(DRAFT) - Taxonomy
Species FINCH, NIHOA
Species Id ESIS101042
Date 14 MAR 96
TAXONOMY
NAME - FINCH, NIHOA
OTHER COMMON NAMES - FINCH, NIHOA; FINCHBILL, NIHOA; FINCH-BILL, NIHOA; FINCH, LAYSAN; HONEYCREEPER; TELESPIZA and NIHOA
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 - ULTIMA,
SCIENTIFIC NAME - TELESPYZA ULTIMA
AUTHORITY -
TAXONOMY REFERENCES -
COMMENTS ON TAXONOMY -
Nihoa Finch
Telespyza ultima Bryan, 1917
KINGDOM: Animal GROUP: Bird
PHYLUM: Chordata CLASS: Aves
ORDER: Passeriformes FAMILY: Fringillidae
The Nihoa finch (Telespyza ultima Bryan 1917) resembles the
closely related Laysan finch (Telespyza cantans) in many respects,
including plumage (01,08,09,10,37). In fact, Nihoa finches have been
referred to as a "dwarfed" form of the Laysan finch (01). In adult
males, the head, neck, back, throat, breast, and secondary edgings are
yellow; the flanks, lower back, and rump are gray, and there is a gray
band between the neck and the mid-back. In adult females, the sides
of the head, the throat, breast, and secondary edgings are yellow; the
head and back feathers are edged with yellow and steaked with black.
The back is also streaked. The flanks are drab gray. Both sexes have
whitish abdomens (08,10).
Unlike Laysan finches, Nihoa finches acquire adult plumage in a
single year (10). Nihoa finches are also smaller than Laysan finches
(01,07,10,36), and are reported to have less obvious sexual
dimorphism. In addition, immature Nihoa finches are darker and more
Taxonomy - 1 (DRAFT) - Taxonomy
Species FINCH, NIHOA
Species Id ESIS101042
Date 14 MAR 96
extensively streaked than immature Laysan finches (10).
The weights of six captive Nihoa finches ranged between 21 and 28
grams (08).
When the Nihoa finch was first described by Bryan (01), he
clearly recognized its relationship to the Laysan finch; consequently,
he assigned it to the same genus (01,11). Unfortunately, he as well
as others (13), misspelled the genus as Telespiza (as opposed to
Wilson's original spelling of Telespyza) and subsequently both of
these spellings appear frequently in the literature. Telespyza is now
accepted as the correct spelling (12).
Bryan considered that this species was very likely to be the last
native Hawaiian passerine discovered (01), and thus he named it ultima
(as it turned out, he was mistaken).
The Nihoa finch has sometimes been considered a subspecies: e.g.
Telespiza cantans ultima or Psittirostra cantans ultima (02,07,12,36,
37). However, Banks and Laybourne (10) reviewed the Laysan and Nihoa
finches and concluded that they should be classified as distinct
species, and not subspecies, based on sufficient differences between
them such as age and sexual dimorphism, plumage sequence, size and
color differences.
In some older literature, the Nihoa finch was placed in the genus
Psittirostra (02,03,04,05,36), which includes another heavy-billed
honeycreeper, the 'O'u (Psittirostra psittacea). 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.
Other common names for the Nihoa finch which were found in the
literature are: Nihoa finchbill (02), Nihoa finch-bill (Western
Hemisphere Convention Annex, 1967) Laysan finch (03,37), Nihoa
Telespiza (06), and honeycreeper (50 CFR 17.11).
Nihoa finches, along with the other endemic 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 (12). This
reclassification is partly based on the work done by Raikow on
Hawaiian honeycreeper myology (14,15).
Photos of Nihoa finches can be seen in Sincock and Kridler, 1977
(02); Berger, 1972 (04); Berger, 1987 (08); and the Endangered Species
Technical Bulletin (16).
Both Clapp et al., 1977 (17) and Banko, 1979 (05) have compiled
location lists for Nihoa finch specimens; the latter is a more current
and complete list. Banko lists 73 specimens in 8 museums. He reports
that the type specimen and three paratypes are held at the Los Angeles
County Museum of Natural History in Los Angeles, as G. Willett
reported in 1945 (35).
