(DRAFT) - Taxonomy
Species CONDOR, CALIFORNIA
Species Id ESIS101045
Date 14 MAR 96
TAXONOMY
NAME - CONDOR, CALIFORNIA
OTHER COMMON NAMES - CONDOR, CALIFORNIA; VULTURE and CALIFORNIA
ELEMENT CODE -
CATEGORY - Birds
PHYLUM AND SUBPHYLUM - CHORDATA,
CLASS AND SUBCLASS - AVES,
ORDER AND SUBORDER - FALCONIFORMES,
FAMILY AND SUBFAMILY - CATHARTIDAE,
GENUS AND SUBGENUS - GYMNOGYPS,
SPECIES AND SSP - CALIFORNIANUS,
SCIENTIFIC NAME - GYMNOGYPS CALIFORNIANUS
AUTHORITY -
TAXONOMY REFERENCES -
COMMENTS ON TAXONOMY -
California Condor
Gymnogyps californianus (Shaw, 1798)
KINGDOM: Animal GROUP: Bird
PHYLUM: Chordata CLASS: Aves
ORDER: Falconiformes FAMILY: Cathartidae
Condors are among the largest flying birds in the world. Adults
weigh approximately 9 kg and have a wing span up to 2.9 m. Adults are
black except for white underwing linings and edges of the upper
secondary coverts. The head and neck are mostly naked; the skin on
the neck area is gray, grading into various shades of yellow, red, and
orange on the head. Males and females cannot be distinguished by size
or plumage characteristics. Five or six years are required for
individuals to attain adult characteristics (10). Wilbur observed
that birds 5 years old are essentially indistinguishable from adults,
and most earlier subadult age classes cannot be separated with
certainty. Among subadults, the age class that can be most reliably
distinguished is the so-called "ring-necked" stage of birds from 3 to
3 1/2 years old. The heads of juveniles are grayish-black, and the
wing linings are variously mottled or completely dark.
The California condor is a member of the family Cathartidae or
Taxonomy - 1 (DRAFT) - Taxonomy
Species CONDOR, CALIFORNIA
Species Id ESIS101045
Date 14 MAR 96
New World vultures, a family of seven species including the closely
related Andean condor (Vultur gryphus) and the sympatric turkey
vulture (Cathartes aura). The inclusion of the Cathartidae in the
order Falconiformes is uncertain. Taxonomists now believe that New
World vultures should be included in the order Ciconiiformes (15).
The following is a list of scientific name variations for the
California condor (also known as the California vulture) as cited in
Wilbur (04): Vultur californianus, Vultur columbianus, Cathartes
californianus, Pseudogryphus californianus, Enops californiana,
Cathartes vulturinus, Sarcorhamphus californianus, Catharista
californiana, and Gymnogyps californicus (04).
The California condor belongs to the genus Gymnogyps (Lesson) and
the species californianus (Shaw 1798). The type specimen was
collected on the coast of California in 1797 and is now in the
ornithological collection at the British Museum (04).
Taxonomy - 2 (DRAFT) - Status
Species CONDOR, CALIFORNIA
Species Id ESIS101045
Date 14 MAR 96
STATUS
Coded Status
E: Federal Endangered
Federal Migratory
Game (Consumptive Recreational)
Non-consumptive recreational
Ceremonial/Cultural
COMMENTS ON STATUS -
U.S. STATUSES AND LAWS:
The California condor (Gymnogyps californianus) 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
Critical Habitat has been designated in Ventura, Los Angeles, Santa
Barbara, San Luis Obispo, Kern, and Tulare Counties, California
(50 CFR 17.95(b)).
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.
The species is protected by the Migratory Bird Treaty Act
(16 U.S.C. 703-711 et seq.) under Gymnogyps californianus (50 CFR
10.13).
Status - 1 (DRAFT) - Status
Species CONDOR, CALIFORNIA
Species Id ESIS101045
Date 14 MAR 96
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: California
DESIGNATED STATUS: Endangered
ADMINISTRATIVE AGENCY: California Dept. of Fish and Game
STATE STATUTE: California Endangered Species Act; Fish and Game
Code Chapt. 1.5, Art. 1, Sec. 2050.
