake) were
disturbed, there could be adverse impacts on the ability of Laysan
finches to forage and find cover, or nesting sites.
Although they can tolerate high environmental temperatures,
Laysan finches have been demonstrated to have an environmental heat
tolerance similar to other passerines (07). Habitat temperature
extremes for Pearl and Hermes and Laysan probably approximate the
temperatures found on Midway 11-32 deg. C (52 deg. F to 89 deg. F).
The average annual temperature at Midway has been reported as 22 deg.
C (72 deg. F). During 1969 to 1974, a temperature range from 3-33
deg. C (38-92 deg. F) was recorded on Laysan (03). The average annual
precipitation from Midway has been reported to range from 73.6-149.8
cm) (29 to 59 inches) (03).
Laysan Island and Pearl and Hermes Reef average about 11 and
3 m (35 ft. and 10 ft.) in elevation, respectively (34).
Other specific environmental or life stage requirements such as
roosting and courtship display sites, per cent cover and vegetation
height in suitable habitat, precipitation, and moisture requirements
are not currently known.
Habitat Associations - 2 (DRAFT) - Food Habits
Species FINCH, LAYSAN
Species Id ESIS101041
Date 14 MAR 96
FOOD HABITS
TROPHIC LEVEL -
OMNIVORE
LIFESTAGE FOOD FOOD PART
General Roots/Tubers/Rhizomes-Herbaceous
General Evergreen Shrubs-Leaves/Twigs
General Evergreen Shrubs-Flowers/Fruit/Seed
General Fish
General Carrion
General Poaceae
General
General Forb Leaves/Stems
General Forb Flowers/Fruit/Seed
General Arthropods
General Aves
Food Habits - 1 (DRAFT) - Environment Associations
Species FINCH, LAYSAN
Species Id ESIS101041
Date 14 MAR 96
ENVIRONMENTAL ASSOCIATIONS
G = General A = Adult
LIM = Limiting RA = Resting Adult
J = Juvenile FA = Feeding Adult
RJ = Resting Juvenile BA = Breeding Adult
FJ = Feeding Juvenile P = Pupae
L = Larvae E = Egg
RL = Resting Larvae
FL = Feeding Larvae
LIFESTAGE ENVIRONMENTAL ASSOCIATIONS
G Aquatic Features: Springs [flowing]
G Coastal Features: Reefs
G Coastal Features: Sandy offshore islands
G Coastal Features: Vegetated offshore islands
G Terrestrial Features: Burrows
G
Environment Associations - 1 (DRAFT) - Life History
Species FINCH, LAYSAN
Species Id ESIS101041
Date 14 MAR 96
LIFE HISTORY
FOOD HABITS:
Laysan finches appear to be a classic example of an omnivore (03,
11,15,26). Their diet includes plant seeds, leaves, flowers, and
stems, as well as insects, eggs, and sometimes carrion.
Laysan finches on Laysan Island have been observed feeding on
leaves, stems, flowers, and seeds of Sesuvium portulacastrum (03,49);
leaves and seeds of Eragrostis variabilis (03,15,39); leaves, seeds,
stems, roots, and buds of Boerhavia diffusa (03,10,15,31,52); leaves,
stems, seeds, flowers, and seedlings of Tribulus cistoides
(03,10,15,31,39,49,52); leaves, apical buds, and seeds of
Portulaca spp. (03,15,33,39); seed heads and leaf stems of
Cenchrus echinatus (03,39,49); fruits, flower buds, fleshy leaves, and
fleshy stems of Scaevola taccada (03,19,49); flower buds and flower
centers of Ipomoea sp. (15,31,49); flower centers of Nicotiana tabacum
(15); inflorescences of the few coconut palms, Cocos nucifera (15);
and leaves of Tournefortia argentea (33). finches have been seen
eating flowers, seeds, and leaves of Conyza bonariensis (49); seed
heads of Cyperus laevigatus (49); roots and leaves of Heliotropium
curassavicum (49); fruit, flowers, and flower stalks of Sicyos spp.
(49); seed heads of Fimbristylis pycnocephala (49); and seed heads of
Cynodon dactylon (49). Seeds and leaves of Pluchea indica and leaves
of Chenopodium oahuense have each been observed being eaten on one
occasion (49).
On Pearl and Hermes Reef, the introduced population of Laysan
finches have additionally been reported to feed on seeds of the
introduced grass Setaria verticillata (03,13,38); seeds of Solanum
(03); seeds of Sonchus (13); seeds of Chenopodium (13); and blades of
Lepturus (13). They have been seen biting the soft stems of the wild
mustard Brassica (03).
The Laysan population has a greater variety of available food
sources (39) than the Pearl and Hermes population.
Most observers have recorded that Laysan finches will crack and
eat bird eggs (03,06,10,11,15,27), and especially tern eggs (03,27,36,
37). Conant believes that the smaller seabird eggs are at greater
risk, since the larger eggs probably cannot be cracked by the finches
(39), although finches will eat any egg which is open (15). Booby
(Sula spp.) and albatross (Diomedea spp.) eggs are eaten once they
have been opened, but have never been observed to initially be cracked
open by the finches themselves; rotten eggs seem to be as attractive
to the finches as fresh eggs (49). Warner (27) did not think that the
finches preyed heavily on Laysan duck eggs (Anas laysanensis, another
endangered species), although he did think it was a potential problem
prior to the initiation of breeding by sooty terns during spring (e.g.
