Federal Register: June 6, 2001 (Volume 66, Number 109)
DOCID: FR Doc 01-14171
DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
CFR Citation: 50 CFR Part 17
RIN ID: RIN 1018-AG99
NOTICE: PROPOSED RULES
ACTION: Endangered and threatened species:
DOCUMENT ACTION: Proposed rule.
SUBJECT CATEGORY:
Endangered and Threatened Wildlife and Plants; Proposed Determination of Critical Habitat for the O`ahu `Elepaio
DATES: Comments
We will consider comments from all interested parties received by August 6, 2001.
Public Hearings
Requests for public hearing must be received by July 23, 2001.
DOCUMENT SUMMARY:
We, the U. S. Fish and Wildlife Service (Service), propose designation of critical habitat for the O`ahu `elepaio, a bird, pursuant to the Endangered Species Act of 1973, as amended (Act). The proposed critical habitat consists of five units whose boundaries encompass a total area of approximately 26,853 hectares (ha) (66,354 acres (ac)) on the island of O`ahu, Hawai`i.
Critical habitat identifies specific areas, both occupied and unoccupied, that are essential to the conservation of a listed species and that may require special management considerations or protection. The primary constituent elements for the O`ahu `elepaio are those habitat components that are essential for the primary biological needs of foraging, nesting, rearing of young, intraspecific communication, roosting, dispersal, genetic exchange, or sheltering. All areas proposed as critical habitat for the O`ahu `elepaio contain one or more of the primary constituent elements.
We solicit data and comments from the public on all aspects of this proposal, including data on economic and other impacts. We may revise this proposal to incorporate or address new information received during the comment period.
SUMMARY:
Critical habitat designations—; O’ahu ’elepaio,
SUPPLEMENTAL INFORMATION
Background
The Hawaiian archipelago consists of eight main islands and the numerous shoals and atolls of the northwestern Hawaiian Islands. The islands were formed sequentially by basaltic lava that emerged from a hot spot in the earth's crust located near the current southeastern coast of the island of Hawai`i (Stearns 1985). O`ahu, the third oldest main island, is 2.5 million to 3.5 million years old and is heavily weathered. O`ahu has two principal mountain ranges, the Ko`olau and the Wai`anae Mountains, separated by a gently sloping plateau. The Ko`olau Mountains extend 60 kilometers (km) (37 miles (mi)) from northwest to southeast along the eastern half of the island. The windward (northeastern) slope of these mountains is characterized by steep cliffs and short ridges less than 6 km (4 mi) long. The leeward (southwestern) slope is characterized by parallel ridges as long as 18 km (11 mi), alternating with steepsided stream valleys. The peak elevation in the Ko`olau Mountains occurs at Pu`u Konahuanui (955 meters (m); 3,105 feet (ft)). The drier Wai`anae Mountains run from northwest to southeast in a 32km (20mi) arc along the western half of O`ahu, in the rainshadow of the Ko`olau Range. Both the windward and leeward slopes of the Wai`anae Mountains are characterized by steep cliffs and ridges less than 5 km (3 mi) in length. The peak elevation occurs at Mt. Ka`ala (1,230 m; 4,025 ft). Approximately 36 percent (134,300 acres) of O`ahu is forested (Buck et al. 1988). Of these forested lands, approximately 49 percent is primarily native forest dominated by koa (Acacia koa) and `ohi`a (Metrosideros polymorpha), with the remainder, 51 percent, dominated by introduced species, e.g., common guava (Psidium guajava), strawberry guava (P. cattleianum), christmasberry (Schinus terebinthifolius), mango (Mangifera indica), and several species of eucalypts (Buck et al. 1988).
The O`ahu `elepaio (Chasiempis sandwichensis ibidis) is a small
forestdwelling bird (12.5 grams (0.43 ounces)) average weight; 15
centimeters (6 inches) total body length), and is a member of the
monarch flycatcher family Monarchidae (VanderWerf 1998). It is dark
brown above and white below, with light brown streaks on the breast.
The tail is long (6.5 cm, 2.6 in.) and often held up at an angle.
Adults have conspicuous white wing bars, a white rump, and white tips
on the tail feathers. The throat is white with black markings in both
sexes, but males tend to have more black than females, especially on
the chin. Juveniles and subadults are rufous above and on the breast,
with a white belly and rusty wingbars. The bill is mediumlength,
straight, and black, with the base of the lower mandible bluishgray in adults
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and yellow in juveniles. The legs and feet are dark gray and the iris
is dark brown. Males average approximately 10 percent larger than
females in wing length, tarsus length, and weight, but bill length does not differ between the sexes (VanderWerf 1998).
Three subspecies of `elepaio are recognized, each endemic to a single island: The O`ahu `elepaio; the Hawai`i `elepaio (Chasiempis sandwichensis sandwichensis); and the Kaua`i `elepaio (C. s. sclateri). The forms on different islands are similar in ecology and behavior, but differ somewhat in coloration and vocalizations (Conant 1977, van Riper 1995, VanderWerf 1998). The taxonomy used in this rule follows Pratt et al. (1987) and Pyle (1997), in which all forms are regarded as subspecies, but the form on each island was originally described as a separate species. The O`ahu form was known as C. s. gayi (Wilson 1891) until Olson (1989) pointed out that the epithet ibidis (Stejneger 1887) has priority. The `elepaio comprises a monotypic genus that is endemic to the Hawaiian archipelago (VanderWerf 1998). Its closest relatives are other monarch flycatchers from the Pacific region (Pratt et al. 1987, Sibley and Ahlquist 1985).
O`ahu `elepaio occur in a variety of forest types, but are most common in riparian vegetation along streambeds and in mesic forest with a tall canopy and a welldeveloped understory (Shallenberger and Vaughn 1978, VanderWerf et al. 1997). Population density is roughly 50 percent lower in shorter dry forest on ridges (VanderWerf et al. 1997). They are not currently found in very wet, stunted forest on windswept summits or in very dry shrub land, but these areas may be used by individuals dispersing among populations. Forest structure appears to be more important to `elepaio than plant species composition (VanderWerf et al. 1997), and unlike many Hawaiian forest birds, `elepaio have adapted well to disturbed forest composed of introduced plants (Conant 1977, VanderWerf et al. 1997, VanderWerf 1998). Fifty five percent of the current range is dominated by introduced plants and 45 percent is dominated by native plants (Hawai`i Heritage Program 1991). This observation does not imply that `elepaio prefer introduced plant species, but simply reflects a preference by `elepaio for riparian vegetation in valleys and the high degree of habitat disturbance and abundance of introduced plants in riparian areas (VanderWerf et al. 1997). Of the 45 percent dominated by native plants, 23 percent is categorized as wet forest, 17 percent as mesic forest, and 5 percent as dry forest, shrub land, and cliffs (Hawai`i Heritage Program 1991).