Taxonomy - 2 (DRAFT) - Status
Species FINCH, NIHOA
Species Id ESIS101042
Date 14 MAR 96
STATUS
Coded Status
E: Federal Endangered
COMMENTS ON STATUS -
U.S. STATUSES AND LAWS:
The Nihoa finch (Telespyza ultima) 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: Dept. of Land and Natural Resources
STATE STATUTE: Hawai'i Revised Statutes, Chapter 195D.
INTERNATIONAL STATUSES, TREATIES, AND AGREEMENTS:
Status - 1 (DRAFT) - Status
Species FINCH, NIHOA
Species Id ESIS101042
Date 14 MAR 96
The Nihoa 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 29566/29577 - Notice of status 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 - Notice of Review
Status - 2 HABITAT ASSOCIATIONS
HABITAT - TERRESTRIAL
TERRESTRIAL
COASTAL
LAND USE -
Mixed Rangeland
Streams and Canals
Bare Exposed Rock
Mixed Barren Land
NATIONAL WETLAND INVENTORY CODES
NWI NWICLS NWIMOD NWISPEC
Riverine, intermittent RB1
COMMENTS ON HABITAT ASSOCIATIONS -
The Nihoa finch is endemic to the steep, rocky, shrubby island
of Nihoa (in the past, sometimes called "Bird Island" or "Moku Manu"
(22)) in the Hawaiian Islands National Wildlife Refuge (09,12). Nihoa
is approximately 156 acres in size (09). The Northwestern Hawaiian
Islands Passerine Recovery Plan (02) lists the present essential
habitat for the Nihoa finch as: "All land to the mean lower low water
line on Nihoa Island (approximately 62 ha (153 acres)).
Nihoa finches appear to prefer open but vegetated habitat (25).
They are also reported to use all parts of Nihoa Island (02).
About twenty-five species of plants have been reported for Nihoa,
but only four are abundant (listed in descending order of abundance):
Chenopodium oahuense, Solanum nelsoni, Sida fallax, and Eragrostis
variabilis (25,26). Other principal species include (in descending
order of abundance): the endemic palm Pritchardia remota, Sesbania
tomentosa, Euphorbia celastroides, Ipomoea indica, Panicum torridum,
and Schiedea verticillata. Less common plants are: Portulaca
oleracea, Portulaca villosa, Portulaca lutea, Ipomoea pes-caprae,
Rumex giganteus, Heliotropium currassavicum, Sicyos nihoaensis, and
Amaranthus brownii. The mixture of plants has been described as
"heterogeneous" (02), although some zonation (Eragrostis along ridges,
Euphorbia along cliff edges, and Pritchardia in the valleys) exists
(26).
One study on Nihoa finches demonstrated that their presence was
positively correlated with Sida fallax height and cover. There was
also a significant positive correlation with mean and maximum Solanum
nelsoni height (25).
Nihoa finches prefer to nest in the rock outcroppings, in rocky
crevices, or in small holes (i.e. resembling burrows) under piles of
loose rock (02,03,07,17,25) on Nihoa.
The Nihoa finches frequently congregate near the few fresh water
seeps or near ephemeral puddles of fresh water (17,25). It is
possible that each bird may visit a seep once a day (25). Conant (25)
found that one of several fresh water seeps was visited by 273 Nihoa
finches during eight hours of observation and concluded that access to
fresh water may well be essential to the Nihoa finch.
If the vegetation, fresh water seeps, or rocky areas were
disturbed, there could be adverse impacts on the ability of Nihoa
finches to forage, find cover, or nesting sites.
Rainfall on Nihoa is probably similar to that on French Frigate
Shoals, which varied from 26 to 54 inches per year during 1967 to 1974
(02).
Habitat Associations - 1 Average monthly temperatures are also probably similar to French
Frigate Shoals, where the daytime temperature averages 75 degrees F
+/- a few degrees. On Nihoa itself, Sincock and Kridler (02) recorded
maximum and minimum temperatures of 88 and 54 degrees F during their
visits from 1969 through 1974.
The elevation of Nihoa rises from sea level to approximately 900
feet at Miller's and Tanager Peaks on the west and east ends of the
island (09). It is a difficult island to land on, due to its rocky
shore and nearly inaccessible beach (02,40); steep cliffs are on three
of its four sides.