May). Moulton and Weller (53) reported that 6 out of 7 active Laysan
duck nests which they located suffered at least some egg predation by
Laysan finches. However, they did not mention during what stage of
incubation the predation occurred, nor whether or not their own
presence flushed the hen off the nest, thus exposing the eggs.
Seabird eggs which have been reported to be Laysan finch prey include:
brown noddies (Anous stolidus) (03,15,35); sooty terns (Sterna
fuscata) (03,27); grey-backed terns (Sterna lunata) (03,06,15);
Life History - 1 (DRAFT) - Life History
Species FINCH, LAYSAN
Species Id ESIS101041
Date 14 MAR 96
bulwer petrels (Bulweria bulwerii) (15); wedge-tailed shearwaters
(Puffinus pacificus) (15); sooty storm-petrels (Oceandroma tristrami)
(15); white terns (Gygis alba) (15); and black noddies (Anous minitus)
(03,15). Predation on eggs is aggravated by the presence of humans
and human activity, because people may flush breeding birds from their
eggs and increase exposure time to possible finch predation (15,49).
However, bristle-thighed curlews (Numenius tahitiensis) and ruddy
turnstones (Arenaria interpres) have also been observed to eat seabird
eggs (15), and possibly they account for some of the reported egg
predation by finches (49).
Laysan finches are also reported to eat insects (03,10,11,35) and
larvae (10), including brine fly pupae, maggots, and the scale insects
found on Eragrostis (39). Sincock and Kridler (03) observed finches
eating the flesh and maggots in the flesh of a dead Laysan albatross
chick (Diomedea immutabilis). Morin (49) observed a finch eating the
flesh and/or maggots of a dead Bonin petrel chick (Pterodroma
hypoleuca). Other observers have reported that the flesh of dead
animals (e.g. seabirds, monk seals, and fish), is sometimes taken (10,
11,15,39,49).
Laysan finches have also been seen entering seabird burrows, but
it is unclear what they might be getting or doing there (39); possibly
they are looking for invertebrates or preying on eggs. Another
possibility is that they are eating and/or searching for edible roots,
such as Boerhavia, which seems to be an attractive food item. These
roots are frequently exposed by seabird burrow digging (49).
Captive Laysan finches in the Honolulu Zoo were reported to eat
sunflower and millet seeds, parakeet and canary seed mixes, raw and
hard-boiled eggs, "mockingbird food" diet, mealworms, oranges, apples,
bananas, papayas, and greens, such as Manoa lettuce (18).
After a rain on Laysan Island, Laysan finches have been seen to
probe the bases of the Eragrostis clumps, presumably for fresh water
(03). At other times Sincock and Kridler saw them drink from the lake
(03); it should be noted that although the overall lake is hypersaline
the finches were probably taking water from some of the several fresh
water springs that border and feed the lake. In 1986, finches were
observed apparently drinking water from the lake next to the east side
"blowout;" this area is known to be fed by fresh water seep(s) (49).
Conant (39) has seen them squeeze moisture from Portulaca leaves and
also grass stems; they have also been seen to squeeze moisture from
Heliotropium leaves (49). On a very few occasions, they have been
observed twirling Cynodon dactylon stems in their beaks, possibly for
moisture (49). During hot and dry weather, wild finches seemed to
actively seek fresh water, whereas this was not noticed during cool
and/or moist weather (49). In captivity, Laysan finches were never
seen to drink water (18).
There is certainly some seasonality in the food sources available
to the finches; seabird eggs are available during the species' various
breeding season, but are not in constant supply year-round. Also,
vegetation changes due to rain (or lack thereof) probably cause the
production of varying amounts of seeds and other plant parts (28), as
well as invertebrates.
No information giving food requirements or preferences for the
different life stages of wild Laysan finches could be located. In
Life History - 2 (DRAFT) - Life History
Species FINCH, LAYSAN
Species Id ESIS101041
Date 14 MAR 96
the Honolulu Zoo, Throp (18) reported that the captive Laysan finches
fed their young hatchlings animal food and egg for the first two
weeks; later other items were added to the diet.
HOME RANGE/TERRITORY:
The Laysan finch has not been reported to be territorial,
although at least a small nesting territory seems to be maintained
during the protracted breeding season (49). Kramer (31) and Conant
(19) reported that paired males drove off other males when approached.
Kramer also reported that many finches, especially males, entered
empty shearwater burrows; he thought this might be general exploration
of potential nesting area. However, it is more likely that this
behavior is simply a foraging behavior (49).
Feeding areas do not seem to be defended, although particularly
preferred individual food items (such as exposed Boerhavia root or an
open albatross egg) will sometimes be defended (49).
At least some finches seem to have habitual foraging areas (49).
PERIODICITY:
Laysan finches are apparently a diurnal species. The reported
observation of finches were made during daytime hours and no unusual
patterns, either daily or seasonally, were noted (03,15,19). During a
February to August visit in 1986, finches were never seen before dawn
or after dusk (49).
MIGRATION PATTERNS:
Laysan finches are a non-migratory species (08). They are
endemic to Laysan Island (26), although a small introduced population
now lives on Pearl and Hermes Reef.
