(DRAFT) - Taxonomy
Species KITE, SNAIL, EVERGLADE
Species Id ESIS104011
Date 14 MAR 96
TAXONOMY
NAME - KITE, SNAIL, EVERGLADE
OTHER COMMON NAMES - KITE, SNAIL, EVERGLADE; KITE, SNAIL;KITE, EVERGLADE;KITE, EVERGLADES; KITE, EVERGLADE, FLORIDA; KITE, SNAIL, FLORIDA; HAWK and SNAIL;GAVILAN CARACOLERO
ELEMENT CODE -
CATEGORY - Birds
PHYLUM AND SUBPHYLUM - CHORDATA,
CLASS AND SUBCLASS - AVES,
ORDER AND SUBORDER - FALCONIFORMES,
FAMILY AND SUBFAMILY - ACCIPITRIDAE,
GENUS AND SUBGENUS - ROSTRHAMUS,
SPECIES AND SSP - SOCIABILIS, PLUMBEUS
SCIENTIFIC NAME - ROSTRHAMUS SOCIABILIS PLUMBEUS
AUTHORITY -
TAXONOMY REFERENCES -
COMMENTS ON TAXONOMY -
Everglade Snail Kite
Rostrhamus sociabilis plumbeus Ridgway, 1874
KINGDOM: Animal GROUP: Bird
PHYLUM: Chordata CLASS: Aves
ORDER: Falconiformes FAMILY: Accipitridae
Adult Everglade snail kites are sexually dimorphic, with females
slightly larger than males. The adult male is slate gray with black
wing tips. The square tail is black with a large white patch at its
base and a narrow white terminal band. The unfeathered soft parts of
the adult male are orange-red and become more intense during the
breeding season. The eyes of adults are red and those of immatures
are brown. Females and immature males are brown and buffy above with
the underparts white to buffy and heavily streaked with dark brown.
The tail pattern of the brown-plumaged birds is similar to that of the
adult male. The color of the soft parts of all females and immature
males ranges from yellow to orange (04). In the field, adult females
can not be distinguished from immature males except by eye color or
behavior during breeding (05).
The snail kite, Rostrhamus sociabilis (Vieillot), of the Family
Accipitridae, Subfamily Milvinae (true kites), is a wide-ranging New
Taxonomy - 1 (DRAFT) - Taxonomy
Species KITE, SNAIL, EVERGLADE
Species Id ESIS104011
Date 14 MAR 96
World species found primarily in lowland freshwater marshes in
tropical and subtropical America. Four subspecies have been
recognized: (1) R. s. plumbeus Ridgway, in Florida; (2) R. s. levis
Friedmann, in Cuba; (3) R. s. major Nelson and Goldman, in Mexico,
Belize, and Guatemala; and (4) R. s. sociabilis (Vieillot), in Central
and South America (01,02). For descriptions of these see Friedmann
(02). The plumages of the subspecies are the same, and bill, wing,
and tarsus measurements overlap considerably (02). Recently Amadon
(03) reexamined the taxonomic status of the four subspecies and
concluded that plumbeus and levis are not distinct. He synonymized
the subspecies levis with the subspecies plumbeus, with which there is
some agreement (04). As size is the only character distinguishing the
subspecies (01,02) and the measurements exhibit overlap, the
separation of this species into subspecies is still open to question
(04). The species was identified as Rosthramus sociabilis in the
Western Hemisphere Convention Annex under Cuba's listing in 1941.
The common name for the Everglade snail kite was officially
changed to snail kite in 1982 by the American Ornithologist's Union
(33). However, it is also known by the common names Everglade kite or
Everglades kite (ISIS), Florida everglade kite (IUCN, 1979), snail
hawk (32), and Gavilan caracolero (Spanish-Cuba).
Taxonomy - 2 (DRAFT) - Status
Species KITE, SNAIL, EVERGLADE
Species Id ESIS104011
Date 14 MAR 96
STATUS
Coded Status
Florida; Federal Endangered
Florida; Officially Listed
E: Federal Endangered
Federal Migratory
Non-consumptive recreational
COMMENTS ON STATUS -
U.S. STATUSES AND LAWS:
The Everglade snail kite (Rostrhamus sociabilis plumbeus) 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 subspecies has this status
wherever found including the State of Florida. Critical Habitat has
been designated in areas of land (predominantly marsh), water, and
airspace in all or parts of: (1) St. Johns Reservoir, Indian River
Co.; (2) Cloud Lake and Strazzulla Reservoirs, St. Lucie Co.; (3)
Western parts of Lake Okeechobee, Glades and Hendry Cos.; (4)
Loxahatchee NWR, Palm Beach Co.; (5) Central and southern Florida
Flood Control District Water Conservation Area, Palm Beach, Broward,
and Dade Cos.; and (6) Everglades Nat. Park, Dade Co. (50 CFR
17.95(b)).
