(DRAFT) - Taxonomy
Species FALCON, APLOMADO, NORTHERN
Species Id ESIS102005
Date 14 MAR 96

TAXONOMY

NAME - FALCON, APLOMADO, NORTHERN

OTHER COMMON NAMES - FALCON, APLOMADO, NORTHERN; FALCON, APLOMADO; HALCON FAJADO O PLOMIZO;HALCON FAJADO; HALCON AZUL PLOMIZO;HOBBY and ORANGE-CHESTED; HALCON AZUL PLOMIZO MEXICANO

ELEMENT CODE -

CATEGORY - Birds

PHYLUM AND SUBPHYLUM - CHORDATA,

CLASS AND SUBCLASS - AVES,

ORDER AND SUBORDER - FALCONIFORMES,

FAMILY AND SUBFAMILY - FALCONIDAE,

GENUS AND SUBGENUS - FALCO,

SPECIES AND SSP - FEMORALIS, SEPTENTRIONALIS

SCIENTIFIC NAME - FALCO FEMORALIS SEPTENTRIONALIS

AUTHORITY -

TAXONOMY REFERENCES -

COMMENTS ON TAXONOMY -
Northern Aplomado Falcon

Falco femoralis septentrionalis Todd, 1916

KINGDOM: Animal GROUP: Bird

PHYLUM: Chordata CLASS: Aves
ORDER: Falconiformes FAMILY: Falconidae

Aplomado falcons are long-tailed falcons intermediate in size
between American kestrels (Falco sparverius) and prairie falcons
(F. mexicanus). A typical adult bird has the following
characteristics: a) bluish-gray dorsum; b) long blackish tail marked
with 8 narrow white bands (only 5-6 bands easily visible); c) pale,
buffy upper breast (sometimes rufous-tinted or grey); d) a broad,
blackish band or cummerbund on the lower breast and upper abdomen
(often with small, whitish crossbars); e) rufous feathers on the lower
abdomen and under coverts; f) blackish wing linings with numerous,
small, whitish crossbars, g) white-edged remiges that form a narrow
white line on the trailing edges of the wings; and h) a bold, striped
facial pattern. Cere, eye-ring, legs, and feet are bright yellow.
Sexes are similar, with males noticeably smaller than females (02).
A typical immature is brownish-grey dorsally and has dark
streaks on a cinnamon upper breast. Crossbars on the cummerbund,
Taxonomy - 1 (DRAFT) - Taxonomy
Species FALCON, APLOMADO, NORTHERN
Species Id ESIS102005
Date 14 MAR 96

tail, and wing linings are narrower than on adults and cinnamon
instead of buff. At fledging, cere and eyerings are blueish-green
while legs and feet are pale yellow (02).
The Northern Aplomado falcon was described in 1916 (03) as the
subspecies Falco femoralis septentrionalis Todd, 1916. Synonyms from
previous descriptions include F. fusco-coerulescens (Vieill. Nouv.
Dict. Hist. Nat. XI, 90, 1819) and Hypotriorchis femoralis (Gray, Gen.
B. fol. sp. 13, 1844). There has been no controversy over the current
names or taxonomic delineation of this subspecies, although Falco
fusco-coerulescens septentrionalis Todd is cited in Friedman, et al.
(21) as the original subspecies usage. The type specimen was an adult
male collected by H.C. Benson on May 6, 1887 (U.S. Natl. Museum
specimen #111,485) near Fort Huachuca Military Reservation, Cochise
County, Arizona (03). Other common names associated with the species
and subspecies include Aplomado falcon, orange-chested hobby, and the
spanish names Halcon azul plomizo mexicano (21), Halcon fajado o
plomizo, Halcon fajado (22), and Halcon azul plomizo (22). Pictures
and/or drawings can be found in a variety of publications and field
guides including "Falcons of the World" (20).