COVER/SHELTER REQUIREMENTS:
There have not been any studies or observations of Laysan finches
which specifically define cover/shelter requirements.
Although no one has reported on roosting requirements, Laysan
finches must need some sort of nocturnal roosting sites. Nocturnal
roosting behavior in captivity was described for a closely related
species, the Nihoa finch, (Telespyza ultima) (35). These captive
Nihoa finches used branches, cement blocks or grass tussocks. On
Laysan, potential perch sites with accumulations of droppings below
them have been seen within Eragrostis clumps; these are possibly
nocturnal Laysan finch roosting sites, since no other passerines occur
on Laysan (49).
In the wild on Laysan, the bunchgrass Eragrostis seems to provide
much of the cover needed by the Laysan finch, as well as nesting and
feeding sites (26). Eragrostis, as well as Pluchea and Scaevola, are
frequently used by fledgling finches as cover (49). However, the
relative importance of Eragrostis as cover/shelter, in relation to the
other vegetation, has not been studied.
On Pearl and Hermes Reef, the introduced Laysan finch population
uses a variety of plants for cover and shelter; Eragrostis is not as
abundant there as it once was (19).
REPRODUCTIVE SITE REQUIREMENTS:
Life History - 3 (DRAFT) - Life History
Species FINCH, LAYSAN
Species Id ESIS101041
Date 14 MAR 96
Laysan finch nests on Laysan are almost always located in clumps
of the bunchgrass Eragrostis (03,05,06,10,11,13,15,49,52), although
prior to the devegetation of Laysan Island in the early 1900's, bushes
(Chenopodium) were also used (05,06,10,11,15). In 1986, a single nest
with eggs was found on the ground underneath dense Cyperus laevigatus
(49). The introduced population of Laysan finches on Pearl and Hermes
Reef also in the past used primarily Eragrostis clumps as nest sites,
but a few nests were reported in Solanum, Setaria, Sonchus, and
underneath boards (03,13). However, only one of the approximately 90
nests found by Conant (19) at Pearl and Hermes in 1984, 1985, and 1986
was in Eragrostis, which has decreased significantly in abundance
since the 1960's.
On Laysan, nests are usually placed in the middle of the
Eragrostis tussock, where they are partially or (more often)
completely hidden from view (05,15). Clumps of Eragrostis near old
Scaevola bushes have been reported to be favored sites (15). On
Laysan, whenever possible, finches seem to prefer to hide the nest in
the densest part of the Eragrostis clump; this probably provides some
thermo-regulatory protection from extremes of wind, rain, and sun. It
also may provide some degree of protection from other finches,
although it is uncertain whether or not they prey on each other's
nests (49).
The nest cup itself is reportedly made of grass, small twigs, and
rootlets (05,10,11,15). For seven nests reported in Ely and Clapp
(15), the mean nest height above the ground was 32.3 cm (13.1 in.),
and ranged from 10-43 cm (4-17 in.). The mean bowl depth and width
for the same seven nests were 5.1 and 7.4 cm (2.1 and 2.9 in.),
respectively.
In captivity, Laysan finches reportedly did not nest successfully
until the nest cup could be concealed in a heavy bunch of long-leaved,
broad-leaved grass (18).
No information on display or nursery area requirements was
located in the literature reviewed.
REPRODUCTIVE CHARACTERISTICS:
Only one reference was located which provided an estimate of
age-at-first-breeding in Laysan finches. Sincock and Kridler (03)
banded a Laysan finch at Pearl and Hermes Reef on March 23, 1968,
which was reported to be less than a year old. On February 10, 1969,
the same bird was found on a nest with two downy young and one egg;
this information places her approximate age at the time somewhere
between 12 and 22 months.
There was no information located during a literature review as
to minimum and maximum breeding ages.
Many observers have reported on the breeding phenology of the
finches (03,10,11,13,15,36,40,41), usually during short visits. It
appears that May to July is (at least sometimes) the peak time for
nesting (03,10,15,36). Generally, courtship behavior begins in March
and April (31,39), followed by May nest building (42) and egg laying
(03,06,36) and young in June (03,10,11).
On Laysan, begging young have been seen as late as September (03,
15,41) and as early as April (49). On Pearl and Hermes Reef, nests
with eggs and young have been found in February, March, April, May,
Life History - 4 (DRAFT) - Life History
Species FINCH, LAYSAN
Species Id ESIS101041
Date 14 MAR 96
June, and August (13,19). Begging young have been seen as early as
March (19). There is an extended breeding season, since breeding
activities have been recorded from February to September (03).
Conant (40) suggested that the active nests she saw on Pearl and
Hermes Reef in June, July, and August of 1984 and 1985 were possibly
renests due to the large number of older fledglings and independent
young-of-the-year present.
The average number of reproductive periods per year is unknown,
although in 1986 one wild banded female laid at least two complete
clutches (49). (A single chick fledged from the first clutch, but the
chicks from the second clutch died before fledging, possibly due to
the poor weather.)
Laysan finches establish a pair bond (31,39), and are apparently
monogamous. Duration of pairing is unknown.
The most common clutch size is apparently three eggs (05,06,18,
35), although on Laysan a four egg clutch is not unusual (49). The
clutch size can vary from one to five (05,06,11,35,49). There is
reportedly great variation in the color and especially the size of the
eggs (05,06,49).