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 Rostrhamus sociabilis,
snail kite (50 CFR 10.13).
RESPONSIBLE FEDERAL AGENCIES:
USFWS -Responsible for the management/recovery, listing, and
law enforcement/protection of this species.
BIA -Responsible for the law enforcement/protection of this
Status - 1 (DRAFT) - Status
Species KITE, SNAIL, EVERGLADE
Species Id ESIS104011
Date 14 MAR 96
species with applicable State and Federal laws on
public lands under their control. Also responsible
for management/recovery on Bureau of Indian Affairs
lands.
DOD -Responsible for the law enforcement/protection of this
species with applicable State and Federal laws on
public land under their control. Also responsible for
management/recovery on Department of Defense lands.
NPS -Responsible for the law enforcement/protection of this
species with applicable State and Federal laws on
public lands under their control. Also responsible
for conservation (Nat. Park System Organic Act - 16
U.S.C. 1, 2-3)/management/recovery on National Park
Service lands. Taking, possessing, or disturbing of
Federally listed species is prohibited on NPS lands
(36 CFR 2.1, 2.2, and 2.3).
USFS -Responsible for the law enforcement/protection of this
species with applicable State and Federal laws on
public lands under their control. Also responsible
for management/recovery on Forest Service lands. The
Forest Service is responsible for integrating
management, protection, and conservation of Federally
listed species into the Forest Planning process
(36 CFR 219.19 and 219.20). Management practices that
would cause detrimental changes in water temperature
or composition, water course blockage, or sediment
deposits within 100 feet of the edges of perennial
streams, lakes or other bodies of water are prohibited
(36 CFR 219.27(e)).
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: Florida
DESIGNATED STATUS: Endangered
ADMINISTRATIVE AGENCY: FL Game and Freshwater Fish Comm.
STATE STATUTE: Florida Admin. Code, Sec. 39-27.03-.05; Florida
Endangered and Threatened Species Act of 1977,
Sec. 372.072, Florida Statutes
INTERNATIONAL STATUSES, TREATIES, AND AGREEMENTS:
The snail kite is listed in CITES, Appendix II. R. s. plumbeus
is also listed as Rare in the IUCN Red Data Book, Vol. 2, 1979. The
subspecies is listed by the U.S. (1970) and the species
Rostrhamus sociabilis was listed by Cuba (1941) in the Convention
on Nature Protection and Wildlife Preservation in the Western
Hemisphere Annex.
Status - 2 (DRAFT) - Status
Species KITE, SNAIL, EVERGLADE
Species Id ESIS104011
Date 14 MAR 96
ECONOMIC STATUSES:
The species provides no positive or negative direct commercial
values. It does provide scientific, recreational, educatonal, and
asthetic values to man.
67/03/11:32 FR 04001/ - Listed
75/05/16:40 FR 21499/21500 - Intent to determine Critical Habitat
76/12/03:41 FR 53074/53075 - Proposed rule, determination of CH
77/08/11:42 FR 40685/40690 - Final rule, determination of CH
77/09/22:42 FR 47840/47845 - Final rule, correct. & aug. of publ. CH
79/05/21:44 FR 29566/29577 - Five year review
85/07/22:50 FR 29901/29909 - Five year review
Status - 3 HABITAT ASSOCIATIONS
HABITAT - TERRESTRIAL
TERRESTRIAL
INLAND AQUATIC
LAND USE -
Residential
Cropland and Pasture
Orchards, Groves, Vineyards, Nurseries,
Streams and Canals
Lakes
Reservoirs
Forested Wetland
NATIONAL WETLAND INVENTORY CODES
NWI NWICLS NWIMOD NWISPEC
Riverine, intermittent UB4
Riverine, intermittent UB3
Riverine, intermittent UB2
Riverine, intermittent SB4
Riverine, intermittent SB3
Riverine, intermittent SB2
Riverine, intermittent OW0
4FL
Riverine, intermittent FL3
Riverine, intermittent FL2
Riverine, intermittent AB5
Riverine, intermittent AB4
Riverine, intermittent AB2
Riverine, lower perennial UB4
Riverine, lower perennial UB3
Riverine, lower perennial UB2
Riverine, lower perennial SB4
Riverine, lower perennial SB3
2SB
Riverine, lower perennial OW0
Riverine, lower perennial EM
Riverine, lower perennial AB5
Riverine, lower perennial AB4
Riverine, lower perennial AB2
Lacustrine, limnetic OW0
Lacustrine, littoral EM
Lacustrine, littoral AB
Palustrine UB4
Palustrine UB3
0UB
Palustrine OW0
Palustrine FO
Palustrine EM6
Palustrine EM5
Palustrine EM4
Palustrine EM3
Palustrine EM2
Palustrine EM1
Palustrine AB5
Palustrine AB4
Palustrine AB2
Habitat Associations - 1 COMMENTS ON HABITAT ASSOCIATIONS -
The snail kite generally inhabits large inland freshwater marshes
with unobstructed air space and low vegetation. There are usually few
tree islands in wetlands occupied by the kite, although there are
generally scattered shrubs or small, low trees, mainly willow (Salix
caroliniana), dahoon holly (Ilex cassine), wax myrtle (Myrica
cerifera), pond apple (Annona glabra), and bald cypress (Taxodium
distichum), which serve as perches and nesting sites. All nests are
built over water 12-115 cm deep (25). The most frequently used
nesting substrates are coastal-plain willow 44.9%, cattail (Typha
spp.) 16.6%, and wax myrtle 12.8%.