Other specific environmental or life stage requirements such as
roosting and courtship display sites, precipitation, and precise
moisture requirements are not currently known.
Habitat Associations - 2 (DRAFT) - Food Habits
Species FINCH, NIHOA
Species Id ESIS101042
Date 14 MAR 96
FOOD HABITS
TROPHIC LEVEL -
OMNIVORE
LIFESTAGE FOOD FOOD PART
General Forb Leaves/Stems
General Evergreen Shrubs-Leaves/Twigs
General Evergreen Shrubs-Flowers/Fruit/Seed
General Evergreen Trees-Flowers/Fruit/Seed
General Arthropods
General
General Forb Flowers/Fruit/Seed
General Aves
Food Habits - 1 (DRAFT) - Environment Associations
Species FINCH, NIHOA
Species Id ESIS101042
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: Rocky offshore islands
G Coastal Features: Vegetated offshore islands
G Terrestrial Features: Loess Hills
G Terrestrial Features: Burrows
G Terrestrial Features: Talus
G Terrestrial Features: Cliffs/ledges
G Terrestrial Features: Rock outcrops
Environment Associations - 1 (DRAFT) - Life History
Species FINCH, NIHOA
Species Id ESIS101042
Date 14 MAR 96
LIFE HISTORY
FOOD HABITS:
Nihoa finches are a classic example of an omnivore (25). Their
diet consists of plant seeds, leaves, flowers, buds, fruit, insects,
and eggs (02,03,04,07,08,17,18,19,25,26,27).
Nihoa finches have been observed feeding on green flower heads
and fruit of Chenopodium (03,26), partly green seeds of Portulaca
villosa (03), and seeds and leaf buds of Sida fallax (25,26).
When the introduced population of Nihoa finches was still extant
on French Frigate Shoals, finches were also observed to feed on seeds
of Casuarina, Chenopodium, Tribulus, and Lepturus (18). On Nihoa,
Kramer reported that the majority of the finches foraged under the
closed canopy of Chenopodium, Solanum, and Sida (19).
Nihoa finches are reported to eat insects (04,25,26) and seabird
eggs (02,03,07,17,25), especially tern eggs (02). However, like the
Laysan finch (Telespyza cantans), Nihoa finches probably cannot crack
the larger eggs (28), although they would probably eat any egg which
is open (29). Seabird eggs which are reported to be preyed upon by
Nihoa finches include: bulwer petrels (Bulweria bulwerii) (27);
brown noddies (Anous stolidus pileatus) (04,17,27); Grey-backed terns
(Sterna lunata) (17); Red-footed boobies (Sula sula rubripes) (17);
and wedge-tailed shearwaters (Puffinus pacificus chlororhynchus) (17).
Berger concluded that the preferred diet of captive Nihoa finches
was mixed bird seed, lettuce, oranges, papayas, and whole, cracked
chicken eggs. He also supplemented their diet with fruit flies
(larvae and pupae), protein cereal and carrots (08).
Berger (08) observed that captive Nihoa finches appeared to take
fresh water daily. Wild finches have also been reported to congregate
near the fresh water seeps on Nihoa (17,25). It has been suggested by
at least one observer (25) that each Nihoa finch visits a seep once a
day.
There is certainly some seasonality in the food sources available
to the Nihoa finches; seabird eggs are available during their various
breeding seasons, but are not in constant supply year-round (17).
Also, vegetation changes due to rain (or lack thereof) probably cause
the production of varying amounts of seeds and other plant parts (20),
as well as insects.
No information was availalbe which gave food requirements or
preferences for the different life stages of wild Nihoa finches.
However, in the closely related Laysan finch, Throp (24) reported that
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:
Conant (25) reports that it is not clear whether or not Nihoa
finches defend a large nesting territory. Her observations at a
single active nest revealed that the male finch chased other birds
from an area within 3 to 4 meters (10-13 feet) of the nest site.
No other information on territory or home range was located.
More research is needed on this aspect of Nihoa finch ecology.
PERIODICITY:
Life History - 1 (DRAFT) - Life History
Species FINCH, NIHOA
Species Id ESIS101042
Date 14 MAR 96
Nihoa finches are a diurnal species. Captive Nihoa finches were
reported to roost at night in the branches, grass tussocks, and the
cement blocks in their cage (08).