Plant species composition in `elepaio habitat varies considerably depending on location and elevation, but some of the most common native plants in areas where `elepaio occur are `ohi`a, papala kepau (Pisonia umbellifera), lama (Diospyros sandwicensis), mamaki (Pipturus albidus), kaulu (Sapindus Oahuensis), hame (Antidesma platyphyllum), and `ala Pouteria sandwicensis), and some of the most common introduced plants are guava, strawberry guava, kukui (Aleurites moluccana), mango, Christmasberry, and ti (Cordyline terminalis) (VanderWerf et al. 1997, VanderWerf 1998).
The current population of O`ahu `elepaio is approximately 1,982 birds distributed in six core subpopulations and several smaller subpopulations (Table 1, Figure 1; VanderWerf et al. in press). The only previous population estimate (200500 birds; Ellis et al. 1992) was not accurate because little information was available when the estimate was made. The number of birds is divided about evenly between the Wai`anae Mountains in the west and the Ko`olau Mountains in the east, with three core subpopulations in each mountain range. At least 10 tiny remnant subpopulations consisting mostly or entirely of males remain in both the Wai`anae and Ko`olau mountains (Table 1). These subpopulations were much larger or continuous with other subpopulations in the past, but because of their very small size, skewed sex ratio, and geographic isolation, these relicts likely will disappear in a few years as the last adults die.
The breeding population, about 1,774 birds, is less than the total
population because of a malebiased sex ratio; only 84 percent of
territorial males have mates in large populations (n = 147, E.
VanderWerf unpubl. data), and many small, declining populations contain
mostly males (Table 1). The effective population size is probably even
smaller than the breeding population because of the geographically
fragmented distribution (Grant and Grant 1992). Natal dispersal
distances in elepaio are usually less than one km (0.62 mi) and adults
have high site fidelity (VanderWerf 1998), but most elepaio populations
on O`ahu are separated by many kilometers of unsuitable urban or
agricultural habitat. There may be some exchange among subpopulations
within each mountain range, but dispersal across the extensive
pineapple fields that separate the Wai`anae and Ko`olau mountains is
unlikely. While the current distribution superficially appears to
constitute a metapopulation, it is uncertain if dispersal occurs among subpopulations.
Table 1.Estimated Size and Area of O`ahu `Elepaio Subpopulations
[Data from VanderWerf et al. (in press). Letters before each
subpopulation correspond to those on Figure 1.] Total Breeding
Subpopulation population population Area (ha) size size
Wai`anae Mountains:
A. southern Wai`anae 458 418 1,170 (Honouliuli Preserve,
Lualualei Naval Magazine)...
B. Schofield Barracks West 340 310 532 Range.......................
C. Makaha, Wai`anae Kai 123 112 459 Valleys.....................
D. Pahole, Kahanahaiki....... 18 4 256
E. Schofield Barracks South 6 0 20 Range.......................
F. Makua Valley.............. 7 2 49
G. Ka`ala Natural Area 3 0 21 Reserve.....................
H. Makaleha Gulch............ 2 0 7
I. Kuaokala.................. 3 2 14
J. Kaluakauila Gulch......... 1 0 6 Ko`olau Mountains:
K. southern Ko`olau (Pia, 475 432 1,063 Wailupe, Kapakahi,
Kuli`ou`ou, Wai`alae Nui)...
L. Waikane, Kahana Valleys... 265 242 523
M. central Ko`olau (Moanalua, 226 206 1,396 north and south Halawa,
`Aiea, Kalauao).............
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N. Palolo Valley............. 46 42 78
O. Waihee Valley............. 5 4 32
P. Manoa..................... 2 0 19
Q. Hau`ula................... 1 0 4
R. Waianu Valley............. 1 0 8
Total...................... 1,982 1,774 5,657 BILLING CODE 431055M
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Before humans arrived, forest covered about 127,000 ha (313,690 ac) on O`ahu (Figure 2; Hawai`i Heritage Program 1991), and it is likely that `elepaio once inhabited much of that area (VanderWerf et al. in press). Reports by early naturalists indicate that `elepaio were once widespread and abundant on O`ahu. Bryan (1905) called the O`ahu `elepaio ``the most abundant Hawaiian species on the mountainside all the way from the sea to well up into the higher elevations.'' Perkins (1903) remarked on its ``universal distribution * * *, from the lowest bounds to the uppermost edge of continuous forest.'' Seale (1900) stated the `elepaio was ``the commonest native land bird to be found on the island,'' while MacCaughey (1919) described it as ``the most abundant representative of the native woodland avifauna'' and ``abundant in all parts of its range.'' The historical range of the O`ahu `elepaio thus apparently included most forested parts of the island, and it was formerly abundant.
Despite its adaptability, the O`ahu `elepaio has seriously declined since the arrival of humans, and it has disappeared from many areas where it was formerly common (Shallenberger 1977, Shallenberger and Vaughn 1978, Williams 1987, VanderWerf et al. 1997). The aggregate geographic area of all current subpopulations is approximately 5,657 ha (13,972 ac; Table 1). The O`ahu `elepaio thus currently occupies only about 4 percent of its original prehistoric range, and its range has declined by roughly 96 percent since humans arrived in Hawai`i 1,600 years ago (Kirch 1982). In 1975, `elepaio inhabited approximately 20,900 ha (51,623 ac) on O`ahu, almost four times the area of the current range (Figure 2; VanderWerf et al. in press). The range of the O`ahu `elepaio has thus declined by roughly 75 percent in the last 25 years.
Much of the historical decline of the O`ahu `elepaio can be
attributed to habitat loss, especially at low elevations. Fiftysix
percent of the original prehistoric range has been developed for urban
or agricultural use, and practically no `elepaio remain in developed areas (VanderWerf et al. in press).
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However, many areas of O`ahu that recently supported `elepaio and
still contain apparently suitable forest habitat are currently
unoccupied, demonstrating that habitat loss is not the only threat.
Recent declines in O`ahu `elepaio populations are due to a combination
of low adult survival and low reproductive success. Both annual adult
survival and reproductive success are lower on O`ahu (0.76, 0.33,
respectively) than in a large, stable population of another subspecies
of `elepaio at Hakalau Forest National Wildlife Refuge on Hawai`i
Island (0.85, 0.62; VanderWerf 1998). The main cause of reduced adult
survival on O`ahu appears to be diseases, particularly avian pox
(Poxvirus avium) and avian malaria (Plasmodium relictum), which are carried by the introduced southern house mosquito (Culex
quinquefasciatus). Annual survival of birds with active avian pox
lesions (60 percent) was lower than annual survival of healthy birds
(80 percent; E. VanderWerf unpubl. data). Malaria is a serious threat
to many Hawaiian forest birds (Warner 1968, van Riper et al. 1986,
Atkinson et al. 1995), but its effect on `elepaio has not been investigated.