The kite hunts mainly over extensive, shallow (water depth
0.2 - 1.3 m) sloughs of white waterlily (Nymphaea odorata) and wet
prairies or flats of spikerush (Eleocharis elongata and E. cellulosa)
that retain some surface water through the dry season in most years.
Such areas occur in extensive stands of sawgrass (Cladium jamaicensis)
or cattails (Typha domingensis and T. angustifolia) or on flat river
courses and margins of large shallow lakes (05,13,17). Approximately
97% of foraging bouts are over aquatic sloughs and wet prairies (25).
Other flooded freshwater marsh habitats used for hunting include:
Shallow littoral zones of lakes and ponds, old alligator holes,
shallow river margins with aquatic vegetation, canals, and ditches
(25).
Kites in Florida, with a few rare exceptions, are completely
dependent upon the apple snail (Pomacea paludosa) for food (05,06,18,
19). Snails are available to kites only when the marsh is flooded
(05). Snails are captured while they are near the water surface
feeding, traversing, or while resting on aquatic vegetation below the
surface (25). Kites hunt over relatively open water areas, containing
minimal emergent aquatic vegetation (05,25). Kites hunt by two
methods; still-hunting (initiated from a convenient perch over water)
and course-hunting (on the wing) (23,24,25).
The creation of water conservation areas (reservoirs) has been a
great secondary benefit to the kite population by flooding parts, or
all of the area for several years.
Lands surrounding snail kite habitat are used for such purposes
as urban residential areas, croplands (including mellons, rice, corn,
and other vegetables), pasture, and citrus groves. These uses have
directly replaced snail kite habitat and they continue to influence
the remaining kite habitat by affecting water quality within Lake
Okeechobee and surrounding marshes (35,36,37).
Habitat Associations - 2 (DRAFT) - Food Habits
Species KITE, SNAIL, EVERGLADE
Species Id ESIS104011
Date 14 MAR 96
FOOD HABITS
TROPHIC LEVEL -
CARNIVORE
LIFESTAGE FOOD FOOD PART
General Molluscs
Food Habits - 1 (DRAFT) - Environment Associations
Species KITE, SNAIL, EVERGLADE
Species Id ESIS104011
Date 14 MAR 96
ENVIRONMENTAL ASSOCIATIONS
G = General A = Adult
LIM = Limiting RA = Resting Adult
J = Juvenile FA = Feeding Adult
RJ = Resting Juvenile BA = Breeding Adult
FJ = Feeding Juvenile P = Pupae
L = Larvae E = Egg
RL = Resting Larvae
FL = Feeding Larvae
LIFESTAGE ENVIRONMENTAL ASSOCIATIONS
G Coastal Features: Vegetated offshore islands
G Snags: Unknown
G
Environment Associations - 1 (DRAFT) - Life History
Species KITE, SNAIL, EVERGLADE
Species Id ESIS104011
Date 14 MAR 96
LIFE HISTORY
FOOD HABITS:
The snail kite is a specialist whose diet consists of freshwater
Pomacea snails (05,20,21,22,23,24,25). With a few rare exceptions,
kites in Florida are completely dependent upon the apple snail
(Pomacea paludosa) for food (05,06,18,19,25). The birds hunt in a
number of flooded freshwater marsh habitats: Aquatic sloughs, wet
prairies, shallow littoral zones of lakes and ponds, old alligator
holes, shallow river margins with aquatic vegetation, canals, and
ditches (25). Approximately 97% of the foraging bouts are over
aquatic sloughs and wet prairies (25). Snails are captured while they
are near the water surface feeding, traversing, or while resting on
aquatic vegetation below the surface (25).