Taxonomy - 2 (DRAFT) - Status
Species FALCON, APLOMADO, NORTHERN
Species Id ESIS102005
Date 14 MAR 96

STATUS

Coded Status

E: Federal Endangered
Federal Migratory

Game (Consumptive Recreational)
Non-consumptive recreational

COMMENTS ON STATUS -
U.S. STATUSES AND LAWS:
The Northern Aplomado falcon (Falco femoralis septentrionalis)
has been designated as Endangered 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 subspecies has this status wherever found
including the States of Arizona, New Mexico and Texas; in Mexico and
in Guatemala.
This subspecies 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 subspecies is protected by the Migratory Bird Treaty Act
(16 U.S.C. 703-711 et seq.) under the species name Aplomado falcon
(Falco femoralis) (50 CFR 10.13).

RESPONSIBLE FEDERAL AGENCIES:

USFWS -Responsible for the management/recovery, listing, and
Status - 1 (DRAFT) - Status
Species FALCON, APLOMADO, NORTHERN
Species Id ESIS102005
Date 14 MAR 96

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: Arizona
DESIGNATED STATUS: Nongame and Group 1
ADMINISTRATIVE AGENCY: Arizona Game and Fish Department
STATE STATUTE: AZ Rev. Stat. 17-101 A 21, and AZ Rules and Regs.
12-4-210.

STATE: New Mexico
DESIGNATED STATUS: Endangered, Group No. 1
ADMINISTRATIVE AGENCY: New Mexico Dept. of Game and Fish
STATE STATUTE: Reg. 624, Sec. 17-2-41 NM Stat. Annot.

STATE: Texas
DESIGNATED STATUS: Protected nongame
ADMINISTRATIVE AGENCY: Texas Parks and Wildlife Dept.
STATE STATUTE: Tex. Parks and Wildl. Code, Sec. 43.021-43.030,
and 65.173 (127.70.12.003).

INTERNATIONAL STATUSES, TREATIES, AND AGREEMENTS:
All species in the family Falconidae are listed in Appendix II of
CITES which includes the Aplomado falcon. Covered under the
Convention for the Protection of Migratory Birds and Game Mammals,
1936, United States - Mexico, T.S. No. 912. The species is listed as
an endemic species in danger of extinction in Mexico. The Northern
Aplomado falcon appeared on the U.S. list for the Convention on Nature
Preservation and Wildlife Protection in the Western Hemisphere Annex
in 1967 but does not appear on the 1970 revision.

ECONOMIC STATUSES:
This falcon has been used in falconry, though not extensively.
It has a non-consumptive recreational value to birding enthusiasts and
value as a component of Arizona's, New Mexico's, and Texas' natural
heritage of biotic diversity.

82/12/30:47 FR 58454/58460 - Notice of Review
85/04/05:50 FR 13708/13722 - Migratory Bird Treaty Act List
85/05/20:50 FR 20810/20814 - Proposed Rule
86/02/25:51 FR 06686/06690 - Final Rule, Endangered