STATE: Arizona, Nevada, Oregon, Utah, and Washington
DESIGNATED STATUS: Recognized Endangered
ADMINISTRATIVE AGENCY: (AZ) Game and Fish Dept.,
(NV) Board of Wildl. Commissioners,
(OR) Dept. of Fish and Wildl.,
(UT) Dept. of Natural Resour.,
(WA) Dept. of Game
STATE STATUTE: (AZ) AZ Rev. Stat. 17-101 to 17-306, AZ Admin.
Rules and Regs. 12-4-314.
(NV) Nev. Admin Code 503.015 to 503.080 12/21/81.
(OR) OR Rev. Stat. 498.026.
(UT) UT Code Annot. 23-13-2 to 23-13-4.
(WA) WA Admin. Code 232-12-014 Rev. Code of WA
Annot. 77.16.040, 77.16.120.
INTERNATIONAL STATUSES, TREATIES, AND AGREEMENTS:
The California condor is listed in the Convention on Nature
Protection and Wildlife Preservation in the Western Hemisphere Annex
(1970). The IUCN lists the condor as endangered, 1979. The
California condor is also listed in Appendix I of CITES.
ECONOMIC STATUSES:
At one time, condor skins and quills were collected by Indians
for ceremonial use. Capturing condors for sport was also a problem
but current laws prevent both from being a problem. Condors in the
wild provided a non-consumptive recreational value to birding
enthusiasts.
67/03/11:32 FR 04001/ - Listed, Endangered w/ Crit. Hab.
75/05/16:40 FR 21499/21500 - Determination of Crit. Hab.
75/12/16:40 FR 58308/58312 - Proposed Crit. Hab.
Status - 2 (DRAFT) - Status
Species CONDOR, CALIFORNIA
Species Id ESIS101045
Date 14 MAR 96
76/09/24:41 FR 41914/41916 - Final rule; Crit. Hab.
77/02/22:42 FR 10462/10488 - Implementation of CITES
79/05/21:44 FR 29566/29577 - Notice of Status Review
85/02/04:50 FR 04918/ - Proposed ACEA status for Condor habitat.
85/04/05:50 FR 13708/13722 - Final rule, Migratory Bird listing.
85/07/22:50 FR 29901/29909 - Notice of Review
85/10/28:50 FR 43612/43613 - Permit PRT 682928 for taking 3 condors.
85/12/05:50 FR 49883/49886 - Notice of availability of EA re: trapping
86/01/06:51 FR 00689/00690 - Receipt of permit, L.A. Zoo.
86/01/13:51 FR 01445/01446 - Environ. assess. for trapping/release.
Status - 3 HABITAT ASSOCIATIONS
HABITAT - TERRESTRIAL
TERRESTRIAL
COMMENTS ON HABITAT ASSOCIATIONS -
The California condor had three basic habitat needs when it
existed in the wild: nesting sites, roosting sites, and feeding
habitat. Nesting areas - condors nested in various types of caves,
crevices, and potholes in isolated areas of the Coast and Transverse
Ranges. Judging from historical records, suitable locations were
found scattered throughout the coastal mountains. Two nests have been
recorded in giant sequoias in the Sierra Nevada, Tulare County, and
this may have been a regular occurrence for condors resident in this
area (09).
In the past 15 years condors had nested in San Luis Obispo,
Ventura, Los Angeles, Santa Barbara, and Tulare Counties. Although
potential (and apparently suitable) nesting habitat still remained
over a relatively large geographical region of coastal and interior
mountains in central and southern California, the present known
populations of condors are isolated in captivity and such habitat
needs provide information for possible sites for future released
birds. All but one nest site known to have been active since 1979,
have been in a narrow belt of chapparal and coniferous forested
mountains from central Santa Barbara County across northern and
central Ventura County to northwestern Los Angeles County. The total
area was approximately 90 km (56 mi) from west to east, only about
15 km (9 mi) from north to south, and entirely within the boundaries
of the Los Padres and Angeles National Forests. A pair of condors
were found in March of 1984 nesting in a giant sequoia in Tulare
County. This discovery indicated that they may have been nesting in
this area over the years since the new nest was only a few miles from
a giant sequoia nest active in 1951.
Roosting areas - California condors often had traditional
roosting sites near important foraging grounds. A typical site had
rock cliffs, dead snags, or stands of live conifers and was in an
isolated area. Foraging condors may have utilitzed a wide variety of
less typical sites, such as large oak trees and rock outcroppings.
Roosting sites are of major importance in the life of the condor.
