Endangered and Threatened Wildlife and Plants; Advance Notice of a Proposal To Remove the American Peregrine Falcon From the List of Endangered and Threatened Wildlife

SUMMARY: The U.S. Fish and Wildlife Service (Service) is reviewing the

status of the American peregrine falcon (Falco peregrinus anatum),

currently classified as endangered under the U.S. Endangered Species

Act. Data currently on file with the Service indicate that this

subspecies has recovered following restrictions on the use of

organochlorine pesticides in the United States and Canada and because

of management activities including the reintroduction of captive-bred

peregrine falcons. Therefore, the Service intends to propose removal of

the subspecies from the list of endangered and threatened wildlife and

the critical habitat designation. The Service will also propose to

remove the similarity of appearance provision that currently exists for

all free-flying Falco peregrinus within the 48 conterminous States.

Protection provided to American peregrine falcons by the Migratory Bird

Treaty Act will not be affected. To ensure that the Service's proposal

is based on the best available scientific information, the Service

seeks data and comments from the public.

DATES: Comments from all interested parties must be received by August

29, 1995 to ensure consideration in the proposed rule.

ADDRESSES: Comments and other materials concerning this notice should

be sent to Judy Hohman, Acting Field Supervisor, U.S. Fish and Wildlife

Service, Ecological Services, Ventura Field Office, 2493 Portola Road,

Suite B, Ventura, California 93003. Comments and materials received

will be available for public inspection, by appointment, during normal

business hours at the above address.

FOR FURTHER INFORMATION CONTACT: Robert Mesta at the above address

(Phone: 805/644-1766).

SUPPLEMENTARY INFORMATION:

Background

The American peregrine falcon (Falco peregrinus anatum) occurs

throughout much of North America, from the subarctic boreal forests of

Canada and Alaska south to Mexico. It nests from central Alaska,

central Yukon Territory, and northern Alberta and Saskatchewan, east to

the Maritimes and south (excluding coastal areas north of the Columbia

River in Washington and British Columbia) throughout Canada and the

United States to Baja California, Sonora, and the highlands of central

Mexico. The central Canadian provinces of Saskatchewan and Manitoba,

and the central United States, including North and South Dakota,

Nebraska, Kansas, Oklahoma, and Texas outside of Trans-Pecos, have

historically contained relatively few nesting American peregrine

falcons. Thus, the plains area of the continent effectively separates

the more suitable nesting habitat and historically dense nesting areas

of temperate eastern and western North America. Birds that nest in

subarctic areas generally winter in South America, while those that

nest at lower latitudes exhibit variable migratory behavior or are

nonmigratory (Yates et al. 1988).

Peregrine falcons declined precipitously in North America following

World War II (U.S. Fish and Wildlife, 1993). Research implicated

organochlorine pesticides, particularly the pesticide DDT (dichloro

diphenyl trichloroethane) applied in the United States and Canada

during this same period as causing the decline (for a review, see

Risebrough and Peakall 1988). Use of these chemicals peaked in the

1950's and early 1960's and continued through the early 1970's.

Organochlorines can affect peregrine falcons either by causing direct

mortality or by adversely affecting reproduction by causing egg

breakage, addling, hatching failure, and abnormal reproductive behavior

by the parent birds (Risebrough and Peakall 1988). DDE, a metabolite of

DDT, prevents normal calcium deposition during eggshell formation,

resulting in thin-shelled eggs that are susceptible to breakage during

incubation.

During the period of DDT use in North America, shell thinning and

nesting failures were widespread in peregrine falcons, and in some

areas successful reproduction virtually ceased (Hickey 1969). As a

result, there was a rapid and significant decline in the number of

peregrine falcons in many areas of North America. The degree of

exposure to these pesticides varied by region, and peregrine falcon

numbers in more contaminated areas suffered greater declines. Those

that nested outside of agricultural and forested areas where DDT was

heavily used were affected less, although some individuals wintered in

areas of pesticide use and presumably all individuals ate some

migratory prey containing organochlorines (for reviews, see Hickey

1969; Kiff 1988). Peregrine falcons nesting in the agricultural and

forested areas east of the Mississippi River in the United States and

in eastern Canada south of the boreal forest were the most heavily

contaminated and were essentially extirpated by the mid-1960's (Berger

et al. 1969).