Reported observations of wild finches were made during the
daytime hours and no unusual patterns, either daily or seasonally,
were reported (02,08,17,25).
MIGRATION PATTERNS:
Nihoa finches are a non-migratory species (12). They are endemic
to Nihoa Island in the Hawaiian Islands National Wildlife Refuge (09).
COVER/SHELTER REQUIREMENTS:
There have not been many studies or observations on Nihoa finches
which define specific cover/shelter requirements.
Based on observation with captive Nihoa finches, it appears that
wild Nihoa finches must require nocturnal roosting sites. Captive
finches have been observed to roost in the branches, grass tussocks,
and cement blocks in their cage (08).
In the wild, Nihoa finches nest in rock crevices or under piles
of loose rock (25). These rocky sites appear to be a specific need
for long-term Nihoa finch survival.
The presence of Nihoa finches also appears to be correlated with
Sida fallax and Solanum (25); both plants are probably important for
food as well as cover.
REPRODUCTIVE SITE REQUIREMENTS:
Nihoa finches usually build their nests in holes or crevices in
or under rocks (02,03,07,17,25). Sincock and Kridler (02) reported
finding 13 nests in small, fist-size holes in the rimrock along a
gulch, and Conant (25,39) found 12 nests all in holes in rock faces or
in rock piles. When Nihoa finches were introduced onto Tern Island,
French Frigate Shoals, they nested in holes in a brick pile (02).
Captive Nihoa finches have nested in cement blocks, and one reportedly
also began a nest in a 6-inch diameter elbow pipe (08).
The nest itself is made of twigs, grass, and large seabird (e.g.,
frigatebird and booby) feathers (02,03). Shredded paper is also used
when it is available (02,18) due to the presence of humans.
No information on display or nursery area requirements was
located in the reviewed literature.
REPRODUCTIVE CHARACTERISTICS:
The literature review on Nihoa finches did not reveal any
information on age at sexual maturity, or minimum and maximum
breeding ages. An adult female Nihoa finch which was color-banded by
Conant (25) in 1980 had first been marked with a numbered USFWS band
in 1968, when its age was unknown. Although its breeding status was
unconfirmed, the finch was at least 12 years old when it was rebanded.
Conant (25) estimated that the Nihoa finch breeding season may
span the months from February to August. Clapp et al., (17) suggested
that nesting ran principally from February to at least April. Sincock
and Kridler suggested that nesting occurs during the winter and
spring, with a peak in March (02). In captivity, Berger reported that
his Nihoa finches nested from March to June in 1972, and from March to
Life History - 2 (DRAFT) - Life History
Species FINCH, NIHOA
Species Id ESIS101042
Date 14 MAR 96
May and in September and November 1973 (08).
In captivity, a female was observed to solicit copulation during
late December (08) and copulation was observed in early January.
In wild Nihoa finches, nest building has been reported in March
(30). Eggs have been found in the months of March (02) and July (25).
Young have been found in the nest in March (02,03). Juveniles have
been observed in late June and early July (27).
There is no information on the number of nesting attempts that
may be undertaken by wild birds during the breeding season.
In one captive female, at least three nesting attempts were made
between January and July (08). Another captive female raised a
fledgling to independence by July, but began a second clutch before
the fledgling was independent (08).
Nihoa finches are apparently monogamous (08); the duration of
pairing is unknown.
The most frequent clutch size recorded is three (09). Sincock
and Kridler (02) report a maximum clutch of four nestlings per nest;
however, their observation of a total of 38 eggs and nestlings in 13
nests averages to approximately three eggs/young per nest. Conant
(40) observed one 5-egg clutch, one 4-egg clutch, and two 3-egg
clutches in April of 1983.
In captivity, the incubation period for one nest was 15 days and
9 hours. The female on this nest did not begin incubation until after
the third egg was laid (08). The length of incubation in wild nests
has not been reported.
PARENTAL CARE:
There is very little information available on parental care in
wild Nihoa finches.
The young of Nihoa finches are altricial (08), like all
passerines.
In captivity, only the female Nihoa finch has been reported to
incubate eggs; the male feeds the female during incubation and also
(at least on one occasion) the male as well as the female fed the
nestlings and fledglings (08).