Depending upon weather conditions and the hunger of the bird, a condor
may have spent many hours perched at a roost.
Feeding habitat - most condor foraging occurred in open grassland
and oak-savannah habitats, primarily in the foothills surrounding the
southern San Joaquin Valley. Most foraging sites were at lower
elevations than most roosting and nesting sites. The important
foraging areas were primarily private grazing lands. Although the
condor was not so ungainly on the ground as portrayed in popular
literature, it did require fairly open terrain for feeding. This
ensured easy take-off and approach and made food-finding easier.
Condors apparently depend on sight rather than smell to locate food.
It appeared likely that condors regularly located food by the presence
of other birds, such as eagles and ravens. Because of their great
mobility, condors foraged over great distances. It was not uncommon
for a condor to travel 80 - 160 km (50 - 100 mi) per day (04).
Habitat Associations - 1 (DRAFT) - Food Habits
Species CONDOR, CALIFORNIA
Species Id ESIS101045
Date 14 MAR 96
FOOD HABITS
TROPHIC LEVEL -
CARNIVORE
LIFESTAGE FOOD FOOD PART
General Carrion
Food Habits - 1 (DRAFT) - Environment Associations
Species CONDOR, CALIFORNIA
Species Id ESIS101045
Date 14 MAR 96
ENVIRONMENTAL ASSOCIATIONS
Environment Associations - 1 (DRAFT) - Life History
Species CONDOR, CALIFORNIA
Species Id ESIS101045
Date 14 MAR 96
LIFE HISTORY
FOOD HABITS:
Currently, all known condors are held in captivity and are being
supplied carcasses and carrion as a food source.
California condors feed only on the carcasses of dead animals.
Historically, this probably included deer, elk, pronghorn, whales, sea
lions, and smaller mammals. Although many species are eaten, Koford
noted in 1953 that domestic cattle constituted the most important food
source by far. Cattle were even more important late in the condors
wild existance, than during Koford's research period, because
domestic sheep had declined drastically in California (08). In one
important condor foraging area, periods of greatest condor use
correlated with the period of cattle abortions and births (04). Mule
deer (Odocoileus hemionus), although possibly a "preferred" food (10),
tended to drift toward canyon bottoms to die (09,11), where steep
terrain and brush interfered with condor foraging. Carcasses under
brush were hard to see, and condors apparently could not locate food
by odor (12,13). Thus, although deer may have been important as food
in some locations or during some seasons, they may have never been a
major food item for condors because other large herbivores were
abundant, until the introduction of cattle. Expansion of the deer
population in some areas (13) and apparent declines in other areas may
not have altered condor food supplies overall. Ground squirrels
(Spermophilus beechyi) killed by animal damage control programs have
been locally important food sources in the past (10) but were seldom
available in significant numbers.
HOME RANGE/TERRITORY:
Intruding condors were sometimes tolerated to the extent that
resident pairs allowed them to stand in the nest entrances, but in
other cases there had been vigorous territorial defense. Two pairs
observed in 1982 had chosen nest sites only 2.6 km apart and
established a sharply defined territorial boundary between them,
maintained with repeated aggressive encounters. Yet one of the two
pairs was observed on one occassion allowing a third pair of condors
to closely approach its nest site and even copulated in the vicinity
of the nest. Koford (10) observed very few signs of intraspecific
territoriality in the species. Reasons for the variability in
territorial defense against conspecifics are unknown.
PERIODICITY:
The California condor is a diurnal species.
MIGRATION PATTERNS:
The California condor was considered non-migratory when in the
wild.
COVER/SHELTER REQUIREMENTS:
The California condor had three basic requirements when it
occurred in the wild: nesting sites, roosting sites, and feeding
habitat.
Nesting areas - Condors nested in various types of caves,
Life History - 1 (DRAFT) - Life History
Species CONDOR, CALIFORNIA
Species Id ESIS101045
Date 14 MAR 96
crevices, and potholes in isolated areas of the Coast and Transverse
Ranges. Judging from historical records, suitable locations were
found scattered throughout the coastal mountains. Two nests had been
recorded in giant sequoias in the Sierra Nevada, Tulare County, and
this may have been a regular occurrence for condors residing in this
area (09).
Roosting areas - California condors often had traditional
roosting sites near important foraging grounds. A typical site had
rock cliffs, dead snags, or stands of live conifers and was in an
isolated area. Foraging condors may have utilitzed a wide variety of
less typical sites, such as large oak trees and rock outcroppings.