Due to population declines of American peregrine falcons, the

Service, in 1970, listed this subspecies as endangered under the

Endangered Species Conservation Act of 1969 (P.L. 91-135, 83 Stat.

275). American peregrine falcons were included in the list of

threatened and endangered foreign species on June 2, 1970 (35 FR 8495),

and were included in the United States list of endangered and

threatened species on October 13, 1970 (35 FR 16047). The subspecies

was subsequently listed under the Endangered Species Act (Act) of 1973,

as amended (16 U.S.C. 1531 et seq.).

Recovery Implementation

The most significant event in the recovery of the peregrine falcon

was the restriction placed on the use of organochlorine pesticides. Use

of DDT was restricted in Canada in 1970 and in the United States in

1972 (37 FR 13369, July 7, 1972). Restrictions that controlled the use

of aldrin and dieldrin were imposed in the United States in 1974 (39 FR

37246, October 18, 1974). Since implementation of these restrictions,

residues of the pesticides have significantly decreased in many regions

where they were formerly used. Consequently, reproductive rates in most

surviving peregrine falcon populations in North America improved, and

numbers began to increase (Kiff 1988).

Section 4(f) of the Act directs the Service to develop and

implement recovery plans for listed species. Recovery teams produced

four regional recovery plans for the American peregrine falcon in the

United States. In addition, the Canadian Wildlife Service published an

Anatum Peregrine Falcon Recovery Plan (Erickson et. al. 1988) for

American peregrine falcons in Canada. No recovery plan or recovery

objectives were established for Mexico.

Several of the recovery plans called for captive-rearing and

release of falcons in several regions of North America. In the eastern

United States, where American peregrines were extirpated, the initial

objective was to reestablish the peregrine through the release of

[[Page 34407]]

offspring from a variety of wild stocks. Peregrine falcons were raised

in captivity from parents of various subspecies, including subspecies

then listed as endangered (anatum, tundrius, peregrinus), unlisted

subspecies (pealei, brookei, etc.), and combinations thereof. The first

experimental releases of captive-produced young occurred in 1974 and

1975 in the United States. Later, reintroduction was also pursued in

eastern Canada, but breeding stock was limited to pure Falco peregrinus

anatum. Because the birds released into the eastern United States were

readily identifiable as peregrine falcons, but were not readily

identifiable as to subspecies or genetic background, enforcement of the

taking prohibitions of the Act for listed subspecies was a problem. The

Service found it difficult to prosecute under section 9 of the Act for

the take of a listed peregrine falcon because the released stocks of

listed, unlisted, and mixed-parentage offspring were almost

indistinguishable. To ensure the protection from illegal take of

American and arctic (F. p. tundrius) peregrine falcons that may be

nesting, migrating, or wintering in the lower 48 States, the Service

designated any free-flying peregrine (Falco peregrinus) found within

the lower 48 States as Endangered due to Similarity of Appearance in

accordance with section 4(e) of the Act (49 FR 10520, March 20, 1984),

thereby extending the taking prohibitions of section 9 to these birds.

In contrast to eastern populations, small numbers of American

peregrine falcons in western North American survived the pesticide era

and all birds released to augment wild populations were pure anatum

subspecies, maintaining the genetic integrity of the subspecies. In

Alaska and northwest Canada, populations were locally depressed but

enough individuals survived the pesticide era that populations began to

expand without the need for release of captive-bred falcons. Likewise,

in the southwest United States, very few captive-bred birds were

released, and populations recovered naturally as a result of

restrictions on the use of organochlorine pesticides. In southwest

Canada, the northern Rocky Mountain States, and the Pacific coast

States, however, local populations were greatly depressed or

extirpated, and over 3400 young American peregrine falcons were

released to promote recovery in those areas (Enderson et al., in litt.