Based on captive Laysan finch observations, the reported
incubation period is approximately 16 days (18), but might be as short
as 12 to 14 days (35). For wild eggs, 16 days seems to be the usual
incubation length. Eggs are usually laid one-a-day until the clutch
is complete, and incubation by the female seems to begin when the
first egg is laid; the eggs hatch asynchronously and in the order of
laying. It may take up to 3 days for all the eggs to hatch; this
causes noticeable size differences between some or all of the chicks
(49).
PARENTAL CARE:
No significant studies have been conducted on parental care in
Laysan finches, although a small amount of anecdotal information is
available.
The young of Laysan finches are altricial (18), like all
passerines.
In captivity, only the female Laysan finch has been reported to
incubate eggs and brood young; the male, however, does conduct nest
defense and the majority of the feeding (18). These roles appear to
be the same in wild finches as well (49).
In captive Laysan finches, one clutch hatched on July 12, 1966,
and the young fledged on August 3 (approximately 23 days), and were
independent by September (approximately 52 days after hatching). In
another captive nest, chicks were reported to fledge in about 26 days
(18). Unpublished data for wild nests on Laysan in 1986 suggests that
chicks probably fledge sometime between 23 and 28 days of age (49).
These are long nestling periods for a passerine bird.
In wild Laysan finches, the duration of the family bond is not
well documented. On Laysan in 1986, one banded fledgling from an
April clutch was seen begging from and following both banded parents
on June 11, when it was 46 or 47 days old (49); this is very similar
to the 52 days reported above for a captive bird (18). Woodside (41)
reported that in September 1961 he saw several immatures still being
fed or following their parents. He also reported that he found no
Life History - 5 (DRAFT) - Life History
Species FINCH, LAYSAN
Species Id ESIS101041
Date 14 MAR 96
active nests. It is thought that the peak nesting time is usually May
to July (03,10,15,36), so it appears likely that there is some
duration to the family bond.
POPULATION BIOLOGY:
The current limiting factors for Laysan finches are probably food
supply, weather, and possibly nesting sites. This conclusion is based
on the amazing recovery of this species from an estimated low of 100
in 1923 after Laysan Island was devegetated (03,15,22). The Laysan
population is now thought to be relatively stable at at least 10,000
(22); all of these birds occupy approximately only 187 ha. (463 acres)
of habitat. The Laysan population is probably at or near to the
carrying capacity (26); however, the carrying capacity probably
changes from year to year due to variations in weather and plant
productivity.
In 1976, an extremely high population estimate of 20,802 birds
was reported on Laysan (03,30); this represents about 45 Laysan
finches per acre of vegetated habitat.
The largest known population increase on Laysan occurred between
August 1975 and August 1976, when the population estimate went from
about 14,786 +/- 20 percent to 20,802 +/- 14 percent. For the
introduced Laysan finches on Pearl and Hermes Reef, the largest
increase was between June 1972 and March 1973 when the estimate rose
from 373 to 730. The latter represents a minimum increase of 1.9
young per pair (assuming all of the 1972 birds were adults and had
bred). Sincock and Kridler (03) thought that 730 birds was about the
carrying capacity of Southeast Island in Pearl and Hermes Reef; that
represents about 23 birds per acre of habitat.
Pre-breeding, breeding, and post-breeding censuses conducted on
Laysan in 1986 indicated that different population estimates may be
made during different stages of the same breeding season, possibly due
to changes in behavior and conspicuousness. For example, during the
May count when many females were laying or incubating eggs, the count
was noticeably lower than both the pre-breeding and post-breeding
estimates (49).
The only longevity information which was located described a
recaptured wild Laysan finch which had been banded 63 months
previously; the bird was at least 5 years and 3 months old (03).
However, one wild, banded, twelve-year-old Nihoa finch (Telespyza
ultima), a close relative of the Laysan finch, was recaptured in 1980;
it had originally been banded in 1969, and was judged to be at least
a year old in 1969 (19). It is probably that Laysan finches have
similar longevity potential.
No information on survival rates, mortality rates, sex ratios,
recovery potential, or turnover rate was located during the
literature review.
SPECIES INTERRELATIONSHIPS:
Laysan finches will crack and eat eggs of other birds, and
therefore sometimes function as a predator (03,06,10,11,15,27). They
appear especially fond of tern eggs (03,27,36,37). Conant believes
that the smaller seabird eggs are at greatest risk, since the larger
eggs probably cannot be cracked by the finches (39), although finches
Life History - 6 (DRAFT) - Life History
Species FINCH, LAYSAN
Species Id ESIS101041
Date 14 MAR 96
will eat any egg which is open (15). Warner (27) did not think that
the finches were preying heavily on Laysan duck eggs (Anas
laysanensis, another endangered species), although he did think it was
possibly a problem prior to the arrival of the sooty terns for
breeding during spring. Moulton and Weller (53) reported that 6 out
of 7 active Laysan duck nests which they located suffered at least
some egg predation by Laysan finches. However, they did not mention
when the predation occurred, and whether or not their own presence
flushed the hen off the nest, thus exposing the eggs. They also
concluded that Laysan finches were probably a serious problem only
when they were abundant or when human disturbance caused ducks to
desert their nests. Seabird eggs which have been reported to be
actively preyed upon by Laysan finches include: brown noddies (Anous
stolidus) (03,15,35); sooty terns (Sterna fuscata) (03,27);
grey-backed terns (Sterna lunata) (03,06,15); bulwer petrels (Bulweria
bulwerii) (15); wedge-tailed shearwaters (Puffinus pacificus) (15);
sooty storm-petrels (Oceanodroma tristrami) (15); white terns (Gygis
alba) (15); and black noddies (Anous minutus) (03,15).