In wild Nihoa finches, male finches were observed chasing other
finches from the area 3 to 4 meters (10-13 feet) around the nest (25).
For one nest of captive Nihoa finches, the eggs hatched on June
26 and the young left the nest on July 19, a period of about 24 days
(08). One of these young was first observed to sing when it was about
65 days old (08).
No information was located concerning the duration of the family
bond.
POPULATION BIOLOGY:
The current limiting factors for Nihoa finches are probably food
supply, weather, and nesting sites. This conclusion is partly based
on the fact that their habitat on Nihoa, although encompassing the
whole island (02), is only about 156 acres in size (09). The
population appears to fluctuate from year to year (02,09); it may be
that the carrying capacity of the island fluctuates and is the cause
of some of these population fluctuations (09). In addition, weather
(e.g., storms, droughts) may cause stochastic population changes.
Life History - 3 (DRAFT) - Life History
Species FINCH, NIHOA
Species Id ESIS101042
Date 14 MAR 96
However, Clapp et al. (17) did not think there were pronounced
seasonal changes in population numbers.
The highest recorded population density for Nihoa finches was
43 per acre (6,686 total) in 1968. During the period from 1964 to
1980, the population estimates fluctuated between 1,318 and 6,686 (02,
09,31,32,40). Other estimates have been: 500 to 1,000 in 1940 (07);
800 to 1,200 (19); 2,500 to 5,000 in 1964 (30); 1,608 in 1980 (16);
and 3,194 +/- 890 in 1985 (33). The precision and accuracy of these
population estimates are extremely variable.
Longevity in Nihoa finches has been reported for captive birds.
Berger (34) had a total of ten captive Nihoa finches die at the
following ages (in months): 18.5, 25, 25, 61, 71.5, 72, 72.4, 81, 94,
and 112 (a range from 1.5 to 9.3 years). Four other of his captive
Nihoa finches died within 6 months of capture. An adult female Nihoa
finch which was colored banded by Conant (25) in 1980 had first been
marked with a numbered USFWS band in 1968, when its age was unknown.
Thus, Nihoa finches may live up to 12 or 13 years in the wild.
No information on survival rates, mortality rates, sex ratios,
recovery potential, or turnover rate was located during the literature
review.
SPECIES INTERRELATIONSHIPS:
Nihoa finches will crack and eat eggs of other birds, and
therefore sometimes act as a predator (02,03,07,08,17,25,27). They
appear to be especially fond of tern eggs (02).
See "Food Habits" above for seabird eggs which have been reported
to be Nihoa finch prey.
The presence of humans aggravates egg predation by the finches
because it can cause breeding adult seabirds to flush from and remain
off of their eggs, exposing the eggs to finch predation (02,40).
OTHER LIFE HISTORY DESCRIPTORS:
Over the years, many population estimates have been reported for
Nihoa finches on Nihoa (02,16,19,30,31,32,33) ranging from a low
estimate of 500 to 1000 in 1940 (07) to a high of 6686 in 1968 (02).
In 1980, three different census methods yielded population estimates
of 1499 +/- 250, 1608 +/- 418, and 2219 +/- 173 (40).
Like many insular species, Nihoa finches are quite fearless and
are "so tame that by exercising a little patience one was able to make
these birds approach to within a distance of one or two feet" (07).
The Nihoa finch is said to have a sweet song "resembling a
canary" (01). Berger (04) reported that both sexes sing although the
males were more "persistent" in singing. He also reported that the
finches' songs have a canary-like quality.
Life History - 4 (DRAFT) - Management Practices
Species FINCH, NIHOA
Species Id ESIS101042
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
Existing
Adverse Food Supply Reduction
Existing Food Supply Reduction
Adverse Disease
Existing Disease
Adverse Parasites
Existing Parasites
Adverse Soil compaction by heavy equipment in mine areas
Existing Soil compaction by heavy equipment in mine areas
Adverse Exotic/Feral/Introducted Species
Existing Exotic/Feral/Introducted Species
Adverse Erosion
Existing Erosion
Adverse Vegetation Composition Changes
Existing Vegetation Composition Changes
Adverse Fire
Existing Fire
COMMENTS ON MANAGEMENT PRACTICES -
The Nihoa finch is endemic to Nihoa Island (also obsoletely
called "Moku Manu" or "Bird Island" (22)), a small, steep island of
approximately 156 acres (02,09). The very small size and fragility
(e.g., susceptibility to fire and impacts of introduced organisms) of
the historic range is one of the main factors which has been used in
the determination of the Nihoa finch's endangered status (02,16).