1995).

Recovery Status

Population growth was noted in the late 1970's in Alaska (Ambrose

et al. 1988a) and by 1980 in many other areas (Enderson et al., in

litt. 1995). Although the rate of recovery varied somewhat among

regions, local populations throughout North America have increased in

size, and positive trends in all areas suggest that a very large and

extensive recovery of American peregrine falcons has taken place.

Following is a summary of the status of American peregrine falcons in

the five recovery regions.

Alaskan Recovery Plan (1982)--Recovery objectives are (1) to

establish a minimum of 28 nesting pairs in two specified study areas

(the upper Yukon and Tanana Rivers), (2) produce an average of 1.8

young per territorial pair per year (yg/pr), (3) achieve an average

organochlorine concentration in eggs of less than 5 ppm (parts per

million, wet weight basis) DDE, and (4) achieve eggshell thinning

averaging no more than 10 percent thinner than pre-DDT era eggshells.

These objectives were to be attained for 5 years before reclassifying

to threatened status and an additional 5 years before delisting.

In 1994, 69 nesting pairs were present in the two study areas, and

biologists estimate that at least 300 pairs currently nest in Alaska

(R.E. Ambrose, pers. comm., 1995). Productivity surpassed the objective

for the 14th year in 1994. Average DDE residues decreased from 17.0 ppm

in 1967 to 4.2 ppm in 1991 (Ambrose et al. 1988b). It is now apparent

that the 5 ppm objective was very conservative because normal

reproduction occurred for several years before the average

concentration declined to 5 ppm. Eggshells were estimated to be as much

as 20-22 percent thinner statewide than pre-DDT era shells collected in

the mid-1960's. Although the degree of thinning has gradually decreased

over time, shells collected in interior Alaska still average 12.5

percent thinner than pre-DDT era shells, but reproduction has been

sufficient to allow consistent population growth since the late 1970's.

Therefore, the objective for eggshell thinning levels also may be

overly conservative.

Canadian Recovery Plan (1988)--The Anatum Peregrine Falcon Recovery

Plan for Canada divides the historical range of the American peregrine

falcon throughout Canada into three regions subdivided into nine zones.

The zones are (1) Maritime, (2) Great Lakes, (3) Prairies, (4)

Mackenzie River Valley, (5) Northern Mountains, (6) Southern Mountains,

(7) Eastern Mackenzie Watershed, (8) Western Canadian Shield, and (9)

Eastern Canadian Shield. The objectives of the plan are (1) to

establish by 1992 a minimum of 10 territorial pairs in each of zones 1

to 6, and (2) to establish by 1997 in each of 5 of these 6 zones a

minimum of 10 pairs naturally fledging 15 or more young annually,

measured as a 5-year average commencing in 1993. No recovery goals were

established for zones 7, 8, and 9.

In zones 3 through 6 in western and west central Canada, 206 pairs

were found between 1990 and 1993, with minimum targets achieved in each

zone. In east central and eastern Canada, the goal of 10 territorial

pairs has been surpassed in zone 1, the Maritime, but has not

apparently been achieved for zone 2, the Great Lakes. Both captive

releases and natural recruitment have contributed to the current number

of pairs. An assessment of productivity in these populations will not

be conducted until 1997. However, based on current population size and

productivity, with the possible exceptions of zones 2 and 3, it is

likely that this objective will be met by 1997. It is unclear whether

or not the second productivity-based goal has been met for zone 1. In

summary, it appears the goal of 10 territorial pairs has been achieved

for 5 of the 6 recovery zones.

Pacific Coast (U.S.) Recovery Plan (1982)--This plan recommends

that delisting be considered when (1) 185 wild, self-sustaining pairs

are established with the following distribution: California-120,

Oregon-30, Washington-30, Nevada-5; and (2) fledging success averages

1.5 yg/pr for a 5-year period.