The primary reason for low reproductive success is nest predation by the introduced black rat (Rattus rattus). An experiment in which automatic cameras were wired to artificial `elepaio nests containing quail eggs showed that a black rat was the predator in all 10 predation events documented (VanderWerf in press). Control of rats with snap traps and diphacinone (an anticoagulent rodenticide) bait stations was effective at improving `elepaio reproductive success, resulting in an 85 percent increase in nest success and a 127 percent increase in fledglings per pair compared to control areas (VanderWerf 1999). Reproductive success of `elepaio is also affected by disease. Pairs in which at least one bird had pox lesions produced fewer fledglings than healthy pairs or those in which at least one bird had recovered from pox (E. VanderWerf, unpubl. data). Many birds with active pox did not even attempt to nest, and infected birds were sometimes deserted by their mate.
A comprehensive treatment of the life history and ecology of the `elepaio is provided by VanderWerf (1998), from which much of the information below is taken. `Elepaio are nonmigratory and defend all purpose territories yearround. The average territory size on O`ahu was 2.0 ha (4.94 ac) in forest composed of introduced plant species (Conant 1977), but territory size likely varies with vegetation structure. Population density on O`ahu was 50 percent lower in short forest on ridges than in tall riparian forest along streambeds (VanderWerf et al. 1997), and for the related subspecies on Hawai`i, territory size was 50 percent larger in more disturbed forest with an open canopy and grass understory.
O`ahu `elepaio are socially monogamous, and approximately 63 percent of pairs remain together each year (E. VanderWerf, unpubl. data). Site fidelity is high, with 96 percent of males and 67 percent of females remaining on the same territory from year to year. Annual survival of healthy adults is high, approximately 85 percent in males and 70 percent in females (E. VanderWerf, unpubl. data). Young birds wander (or float) while they attempt to acquire a territory and a mate.
The nesting season usually extends from mid FebruaryMay, but active nests have been found from JanuaryJuly (VanderWerf 1998). Nest site selection is not specialized, and nests have been found in a variety of plants, including 6 native species and 13 introduced species (E. VanderWerf, unpubl. data). The nest is a finelywoven, free standing cup made of rootlets, bark strips, leaf skeletons, lichen, and spider silk, and is placed in a fork or on top of a branch (Conant 1977, VanderWerf 1998). Both sexes participate in all aspects of nesting, but the female plays a larger role in nest building and the male provides more food for the nestlings. Clutch size is 1 to 3 eggs, usually 2, and eggs hatch after 18 days. The nestling period is 16 days. Fledglings are fed by their parents for more than a month after leaving the nest, and may remain in the natal territory for up to 9 months, until the start of the next breeding season. Fecundity (reproductive rate) is low; even if nest predators are removed the mean number of fledglings per pair is 0.75 per year (VanderWerf 1999). O`ahu `elepaio will renest once or twice after failure, but they rarely attempt to renest if the first nest is successful. Other than introduced predators, storms with heavy rain and strong winds are the most common cause of nest failure.
The diet and foraging behavior of `elepaio are extremely varied. The diet consists of a wide range of arthropods, particularly insects and spiders, and includes introduced species such as fruit flies (Tephritidae; VanderWerf 1998). Large prey, such as moths and caterpillars, are beaten against a branch before being eaten. In a study on Hawai`i Island, VanderWerf (1993, 1994) found that `elepaio foraged at all heights on all available plant species, and that they caught insects from a variety of substrates, including the ground and fallen logs (2 percent), trunks (5 percent), branches (24 percent), twigs (38 percent), foliage (20 percent), and in the air (11 percent). `Elepaio are versatile and agile in pursuit of prey, using a diversity of foraging behaviors that is among the highest recorded for any bird, including perchgleaning (48 percent), several forms of flightgleaning (30 percent), hanging (11 percent), aerial flycatching (7 percent), and active pursuit (4 percent) (VanderWerf 1994).
Previous Federal Action
We were petitioned by Mr. Vaughn Sherwood on March 22, 1994, to list the O`ahu `elepaio as an endangered or threatened species with critical habitat. The November 15, 1994, Animal Notice of Review (59 FR 58991) classified the O`ahu `elepaio (then Chasiempis sandwichensis gayi) as a category 1 candidate. Category 1 candidates were those species for which we had sufficient data in our possession to support a listing proposal. On June 12, 1995 (60 FR 30827), we published a 90day petition finding stating that the petition presented substantial information that listing may be warranted. On February 28, 1996 (61 FR 7596), and September 19, 1997 (62 FR 49398), we published notices discontinuing candidate category designations, and the O`ahu `elepaio was listed as a candidate species. Candidate species are those for which we have on file sufficient information on biological vulnerability and threats to support proposals to list as threatened or endangered. On October 6, 1998 (63 FR 53623), we published the proposed rule to list the O`ahu `elepaio as an endangered species. Because C. s. gayi is a synonym of C. s. ibidis, the proposed rule constituted the final 12month finding for the petitioned action. On April 18, 2000 (65 FR 20760), we published the final rule to list the O`ahu `elepaio as an endangered species.
Section 4(a)(3) of the Act, as amended, and implementing
regulations (50 CFR 424.12) require that, to the maximum extent prudent
and determinable, the Secretary designate critical habitat at the time
a species is determined to be endangered or threatened. Our regulations
(50 CFR 424.12(a)(1)) also state that designation of critical habitat
is not prudent when one or both of the following situations exist(1)
the species is threatened by taking or other activity and the
identification of critical habitat can be expected to increase the
degree of threat to the species, or (2) such designation of critical habitat would not be beneficial
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to the species. In the proposed listing rule we indicated that
designation of critical habitat for the O`ahu `elepaio was not prudent
because we believed a critical habitat designation would not provide
any additional benefit beyond that provided through listing as
endangered. Based partly on comments we received on the proposed
listing rule and on recent court rulings which address the prudency
standard, in the final listing rule we determined that a critical
habitat designation for the O`ahu `elepaio was prudent because such a
designation could benefit the species beyond listing as endangered by
extending protection under section 7 of the Act to currently unoccupied
habitat and by providing informational and educational benefits.
Although we determined in the final listing rule that critical habitat designation for the O`ahu `elepaio would be prudent, we also indicated in the final listing rule that we were not able to develop a proposed critical habitat designation for the O`ahu `elepaio at that time due to budgetary and workload constraints. However, on June 28, 2000, the United States District Court for the District of Hawai`i established, in the case of Conservation Council for Hawai`i v. Babbitt, CIV. NO. 0000001 HGBMK, a timetable to designate critical habitat for the O`ahu `elepaio, and ordered that the Service publish the final critical habitat designation by October 31, 2001. This proposed rule responds to the court's order.