One past impact on the Nihoa finches has been human disturbance;
for example, in the 1880's, a picnic expedition to Nihoa started a
brush fire which "must have killed off many birds" (23).
Another past impact has been unauthorized military use of Nihoa,
as well as other remote islands (19,20,21), although in most recent
years this has not been reported to be a problem. Unfortunately, some
of the non-native weed and insect species on Nihoa probably arrived
there in this way on equipment and clothing (20). Also heavy
equipment use can result in direct incidental mortality as well as
contributing to increased erosion of habitat. If the vegetation,
fresh water seeps, or rocky areas were disturbed, there could be
adverse impacts on the ability of Nihoa finches to forage, find cover,
or nesting sites.
Management Practices - 1 (DRAFT) - Management Practices
Species FINCH, NIHOA
Species Id ESIS101042
Date 14 MAR 96
Nihoa finches, like Laysan finches (Telespyza cantans), are very
attracted to standing fresh water; Amerson (18) reported that
introduced Nihoa finches on French Frigate Shoals drowned both in an
uncovered bucket and an uncovered 55 gallon drum of fresh water.
The factors which presently threaten the Nihoa finch population
on Nihoa are:
- human activity (02,18);
- the introduction of pest plants or animals (e.g. predators
or insects and parasites) via natural or man-made causes
(02,20), which may compete with food plants and/or reduce
food supplies;
- unauthorized and emergency landings, especially those which
may cause exotic introductions (02,19,20,21);
- fire (02,23);
- avian diseases, which could arrive either naturally or due
to human activities (01,09). A closely related species, the
Laysan finch, has been shown in captivity to be extremely
susceptible to bird diseases. This is probably due to the
natural isolation of these insular species; the Laysan
finches were shown to be susceptible to "common infections"
such as Staphylococcus and Poxvirus avium (avian pox) (02,
24,38);
- weather (e.g. hurricanes or droughts) which destroy habitat
(02), and food supply as a result of the latter.
Future threats to Nihoa finches in the wild are the same as the
present threats which are listed above, except that unauthorized
landings will increase if the fishing industry expands in the waters
around the Northwestern Hawaiian Islands. The increase in
unauthorized landings will increase the accidental introduction of
pest plants and animals (e.g. due to seeds on clothing, rats or
insects from landed boats). Also, as the number of pest plants and
insects, and also avian diseases and parasites, increase throughout
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 Nihoa Island should increase, and more
intensive monitoring will be necessary.
There is certainly some seasonality in the food sources available
to the Nihoa finches; Seabird eggs are available during their various
breeding seasons, but are not in the constant supply year round (17).
Also, vegetation changes due to rain (or lack thereof) probably cause
the production of varying amounts of seeds and other plant parts (20),
as well as insects. Drought could very well bring on a food shortage.
In the case of the Nihoa finch, the numerical abundance of the
species is less relevant to its endangered status than is its limited
(approximately 156 acres) native range and fragile ecosystem (02,16),
and the documented fluctuations in population numbers (02).
APPROVED PLAN:
U.S. Fish and Wildlife Service. 1984. Northwestern Hawaiian Islands
Passerines Recovery Plan. U.S. Fish and Wildl. Serv., Portland, OR.
Management Practices - 2 (DRAFT) - Management Practices
Species FINCH, NIHOA
Species Id ESIS101042
Date 14 MAR 96
66 pp.
This hardy little finch, a relect surviving from a time before
the first Polynesian settlement of the main Hawaiian Islands, now
flourishes on Nihoa Island, an outpost at the margin of its once much
greater range. This population exists at astonishingly high density,
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 insular 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 Nihoa finches have lost all
effective defensives. Protecting Nihoa 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 (especially via boat) to
Nihoa Island;
2) preventing establishment of alien organisms (plant and
animals) and setting up a plan to monitor the island and to
eliminate such organisms should they reach the island;
3) preventing the outbreak of avian disease;
4) monitoring the species and its habitat; and
5) establishing a captive flock of Nihoa finches, should some
calamity befall their present habitat.