The current Pacific population of American peregrine falcon totals

approximately 224 pairs, and the State-specific objectives for number

of pairs have been met. Although close, productivity objectives have

not been met throughout the Pacific population; however, reproduction

has been sufficient to maintain a positive population growth. The

release of captive bred American peregrines into this population ceased

in 1992, and the effect of releases on population growth and stability

in this region is not yet known. However, if the current population

level is maintained or continues to increase, the population could be

considered self-sustaining. Current reproduction supports an expanding

population despite high organochlorine residue concentrations and

associated eggshell thinning in some areas.

Rocky Mountain/Southwest Population Recovery Plan (revised 1984)--

The objectives for reclassification are (1) a minimum of 183 breeding

pairs with the following distribution: Arizona 46, Colorado 31, Idaho

17, Montana 20, Nebraska 1, New Mexico 23, North Dakota--1, South

[[Page 34408]]

Dakota--1, Texas--8, Utah--21, and Wyoming 14; (2) average production

of 1.25 yg/pr without manipulation; and (3) eggshell thickness within

10 percent of pre-DDT eggshells for a 5-year span. When these

objectives are reached or significant new data are obtained, the

objectives and species classification would be reassessed.

Based on 1994 surveys, the current Rocky Mountain/Southwest

population consists of 559 breeding pairs, surpassing this recovery

objective by 376 pairs. With the exception of Montana, Idaho, Nebraska,

and North and South Dakota, all States within the Rocky Mountain/

Southwest population have met their specific recovery goals for

breeding pairs. Although much of this increase is undoubtedly

attributable to natural growth, a substantial amount also resulted from

releases of captive bred young, and an increased survey effort, and a

gradual increase in the number of breeding areas that have been checked

for the presence of peregrines. The second objective of 1.25 yg/pr for

5 years has not been met in all States, but the current reproductive

level has been sufficient to support considerable population growth.

Based on degree of recovery achieved and a general trend toward thicker

eggshells, the original eggshell thickness objective appears

unnecessary for the recovery.

Eastern (U.S.) Population Recovery Plan (1979; revised 1985 and

1991)--This plan reflects some of the earliest scientific

recommendations regarding peregrine falcon recovery through

reintroduction of captive bred offspring. Release of progeny of various

listed and unlisted subspecies, and combinations thereof, commenced in

the eastern United States in 1974 and 1975. The current plan indicates

that the peregrine should be considered recovered when a minimum of 20-

25 nesting pairs are established in each of five recovery units and are

sustained for a minimum of 3 years, and, overall, a minimum of 175-200

pairs demonstrate successful, sustained nesting. The five recovery

units are (1) Mid-Atlantic Coast, (2) Northern New York and New

England, (3) Southern Appalachians, (4) Great Lakes, and (5) Southern

New England/Central Appalachians.

Substantial progress has been made toward achieving the recovery

criteria, with three of the five recovery units (Mid Atlantic Coast,

Northern New York, and Great Lakes) having surpassed the identified

target of 20-25 nesting pairs for 3 years. The remaining two units--the

Southern Appalachians and southern New England/Central Appalachians

have not done so (10 pairs and 5 pairs respectively, located in 1994),

and are unlikely to reach their goal in the near future due to great

horned owl (Bubo virginianus) predation and other factors. Overall, in

excess of 150 pairs have established nesting territories in the five

units, and the recovery target of 175-200 pairs will likely be reached

by 1996 or 1997 (M. Amaral, in litt., 1995).

Mexico--None of the recovery plans written for peregrine falcons in

North America established recovery criteria for American peregrine

falcons that nest in Mexico. Furthermore, there is very little

historical or recent information on peregrine falcons in Mexico with

which to accurately assess current status in this area. Most of the

research that has been conducted took place on the Baja Peninsula and

in the Gulf of California. It is likely the status of the subpopulation

is similar to that of the subpopulation occupying similar habitat in

nearby Arizona (G. Hunt, pers. comm., 1995). There are no recent data

known to the Service that indicate local American peregrine falcon

populations in Mexico are declining, are imperiled by organochlorine

pesticides, or have not recovered in recent years similarly to local

populations in the United States and Canada.