Status - 2 HABITAT ASSOCIATIONS

HABITAT - TERRESTRIAL
TERRESTRIAL

COMMENTS ON HABITAT ASSOCIATIONS -
Typical habitat for Falco femoralis septentrionalis (Northern
Aplomado falcon) is open woodland, savanna, or open grassland. In the
Chihuahuan Desert, Northern Aplomado falcons lived in grasslands
containing scattered mesquite and yucca (Yucca elata) (12,13,14,15).
On the Gulf-coastal plain of Texas and northeastern Mexico, Aplomados
nested in yucca and mesquite savannas. Further south Aplomados
inhabit a number of other savanna associations including: a) oak
savanna, b) palm savanna, c) savanna associations dominated by
Crescentia cujete, d) open woodland dominated by palo de roas trees
(Tabebuia rosea), e) Acacia farnesiana savana, f) cut-over rainforest,
and g) plowed and fallow farmlands containing scattered trees (01).
Rainfall within the range of this species varies from a high of
1700 mm per annum in eastern Mexico to as little as 200 mm per annum
in the Chihuahuan Desert (15). In eastern and central Mexico daily
temperatures average 27 degrees Celsius during the warmer months.
Winter temperatures average 10 degrees Celsius in central Mexico.
During the rainy season (May-October) in eastern Mexico temperatures
average 23 degrees Celsius. In much of the Chihuahuan Desert on the
Central Plateau rainfall is biseasonal. Most precipitation falls in
late summer, with the remainder coming from December-April. In both
regions, Aplomado falcons nest mainly between March and June.
The characteristics of Aplomado falcon nesting habitat in eastern
Mexico were summarized as follows (01): a) distances between trees
averaged 45 m (s.d. +/-43 m), ranging from 100 m to a couple of yards;
b) average density of trees was 19/40 ha (100 acres); c) the height of
trees at active sites averaged 9 m (s.d. +/-4.8 m); and d) ground
cover tended to be bery dense below 0.25 m. Occupied nesting
territories had taller trees and less vegetation below 1 m than
unoccupied sites. Taller trees provide better perches from which to
spot prey. Similarly, sparser ground cover provides less cover for
prey. Both factors would contribute to the hunting success of
Aplomados and improve overall territory quality. In summary,
essential components of the habitat of the Northern Aplomado falcon
include the following: a) open terrain with scattered trees,
b) relatively low ground cover, c) an abundance of small to medium
sized birds (20-200 g), and d) a supply of nesting platforms -- stick
nests or large bromeliads (01,02).

Habitat Associations - 1 (DRAFT) - Food Habits
Species FALCON, APLOMADO, NORTHERN
Species Id ESIS102005
Date 14 MAR 96

FOOD HABITS

TROPHIC LEVEL -
CARNIVORE

LIFESTAGE FOOD FOOD PART
General Reptilia
General Mammalia
General Arthropods
General Aves

Food Habits - 1 (DRAFT) - Environment Associations
Species FALCON, APLOMADO, NORTHERN
Species Id ESIS102005
Date 14 MAR 96

ENVIRONMENTAL ASSOCIATIONS

Environment Associations - 1 (DRAFT) - Life History
Species FALCON, APLOMADO, NORTHERN
Species Id ESIS102005
Date 14 MAR 96

LIFE HISTORY

FOOD HABITS:
The most extensive studies on Falco femoralis septentrionalis
were conducted by Hector (01,06) in eastern Mexico. He sampled the
food habits of the species by collecting prey remains and by observing
hunting falcons. Forty-three species of birds were represented in the
sample of prey remains. Unidentified birds contributed only 7.6
percent of total prey biomass. The five species contributing the most
biomass were the mourning dove (Zenaida macroura), white-winged dove
(Z. asiatica), groove-billed Ani (Crotophaga sulcirostris), female
great-tailed grackle (Quisclaus mexicanus), and yellow-billed cuckoo
(Coccyzus americanus). Common ground doves (Columbina passerina),
Northern bobwhite (Colinus virginianus), meadowlarks (Sturnella sp.),
and tropical kingbirds (Tyrannus melancholicus) were also commonly
taken.
Prey remains are rather insensitive to the presence of small prey
items (16,17). Of 256 prey remains, only 15 (5.9 percent) were
insects. However, of 234 prey captures observed, 152 (65.0 percent)
were insects. Beetles, wasps, cidadas, moths, and butterflies were
taken (01). But the 76 birds that were captured by falcons under
observation contributed 97 percent of the dietary biomass recorded by
this study method. Although insects are very small compared to
typical avian prey, they seemed to be easily captured and abundant
enough to make it feasible for the falcons to capture them in large
numbers.
White-winged doves, mourning doves, female great-tailed grackles,
and two size-classes of unidentified birds were the five "species"
most commonly taken (by biomass) by falcons under observation.
Grove-billed ani and yellow-billed cuckoo ranked eighth and ninth.
The highest ranked insect category (unidentified) ranked 14th.
Prey size: The weight of prey remains averaged 82.2 g, while the
average weight of prey represented in the sample of observed feedings
and captures was 23.8 g. The largest prey animal detected was an
adult plain chachalaca (Ortalis vetula); average weight for this
species was given as 830 g and Hector (06) felt that this species was
near the upper size limit of prey taken by Aplomados.
In dryer parts of their range these falcons preyed on lark
buntings (Calamospiza melanocorys), lark sparrows (Chondestes
grammacus) (Ligon 1909 notes in 02); horned Larks (Eremophila
alpestris), dragonflies and crickets (R.T. Kellogg in 18); bats (13);
quail, ground-doves, "smaller species of ducks", pigeons, and
sandpipers (Grayson in 19); kangaroo rats (Dipodomys sp.) (stomach
contents of a male collected by R.D. Camp in 12); and small reptiles
(12).