On November 9, 2000, we mailed letters to 32 landowners on O`ahu informing them that the Service was in the process of designating critical habitat for the O`ahu `elepaio and requesting from them information on management of lands that currently or recently (within the past 25 years) supported O`ahu `elepaio. The letters contained a fact sheet describing the O`ahu `elepaio and critical habitat, a map showing the historic and current range of the O`ahu `elepaio, and a questionnaire designed to gather information about land management practices, which we requested be returned to us by November 27, 2000. We received 11 responses to our landowner mailing with varying types and amounts of information on current land management activities. Some responses included detailed management plans, provided new information on locations where `elepaio have been observed recently, and described management activities such as fencing, hunting, public access, fire management, methods for controlling invasive weeds and introduced predators, and collaboration with conservation researchers. In addition, we met with several landowners and managers, including the U.S. Army and the Hawai`i State Division of Forestry and Wildlife, to obtain more specific information on management activities and suitability of certain habitat areas for `elepaio. The information provided in the responses and during meetings was considered and incorporated into this proposed rule.
Critical Habitat
Critical habitat is defined in section 3, paragraph (5)(A) of the Act as(i) the specific areas within the geographic area occupied by a species, at the time it is listed in accordance with the Act, on which are found those physical or biological features (I) essential to the conservation of the species and (II) that may require special management considerations or protection; and (ii) specific areas outside the geographic area occupied by a species at the time it is listed, upon a determination that such areas are essential for the conservation of the species. ``Conservation,'' as defined by the Act, means the use of all methods and procedures that are necessary to bring an endangered or a threatened species to the point at which listing under the Act is no longer necessary.
Critical habitat receives protection under section 7 of the Act through the prohibition against destruction or adverse modification of critical habitat with regard to actions carried out, funded, or authorized by a Federal agency. Section 7 also requires conferences on Federal actions that are likely to result in the destruction or adverse modification of proposed critical habitat. In our regulations at 50 CFR 402.02, we define destruction or adverse modification as ``the direct or indirect alteration that appreciably diminishes the value of critical habitat for both the survival and recovery of a listed species. Such alterations include, but are not limited to, alterations adversely modifying any of those physical or biological features that were the basis for determining the habitat to be critical.'' Aside from the added protection that may be provided under section 7, the Act does not provide other forms of regulatory protection to lands designated as critical habitat. Because consultation under section 7 of the Act does not apply to activities on private or other nonFederal lands that do not involve a Federal nexus, critical habitat designation would not afford any additional protections under the Act against such activities.
Critical habitat also provides nonregulatory benefits to the
species by informing the public and private sectors of areas that are
important for species recovery and where conservation actions would be
most effective. Designation of critical habitat can help focus
conservation activities for a listed species by identifying areas that
contain the physical and biological features that are essential for
conservation of that species, and can alert the public as well as land
managing agencies to the importance of those areas. Critical habitat also identifies areas that may require special management
considerations or protection, and may help provide protection to areas
where significant threats to the species have been identified or help to avoid accidental damage to such areas.
In order to be included in a critical habitat designation, the habitat must be ``essential to the conservation of the species.'' Critical habitat designations identify, to the extent known and using the best scientific and commercial data available, habitat areas that provide essential life cycle needs of the species (i.e., areas on which are found the primary constituent elements, as defined at 50 CFR 424.12(b)). Section 3(5)(C) of the Act states that not all areas that can be occupied by a species be designated as critical habitat unless the Secretary determines that all such areas are essential to the conservation of the species. Our regulations (50 CFR 424.12(e)) also state that, ``The Secretary shall designate as critical habitat areas outside the geographic area presently occupied by the species only when a designation limited to its present range would be inadequate to ensure the conservation of the species.''
Section 4(b)(2) of the Act requires that we take into consideration the economic impact, and any other relevant impact, of specifying any particular area as critical habitat. We may exclude areas from critical habitat designation when the benefits of exclusion outweigh the benefits of including the areas within critical habitat, provided the exclusion will not result in extinction of the species.
Our Policy on Information Standards Under the Endangered Species
Act, published on July 1, 1994 (59 FR 34271), provides criteria,
establishes procedures, and provides guidance to ensure that decisions
made by the Service represent the best scientific and commercial data
available. It requires that our biologists, to the extent consistent
with the Act and with the use of the best scientific and commercial
data available, use primary and original sources of information as the basis for
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recommendations to designate critical habitat. When determining which
areas are critical habitat, a primary source of information should be
the listing rule for the species. Additional information may be
obtained from a recovery plan, articles in peerreviewed journals,
conservation plans developed by states and counties, scientific status
surveys and studies, and biological assessments or other unpublished materials (i.e., gray literature).
Section 4 requires that we designate critical habitat based on what we know at the time of the designation. Habitat is often dynamic, however, and populations may move from one area to another over time. Furthermore, we recognize that designation of critical habitat may not include all of the habitat areas that may eventually be determined to be necessary for the recovery of the species. For these reasons, all should understand that critical habitat designations do not signal that habitat outside the designation is unimportant or may not be required for recovery. Habitat areas outside the critical habitat designation will continue to be subject to conservation actions that may be implemented under section 7(a)(1) and to the regulatory protections afforded by the section 7(a)(2) jeopardy standard and the section 9 take prohibition, as determined on the basis of the best available information at the time of the action. It is possible that federally funded or assisted projects affecting listed species outside their designated critical habitat areas could jeopardize those species. Similarly, critical habitat designations made on the basis of the best available information at the time of designation will not control the direction and substance of future recovery plans, habitat conservation plans, or other species conservation planning and recovery efforts if new information available to these planning efforts calls for a different outcome.
Methods
As required by the Act and regulations (section 4(b)(2) and 50 CFR Sec. 424.12), we used the best scientific information available to determine areas that contain the physical and biological features that are essential for the survival and recovery of the Oahu elepaio. This information included: peerreviewed scientific publications (Conant 1977; Banko 1981; VanderWerf 1993, 1994, 1998, in press; VanderWerf et al. 1997, in press); the final listing rule for the O`ahu `elepaio (65 FR 20760); unpublished reports by the Hawaii State Division of Forestry and Wildlife (VanderWerf 1999); the Hawaii Natural Heritage Program database; the Sightings database from the Occurrence and Status of Birds in Hawaii project maintained at Bishop Museum in Honolulu; the Oahu Forest Bird Survey conducted in 1991 by the Hawaii State Division of Forestry and Wildlife; field trip reports in the Elepaio (journal of the Hawaii Audubon society); and responses to the Oahu elepaio critical habitat outreach package mailed to Federal, State, and private land managers and landowners.