Kites hunt by two methods; still-hunting (initiated from a
convenient perch over water) and course-hunting (on the wing) (23,24,
25). In both methods snails are taken by the bird while hovering or
flying very slowly above the water surface. Snails are captured with
the talons, while seldom getting the feathers of the wings, tail, or
body wet in the process (kites do not plunge to capture prey as do
ospreys and eagles) (05,23,25). Kites hunt over relatively open water
areas, containing minimal emergent aquatic vegetation (05,25). The
captured snail is taken to a perch where the operculum is removed and
discarded, the soft tissue of the snail extracted, the shell dropped,
and the soft parts then eaten (23,25). Kites always avoid eating the
albumen glands of female snails and often discard all or part of the
viscera (25). Adults feed their young extracted snails (25). Kites
hunt throughout the day with intermittent periods of individual
inactivity (particularly between 10 am and 3 pm) (25).
HOME RANGE/TERRITORY:
In Florida the snail kite is nomadic, highly gregarious, and
generally forages over communal hunting areas (05,25). Territorial
defense of hunting sites does occur but appears to be relatively
infrequent (25,26). Kites roost communally, often in association with
colonial waterbirds (27), and nest in loose colonies or singularly
(28). Roosting and nesting are often at the same site (27,28).
Several males may perform aerial courtship displays at the same time
over the nesting area (28).
PERIODICITY:
Snail kites are strictly diurnal (27). Except as required during
the breeding season, there is little change in the type of daily
activity through the course of a year except for dispersal by some
individuals (05,12,25,28).
MIGRATION PATTERNS:
In the true sense of the word, R. s. plumbeus is non-migratory.
Kites are nomadic in Florida. This nomadic behavior probably
represents a response to changes in water levels and food availability
(05). Birds in the more northern part of the range in Florida may, in
some years, move further south on the peninsula during colder months
since apple snails are less active in cold weather (05,13,25). In
Life History - 1 (DRAFT) - Life History
Species KITE, SNAIL, EVERGLADE
Species Id ESIS104011
Date 14 MAR 96
some years, there may be dispersal to other localities following
completion of breeding (13).
COVER/SHELTER REQUIREMENTS:
Snail kites require large freshwater marshes with low stature
vegetation and numerous open aquatic sloughs and wet prairies for
hunting, with scattered single or clumps of low trees or shrubs for
resting, feeding perches, hunting perches, roosting sites, and nesting
substrates. Sites with dense mats of floating vegetation, extensive
areas of unbroken stands of dense vegetation, and large close canopy
stands of trees are generally avoided. Birds tend to prefer areas
with relative open vistas in all directions (05,13,25,27,28).
REPRODUCTIVE SITE REQUIREMENTS:
Courtship displays take place in the air space over and around
the nesting site and breeding takes place while perched in the
vicinity of the site (05,28,29). All nests are built over water
12-115 cm deep (25). The most frequently used nesting substrates are
coastal-plain willow (Salix caroliniana) 44.9%, cattail (Typha spp.)
16.6%, and wax myrtle (Myrica cerifera) 12.8%. The nests are usually
large, bulky, loosely woven structures composed mostly of dry sticks
and usually some sawgrass (Cladium jamaicensis) and lined with finer
materials (29). Much of the nest cup is of green plant materials
(29). The height of nests above water ranges from 0.4 to 3.7 m with a
mean of 1.6 m (29). The male generally does most if not all of the
nest construction (28,29).
REPRODUCTIVE CHARACTERISTICS:
Nesting may occur in loose colonies or singularly (28).
Courtship display takes place any time during the day in the air or at
a perch (29). Aerial displays include undulating flight, slow flight,
grappling, tumbling, pendulum flight, and mutual soaring, and may
include carrying a stick in the bill and vocalizations (28).
Courtship feeding and/or presentation of a stick to a female by the
male often takes place prior to copulation (28).
Breeding by snail kites generally takes place by the time the
birds are 3 to 4 years old but on occasion they may breed as young as
one year of age (05,30). Copulation takes place while perched, lasts
3 to 30 seconds per breeding attempt, and may occur from early stages
of nest construction through laying of eggs in a completed nest (28).
Clutch size ranges from 1 to 6 eggs with a mean of 2.92 (N=313
clutches) (28). Both members of the pair share in incubation (28).
Incubation ranges from 24 to 30 days with a mean of 27.4 days and may
begin after the first egg is laid, but generally begins after the
second egg is deposited (28). The pair bond is probably for only one
nesting cycle (30). The beginning of breeding activities in Florida
varied from year to year. Some breeding activity has been recorded in
Florida every month, but not necessarily in the same year (28). Peak
egg laying months were February, March, and April with substantial
activity in January and May (28).