Introduction of Nihoa finches to other leeward or offshore Hawaiian
islands was not considered by the plan and would probably not be
practical, owing to the absence of other high islands free of rats.
Maintaining these finches on only one island exposes them to a greater
risk of extinction.
Ongoing recovery actions are: (1) review of the Hawaiian Islands
NWR Master Plan and (2) recent population surveys.
Management Practices - 3 (DRAFT) - References
Species FINCH, NIHOA
Species Id ESIS101042
Date 14 MAR 96
References
***** REFERENCES FOR ALL NARRATIVES EXCEPT N-OCCURRENCE *****
01 Bryan, W.A. 1917. Description of Telespiza ultima from Nihoa
Island. Auk 34:70-72.
02 Sincock, J.L. and E. Kridler. 1977. The extinct and endangered
endemic birds of the Northwestern Hawaiian Islands. Unpub. ms.
U.S. Fish and Wildl. Serv., Honolulu, HI. 111 pp.
03 Richardson, F. 1954. Report on the two native passerines of Nihoa
Hawaii. Condor 56:224.
04 Berger, A.J. 1972. Hawaiian birdlife. The Univ. Press of Hawaii,
Honolulu. 270 pp.
05 Banko, W.E. 1979. History of endemic Hawaiian birds specimens in
museum collections. CPSU/UH Avian History Report 2. Coop. Nat.
Park Res. Studies Unit, U.H. Manoa, Dept. of Botany, Honolulu.
80 pp.
06 Munro, G.C. 1960. Birds of Hawaii. Revised ed. C.E. Tuttle Co.,
Inc., Rutland, VT. 192 pp.
07 Vanderbilt, G. and R.M. de Schauensee. 1941. Zoological results
of the Vanderbilt Nihoa Expedition. I. Summary of zoological
explorations and the birds of Nihoa. Notulae Naturae, Acad. Nat.
Sci., Phila., No. 86:1-14.
08 Berger, A.J. 1981. Hawaiian birdlife. 2nd Ed. The Univ. Press
of HI, Honolulu. 260 pp.
09 U.S. Fish and Wildlife Service. 1984. Recovery plan for the
Northwestern Hawaiian Islands passerines. U.S. Fish and Wildlife
Serv., Portland, OR. 66 pp.
10 Banks, R.C. and R.C. Laybourne. 1977. Plumage sequence and
taxonomy of Laysan and Nihoa finches. Condor 79(3):343-348.
11 Wilson, S.B. 1890. On a new finch from Midway Island, North
Pacific. Ibis 33(2):339-341.
12 American Ornithologists' Union. 1983. Checklist of North American
birds. 6th ed. Allen Press, Inc., Lawrence, KS. 877 pp.
13 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.
14 Raikow, R.J. 1976. Pelvic appendage myology of the Hawaiian
honeycreepers (Drepanididae). Auk 93:774-492.
15 Raikow, R.J. 1977. Pectoral appendage myology of the Hawaiian
honeycreepers (Drepanididae). Auk 94:331-342.
16 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.
17 Clapp, R.B., E. Kridler and R.R. Fleet. 1977. The natural history
of Nihoa Island, Northwestern Hawaiian Islands. Atoll Res. Bull.,
No. 207. Smithsonian Inst., Wash., D.C. 147 pp.
18 Amerson, Jr., A.B. 1971. The natural history of French Frigate
Shoals, Northwestern Hawaiian Islands. Atoll Res. Bull., No. 150.
Smithsonian Inst., Wash., D.C. 383 pp.
19 Kramer, R.J. 1961. Report on a trip to Nihoa Island. Unpub.
20 Kramer, R.J. and J.W. Beardsley. 1962. A report on a survey trip
References - 1 (DRAFT) - References
Species FINCH, NIHOA
Species Id ESIS101042
Date 14 MAR 96
to the Hawaiian Islands National Wildlife Refuge, Entomological
report. Unpub. HI Dept. of Fish and Game, Honolulu, HI. 17 pp.