The distribution and abundance of the O`ahu `elepaio have declined seriously in the last few decades (Williams 1987; O`ahu `elepaio final listing rule, 65 FR 20760; VanderWerf et al. in press). The area currently occupied by the O`ahu `elepaio represents only about four percent of the species' original range, and the distribution has contracted into numerous small fragments (Figure 2). Moreover, the remaining elepaio subpopulations are small and isolated, comprising six core subpopulations that contain between 100 and 500 birds, and numerous small remnant subpopulations, most of which contain fewer than 10 birds (Table 1). Even if the threats responsible for the decline of the elepaio were controlled, the existing subpopulations would be unlikely to persist because their small sizes make them vulnerable to extinction due to a variety of natural processes. Small populations are particularly vulnerable to reduced reproductive vigor caused by inbreeding depression, and they may suffer a loss of genetic variability over time due to random genetic drift, resulting in decreased evolutionary potential and ability to cope with environmental change (Lande 1988, IUCN 2001). Small populations are also demographically vulnerable to extinction caused by random fluctuations in population size and sex ratio and to catastrophes such as hurricanes (Lande 1988). Survival and reproduction of `elepaio are known to fluctuate among years in response to variation in disease prevalence and predator populations (VanderWerf 1998, 1999), possibly due to El Nino episodes and variation in rainfall, which may exacerbate the threats associated with small population size (Lande 1988).
Elepaio are highly territorial; each pair defends an area of a certain size, depending on the forest type and structure, resulting in a maximum population density or carrying capacity (VanderWerf 1998). Although elepaio have declined islandwide and the range has contracted, density in the remaining core subpopulations is high, and much of the currently occupied land is at or near carrying capacity and cannot support many more `elepaio than it currently supports (VanderWerf et al. 1997, in press). Consequently, each of the currently occupied areas is too small to support an `elepaio population large enough to be considered safe from extinction. In order for the number of birds in each subpopulation to increase, additional land must be available for young birds to establish new territories and attract mates. The potential for expansion is especially important for the smallest subpopulations that currently contain only a few individuals. Because of their very small size and often skewed sex ratio, these tiny subpopulations are unlikely to persist more than a few generations if limited to the currently occupied area.
Elepaio are also relatively sedentary; adults have high fidelity to their territory and juveniles rarely disperse more than one km (0.62 mi) in search of a territory (VanderWerf 1998). Because the areas currently occupied by elepaio are separated from each other by many kilometers (Figure 1) and elepaio are unlikely to disperse long distances, the existing subpopulations probably are isolated (VanderWerf et al. in press). The O`ahu `elepaio evolved in an environment with large areas of continuous forest habitat covering much of the island (Figure 2), and their dispersal behavior is not adapted to a fragmented landscape. In the past, subpopulations were less isolated and dispersal and genetic exchange among different parts of the island probably was more frequent. Maintaining or restoring links among subpopulations by providing opportunities for dispersal would increase the overall effective population size through metapopulation interactions, thereby helping to alleviate the threats associated with small population size, and would better reflect the conditions under which the life history characteristics of dispersal evolved. In particular, enlargement of small subpopulations by expansion onto adjacent lands not only would increase the chances of their longterm survival, but also would improve connectivity among subpopulations by enhancing their value as ``stepping stones'' within the distribution of the entire population.
Section 3(5)(A)(i) of the Act provides that areas outside the
geographical area currently occupied by the species may meet the
definition of critical habitat upon determination that they are
essential for the conservation of the species. Because of the
territorial nature of the O`ahu `elepaio, its small total population
size, limited range, fragmented distribution, and resulting vulnerability to genetic, demographic,
[[Page 30381]]
and environmental threats, we find that inclusion of currently
unoccupied areas identified as containing the primary constituent
elements is essential to the conservation of the species. The final
rule listing the O`ahu `elepaio as endangered emphasized that the
``small total population size, limited distribution, and population
fragmentation make this taxon particularly vulnerable to reduced
reproductive vigor and the effects of naturally occurring events'' (65
FR 20760). Recovery will require restoration of `elepaio in areas that
were formerly inhabited but that are not currently occupied, through
natural dispersal, translocation, and/or release of captive birds.
Unoccupied areas adjacent to currently occupied areas are needed for
recovery to allow expansion of existing subpopulations and help
alleviate the threats associated with small population size. Unoccupied
lands linking subpopulations are needed for recovery to provide
opportunities for dispersal among subpopulations and promote genetic
exchange and metapopulation function. Specifically, each of the
existing core populations in PaholeKahanahaiki, MakahaWai`anae Kai,
Schofield Barracks West Range, the southern Wai`anae Mountains, the
central leeward Ko`olau Mountains, WaikaneKahana, and the southern
leeward Ko`olau Mountains are small and isolated, and are unlikely to
be viable on their own. The longterm chances for persistence of these
subpopulations would increase if each subpopulation increased in size
by expanding onto adjacent lands and if the connectivity among the
subpopulations was enhanced by occasional dispersal of individuals across intervening lands.
We determined the amount and spatial arrangement of critical habitat needed to support a viable population of O`ahu `elepaio. Because a recovery plan for the O`ahu `elepaio has not been completed yet, in making this determination we looked to the historical distribution of the O`ahu `elepaio for a model of a viable population. The best and most recent information available on the distribution of an apparently viable O`ahu `elepaio population is from 1975, when extensive surveys were conducted over much of the island (Shallenberger 1977, Shallenberger and Vaughn 1978, Banko 1981). `Elepaio began declining on O`ahu before 1975 and had already disappeared from some parts of the island (Figure 2; Conant 1977, Williams 1987, VanderWerf et al. in press), but in 1975 the subpopulations were still relatively large and birds were distributed in two wellconnected metapopulations, one in the Wai`anae Mountains and one in the Ko`olau Mountains. The areas occupied since 1975 also are likely to be most suitable for recovery because they supported `elepaio for a longer period. The number and distribution of O`ahu `elepaio in 1975 has allowed for the persistence of a population, albeit in a declining state, for more than 25 years. We believe that active management of threats, including nest predation and disease, in areas reflecting the distribution in 1975 would allow for longterm recovery. This approach is consistent with the approved recovery outline for the O`ahu `elepaio; if, after critical habitat for the O`ahu `elepaio is designated, a final approved recovery plan for Hawaiian forest birds calls for a different approach to the conservation of the O`ahu `elepaio, we will consider amending the critical habitat designation, subject to resource and workload priorities.
Primary Constituent Elements
In accordance with section 3(5)(A)(i) of the Act and regulations at
50 CFR 424.12, in determining which areas to propose as critical
habitat, we are required to consider those physical and biological
features that are essential to the conservation of the species and that
may require special management considerations and protection. Such
features are termed Primary Constituent Elements, and include but are
not limited to: space for individual and population growth and for
normal behavior; food, water, air, light, minerals and other
nutritional or physiological requirements; cover or shelter; sites for
nesting and rearing of offspring; and habitats that are protected from
disturbance and are representative of the historic geographical and ecological distributions of the species.
`Elepaio are adaptable and able to forage and nest in a variety of
forest types composed of both native and introduced plant species
(Conant 1977, VanderWerf 1993, 1994, 1998). Nest site selection by
`elepaio is nonspecialized; nests have been found in seven native and
13 introduced plant species (E. VanderWerf, unpubl. data).