The presence of humans aggravates egg predation by the finches
because humans may flush breeding adult seabirds from their eggs, thus
exposing them to finches (15). Also, bristle-thighed curlews
(Numenius tahitiensis) and ruddy turnstones (Arenaria interpres) have
been observed eating seabird eggs (15), and possibly account for some
of the reported egg predation by Laysan finches (49).
Laysan finches are also suspected to sometimes prey
intraspecifically on other Laysan finch eggs (19), although this has
never been documented.
Apparently finches are themselves infrequently a prey item.
Walker (37) reported seeing a curlew carrying a freshly killed Laysan
finch, which he speculated the curlew had killed. This is probably
not a significant source of mortality.
Laysan finches are true omnivores. Their diet includes many
parts of most plants found on Laysan; their overall impact in
regulating the vegetation on Laysan Island is unknown.
OTHER LIFE HISTORY DESCRIPTORS:
Over the years, many population estimates have been reported for
Laysan finches on Laysan (03,15,30,36,41,42,43,44,45,46), ranging from
a low of 100 or less in 1923 to a high of 20,802 in 1976. Since the
introduction of Laysan finches on Pearl and Hermes Reef in 1967,
population estimates have also been made, which have ranged from 107
to 730 (03,22,40,45,46).
Like many insular species, Laysan finches appear to be quite
fearless, and are easy to catch with a hand net (10) or simple traps
(49). Observers frequently comment on their "tameness" (26,35).
The Laysan finch has a sweet song (10,49), which has been
described as canary-like (14) or linnet-like (06); Laysan finches have
also been said to have a clear metallic note (02).
Life History - 7 (DRAFT) - Management Practices
Species FINCH, LAYSAN
Species Id ESIS101041
Date 14 MAR 96
MANAGEMENT PRACTICES
RESULT MANAGEMENT PRACTICE
Beneficial Controlling/Restricting Boating Activities
Beneficial Restricting/regulating human disturbance of populations
Beneficial Controlling/Removing Nonnative Vegetation
Beneficial Stocking captive-reared wild-strain animals
Beneficial Disease Control Measures
Beneficial Controlling/Removing Invertebrates
Beneficial Controlling/Removing Exotic Vertebrates
Adverse Incidental Capturing/Killing
Existing Incidental Capturing/Killing
Adverse Collecting
Existing Collecting
Adverse
Existing
Adverse Food Supply Reduction
Existing Food Supply Reduction
Adverse Disease
Existing Disease
Adverse Parasites
Existing Parasites
Adverse Predation
Existing Predation
Adverse Soil compaction by heavy equipment in mine areas
Existing Soil compaction by heavy equipment in mine areas
Adverse Competition
Existing Competition
Adverse Exotic/Feral/Introducted Species
Existing Exotic/Feral/Introducted Species
Adverse Vegetation Composition Changes
Existing Vegetation Composition Changes
Adverse Fire
Existing Fire
COMMENTS ON MANAGEMENT PRACTICES -
The Laysan finch is endemic to Laysan (or obsoletely,
"Moller") Island, of which approximately 187 ha. (463 acres) is
suitable finch habitat (03). The small size and fragility of the
historic range is one of the main factors which has been used in the
determination of the Laysan finch's endangered status (22).
Beginning in 1890, Laysan Island was variously exploited due to
guano mining, the introduction of rabbits and guinea pigs, Japanese
feather hunters, and human habitation (03,15). Due to the lack of
predators, the rabbit population exploded, and had largely devegetated
the island by 1923. The lack of adequate food and cover, coupled with
sandstorms, caused the extinction of two of the three endemic land
bird species on Laysan, as well as the endemic Laysan rail, and some
endemic plant species (03,15). The last rabbits were exterminated by
the Tanager Expedition in 1923. The Laysan finch somehow survived the
devastation, probably due to its omnivorous eating habits (14),
Management Practices - 1 (DRAFT) - Management Practices
Species FINCH, LAYSAN
Species Id ESIS101041
Date 14 MAR 96
although it has been estimated that the finch population on Laysan
dropped to as few as 3 dozen to 100 birds (03,22). Amaden, 1952 (52)
reports that the Laysan finch on Laysan became extinct due to the
rabbit devegetation, but was successfully reintroduced from the (now
extirpated) introduced Laysan finch population on Midway Atoll. This
report is being pursued for verification (49)).
In the late 1800's and early 1900's, it was also reported that
Laysan finches were captured on Laysan by passing ships and brought to
Honolulu as cage birds (02,04,10). Henshaw reported that the captive
birds did not survive long in Honolulu (04).
Another past impact in the Northwestern Hawaiian Islands has been
unauthorized military activity on Laysan (23) and other islands (03),
although since the early 1960's this has not been reported as a
problem. This may have resulted in some incidental mortality of
finches. Unfortunately, some of the non-native weed species in the
Northwestern Hawaiian Islands, including Laysan, probably arrived
there during military activities, transported on equipment and
clothing.