Roosting sites were of major importance in the life of the condor.
Depending upon weather conditions and the hunger of the bird, a condor
may have spent many hours perched at a roost.
Feeding habitat - most condor foraging occurred in open grassland
and oak-savannah habitats, primarily in the foothills surrounding the
southern San Joaquin Valley. Most foraging sites were at lower
elevations than most roosting and nesting sites. The important
foraging areas were primarily private grazing lands. Although the
condor was not so ungainly on the ground as portrayed in popular
literature, it did require fairly open terrain for feeding. This
ensured easy take-off and approach and made food finding easier, since
condors apparently depended on sight rather than smell to locate food.
REPRODUCTIVE SITE REQUIREMENTS:
Nest Sites: California condors, like other cathartids, were
cavity nesters (10). Nest sites ranged from potholes or other kinds
of caves in cliffs to crevices among boulders on steep slopes and
occasionally burnt-out holes in giant sequoia trees (Sequoiadendron
giganteum). The most usual sites were caves in cliffs. It did not
appear that individual condors were rigid in the kinds of sites they
used, as one bird that nested in a giant sequoia in 1984 used a cliff
pothole site in earlier years.
A study of 68 recent and historic nest sites (14) indicates that
nest elevations have ranged from 460 to 1,830 m, with a preponderance
of sites about 600 to 1,000 m above sea level. Most have been located
in the Upper Sonoran Life Zone though a few have been as high as the
Transition Zone. Nests at low elevations tended to face north, while
high elevation nests tended to face south, as has been seen also in
Golden Eagles (Mosher and White 1976), but the overall distribution
of nest orientations had been random. The differences between
orientations of high and low elevation nests may have been related to
temperature regulation.
Entrance sizes of nests were exceedingly variable, with the only
obvious restriction being that the entrances had to be large enough to
allow entry by the birds. Entrance heights have ranged from 30 cm to
5.5 m, while widths have ranged from 20 cm to 2.4 m. Nest depths have
ranged from 0.6 m to 14.6 m, with a preponderance of sites about
1.5 to 2.0 m deep. Eggs have generally been placed as far back in the
cavities as there had been a suitable level substrate and an
adequately high ceiling. The lowest ceiling recorded at the egg
position was only 38 cm high, and the distribution of ceiling heights
at the egg position peaked strongly between 50 and 75 cm. Not all egg
Life History - 2 (DRAFT) - Life History
Species CONDOR, CALIFORNIA
Species Id ESIS101045
Date 14 MAR 96
substrates have been level. Six sites with nest bottoms sloping more
than 5 degree had been located (06). Of the 68 sites studied by
Snyder et al., (14) 23 were accessible to man without climbing aids,
15 were easy walk-ins.
All condor pairs observed, when in the wild, over a period of
several years have had more than one nest site. The general rule,
at least in the most recent years, had been for pairs to change nest
sites in successive nestings, regardless of whether they had succeeded
or failed in the sites. While most sites examined had shown evidence
of repeated use by condors, many years often passed between occupancy.
Alternate nest sites were commonly not in view from one another and
often occurred in different canyons.
REPRODUCTIVE CHARACTERISTICS:
Courtship and nest site selection by breeding condors usually
occurred in December through the spring months. Condors lay a single
egg between late January and May (16); it is incubated by both parents
and hatches after about 56 days. Because of the long period of
parental care, it has been assumed that condor pairs normally nested
every other year. However, this pattern seemed to vary depending on
the time of year that the nestling fledged and on food availability.
For example, if the nestling fledged in late summer or early fall, its
parents may have nested the following year. But consecutive-year
nesting likely would result in the egg being laid late during the
second year.
Condor can lay replacement eggs if their first (18), or even
their second egg is lost (17). Whether they lay a replacement egg may
depend on the time of year, at what stage of incubation the egg is
lost, individual variation, and perhaps genetic factors. Because
subadult birds have never been members of breeding pairs, Koford (10)
concluded that age at first reproduction in California condors is at
least 6 years. But the age is more likely to be at least 8 years,
based on knowledge of the age at first breeding among other large bird
species with long reproductive periods. A California condor in the
National Zoological Park (03) was 12 years old when it laid its first
egg (19). Condors apparently mate for life. One radioed pair had
been seen together from 1982 through 1985, laying 6 eggs during that
period (20).