Summary

In accordance with 50 CFR 424.11(d), a species may be delisted if

the best scientific and commercial data available substantiate that

neither endangered nor threatened status is appropriate because the

species is recovered, extinct, or the original data for classification

of the species were in error, and that the five factors presented in

section 4(a)(1) of the Act are no longer applicable to the species.

Exposure to organochlorine pesticides caused drastic population

declines in American peregrine falcons. Following restrictions on the

use of organochlorines in the United States and Canada, residues in

eggs declined and reproduction rates improved. Improved reproduction,

combined with the release of thousands of captive-reared young, has

allowed the American peregrine falcon to recover. Pesticide residues,

reproductive rates, and the rate of recovery have varied among regions

within the vast range of the subspecies. In some areas, such as

portions of California, the lingering effects of pesticides have caused

reproductive rates to remain low, and recovery may not yet be complete.

Point source contamination may cause continued reproductive problems in

these areas in California, and the recovery in these areas may not be

complete for many years. In eastern and southwestern Canada, the rate

of recovery, or onset of recovery, apparently lagged behind most other

areas within the range of this population segment; but, recent trends

suggest that historical nest sites will continue to be gradually

recolonized in this area. Although the recovery of the American

peregrine falcon is not complete throughout all parts of the historical

range, those areas in which recovery has been exceptionally slow

comprise a small portion of the range of the subspecies. Furthermore,

evidence collected in recent years shows that a combination of

lingering residues of organochlorines in North America and

contamination resulting from the continued use of organochlorines in

Latin America has not prevented a widespread and substantial recovery

of American peregrine falcons. The Service concludes, therefore, that

the continued existence of American peregrine falcons is no longer

threatened by exposure to organochlorine pesticides. The peregrine

would remain protected by the Migratory Bird Treaty Act, which governs

the taking, killing, possession, transportation, and importation of

migratory birds, their eggs, parts, and nests.

Section 4(g)(1) of the Act requires that the Secretary of the

Interior, through the Service, implement a monitoring program for at

least 5 years for all species that have been recovered and delisted.

The purpose of this requirement is to develop a program that detects

the failure of any delisted species to sustain itself without the

protective measures provided by the Act. A monitoring plan for the

American peregrine will be described in the proposed rule.

Public Comments Solicited

The Service intends for the forthcoming proposal to remove the

American peregrine falcon from the Lists of Endangered and Threatened

Wildlife to be based on complete and accurate information. Therefore,

the Service hereby solicits data, comments or suggestions from the

public, other concerned governmental agencies, the scientific

community, industry, or any other interested party, concerning such a

proposal. Comments particularly are sought concerning:

(1) Biological, commercial trade, or other relevant data concerning

any threat (or lack thereof) to this subspecies;

(2) additional information concerning the range, distribution, and

population size of this subspecies;

[[Page 34409]]

(3) current or planned activities in the range of this subspecies

and their possible impacts on this subspecies;

(4) data on population trends in Mexico;

(5) information and comments on the potential impacts of falconry

upon peregrine falcon populations; and

(6) information and comments pertaining to a monitoring plan.

References Cited

A complete list of all references cited herein is available upon

request from the Ventura Ecological Services Field Office (see

ADDRESSES section).

Authors

The primary authors of this notice are Robert Mesta, U.S. Fish and

Wildlife Service, Ventura, Ecological Services Field Office (see

ADDRESSES section), (805/644-1766), Ted Swem, U.S. Fish and Wildlife

Service, Fairbanks Ecological Services Field Office, 1412 Airport Way,

Fairbanks, Alaska 99701 (907/456-0441), and Susan Lawrence, U.S. Fish

and Wildlife Service, Division of Endangered Species, Washington, D.C.,

20240 (703/358-2105).

Authority

The authority for this action is the Endangered Species Act of 1973

(16 U.S.C. 1531 et seq.).

Dated: June 23, 1995.

Mollie H. Beattie,

Director, Fish and Wildlife Service.

[FR Doc. 95-16076 Filed 6-29-95; 8:45 am]

BILLING CODE 4310-55-P