PARENTAL CARE:
Both members of the pair share in care of the young, however, the
Life History - 2 (DRAFT) - Life History
Species KITE, SNAIL, EVERGLADE
Species Id ESIS104011
Date 14 MAR 96
degree of attentiveness of individual pairs varies widely (28).
Hatching is asynchronous and the young are altricial (28). The
nestling period is 23 to 34 days with a mean of 28.7 days (28).
Adults continue to care for the young for up to 30 days after the
young fledge (take first flight from the nest) (05,28,30). The nest
may or may not be actively guarded, but if guarded, the female is the
more aggressive of the pair (29).
POPULATION BIOLOGY:
The snail kite has characteristics of a typical boom-and-bust
species subject to radical, irregular fluctuations in relation to its
food supply. For example, it is nomadic, has a very high intrinsic
rate of increase, and has flexible breeding schedules. Undoubtedly,
kites will increase in direct proportion to areas of continuously
flooded marshes with large apple snail populations. The kite appears
to be strongly adapted to take maximum advantage of favorable
circumstances in a very uncertain environment. Annual census results
from 1969 through 1980 revealed that the upward or downward trend of
the snail kite population in Florida can be predicted based upon water
level conditions (31). Breeding success for the kite was 45.6% or 2.2
young produced per successful nest for the period 1968-1978, and
nestling mortality during this same period was 37 percent. Factors
responsible for nesting failure included predation (44%), adverse
weather (22%), weak nesting substrate (16%), human disturbance (9%),
and miscellaneous (9%) (28). Mortality rate for adult kites is not
known. The sex ratio in the Florida population is also unknown (05).
In captivity kites are known to live at least 13 years, in the wild
at least 9 years, and some individuals probably live to be 10 years
old or more (05). A breeding success rate between 40 to 50% is
probably adequate to maintain the species in Florida (28).
SPECIES INTERRELATIONSHIPS:
The snail kite population in Florida is almost completely
dependent upon the apple snail (Pomacea paludosa) for food and for all
practical purposes the kite takes no other food item (05,06,13,18,19,
20,22,23,25,31). This mollusc is abundant and available to the kite
only when the marsh is flooded (31). However, snails are not
uniformly distributed in a marsh and very little is known about their
ecology and population dynamics (05,13,31). Favorable conditions for
kites in Florida are linked to the depth and duration of marsh
flooding (31). When the marshes go dry (as during drought years,
which are naturally-occuring events, or when water levels are
manipulated by man) the snail population is drastically reduced and it
takes several years to again become abundant enough to support kites
(05,13,31).
OTHER LIFE HISTORY DESCRIPTORS:
None.
Life History - 3 (DRAFT) - Management Practices
Species KITE, SNAIL, EVERGLADE
Species Id ESIS104011
Date 14 MAR 96
MANAGEMENT PRACTICES
RESULT MANAGEMENT PRACTICE
Beneficial Controlling/Restricting Boating Activities
Beneficial Controlling/Restricting Off-Road Vehicles
Beneficial Restricting/regulating human disturbance of populations
Beneficial Maintaining/Controlling Water Flow
Beneficial
Beneficial Developing/maintaining/protecting wetlands
Beneficial Controlling water levels
Beneficial Land Acquisition
Beneficial Water Right Acquisition
Beneficial Controlling pollution [thermal, chemical, physical]
Beneficial Controlling/Restricting Pesticide Use
Beneficial Controlling/Restricting Herbicide Use
Beneficial Controlling/Restricting Agricultural Practice
Beneficial Creating Artificial Habitat/Nesting Structure
Beneficial Reforestation
Beneficial Controlling/Removing Nonnative Vegetation
Beneficial Stocking captive-reared wild-strain animals
Beneficial Restricting Poaching
Beneficial Controlling/Removing Invertebrates
Beneficial Controlling/Removing Native Vertebrates
Adverse Food Supply Reduction
Existing Food Supply Reduction
Adverse Rural Residential/Industrial Areas
Existing Rural Residential/Industrial Areas
Adverse Strip mining
Existing Strip mining
Adverse Water Level Fluctuation
Existing Water Level Fluctuation
Adverse Groundwater drawdown
Existing Groundwater drawdown
Adverse Irrigating
Existing Irrigating
Adverse Dredging
Existing Dredging
Adverse Applying pesticides
Existing Applying pesticides
Adverse Exotic/Feral/Introducted Species
Existing Exotic/Feral/Introducted Species
Adverse
Existing
Adverse Vegetation Composition Changes
Existing Vegetation Composition Changes
COMMENTS ON MANAGEMENT PRACTICES -
The Everglade snail kite is threatened primarily by habitat loss
and destruction.