PARENTAL CARE:
Both parents shared in feeding and brooding the nestling when
they were observed in the wild.
Feeding usually occured daily for the first 2 months, then
gradually diminished in frequency. The chick took its first flight at
about 6 months of age, but was not become fully independent of its
parents until the following year. Parent birds occasionally continued
to feed the chick even after the young bird had begun to make longer
flights to foraging grounds (17). Due to the remaining condors being
in captivity, most care is being done by trained staff members, using
puppets resembling adult birds to prevent "imprinting" on humans.
POPULATION BIOLOGY:
Chicks hatch with their eyes open. Although they are too weak
Life History - 3 (DRAFT) - Life History
Species CONDOR, CALIFORNIA
Species Id ESIS101045
Date 14 MAR 96
to hold their heads up except briefly, they take food readily right
after hatching. At hatching the rate of exchanges by adults increased
dramatically, from one exchange every 2 to 4 days during incubation to
almost-daily exchanges during the first weeks of the nestling period.
The frequency of visits to the nest by adults gradually slowed during
the rest of the nestling period. As a general average, each adult
made about 3-5 feeding visits to the nest each week of the nestling
period.
When in the wild, during the early nestling phase the adults took
turns at the nest as they did during incubation. Brooding is
continuous for about the first 1-2 weeks and becomes less and less
steady over the next 2 weeks, finally ceasing altogether after about
4 weeks. At this time both adults began to be away from the nest area
simultaneously and the chick was left alone overnight for the first
time. Feedings were by regurgitation. During the first 2 weeks,
chicks, at 2 past nests, received about 6 feedings per day (daylight
hours), but this rate gradually declined to a frequency of about
1.2 feedings per day by the time of fledging. Depending on the
structure of the nest site, chicks began to wander outside the nest
entrance as early as 6 weeks of age, either deliberately or because
they fell downslope from the entrance.
First sustained flights were observed at ages ranging from about
5 to 6 months, and have ranged in length from about 20 to 300 m. (17).
First flights have been seen as early as September and as late as
November in recent years, but young have remained completely dependent
on their parents for periods of about a half a year after fledging. A
nestling that fledged relatively early on September 22, 1982, was
first seen following its parents to the foraging grounds on
February 1, 1983. During March 1983, its parents became increasing
aggressive to it and drove it from the nesting area, finally beginning
a new nesting cycle with an egg laid about March 31.
Whether adults ever initiated breeding attempts in years
following late fledgings of young (November or December) is unknown.
Adults had been seen feeding juveniles on the foraging grounds in
summer and fall and it appeared that partial dependency of juveniles
on adults continued as long as about a year after fledging, in some
cases. A captive at the Los Angeles Zoo exhibited begging behavior
until its fifth spring after hatching (21).
Because of the mobility of the once wild condors and the
inaccessibility of much of the species' range, Gymnogyps had always
been a difficult bird to census.
Population estimates of 60 and 40 birds by Koford (10) and Miller
et al. (08), respectively, were based on a number of questionable
assumptions and probably underestimated condor numbers significantly
(14). An annual simultaneous count (October survey) was begun in 1965
and led to a consensus that there were still about 60 birds in
existence in the mid-1960's (22,23). However, totals of the October
survey varied greatly over the years, leading to considerable debate
as to their accuracy and significance (24,25). Nevertheless, there
was an unmistakable overall decline in the totals during the 17-year
period the survey was conducted, and by 1978 Wilbur (25) estimated
only 25 to 35 birds left in the wild.
In 1981, efforts were begun to use photographic identification of
Life History - 4 (DRAFT) - Life History
Species CONDOR, CALIFORNIA
Species Id ESIS101045
Date 14 MAR 96
individuals as a basis for generating population estimates (41).
These efforts revealed that differences in primary feather molt and
damage give a highly reliable means for recognizing individual condors
through time. Analyses of thousands of photographs from throughout
the range of the species led to late summer population estimates of 21
to 24 individuals, including 7 immatures, for 1982; 19 to 22
individuals, including 5 immatures, for 1983; and 15 to 18 (07)
individuals, including 2 immatures for 1984. The loss rate in the
wild increased dramatically in the fall/winter 1984-85, when 6 birds
died in an 8-month period and the number of breeding pairs decreased
drastically from five in 1984 to one in 1985 (05). By May 1985 only 9
wild condors could be found in greatly intensified efforts to
photograph the wild population, and only one breeding pair could be
found of the 5 pairs known in 1984. Of the remaining wild individuals
5 were known to be males and 4 were believed to be females, based on
blood sexing and reproductive history data (09,26). Verner (24)
calculated that a stable condor population would not be possible with
mortality rates over 5 percent annually in adults and 15 percent
annually in immatures. Rates of decline and reproduction in the last
2 years suggest an overall mortality rate exceeding 15 percent for all
ages considered together, again suggesting that the major problems
have been ones of mortality rather than reproduction.