21 Woodside, D.H. and R.J. Kramer. 1961. A report on a survey trip
to the Hawaiian Islands National Wildlife Refuge, Unpub. report.
Hawaii Dept. of Fish and Game, Honolulu, HI. 31 pp.
22 Wetmore, A. 1924. A warbler from Nihoa. Condor 26:177-178.
23 Munroe, G.C. 1941. Birds of Hawaii and adventures in bird study-
an ocean cruise. 'Elepaio 2(6):41-43.
24 Throp, J. 1970. The Laysan finch bill in the Honolulu Zoo.
'Elepaio 31(4):31-34.
25 Conant, S. 1983. Ecological requirements of the Nihoa Millerbird
and the Nihoa finch, including an analysis of management options
for the millerbird. Unpubl. U.S. Fish and Wildl. Serv., Honolulu,
47 pp.
26 Conant, S. 1985. Recent observations on the plants of Nihoa
Island, Northwestern Hawaiian Islands. Pac. Sci. 39(2):135-149.
27 U.S. Fish and Wildlife Service. 1984. Report-biological
investigations: Nihoa, Necker, Laysan, Lisianski, Pearl and Hermes
Reef, Midway. Unpub. Honolulu Office, HI. 16 pp.
28 Conant, S. 1985. Trip report-expedition to Laysan Island. Unpub.
Dept. of Gen. Sci. Univ. of HI at Manoa, Honolulu. 5 pp.
29 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.
30 Walker, R.L. 1964. Unpubl. field notes, HI Dept. of Fish and
Game, Honolulu. 35 pp.
31 U.S. Fish and Wildlife Service. 1977. Hawaiian and Pacific
Islands National Wildlife Refuge Complex narrative report CY 1977.
Unpub., Honolulu Office, HI.
32 Sincock, J. 1978. 1978 endangered species population data for
Leewards. Unpubl. U.S. Fish and Wildlife Service Correspondence
to Barry Brady, Honolulu Office, HI.
33 Fefer, S. 1985. Summary of Hawaiian Islands NWR endangered
species surveys conducted in 1985 for Endangered Species Technical
Bulletin. Unpubl. U.S. Fiah and Wildl. Serv. Memo, Honolulu Off.,
2 pp.
34 Berger, A.J. 1980. Longevity in Hawaiian honeycreepers in
captivity. Wilson Bull. 92(2):263-264.
35 Willett, G. 1945. The type of Telespiza ultima Bryan. Auk
62:139.
36 Amadon, D. 1950. The Hawaiian honeycreepers (Aves, Drepaniidae).
Bull. Am. Mus. Nat. Hist. 95:155-262.
37 Delacour, J. 1928. Les oiseaux des iles Hawaii. Oiseaux
6:183-190; 7:210-221; 8:242-251.
38 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, HI. 584 pp.
39 Conant, S. 1983. Unpubl. data from 1983 expedition to Nihoa.
40 Conant, S., M.S. Collins and C.J. Ralph. 1981. Effects of
observers using different methods upon the total population
estimates of two resident island birds. Studies in avian biol.
No. 6:377-381.
References - 2 (DRAFT) - References
Species FINCH, NIHOA
Species Id ESIS101042
Date 14 MAR 96
***** REFERENCES FOR N-OCCURRENCE NARRATIVE ONLY *****
01 Sincock, J.L. and E. Kridler. 1977. The extinct and endangered
endemic birds of the Northwestern Hawaiian Islands. Unpub. manus.
U.S. Fish and Wildl. Serv., Honolulu, HI. 111 pp.
02 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.
03 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.
04 Clapp, R.B., E. Kridler and R.R. Fleet. 1977. The natural history
of Nihoa Island, Northwestern Hawaiian Islands. Atoll Res. Bull.,
No. 207. Smithsonian Inst., Wash., D.C. 147 pp.
05 Amerson, Jr., A.B. 1971. The natural history of French Frigate
Shoals, Northwestern Hawaiian Islands. Atoll Res. Bull., No. 150.
Smithsonian Inst., Wash., D.C. 383 pp.
06 Olson, S.L. and H.F. James. 1982. Prodromus of the fossil
avifauna of the Hawaiian Island. Smithsonian Contrib. to Zoo. #365
Smithsonian Inst. Press, City of Washington. 59 pp.
References - 3