HOME RANGE/TERRITORY:
Aplomado falcons are, like most raptors, territorial during the
breeding season. They likely remain in the same area (=home range)
throughout the year in eastern Mexico (01). Nesting Aplomado falcons
usually hunt close to their nest (within 500 m) (01).

PERIODICITY:
Life History - 1 (DRAFT) - Life History
Species FALCON, APLOMADO, NORTHERN
Species Id ESIS102005
Date 14 MAR 96

This species is diurnal; they are also more active early in the
day (01), and crepuscular in hunting habits (20).

MIGRATION PATTERNS:
The Aplomados of eastern Mexico can be found on their territories
throughout the year, hunting and feeding together, and defending the
previous year's platform (02). The birds that bred in the United
States, at the northern portion of the historic breeding range, may
have migrated south for the winter though there are some winter
records from the U.S. There appears to have been some autumn
wandering, for the adult male that was collected in Austin County,
Texas, in December 1900 was 160 km (100 miles) beyond known historic
breeding range. Sixteen of 21 dated post-1930 records for the species
in the U.S. were also in late summer, autumn, or winter; likely post
breeding wanderers (02).

COVER/SHELTER REQUIREMENTS:
This species has no special cover/shelter requirements other
than those described for nests under REPRODUCTIVE SITE REQUIREMENTS.

REPRODUCTIVE SITE REQUIREMENTS:
Aplomado falcons do not build their own nests, instead they use
stick platforms created by other species of lay eggs in natural
platforms such as bromeliads. In eastern Mexico, nests of the
roadside hawk (Buteo magnirostris), brown jay (Psilorhinus morio),
gray hawk (Buteo nitidus), and black-shouldered kite (Elanus leucurus)
are used (01). Within the United States, Aplomados nested in
platforms built by Swainson's hawks (Buteo swainsoni), and Chihuahuan
ravens (Corvus cryptoleucus) (12,15). Nests of the white-tailed hawk
(Buteo albicaudatus) were probably also used (01); the habitat
preferences of this hawk closely match those of the Aplomado falcon.

REPRODUCTIVE CHARACTERISTICS:
Courtship consists of aerial displaying by the male, and mutual
soaring and diving by the pair. Northern Aplomado falcons begin
laying eggs at any time between January and July but most clutches
have been collected in April or May. There is some indication that
pairs nest more than once per year in eastern Mexico. Clutches
contain 2-3 eggs with a maximum of four. Both adults take part in
incubation, which requires 32 days. Nestlings fledge about 35 days
after hatching, but remain in the vicinity of the nest for at least a
month after fledging (02).

PARENTAL CARE:
Both adults take part in incubation, which requires 32 days.
Nestlings fledge about 35 days after hatching, but remain in the
vicinity of the nest for at least a month after fledging (02). If
like most raptors, the male does the majority of the hunting while the
young are small, while the female defends the nest, broods the young,
and feeds them when the male brings in food. Both adults provide food
to the fledged young.