Laysan finches were transported to and released on Midway Atoll
in the 1890's and the early part of this century, and they became
established there (03,09,10,15,24,25); however, the finches apparently
could not survive the accidental introduction of rats onto Midway
during World War II, and the Laysan finches on Midway disappeared
entirely by the mid 1940's (03,10,15,18).
The factors which presently threaten the Laysan finch population
on Laysan are:
- human activity (03)
- the introduction of pest plants (which may replace food
sources) or non-native animals (e.g. predators, competitors,
or insect (disease vectors) via natural means and/or
unintentional or intentional human influence (03,27,28)
- unauthorized and emergency landings, especially those which
may result in exotic introductions (see above)
- fire (03)
- avian diseases, which could arrive either naturally or due
to human activities (03,26). Laysan finches in captivity
have been shown to be extremely susceptible to bird diseases
(48). This is probably due to the natural isolation of
their historic range. They are susceptible to common
infections such as Staphylococcus and Poxvirus avium (avian
pox) (03,18,48).
- weather (e.g. hurricanes or droughts) which destroys habitat
and decreases food availability (03,29).
Future threats to Laysan finches in the wild are the same as the
present threats which were listed above, except that unauthorized
landings will undoubtedly increase if the fishing industry expands in
the waters around the Northwestern Hawaiian Islands. An increase in
unauthorized landings would likely increase the accidental
introduction of pest plants and animals (e.g., due to seeds on
clothing, rats or insects on landed boats). Also, as the number of
pest plants and insects, and also avian diseases, increase throughout
Management Practices - 2 (DRAFT) - Management Practices
Species FINCH, LAYSAN
Species Id ESIS101041
Date 14 MAR 96
all the Hawaiian Islands in the future, the frequency of "natural
(e.g. wind- or bird-borne) dispersal of non-native pests or diseases
to remote islands such as Laysan Island will likely increase, and more
intensive monitoring will be necessary.
In the case of the Laysan finch, the numerical abundance of the
species is less relevant to its endangered status than is its limited
(approx. 187 ha. (463 acres)) native range and fragile ecosystem
(03,22), and the documented fluctuations in population numbers (03).
APPROVED PLAN:
U.S. Fish and Wildlife Service. 1984. Northwestern Hawaiian Islands
Passerines Recovery Plan. U.S. Fish and Wildl. Serv., Portland, OR.
67 pp.
This hardy little finch, a relect surviving from a time before
the first Polynesian settlement of the main Hawaiian Islands, now
flourishes on Laysan Is. and Pearl and Hermes Reef, two outposts at
the margin of its once much greater range. These populations exist at
astonishingly high densities, a tribute to the bird's versatility at
exploiting numerous food resources and to a total absence of
predators and major avian diseases on the bird's atoll habitat. The
isolated island environment that fostered the evolution of this
competitive adaptability also shielded the birds from mammalian
predation and mosquito-borne diseases, two sources of mortality
against which Laysan finches have lost all effective defensives.
Protecting Laysan finches from these serious outside threats is the
principal goal of the Northwestern Hawaiian Islands Passerines
Recovery Plan. Proposed recovery actions include:
1) preventing unauthorized access (principally by boat) to
Laysan Is. and Pearl and Hermes Reef,
2) preventing establishment of alien organisms (plant and
animal) and setting up a plan to monitor the islands and to
eliminate such organisms should they reach the islands,
3) preventing the outbreak of avian disease,
4) monitoring the species and its habitat, and
5) establishing a captive flock of Laysan finches, should some
calamity befall their present, habitat.
Further introduction of finches to other Leeward Islands was not
considered by the plan, though Lisianski Is. would be a suitable
choice for establishing an experimental flock of Laysan finches.
Maintaining these finches on only two atolls exposes them to a greater
risk of extinction.
Ongoing recovery actions are: (1) review of the Hawaiian Islands
NWR Master Plan, (2) studies of the Laysan finch by University of
Hawaii, and (3) recent population surveys.
Management Practices - 3 (DRAFT) - References
Species FINCH, LAYSAN
Species Id ESIS101041
Date 14 MAR 96
References
***** REFERENCES FOR ALL NARRATIVES EXCEPT N-OCCURRENCE *****
01 Banks, R.C. and R.C. Laybourne. 1977. Plumage sequence and
taxonomy of Laysan and Nihoa finches. Condor 79(3):343-348.
02 Wilson, S.B. 1890. On a new finch from Midway Island, North
Pacific. Ibis 33(2):339-341.
03 Sincock, J.L. and E. Kridler. 1977. The extinct and endangered
endemic birds of the Northwestern Hawaiian Islands. Unpubl. ms.
U.S. Fish and Wildl. Serv., Honolulu, HI. 111 pp.
04 Henshaw, H.W. 1902. Birds of the Hawaiian Islands; being a
complete list of the birds of the Hawaiian possessions, with notes
on their habits. Thos. G. Thrum, Honolulu, HI Terr. 146 pp.
05 Fisher, W.K. 1903. Birds of Laysan and the Leeward Islands.
Bull. U.S. Fish. Comm. for 1903. Vol. 23(3):769-807.
06 Fisher, W.K. 1903. Notes on the birds peculiear to Laysan Island,
Hawaiian Group. Auk 20(4):384-397.