Originally, more than one-fourth of peninsular Florida was
covered with surface water much of each year (07). The initiation of
Management Practices - 1 (DRAFT) - Management Practices
Species KITE, SNAIL, EVERGLADE
Species Id ESIS104011
Date 14 MAR 96
drainage in the peninsula began in the 1881-1894 period. Construction
of major works (channelization) began in 1905 and continued
intermittently to the present (07,08,09,10). This widespread drainage
has permanently lowered the water table as much as 1.5 m in some areas
of southern Florida (11,12), and up to 2.1 m on the headwaters of the
St. Johns River. The drainage has permitted widespread development of
all types (urban, agricultural, commercial, and industrial) in areas
that were once freshwater marshes occupied by snail kites (05,13).
The cities of Belle Glade, Coral Springs, Moore Haven, and several
others are located totally on land that was once a part of the
Everglades region (04,07).
From 1910 until 1950, little effort was made to control runoff of
fresh water from the Everglades through major canals emptying into the
tidal estuaries of the southeastern Atlantic coast. In the late
1940's the U.S. Army Corps of Engineers began development of the
Central and Southern Florida Flood Control Project and in 1949 the
Central and Southern Florida Flood Control District (now the South
Florida Water Management District) was created. With the construction
of that project and formation of the District, the flow of water to
the sea was controlled and 3 conservation areas (CA1= Loxahatchee NWR,
CA2A & B, and CA3A & B) were created in the Everglades ecosystem to
store water and reduce flooding in developed coastal areas (07,08,12,
14). The creation of these water conservation areas (reservoirs) has
been a great secondary benefit to the kite population by flooding
parts, or all of the area for several years. However, because of
demands for fresh water for agricultural, municipal and industial
uses, there is not enough to maintain large areas of flooded habitat
suitable for kites on a long term basis, particularly during years of
drought. Between the time that drainage began and creation of the
conservation areas, the Everglades was dry much of the time, and
man-created fires were frequent and widespread (15,16). However, the
effect of fire on the snail kite has been inconsequential (30).
In addition to loss of habitat from drainage, large areas of
marsh are heavily infested with water hyacinth (Eichhornia crassipes).
This plant was introduced into Florida on the St. Johns River in 1884
(House Document No. 37, 85th Congress 1957) and was well established
in the southern part of the state by the 1920's (10). If
uncontrolled, the water hyacinth propagates rapidly and forms dense
blankets of vegetation on the water surface. Since kites hunt
visually, areas thus obscured cannot be used by them (05).
Another problem is the introduced punk-tree (Melaleuca
quinquenervia) that is steadily invading the large remaining marshes
in southern Florida, particularly the Everglades and Lake Okeechobee.
If not controlled, punk-tree will eventually convert these freshwater
systems from open marshes to closed-canopy wooded swamps, and kites do
not occupy this type of ecosystem.
A copper compound has been (and is being) used in some citrus
groves as a fungicide. It is possible that application of this
fungicide has contaminated local lakes, reducing or eliminating
populations of the apple snail, the food of the snail kite. However,
no research has been conducted to investigate this possibility (30).
About 49% (6620 sq km) of the original potential kite habitat in
southern Florida has been lost because of drainage and subsequent land
Management Practices - 2 (DRAFT) - Management Practices
Species KITE, SNAIL, EVERGLADE
Species Id ESIS104011
Date 14 MAR 96
uses. Of that portion remaining, only 18% (1222 sq km) was used by
kites from 1967 through 1980. The lack of water to flood the marsh
habitat in drought years is the most critical factor confronting the
species. However, much of the remaining marsh has been modified to
the point that it is no longer suitable for kites (13).
Continuous flooding of a marsh for a period of several years is
needed to develop and sustain an adequate supply of apple snails
(Pomacea paludosa). This snail is generally the only food taken by
kites in Florida, however, there are a few rare exceptions (06).
Apple snails remain active only when the marsh is inundated. If the
marsh dries up, snail numbers are drastically reduced by predation and
survivors burrow into the bottom, becoming unavailable to kites (05).
APPROVED PLAN:
U.S. Fish and Wildlife Service. 1986. Florida Snail Kite (Rostrhamus
sociabilis plumbeus Ridgway) Revised Recovery Plan. U.S. Fish and
Wildlife Service, Atlanta, GA. 48 pp.
The Recovery Plan tasks include: Identifying population and
distribution goals (based on improved understanding of demographics,
limiting factors, genetic problems); restoration and maintenance of
habitat with emphasis on Critical Habitat (map habitat types, identify
control capability, etc.); monitoring of the population and habitat
quality to assess recovery and maintenance of public relations;
education and awareness; and inter-agency communication.
More specifically, these tasks are:
1. Identify demographic and life history characteristics of the
snail kite population. Monitor populations, kite movements, determine
reproductive potential and response to wetland management practices,
assess the genetic structure of the kite population, assess the
impacts of dermestid beetle parasitism, and review and apply data
collected on the neotropical kite populations.