Shallenberger and Vaughn (1978) found the highest relative abundance of
`elepaio in forest dominated by introduced guava and kukui trees, but
they were also found in the following forest types (in order of
decreasing abundance): mixed nativeexotic; tall exotic; koa dominant;
mixed koa`hi'a; low exotic; `hi'a dominant; and `hi'a scrub. This
distribution does not imply that `elepaio prefer introduced plant
species, but probably reflects a preference by `elepaio for riparian
vegetation in valleys and the high degree of habitat disturbance and
abundance of introduced plants in riparian areas. VanderWerf et al.
(1997) found that (1) forest structure was more important to `elepaio
than plant species composition, (2) most birds occurred in areas with a
continuous forest canopy and a dense understory, and (3) population
density was roughly twice as high in tall riparian vegetation in
valleys as in shorter forest on ridges. Fiftyfive percent of the
currently occupied area consists of forest dominated by introduced
plant species, 23 percent is native wet forest, 17 percent is native
mesic forest, and 5 percent is native dry forest and shrub land (VanderWerf et al. in press).
The primary constituent elements required by the O`ahu `elepaio for foraging, sheltering, roosting, nesting, and rearing of young are found in undeveloped areas that support wet, mesic, and dry forest composed of both native and introduced plant species. Higher population density can be expected in tall, closed canopy riparian forest than in low scrubby forest on ridges and summits. In addition, the primary constituent elements associated with the biological needs of dispersal and genetic exchange among populations are found in undeveloped areas that support wet or dry shrub land and wet or dry cliff habitat. `Elepaio may not establish territories in shrub or cliff habitats and may use them only transiently, but areas containing these habitats are important for linking populations by facilitating dispersal and promoting genetic exchange.
Criteria Used To Identify Critical Habitat
We used several criteria to identify and select lands proposed for
designation as critical habitat. We began with all areas that are
currently occupied by `elepaio, excluding one very small, isolated
subpopulation at Hau`ula that contains only a single male (Figure 1;
subpopulation Q). We then added unoccupied lands containing the primary
constituent elements that were needed for conservation of the species.
As discussed in greater detail in the Methods section, in deciding
which unoccupied areas were needed for recovery we used the
distribution of `elepaio in 1975 as a model of a viable population.
Within this area of distribution in 1975 we gave preference to lands
that (a) provided more preferred forest types, (b) were more recently
occupied (since 1975), and (c) were contiguous and formed large [[Page 30382]]
blocks of preferred habitat or provided links between areas of
preferred habitat. We determined the boundaries of proposed critical
habitat units by the extent of suitable forest containing the primary
constituent elements, which in many areas coincided with the boundaries
of State Forest Reserves, Natural Area Reserves, or other conservation
lands. We did not include urban and agricultural lands because they
generally do not contain the primary constituent elements and do not
meet the definition of critical habitat. We included lower Wailupe
Valley, however, which is zoned for urban use but has not yet been
developed, because it contains the primary constituent elements and is
currently occupied by `elepaio, and therefore meets the definition of critical habitat.
We were unable to map the proposed critical habitat unit boundaries in sufficient detail to exclude all existing developed lands that do not contain the primary constituent elements. However, existing development features and structures within the boundaries of the mapped units, such as buildings, roads, aqueducts, antennas, water tanks, agricultural fields, paved areas, lawns, and other urban landscaped areas that do not contain the primary constituent elements are not proposed as critical habitat. Federal actions limited to those areas, therefore, would not trigger a section 7 consultation, unless they affect the species and/or primary constituent elements in adjacent critical habitat.
Proposed Critical Habitat Designation
Lands proposed as critical habitat occur in five separate units and provide the full range of primary constituent elements needed by the O`ahu `elepaio, including: a variety of currently occupied undeveloped forested areas that are used for foraging, roosting, sheltering, nesting, and raising offspring; a variety of currently unoccupied undeveloped forested areas that are adjacent to occupied areas and provide for expansion of existing subpopulations; and shrub land and cliff habitats that link subpopulations and are used for dispersal. If `elepaio were restored throughout each of the proposed critical habitat units, the resulting distribution would closely resemble the distribution in 1975, when the subpopulations were larger and less isolated, the overall population appeared to be viable, and when the O`ahu `elepaio was not considered endangered. The area proposed as critical habitat (26,733 ha) is larger than the area occupied in 1975 (20,900 ha) because the proposed critical habitat contains not only lands expected to support breeding `elepaio populations, but also intervening lands that provide for periodic dispersal and not permanent occupation.
The potential `elepaio population in the area proposed as critical habitat is 10,104 birds, as estimated by multiplying the current density of `elepaio in different parts of the island by the area of each critical habitat unit (Table 2). These estimates are approximate, and the actual population in each unit may be larger if density can be increased beyond current levels, or lower if it proves difficult to establish dense populations in some currently unoccupied areas.
Table 2.Proposed Critical Habitat Units and Potential `Elepaio Populations
[Data on current density from VanderWerf et al. (in press). Unit 4 is
not currently occupied by `elepaio; the density used to estimate the
potential `elepaio population of this unit is an average of the
densities in the two nearest units, central and southern Ko`lau.] `Elepaio
density in Potential
currently `elepaio
Critical habitat unit Area occupied population
parts of in unit unit
1. Northern Wai`anae Mountains... 4,501 ha 0.45 per ha 2,025
11,122 ac 0.18 per ac
2. Southern Wai`anae Mountains... 2,515 ha 0.39 per ha 981
6,215 ac 0.16 per ac
3. Central Ko`olau Mountains..... 14,840 0.33 per ha 4,897
36,669 ac 0.14 per ac
4. KalihiKapalama............... 800 ha 0.39 per ha 312
1,977 ac 0.16 per ac
5. Southern Ko`olau Mountains.... 4,197 ha 0.45 per ha 1,889
10,371 ac 0.18 per ac
All Units........................ 26,853 0.38 per ha 10,104
66,354 ac 0.15 per ac
The approximate area and land ownership within each proposed
critical habitat unit are shown in Table 3. Proposed critical habitat
includes land under Federal, State, and private ownership, with Federal
lands being managed by the Department of Defense and the Department of
the Interior. Proposed lands include most (99 percent) of the species'
current range and encompass approximately 21 percent of the species'
original range. Approximately 21 percent of proposed lands are
currently occupied by `elepaio, and 79 percent are currently unoccupied
but were recently occupied (since 1975). A detailed description of each
unit and reasons for proposing each portion of the unit as critical habitat are presented below.