POPULATION BIOLOGY:
Life History - 2 (DRAFT) - Life History
Species FALCON, APLOMADO, NORTHERN
Species Id ESIS102005
Date 14 MAR 96

Almost nothing is known about the population biology of the
species. Mated pairs have a typical maximum reproductive output of
2-3 young per year, assuming they nest only once per year. Clutches
of four eggs are laid infrequently (01). In eastern Mexico, however,
there is evidence that Aplomados nest at least twice a year (02). In
that area, at least, a pair of Aplomados might produce 6-8 young/year.
Nothing is known about the rates of replacement of adults at nest
sites, the degree of fidelity shown to a mate or a territory, or the
dispersal of the young falcons from their home territories (02).

SPECIES INTERRELATIONSHIPS:
Because of the nature of the diet of the Northern Aplomado
falcon, this species is probably a competitor of other bird-eating
hawks. On the Central Plateau of Mexico the Aplomado nests
sympatraically with peregrine falcons (Falco peregrinus), prairie
falcons (F. mexicanus), and Cooper's hawks (Accipiter cooperii). In
the winter, peregrines, merlins (F. columbarius) and Aplomados coexist
over much of the range of F. femoralis. In addition, bat falcons
(F. rufigularis) nest in close proximity to Aplomados in eastern
Mexico. The diets of the two species are very similar. The effect on
the Aplomado falcon of competition with other raptors is not known.
Aplomados are dependent upon other species for the construction
of most of their nest sites (02).

OTHER LIFE HISTORY DESCRIPTORS:
None.

Life History - 3 (DRAFT) - Management Practices
Species FALCON, APLOMADO, NORTHERN
Species Id ESIS102005
Date 14 MAR 96

MANAGEMENT PRACTICES

RESULT MANAGEMENT PRACTICE

Beneficial Land Acquisition
Beneficial Controlling pollution [thermal, chemical, physical]
Beneficial Reforestation
Beneficial Stocking captive-reared wild-strain animals
Adverse Applying pesticides
Existing Applying pesticides
Adverse Grazing
Existing Grazing
Adverse
Existing
Adverse Vegetation Composition Changes
Existing Vegetation Composition Changes
Adverse Suppressing wildfire
Existing Suppressing wildfire

COMMENTS ON MANAGEMENT PRACTICES -
The biggest threat to the survival of the Northern Aplomado
falcon is the continued use of pesticides in Latin America. Areas
which are structurally suitable for Aplomados may actually be
unsuitable because organochlorine pesticides are applied heavily to
agricultural lands where the falcons' avian prey. Aplomados nesting
in eastern Mexico were heavily contaminated by residues of DDT (04).
Levels of DDE in membranes of 20 clutches of Aplomado eggs collected
in Veracruz (1957-66) averaged 297 ppm (110-530 ppm). In a more
recent sample (1977) of shell fragments from 10 clutches collected
along a 550 mile transect (northern Veracruz to western Campeche) DDE
residue levels averaged 296 ppm (31-1280 ppm) (04). Futhermore,
1954-1967 eggshells were 25.4 percent thinner and 1977 eggshell
fragments were 24.0 percent thinner than pre-DDT shells. These levels
are equivalent to the maximum amount reported for any population of
the peregrine falcon during its decline (07). Thinning of over 20
percent is likely to result in reproductive failure in peregrine
falcons, primarily from egg breakage (05,07). In 1977, two Veracruz
Aplomado falcon nests contained eggs that were apparently crushed
during incubation (04). Aplomados can be expected to suffer from
pesticide-induced reproductive failure wherever they nest close to
areas where DDT is still used (02).
A second threat is brush encroachment. Woody vegetation such as
mesquite (Prosopis glandulosa) and creosote (Larrea tridentata) invade
open grassland or savanna as the result of overgrazing or fire
suppression and other vegetation disturbances (23). In the 1920's
the 144,000 acre Jornada Experimental Range in New Mexico was still
23-34 percent grassland. By the 1950's the area was completely
brushland (09). The decline of suitable habitat for the Aplomado in
Texas (10) and Arizona (11) are similarly documented. Brush
encroachment may still be a problem for the Aplomado, especially in
poorly-managed rangelands (02). Invasion of woody vegetation occurs
very rapidly on artificially maintained tropical pastures; this
Management Practices - 1 (DRAFT) - Management Practices
Species FALCON, APLOMADO, NORTHERN
Species Id ESIS102005
Date 14 MAR 96