2. Manage Florida snail kite habitat. Manage for optimum apple
snail production by developing a management plan to deal with limiting
factors such as water quality (degraded by pesticide, herbicide and
fertilizer runoff from agricultural lands) and water level periodicity
and flow (which affects salinity). Identify drought-related and
potential kite habitats and protect through fee title acquisition,
conservation agreements, lease agreements, etc. Provide nesting sites
using artificial nest structures and planting shrubs suitable for
nesting. Control exotic plants (Melaleuca quinquenervia and
Eichhornia crassipes) through the use of herbicides and water level
fluctuation (coordinate these efforts with management of the apple
snail). Investigate the effectiveness of artificial perches.
3. Prevent human disturbance. Control airboats and other off-road
vehicles. Prevent indiscriminent shooting of kites. Limit human
access to nesting colonies.
4. Ensure public and agency understanding and support of, and
Management Practices - 3 (DRAFT) - Management Practices
Species KITE, SNAIL, EVERGLADE
Species Id ESIS104011
Date 14 MAR 96
cooperation in, Florida snail kite management.
5. Review Critical Habitat.
6. Revise recovery goals for kite populations and distribution when
appropriate.
7. Develop an emergency captive propagation program.
Although not specified in the Recovery Plan, controlling native
predators such as raccoons (Procyon lotor), Everglade rat snakes
(Elaphe obsoleta), fish crows (Corvus ossifragus) and cotton mouth
moccasins (Agkistrodon piscivorus) may be needed to reduce egg and
nestling mortality (34).
Ongoing recovery activities include annual surveys conducted by
the Florida Game and Fresh Water Fish Commission; a snail kite alert
program instituted in drought conditions to monitor dispersal;
initiation of development of a marsh management plan for Loxahatchee
National Wildlife Refuge; Section 7 consultation actions;
coordination/education with local government; completion of research;
and publication of much of earlier research work on the species.
Management Practices - 4 (DRAFT) - References
Species KITE, SNAIL, EVERGLADE
Species Id ESIS104011
Date 14 MAR 96
References
***** REFERENCES FOR ALL NARRATIVES EXCEPT N-OCCURRENCE *****
01 Hellmayr, C.E. and B. Conover. 1949. Catalogue of birds of the
Americas. Field Mus. Nat. Hist., Chicago. Zool. Ser. 13, Part 1,
No. 4.
02 Friedmann, H. 1950. The birds of North and Middle America. U.S.
Nat'l. Mus. Bull. 50, Part 11.
03 Amadon, D. 1975. Variation in the Everglade kite. Auk
92:380-382.
04 Sykes, P.W., Jr. 1984. The range of the snail kite and its
history in Florida. Bull. Fla. State Mus., Biol. Sci.
29(6):211-264.
05 Sykes, P.W., Jr. 1979. Status of the Everglade kite in
Florida -- 1968-1978. Wilson Bull. 91:495-511.
06 Sykes, P.W., Jr. and H.W. Kale, II. 1974. Everglade kites feed on
nonsnail prey. Auk 91:818-820.
07 Tebeau, C.W. 1971. A history of Florida. Univ. of Miami Press,
Coral Gables, Florida.
08 Parker, G.G., G.E. Ferguson, S.L. Love, et al. 1955. Water
resources of southern Florida. U.S. Geol. Surv., Water-Supply
Paper 1255.
09 Anon. 1957. Central and southern Florida project. Part 3, Upper
St. Johns River basin and related areas. U.S. Army Corps of
Engineers, Jacksonville, FL.
10 Johnson, L. 1974. Beyond the fourth generation. Univ. Presses of
Florida, Gainesville.
11 Parker, G.G. 1951. Geologic and hydrologic factors in perennial
yield of Biscayne Aquifer. J. Am. Wate Works Assoc. 43:817-834.
12 Klein, H., J.T. Armbruster, B.F. McPherson, and H.J. Freiberger.
1974. Water and the south Florida environment. S. Florida
Environ. Proc. Ecol. Rept. No. DI-SFEP-74-75. U.S. Geol. Surv.,
Atlanta, GA.
13 Sykes, P.W., Jr. 1983. Snail kite use of the freshwater marshes
of South Florida. Florida Field Nat. 11:73-88.
14 Leach, S.D., H.Klein, and E.R. Hampton. 1972. Hydrologic effects
of water control and management of Southern Florida. Bureau Geol.,
Florida Dept. Nat. Resour., Tallahassee.
15 Robertson, W.B., Jr. 1953. A survey of the effects of fire in
Everglades Natonal Park. Natl. Park Serv. Rept. (mimeo),
Homestead, FL. 169 pp.