SPECIES INTERRELATIONSHIPS:
None.
OTHER LIFE HISTORY DESCRIPTORS:
Human disturbance normally would not have caused condors to
abondon their nests, in the sense that they would fly from nest sites
and not return. In fact, some nest had succeeded inspite of repeated
disturbance (10,23). Nevertheless, human disturbance discouraged
condors from nesting in otherwise suitable habitat and may have caused
nest failure. This may also reflect an increased likelihood of human
predation on condors where disturbance is greater.
Sibley (23) found a correlation between the location of past
condor nest sites and the location and magnitude of human activity.
Life History - 5 (DRAFT) - Management Practices
Species CONDOR, CALIFORNIA
Species Id ESIS101045
Date 14 MAR 96
MANAGEMENT PRACTICES
RESULT MANAGEMENT PRACTICE
Beneficial Controlling/Restricting Air Space Usage
Beneficial Controlling/Restricting Off-Road Vehicles
Beneficial Restricting/regulating human disturbance of populations
Beneficial Controlling/Restricting Mining
Beneficial Controlling/Restricting Road Maintainance Actions
Beneficial Maintaining undisturbed/undeveloped areas
Beneficial Land Acquisition
Beneficial Controlling pollution [thermal, chemical, physical]
Beneficial Controlling/Restricting Pesticide Use
Beneficial Stocking captive-reared wild-strain animals
Beneficial Supplemental Feeding
Beneficial Rehabilitating Individuals
Beneficial Restricting Poaching
Beneficial Controlling/Removing Native Vertebrates
Adverse Incidental Capturing/Killing
Existing Incidental Capturing/Killing
Adverse Harassment/Vandalism/Indiscriminate Killing
Existing Harassment/Vandalism/Indiscriminate Killing
Adverse Collecting
Existing Collecting
Adverse Inherent Reproductive Characteristics
Existing Inherent Reproductive Characteristics
Adverse Low Gene Pool
Existing Low Gene Pool
Adverse Rural Residential/Industrial Areas
Existing Rural Residential/Industrial Areas
Adverse Recreational development
Existing Recreational development
Adverse Transmission Lines/Towers
Existing Transmission Lines/Towers
Adverse Reservoirs
Existing Reservoirs
Adverse Applying pesticides
Existing Applying pesticides
Adverse Environmental Contamination/Pollution
Existing Environmental Contamination/Pollution
Adverse Predator control
Existing Predator control
Adverse
Existing
Adverse Vegetation Composition Changes
Existing Vegetation Composition Changes
Adverse Suppressing wildfire
Existing Suppressing wildfire
COMMENTS ON MANAGEMENT PRACTICES -
Causes of continued condor population decline have been
diverse. However, little information is available to document precise
Management Practices - 1 (DRAFT) - Management Practices
Species CONDOR, CALIFORNIA
Species Id ESIS101045
Date 14 MAR 96
causes. Review of historical and recent reproduction of the species
suggest that 50 percent nesting success has been usual over the past
40 years, a rate comparing favorably with that found for several
species of African vultures. Thus, although the nesting success of
the condor has not been particularly high, no clear evidence shows
that it is abnormally low or has changed greatly in recent decades.
It appears that the decline may have resulted more from mortality than
from reproductive factors (06). However, productivity probably was
adversely affected during periods of DDT use in California, and
continues to be a concern. Kiff et al. (07) showed that condor eggs
contaminated with DDT have thinner shells. This thinness may have
caused increased breakage or embryonic death and, hence, lower
productivity. The low numbers of breeding pairs left has resulted in
an inbreeding depression which has led to low viability, low
fecundity, and an abnormal sex ratio (02).