07 Weathers, W.W. and C. VanRiper. 1982. Temperature regulation in
two endangered Hawaiian honeycreepers: the Palila (Psittirostra
bailleui) and the Laysan finch (Psittirostra cantans). Auk 99:667-
674.
08 American Ornithologists' Union. 1983. Checklist of North American
birds. 6th ed. Allen Press, Inc., Lawrence, KS. 877 pp.
09 Bryan, W.A. 1912. The introduction and acclimization of the
yellow canary on Midway Island. Auk 29(3):339-342.
10 Munro, G.C. 1960. Birds of Hawaii. Rev. ed. C.E. Tuttle Co.,
Inc., Rutland, VT. 192 pp.
11 Rothschild, (L.) W. 1893-1900. The avifauna of Laysan and the
neighboring islands: with a complete history to date of the birds
of the Hawaiian Possessions. R.H. Porter, 7 Princes St., London.
3 parts. 320 pp.
12 Bryan, W.A. 1916. An undescribed species of Drepanididae on Nihoa
Hawaiian Group. Auk 33:49-52.
13 Amerson, A.B., et al. 1974. The natural history of Pearl and
Hermes Reef; Northwestern Hawaiian Islands. Atoll Res. Bull., No.
174. Smithsonian Inst., Wash. D.C. 306 pp.
14 Berger, A.J. 1972. Hawaiian birdlife. The Univ. Press of HI,
Honolulu. 270 pp.
15 Ely, C.A. and R.C. Clapp. 1973. The natural history of Laysan
Island, Northwestern Hawaiian Islands. Atoll Res. Bull., No. 171.
Smithsonian Inst., Wash. D.C. 361 pp.
16 Raikow, R.J. 1976. Pelvic appendage myology of the Hawaiian
honeycreepers (Drepanididae). Auk 93:774-792.
17 Raikow, R.J. 1977. Pectoral appendage myology of the Hawaiian
honeycreepers (Drepanididae). Auk 94:331-342.
18 Throp, J. 1970. The Laysan finch bill in the Honolulu Zoo.
'Elepaio 31(4):31-34.
19 Conant, S. 1986. Pers. comm. Dept. of Gen. Sci., Univ. of HI at
Manoa, Honolulu. 96822.
20 Banko, W.E. 1979. History of endemic Hawaiian birds specimens in
museum collections. CPSU/UH Avian History Rept. 2. Coop. Nat.
Park Res. Studies Unit, UH Manoa, Dept. of Botany, Honolulu.
References - 1 (DRAFT) - References
Species FINCH, LAYSAN
Species Id ESIS101041
Date 14 MAR 96
80 pp.
21 Marshall, D.B. 1964. Treasure islands-of wildlife. Audubon Mag.
66:160-165.
22 U.S. Fish and Wildlife Service. 1985. Recovery news: plan
approved for three songbirds of the Northwestern Hawaiian Islands.
Endangered Species Tech. Bull. 10(2):8-10.
23 Woodside, D.H. and R.J. Kramer. 1961. A report on a survey trip
to the Hawaiian Islands National Wildlife Refuge, Unpubl. rept.
HI Dept. of Fish and Game, Honolulu. 31 pp.
24 Wetmore, A. 1925. Bird life among lava rock and coral sand. Nat.
Geographic Mag. 48(1):76-108.
25 Mearns, E.A. 1909. A list of birds collected by Dr. Paul Bartsch
in the Phillipine Islands, Borneo, Guam, and Midway Island, with
descriptions of three new forms. In the Proc. of the U.S. Nat.
Mus. 36, No. 1683:463-478.
26 U.S. Fish and Wildlife Service. 1984. Recovery plan for the
Northwestern Hawaiian Islands passerines. U.S. Fish and Wildl.
Serv., Portland, OR. 66 pp.
27 Warner, R.E. 1963. Recent history and ecology of the Laysan Duck.
Condor 65(1):3-23.
28 Kramer, R.J. and J.W. Beardsley. 1962. A report on a survey trip
to the Hawaiian Islands National Wildlife Refuge, Entomological
report. Unpubl. HI Dept. of Fish and Game, Honolulu. 17 pp.
29 Kramer, R.J. 1963. A report on a survey trip to the Hawaiian
Islands National Wildlife Refuge, Unpubl. HI Dept. of Fish and
Game Honolulu. 26 pp.
30 Sincock, J. 1983. Sampling techniques and analysis: Laysan finch
and Laysan Duck. Unpubl. (Corresp. to Peter Stine). U.S. Fish
and Wildl. Serv., Honolulu, HI.
31 Kramer, R.J. 1959. Some notes and observations on Laysan Island
fauna, Unpubl., HI Dept. of Fish and Game, Honolulu. 8 pp.
32 Lamoureux, C. 1963. The flora and vegetation of Laysan Island.
Atoll Res. Bull. 97:1-14.
33 Newman, A. 1986. Pers. comm. Kokohead, Honolulu, HI 96816.
34 University of Hawaii, Dept. of Geography. 1983. Second Ed. Atlas
of Hawaii. Univ. of HI Press, Honolulu. 238 pp.
35 Berger, A.J. 1981. Hawaiian birdlife. 2nd Ed. The Univ. Press
of HI, Honolulu. 260 pp.