process may have caused Aplomados to desert at least one nesting
territory in Veracruz (01). In eastern Mexico, brush encroachment may
be counterbalanced by destruction of lowland rainforest. The Central
Plateau of Mexico has likely also experienced similar brush
encroachment.

UNAPPROVED PLAN:
No recovery plan has been completed as of yet. The final approved
recovery plan is scheduled for completion in the second quarter, 1988.

The Aplomado falcon has undergone severe losses in range and
numbers in the past, and remaining populations are threatened by
reproductive failure due to pesticide contaminations. Experience with
the endangered peregrine falcon (Falco peregrinus) shows that
pesticide contamination can lead to severe, rapid population declines.
The levels of pesticide contamination and rates of eggshell thinning
found in the remaining populations of Northern Aplomado falcon exceed
those found to have been the cause of nesting failure in populations
of peregrine falcons in the 1960's and 1970's.
Current recovery efforts are aimed at saving the species from the
threats posed by pesticide use in Mexico. Efforts to limit or outlaw
the use of DDT in that country continue, but the prospects are not
good. Meanwhile productivity of the Aplomado continues to suffer
because of it. Therefore on several occasions, the last in the spring
of 1987, biologists have gone to Mexico to collect young from nests
for the captive breeding effort. These birds, based at the World
Center for Birds of Prey in Boise, Idaho will produce more young that
will be hacked into the wild in the United States. Steps needed in
reestablishing breeding populations in the U.S. are:

1) acquire protection for the habitat (purchase, lease, or
agreement);
2) complete and implement a habitat management plan that
improves the habitat for Aplomado falcon;
3) release captive bred birds into the habitat, making
additional releases as necessary, and;
4) annually monitor population numbers and habitat conditions.

The captive breeders at Boise should be maintained, increased,
and managed to provide a large numbers of birds for release.
Long-term ecological studies should be undertaken in the Laguna
Atascosa NWR and other future release sites as soon as releases are
begun, to study:

1) movements and dispersal;
2) population dynamics and habitat conditions, and;
3) the life history and basic ecology of the Aplomado falcon.

Finally, public awareness of the uniqueness of the Aplomado
falcon should be increased through the use of the local, state and
national broadcast and print media.
Current recovery activities: Four young have been hacked each
Management Practices - 2 (DRAFT) - Management Practices
Species FALCON, APLOMADO, NORTHERN
Species Id ESIS102005
Date 14 MAR 96

year since 1985 in south Texas. The 1985 hack site was the King
Ranch; two young died and two others left the area shortly after
fledging due to harassment by king-birds and great horned owl
predation. The 1986 and 1987 hack site was Laguna Atascosa NWR. All
eight birds there fledged successfully and dispersed from the area.

Management Practices - 3 (DRAFT) - References
Species FALCON, APLOMADO, NORTHERN
Species Id ESIS102005
Date 14 MAR 96