Adult California condors have no known regular natural enemies,
and judging from zoo records of condors living to be 30 to 45 years of
age, they have the potential for a long life. Some former causes of
(02) mortality -- egg and skin collecting, collecting for quills,
Indian ceremonial use, and capturing for sport -- are illegal now and
no longer threats to condors. Specific causes of mortality include
shooting and collision. Collisions have occurred with aircraft and
misplaced powerlines, wind turbines, and other obstacles (02). Other
mortality factors may include various forms of poisoning (lead, DDT,
cyanide, strychnine, compound 1080), fouling in oil sumps, and
disease. Whether certain of these potential causes have been dominant
in the decline is unknown. Relatively few condors have been found
dead over the years, and causes of death have been determined in only
a few of these cases (04,08). Moreover, they may represent a biased
sample of birds dying primarily from certain causes, such as shooting.
Lead toxicosis was unknown as a cause of death in California
condors until March 1984, when a high lead level in blood sampled
from a condor trapped in October 1982, raised concerns that condors
possibly were being exposed to excessive levels of this metal. Before
that, concerns over lead contamination in condors had been part of
more general concerns about condors potentially obtaining heavy metals
biologically incorporated in body tissues of their food or in polluted
air. Several captive vultures had earlier died from accidentally
ingesting lead fragments.
Three California condors are known to have died of lead
poisoning, a 5 or 6 year old male found dead in March 1984, a 5 year
old male found dying in April 1985, both in Tulare County and an adult
female found dying in Kern County. A copper-coated lead bullet
fragment was found in the gizzard of the 1984 bird, the same bird that
had an extremely high level of lead in the blood sample taken in
October 1982 (05).
Following the cyanide-poisoning death of a condor in November
1983, apparently from an M-44 coyote control device, the USFWS
modified its Animal Damage Control (ADC) activities in condor range.
Wildfires and improperly managed controlled fires have destroyed
condor habitat in the past. Existing ranches contain condor habitat
and threatened the bird because of agricultural development and
overgrazing which results in erosion of soils and vegetational cover.
Management Practices - 2 (DRAFT) - Management Practices
Species CONDOR, CALIFORNIA
Species Id ESIS101045
Date 14 MAR 96
The recreational use of Pine Mountain/Reyes Peak and Basket Peak
areas threatened the condors key habitat area along with the expansion
of residential and industrial development.
APPROVED PLAN:
U.S. Fish and Wildlife Service. 1984. California Condor Recovery
Plan. U.S. Fish and Wildl. Serv., Portland, OR. 160 pp.
The primary objective is to restore and maintain a
self-sustaining population of California condors in previous habitat
by management of captive propagation, and release into the wild. For
reclassifying to threatened status, there must be 100 bird population
whose production equals or exceeds mortality for 10 years. For
delisting there must be over 100 birds in an existing population and
in one or more additional populations.
These objectives will be attained by:
1. Providing adequate condor habitat for release;
2. Protecting all suitable nesting sites by preventing human
disturbances (including direct human disturbances,
off-road vehicles, road maintenance (including mowing),
and air vehicle overflights near nesting, roosting, and
feeding areas), restricting developments (including mining
activities), environmental modifications, and human use
near all previous nest sites, and restricting air space;
3. Securing privately owned land in previously known condor
nesting sites;
4. Providing adequate roost habitat by restricting
developments, preserving sites, restricting human
activities, closing sanctuaries and other essential
habitats, and developing management plans for roosts when
condors are released into the wild;
5. Providing feeding habitat through preservation of previous
feeding sites, supplemental feeding, promoting the
practice of leaving dead livestock in pastures in the
future;
6. Reducing condor mortality by reducing animal damage
control programs, preventing shootings, monitoring
contaminant exposure, reducing collision hazards (such as
aircraft and misplaced powerlines), controlling predators
which may damage nests and destroy eggs;
7. Preserving habitat selected for re-establishment of
condors;
8. Monitoring the present condors to track success of
management;
9. Implementing information and education program;
10. Maintaining or increasing the condor population size
through a captive breeding program.
Management Practices - 3 (DRAFT) - References
Species CONDOR, CALIFORNIA
Species Id ESIS101045
Date 14 MAR 96
References
***** REFERENCES FOR ALL NARRATIVES EXCEPT N-OCCURRENCE *****
01 American Ornithologists Union. 1983. Check-list of North American
birds. Allen Press, Lawrence, KS.