36 Dill, H.R. and W.A. Bryan. 1912. Report of an expedition to
Laysan Island in 1911. U.S. Dept. Agric. Biol. Surv. Bull. 42
30 pp.
37 Walker, R.L. 1961. Excerpts from Leeward Island journal, Unpubl.
HI Dept. of Fish and Game, Honolulu. 4 pp + 9 attachments.
38 Conant, S. 1984. Trip report to Necker Island and Pearl and
Hermes Reef, Summer 1984. Unpubl. Dept. of Gen. Sci., Univ. of HI,
at Manoa, Honolulu. 3 pp.
39 Conant, S. 1985. Trip report-expedition to Laysan Island, Unpubl.
Dept. of Gen. Sci., Univ of HI at Honolulu. 5 pp.
40 Conant, S. 1985. Trip report-expedition to Pearl and Hermes Reef
and other Northwestern Hawaiian Islands, Unpubl. Dept. of Gen. Sci.
Univ. of HI at Manoa, Honolulu. 4 pp.
41 Woodside, D.H. A report on a trip to the Laysan Island, Unpubl.
HI Dept. of Fish and Game, Honolulu. 42 pp.
References - 2 (DRAFT) - References
Species FINCH, LAYSAN
Species Id ESIS101041
Date 14 MAR 96
42 Fefer, S. 1985. Summary of Hawaiian Islands NWR endangered
species surveys conducted in 1985 for Endangered Species Technical
Bulletin. Unpub. memo. U.S. Fish and Wildl. Serv., Honolulu, HI
2 pp.
43 Brock, V.E. 1951. Laysan Island bird census. 'Elepaio 12(3):
17-18.
44 U.S. Fish and Wildlife Service. 1977. Hawaiian and Pacific
Islands National Wildlife Refuge Complex narrative rept. CY 1977.
Unpubl. Honolulu, HI.
45 Fefer, S. 1983. Trip report: biological investigations: Midway,
Laysan, Lisianski and Pearl and Hermes Reef. Unpubl. U.S. Fish
and Wildl. Serv. Memo, Honolulu, HI. 12 pp.
46 Sincock, J. 1978. 1978 endangered species population data for
Leewards. Unpubl. (Corresp. to Barry Brady). U.S. Fish and
Wildl. Serv., Honolulu, HI.
47 Olson, S.L. and H.F. James. 1982. Prodromus of the fossil
avifauna of the Hawaiian Islands. Smithsonian Contrib. to Zoo.
#365. Smithsonian Inst. Press, City of Wash. 59 pp.
48 van Riper, S. and C. van Riper. 1985. A summary of known
parasites and diseases recorded from the avifauna of the Hawaiian
Islands. In Hawai'is terrestrial ecosystems preservation and
management. CPSU/UH, Honolulu. 584 pp.
49 Morin, M.P. 1986. Pers. comm. Dept. of Zool., Univ. of HI,
Honolulu. 96822.
50 Herbst, D.R. and W.L. Wagner. In press. Alien plants on the
Northwestern Hawaiian islands. Paper presented at the 6th Conf. in
Nat. Sci., Hawaii Volcanoes Nat. Park, HI. June 10-13, 1986.
51 Clark, H.L. 1912. Notes on the Laysan finch. Auk 29:166-168.
52 Amadon, D. 1950. The Hawaiian honeycreepers (Aves, Drepaniidae).
Bull. Am. Mus. Nat. Hist. 95:155-262.
53 Moulton, D.W. and M.W. Weller. 1984. Biology and conservation of
the Laysan Duck (Anas laysanensis). Condor 86(2):105-117.
***** REFERENCES FOR N-OCCURRENCE NARRATIVE ONLY *****
01 Banks, R.C. and R.C. Laybourne. 1977. Plumage sequence and
taxonomy of Laysan and Nihoa finches. Condor 79(3):343-348.
02 Sincock, J.L. and E. Kridler. 1977. The extinct and endangered
endemic birds of the Northwestern Hawaiian Islands. Unpubl. manus.
U.S. Fish and Wildl. Serv., Honolulu, HI. 111 pp.
03 U.S. Fish and Wildlife Service. 1984. Recovery plan for the
Northwestern Hawaiian Islands passerines. U.S. Fish and Wildl.
Serv., Portland, OR. 66 pp.
04 Conant, S. 1984. Trip report to Necker Island and Pearl and
Hermes Reef, Summer 1984. Unpubl. rept., Dept. of Gen. Sci.
Univ. of Hawaii Manoa, Honolulu. 3 pp.
05 Conant, S. 1985. Trip report-expedition to Pearl and Hermes Reef
and other Northwestern Hawaiian Islands, 12 June to 26 July, 1985.
Unpubl. rept., Dept. of Gen. Sci., Univ. of HI Manoa, Honolulu.
4 pp.
06 Bryan, W.A. 1912. The introduction and acclimization of the
yellow canary on Midway Island. Auk 29(3):339-342.
References - 3 (DRAFT) - References
Species FINCH, LAYSAN
Species Id ESIS101041
Date 14 MAR 96
07 Munro, G.C. 1960. Birds of Hawaii. Rev. ed. C.E. Tuttle Co.,
Inc., Rutland, VT. 192 pp.
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10 Mearns, E.A. 1909. A list of birds collected by Dr. Paul Bartsch
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References - 4