Table 3.Approximate Area (Hectares, Acres) of Proposed Critical Habitat Units by Land Ownership
Unit Federal \1\ State County Private Total
1. Northern Wai`anae Mountains................. 822 ha 3,033 ha 646 ha ........... 4,501 ha
2,031 ac 7,495 ac 1,596 ac ........... 11,122 ac
2. Southern Wai`anae Mountains................. 616 ha 377 ha 1,522 ha 2,515 ha
1,523 ac 932 ac 3,760 ac 6,215 ac
3. Central Ko`olau Mountains................... 3,109 ha 3,789 ha 308 ha 7,634 ha 14,840 ha [[Page 30383]]
7,681 ac 9,363 ac 762 ac 18,863 ac 36,669 ac
4. KalihiKap`alama............................ 393 ha 179 ha 228 ha 800 ha
971 ac 442 ac 564 ac 1,977 ac
5. Southern Ko`olau Mountains.................. 3 ha 2,563 ha 480 ha 1,151 ha 4,197 ha
7 ac 6,334 ac 1,187 ac 2,843 ac 10,371 ac
Total.......................................... 4,550 ha 10,155 ha 1,613 ha 10,535 ha 26,853 ha
11,242 ac 25,095 ac 3,987 ac 26,030 ac 66,354 ac
\1\ Federal lands include Department of Defense and U.S. Fish and Wildlife Service. Unit 1: Northern Waianae Mountains
Unit 1 consists of approximately 4,501 ha (11,122 ac) encompassing the higher elevations of the northern Waianae Mountains. It is bounded on the south by Kolekole pass, and on the north, east, and west by forest edge created by human actions. Natural features within the unit include Mt. Kaala, the highest peak on O`ahu at 1,227 m (4,025 feet), several other high peaks along the spine of the Waianae Range, the upper portions of large, broad valleys on the slopes of the Waianae Range, including Waianae Kai, Makaha, Makua, Kahanahaiki, and Kuaokala valleys on the west slope and Haleauau and Mohi`akea gulches on the east slope, and the higher portions of several narrow valleys on the north slope of the Waianae Range. Vegetation consists primarily of mixedspecies wet, mesic, and dry forest communities composed of native and introduced plants, with smaller amounts of dry shrub land and cliff plant communities (Hawaii Heritage Program 1991).
Unit 1 contains two important elepaio core subpopulations: one in upper Haleauau and Mohi`akea gulches above the firebreak road on U.S. Army Schofield Barracks West Range; the other in upper Makaha and Waianae Kai valleys on Waianae Kai State Forest Reserve and City and County of Honolulu land. The unit also includes small scattered elepaio subpopulations in Pahole and Kaala State Natural Area Reserves, Mokulaia, MakuaKeaau, and Kuaokala State Forest Reserves, and the upper portion of the U.S. Army Makua Military Reservation. In addition to protecting lands occupied by the two core `elepaio subpopulations and six smaller subpopulations, proposed lands in Unit 1 provide for expansion of these subpopulations by including currently unoccupied lands that were occupied within the past 30 years and contain the most preferred types of forest. Specifically, currently unoccupied lands in Pahole and Kaala State Natural Area Reserves, Mokulaia, MakuaKeaau, and Kuaokala State Forest Reserves, upper M`akua Valley, and upper Kahanahiki Valley are needed for recovery to allow the number of birds in existing subpopulations to increase. In addition, the current distribution of elepaio in Unit 1 represents a remnant of what was once a single large continuous elepaio population in the northern Waianae Mountains. Inclusion of currently unoccupied forested lands that provide for subpopulation expansion and shrub land and cliff habitats that provide for dispersal among subpopulations will promote needed linkage among subpopulations and help to restore the original metapopulation function that once existed in this area.
Unit 2: Southern Waianae Mountains
Unit 2 consists of approximately 2,515 ha (6,215 ac) encompassing the higher elevations of the southern Waianae Mountains. It is bounded on the north by Kolekole Pass, and on the east, west, and south by forest edge created by human actions. Natural features of the unit include several high peaks along the spine of the southern Waianae Range, including Palikea, Kaua, Kanehoa, and Hapapa, the upper portions of Lualualei and Nanakuli valleys on the west side of the mountains, and the upper portions of numerous narrower valleys on the east side of the mountains. Vegetation consists primarily of mixedspecies mesic and dry forest communities composed of native and introduced plants, with smaller amounts of dry shrub land and cliff communities (Hawaii Heritage Program 1991).
Unit 2 contains the second largest O`ahu `elepaio subpopulation, encompassing several land parcels, including Honouliuli Preserve (which is managed by The Nature Conservancy of Hawaii), Naval Magazine Pearl Harbor Lualualei Branch, Nanakuli State Forest Reserve, and other unmanaged State lands. This unit also contains several scattered `elepaio territories north of the core subpopulation on U.S. Army Schofield Barracks South Range. In addition to protecting currently occupied habitat, proposed lands in Unit 2 include peripheral areas of currently unoccupied habitat in Honouliuli Preserve, Lualualei, and Schofield Barracks South Range that are needed for recovery to allow expansion of the core subpopulation, and dry shrub land and cliff habitats on unmanaged State land between Lualualei and Honouliuli and on Schofield Barracks South Range that provide for dispersal among parts of the southern Waianae subpopulation and between the northern and southern Waianae subpopulations.
Unit 3: Central Koolau Mountains
Unit 3 is the largest unit, encompassing 14,840 ha (36,669 ac) of the higher elevations of the central Koolau Mountains. Natural features of the unit include the summit of the Koolau Range and the upper portions of numerous narrow valleys separated by steep ridges, including (from south to north) Manaikai, Moanalua, South Halawa, North Halawa, Kalauao, Waimalu, Waimano, Mnana, Waiawa, Kapapa, Kaukonahua, and Poamoho on the leeward (western) side, and Waihee, Kaalaea, Waiahole, Waikane, and Kahana on the windward (eastern) side. Vegetation consists primarily of montane and lowland wet and mesic forest, and smaller areas of shrub land and wet cliff plant communities (Hawaii Heritage Program 1991). The higher elevations of the unit are primarily native forest dominated by ohia and koa, but the lower elevations are more disturbed and dominated by a variety of introduced plant species.
Unit 3 contains two important core `elepaio subpopulations: one
located almost entirely on private land in Moanalua, North and South
Halawa, Manaiki, and Kalauao valleys at the southern end of the unit;
the other on the windward side in Kahana Valley State Park and on
private lands in Waikane Valley. The unit also contains a few scattered
`elepaio territories in Waihole State Forest Reserve. Proposed [[Page 30384]]
lands include the existing subpopulations, and also provide for the
expansion and recovery of existing subpopulations by including adjacent
lands in Manaiki, Waimalu, Waimano, Manana, Waiawa, Kapapa, Kaukonahua,
and Poamoho on the leeward (western) side, and in Waihee, Kaalaea,
Waiahole, Waikane, and Kahana on the windward (eastern) side that are
currently unoccupied but were occupied since 1975. Unit 3 also includes
wet shrub land and cliff habitats along the Koolau summit that provide
for dispersal of elepaio between the windward and leeward sides of the
Koolau Mountains. The existing core subpopulations are geographically
distant from each other and probably are isolated. Restoration of
elepaio in intervening areas would increase the chances of dispersal
and genetic exchange between subpopulations and restore metapopulation
function. Currently unoccupied habitat lies on the Oahu Forest National
Wildlife Refuge, U.S. Army Schofield Barracks East Range, U.S. Army
Fort Shafter, Ewa and Waiahole State Forest Reserves, Kahana Valley
State Park, and 9 privately owned parcels. The narrow indentation in
the southern portion of Unit 3 reflects the H3 freeway and adjacent cleared areas in North Halawa Valley.