02 U.S. Fish and Wildlife Service. 1984. Revised California condor
recovery plan. U.S. Fish and Wildl. Serv., Portland, OR. 160 pp.
03 Swann, H.K. 1930. A monograph of the birds of prey. Vol. 1.
Weldon and Wesley, London, England.
04 Wilbur, S.R. 1978. The California condor, 1966-1976: a look at
its past and future. U.S. Fish and Wildl. Serv., North Amer. Fauna
72. Wash., D.C.
05 U.S. Fish and Wildlife Service and California Department of Fish
and Game. 1985. Report to the California Fish and Game Commission
on condor mortality, issues, actions and recommendations.
Sacramento, CA.
06 Snyder, N.F.R. 1983. California condor reproduction, past and
present. Bird Conserv. 1:67-85.
07 Kiff, L.F., et al. 1979. Recent changes in California condor
eggshells. Condor 81:166-172.
08 Miller, A.H., et al. 1965. The current status and welfare of the
California condor. Nat'l. Aud. Soc., Res. Rept. No. 6.
09 Snyder, N.F.R., R.R. Raney and F.C. Sibley. 1986. Nest site
biology of the California condor. Condor 88:228-241.
10 Koford, C.B. 1953. The California condor. Nat'l. Aud. Soc., Res.
Rept. No. 4.
11 Scott, J.N. and R.L. Jurek. 1985. Report to the California Fish
and Game Commission on Condor mortality issues, action and
recommendations. Condor Research Center, Ventura, CA.
12 Beebe, C.W. 1909. New World vultures. Part II. N.Y. Zool. Soc.
Bull. 32:465-470.
13 Stager, K. 1964. The role of olfaction in food location by the
turkey vulture (Cathartes aura). L.A. Co. Mus. Contrib. 81:1-63.
14 Snyder, N.F.R. and E.V. Johnson. (n.d.). A photographic census of
the 1982 California condor population.
15 Rea, A.M. 1983. Cathartid affinities: a brief overview. IN S.R.
Wilbur and J.A. Jackson (eds.). Vulture Biol. and Mgmt. Univ. of
CA Press, Berkeley. pp 26-54.
16 Brodkorb, P. 1964. Catalogue of fossil birds, part 2
(Anseriformes through Califormes). Bull. Florida State Mus., Biol.
Sci. 8:195-335.
17 Snyder, N.F.R. and J.A. Hamber. 1985(ms). Replacement clutching
and annual nesting of California condors.
18 Harrison, E.N. and L.F. Kiff. 1980. Apparent replacement clutch
laid by wild California condor. Condor 82:351-352.
19 Dixon, J. 1924. California condors breed in captivity. Condor
26:192.
20 Hamber, J.A. 1985. Pers. comm. Santa Barbara Mus. of Nat. Hist.
Santa Barbara, CA.
21 Todd. 1974.
22 Rabbelle ad Borneman
23 Sibley, F.C. 1969. Effects of the Sespe Creek Project on the
References - 1 (DRAFT) - References
Species CONDOR, CALIFORNIA
Species Id ESIS101045
Date 14 MAR 96
California condor. U.S. Fish and Wildl. Serv., Patuxent Wildl.
Res. Ctr., Laurel, MD. 19 pp.
24 Verner, J. 1978. California condor: Status of the recovery
effort. U.S. Forest Serv., Gen. Tech. Rept. PSW-23.
25 Wilbur, S.R. 1980. Estimating the size and trend of the
California condor population, 1965-1978. CA Fish and Game.
66:40-48.
26 Kumanmoto, A. 1984. Pers. comm.
***** REFERENCES FOR N-OCCURRENCE NARRATIVE ONLY *****
01 U.S. Fish and Wildlife Service. 1984. Revised California Condor
recovery plan. U.S. Fish and Wildl. Serv., Portland, OR. 160 pp.
02 Wilbur, S.R. 1978. The California condor, 1966-1976: a look at
its past and future. U.S. Fish and Wildl. Serv., N. Amer. Found.
Wash., D.C. 72 pp.
03 Ryser, Jr. F. 1985. Birds of the great basin. Univ. of NV Press,
Reno.
04 Rea, A. 1981. California condor captive breeding: a recovery
proposal. Environ. So. West. Winter 1981, No. 48. San Diego Soc.
of Nat. Hist., San Diego, CA.
05 Koford, C.B. 1953. The California Condor National Audobon Society
Research Report. No. 4.
References - 2