References

***** REFERENCES FOR ALL NARRATIVES EXCEPT N-OCCURRENCE *****

01 Hector, D.P. 1981. The habitat, diet, and foraging behavior of
the Aplomado falcon, Falco femoralis (Temminck). Unpubl. MS Thesis
Oklahoma State Univ., Stillwater.
02 Hector, D.P. 1983. Status report: Falco femoralis
septentrionalis (Todd 1916). Prepared for U.S. Fish and Wildl.
Serv., Albuquerque, NM. 51 pp.
03 Todd, W.E.C. 1916. Preliminary diagnosis of fifteen apparently
new neotropical birds. Proc. Biol. Soc. Wash., 29:95-98.
04 Kiff, L.F., D.B. Peakall, and D.P. Hector. 1978. Eggshell
thinning and organchlorine residues in the bat and aplomado falcons
in Mexico. Proc. 17th Int. Ornith. Congr. 17:949-952.
05 Stickel, W.H. 1975. Pesticides and reproduction in birds of prey.
In: A.D. McIntrye and C.F. Mills (eds.), Ecol. Toxicology Res.
Plenum Publ. Co., NY.
06 Hector, D.P. 1985. The diet of the Aplomado falcon (Falco
femoralis) in eastern Mexico. Condor 87:336-342.
07 Peakall, D.B., and L.F. Kiff. 1979. Eggshell thinning and DDE
levels among peregrine falcons (Falco peregrinus): a global
perspective. Ibis 121:200-204.
08 Enderson, J.H., et al. 1982. Eggshell thinning and organochlorine
residues on Rocky Mountain peregrines, Falco peregrinus, and their
prey. Can. Field-Nat. 96:255-264.
09 Buffington, L.C., and C.H. Herbal. 1967. Vegetation changes on a
semidesert grassland range from 1858 to 1963. Ecol. Monogr.
35:139-164.
10 Johnston, M.C. 1963. Past and present grasslands of southern
Texas and northeastern Mexico. Ecology 44:456-466.
11 Hastings, J.R., and R.M. Turner. 1964. The changing mile: an
ecological study of vegetation change with time in the lower mile
of an arid and semiarid region. Univ. Arizona Press, Tucson.
12 Bendire, C.E. 1887. Notes on a collection of birds' nests and
eggs from southern Arizona territory. Proc. U.S. Nat. Mus.
11:551-558.
13 Ligon, J.S. 1961. New Mexico birds and where to find them. Univ.
New Mexico Press, Albuquerque.
14 Merrill, J.C. 1878. Notes on the ornithology of southern Texas
being a list of birds observed in the vicinity of Fort Brown, Texas
from February 1876 to June 1878. Proc. U.S. Nat. Mus. 1:118-173.
15 Strecker, J.K. 1930. Field notes on western Texas birds. Contr.
Baylor Univ. Mus. 22:1-14.
16 Errington, P.L. 1932. Technique of raptor food habits study.
Condor 34:75-86.
17 Snyder, N.F., and J.W. Wiley. 1976. Sexual size dimorphism in
hawks and owls of North America. Ornith. Monogr. No. 20.
18 Bailey, F.M. 1928. Birds of New Mexico. NM Dept. Game and Fish,
Santa Fe.
19 Lawrence, G.N. 1874. The birds of western and northwestern Mexico
based on collections made by Col. A.J. Grayson, Capt. J. Xanthus,
and Ferd. Bischoff, in the museum of the Smithsonian Institution at
References - 1 (DRAFT) - References
Species FALCON, APLOMADO, NORTHERN
Species Id ESIS102005
Date 14 MAR 96

Wash., D.C. Mem. Bost. Soc. Nat. Hist. Vol. II.
20 Cade, T.J. 1982. The falcons of the World. Comstock/Cornell
Univ. Press, Ithaca, N.Y. 192 pp.
21 Friedmann, H., L. Griscom, and R.T. Moore. 1950. Distributional
check-list of the birds of Mexico. Part I. Pac. Coast Avifauna
No. 29. Cooper Ornith. Club, Berkeley, CA. 436 pp.
22 Birkenstein, L.R., and R.E. Tomlinson. 1981. Native names of
Mexican birds. U.S. Fish and Wildl. Serv. Resour. Publ. 139.
154 pp.
23 U.S. Fish and Wildlife Service. 1986. Final rule for determining
the Northern Aplomado falcon endangered. Fed. Reg. 51:6686-6690.

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