Unit 4: KalihiKapalama
Unit 4 consists of approximately 800 ha (1,977 ac) encompassing the higher elevations of the leeward (western) side of the central K`oolau Mountains above Kalihi and Kapalama. It is bounded on the north by the Likelike Highway and on the south by the Pali Highway. Natural features of the unit include the upper portions of Kalihi, Kamanaiki, and Kapalama valleys. Vegetation consists primarily of mixedspecies wet and mesic forest composed of native and introduced plant species (Hawaii Heritage Program 1991). The higher elevations are primarily native forest dominated by ohia and koa, but the lower elevations are more disturbed and are dominated by introduced plant species. This unit is not known to contain any `elepaio at present, but it was occupied within the last 20 years, still contains suitable forest habitat, and provides an important habitat steppingstone that increases the chances of dispersal and genetic exchange between `elepaio subpopulations in the central and southern K`oolau units. This unit includes lands within the State of Hawaii Honolulu Watershed Forest Reserve, two parcels owned by the City and County of Honolulu, and 3 private parcels.
Unit 5: Southern K`oolau Mountains
Unit 5 consists of approximately 4,197 ha (10,371 ac) encompassing the higher elevations of the southern K`oolau Mountains. It is bounded on the west by the Pali Highway. Natural features of the unit include: the summit of the southern K`oolau Mountains, including Konahuanui, the highest peak in the K`oolau Range at 960 m (3,150 ft), the upper portion of Maunawili Valley on the windward (northern) side of the mountains, and the upper portions of numerous narrow valleys separated by steep ridges on the leeward side, including (from east to west) Kaalakei, Kuliouou, Kupaua, Pia, Kului, Wailupe, Kapakahi, Waialae Nui, Palolo, Manoa, Tantalus, and Pauoa. The vegetation consists primarily of mixedspecies wet, mesic, and dry forest communities, with small areas of mesic shrub land and wet cliff plant communities (Hawaii Heritage Program 1991). The higher elevations are primarily native forest dominated by ohia and koa, but the lower elevations are more disturbed and are dominated by introduced plant species, particularly guava, kukui, christmasberry, and mango.
Unit 5 contains the largest remaining elepaio subpopulation,
located in Kuliouou, Kupaua, Pia, Kului, Wailupe, Kapakahi, and Waialae
Nui valleys, and two smaller elepaio populations located nearby in
Palolo and Manoa valleys. The current distribution of `elepaio in the
southern K`oolau Mountains represents a remnant of what was once a
single large continuous population. In addition to protecting the
largest remaining subpopulation and two smaller subpopulations,
proposed lands in Unit 5 provide for recovery through expansion of
existing subpopulations by including currently unoccupied lands in
Maunawili, Palolo, Manoa, Nuuanu, Tantalus, and Pauoa that were
occupied since 1975 and contain the most preferred forest types.
Proposed lands in Unit 5 also provide for recovery by including shrub
land and wet cliff habitats along the Koolau summit that are used for
dispersal and link subpopulations on the windward and leeward sides of
the K`oolau Mountains, thereby helping to restore metapopulation
function. Restoration of elepaio in unoccupied lands in Tantalus and
Pauoa at the western end of Unit 5 would increase the chances of
dispersal and genetic exchange between the southern K`oolau
subpopulation and the central K`oolau subpopulation. Ownership within
Unit 5 consists of the Honolulu Watershed, Maunawili, and Kuliouou
State Forest Reserves, several parcels owned by the City and County of Honolulu, and nine private parcels.
Effects of Critical Habitat Designation
Section 7 Consultation
Section 7(a) of the Act requires Federal agencies, including the Service, to ensure that actions they fund, authorize, or carry out do not destroy or adversely modify critical habitat to the extent that the action appreciably diminishes the value of the critical habitat for the survival and recovery of the species. Individuals, organizations, states, local governments, and other nonFederal entities are affected by the designation of critical habitat only if their actions occur on Federal lands, require a Federal permit, license, or other authorization, or involve Federal funding.
Section 7(a) of the Act requires Federal agencies to evaluate their actions with respect to any species that is proposed or listed as endangered or threatened and with respect to its critical habitat, if any is designated or proposed. Regulations implementing this interagency cooperation provision of the Act are codified at 50 CFR part 402. Section 7(a)(4) requires Federal agencies to confer with us on any action that is likely to jeopardize the continued existence of a proposed species or result in destruction or adverse modification of proposed critical habitat. Conference reports provide conservation recommendations to assist the agency in eliminating conflicts that may be caused by the proposed action. The conservation recommendations in a conference report are advisory.
We may issue a formal conference report, if requested by the Federal action agency. Formal conference reports include an opinion that is prepared according to 50 CFR 402.14, as if the species was listed or critical habitat designated. We may adopt the formal conference report as the biological opinion when the species is listed or critical habitat designated, if no substantial new information or changes in the action alter the content of the opinion (see 50 CFR 402.10(d)).
If a species is listed or critical habitat is designated, section
7(a)(2) requires Federal agencies to ensure that actions they
authorize, fund, or carry out are not likely to jeopardize the
continued existence of such a species nor to destroy or adversely
modify its critical habitat. If a Federal action may affect a listed
species or its critical habitat, the responsible Federal agency (action
agency) must enter into consultation with us. Through this consultation the Federal action agency would ensure that
[[Page 30385]]
the permitted actions do not destroy or adversely modify critical habitat.
When we issue a biological opinion concluding that a project is likely to result in the destruction or adverse modification of critical habitat, we also provide reasonable and prudent alternatives to the project, if any are identifiable. Reasonable and prudent alternatives are defined at 50 CFR 402.02 as alternative actions identified during consultation that can be implemented in a manner consistent with the intended purpose of the action, that are consistent with the scope of the Federal agency's legal authority and jurisdiction, that are economically and technologically feasible, and that the Director believes would avoid destruction or adverse modification of critical habitat. Reasonable and prudent alternatives can vary from slight project modifications to extensive redesign or relocation of the project. Costs associated with implementing a reasonable and prudent alternative are similarly variable.
Regulations at 50 CFR 402.16 require Federal agencies to reinitiate consultation on previously reviewed actions in instances where critical habitat is subsequently designated and the Federal agency has retained discretionary involvement or control over the action or such discretionary involvement or control is authorized by law. Consequently, some Federal agencies may request
FOR FURTHER INFORMATION CONTACT
Paul Henson, Field Supervisor, or Eric VanderWerf, Biologist, U.S. Fish and Wildlife Service at the above address (telephone: 808/5413441; facsimile: 808/5413470).