16 Hofstetter, R.H. 1974. The effect of fire on the pineland and
sawgrass communities of Southern Florida. Pages 201-212. IN:
Environments of South Florida: Present and past. P.J. Gleason,
ed. Miami Geol. Soc. Mem. 2, Miami, FL.
17 Loveless, C.M. 1959. A study of the vegetation of the Florida
Everglades. Ecology 40:1-9.
18 Woodin, M.C. and C.D. Woodin. 1981. Everglade kite predation on a
soft-shelled turtle. Fla. Field Naturalist 9:64.
19 Takekawa, J.E. and S.R. Beissinger. 1983. First evidence of snail
kite feeding on the introduced snail, Pomacea bridgesi, in Florida.
Fla. Field Naturalist 11:107-108.
References - 1 (DRAFT) - References
Species KITE, SNAIL, EVERGLADE
Species Id ESIS104011
Date 14 MAR 96
20 Howell, A.H. 1932. Florida bird life. Fla. Dept. Game and Fresh
Water Fish Comm., Tallahassee, FL.
21 Haverschmidt, F. 1962. Notes on the feeding habits and food of
some hawks of Surinam. Condor 64:154-158.
22 Stieglitz, W.O. and R.L. Thompson. 1967. Status and life history
of the Everglade kite in the United States. Spec. Sci. Rept.,
Wildl. 109. U.S. Fish and Wildlife Service, Washington, D.C.
23 Snyder, N.F.R. and H.A. Snyder. 1969. A comparative study of
mollusc predation by limpkins, Everglade kites, and boat-tailed
grackles. Living Bird 8:177-223.
24 Beissinger, S.R. 1983. Hunting behavior, prey selection, and
energetics of snail kites in Guyana: Consumer choice by a
specialist. Auk 100:84-92.
25 Sykes, P.W., Jr. [manuscript in review]. Some observations on the
specialized feeding habits of the snail kite in Florida. On file
at U.S. Fish & Wildl. Serv., Southeast Field Sta., School of For.
Resour., Univ. Georgia, Athens 30602.
26 Snyder, N.F.R. and H.A. Snyder. 1970. Feeding territories in the
Everglade kite. Condor 72:492-493.
27 Sykes, P.W., Jr. 1985. Evening roosts of the snail kite in
Florida. Wilson Bull. 97:in press.
28 Sykes, P.W., Jr. [manuscript in review]. Reproduction in the
snail kite. On file at U.S. Fish & Wildl. Serv., Southeast Field
Sta., School of For. Resour., Univ. Georgia, Athens 30602.
29 Sykes, P.W., Jr. [manuscript in review]. Some aspects of the
nesting ecology of the snail kite in Florida. On file at U.S. Fish
& Wildl. Serv., Southeast Field Sta., School of For. Resour., Univ.
Georgia, Athens 30602.
30 Sykes, P.W., Jr. [n.d.] Personal observations. U.S. Fish
& Wildl. Serv., Southeast Field Sta., School of For. Resour., Univ.
Georgia, Athens 30602.
31 Sykes, P.W., Jr. 1983. Recent population trend of the snail kite
in Florida and its relationship to water levels. J. Field
Ornithol. 54:237-246.
32 Kale, H.W., II. 1978. Rare and Endangered biota of Florida. Vol.
2: Birds. Univ. Presses of Florida, Gainesville. 121 pp.
33 American Ornithologists' Union. 1982. Thirty-fourth supplement to
the American Ornithologist's Union check-list of North American
birds. Supplement to the Auk, Volume 99, No. 3, July 1982.
34 Sykes, P.W., Jr. 1987. Some aspects of the breeding biology of
the snail kite in Florida. J. Field Ornithol. 58(2):171-189.
35 Sykes, P.W., Jr. 1985. Pesticide concentations in snail kite eggs
and nestlings in Florida. Condor 87:438.
36 Cheng, T.C. 1980. Final report on the possible effects of
commercial herbicides on the apple snail (Pomacea paludosa) in
Florida. January 31, 1980. Unpubl. Rept. on file at:
Jacksonville Field Office, USFWS, Jacksonville, FL. 13 pp + figs.
37 U.S. Fish and Wildlife Service. 1986. Florida Snail Kite
(Rostrhamus sociabilis plumbeus Ridgway) Revised Recovery Plan.
U.S. Fish and Wildlife Service, Atlanta, GA. 48 pp.
***** REFERENCES FOR N-OCCURRENCE NARRATIVE ONLY *****
References - 2 (DRAFT) - References
Species KITE, SNAIL, EVERGLADE
Species Id ESIS104011
Date 14 MAR 96
01 Sykes, P.W., Jr. 1984. The range of the snail kite and its
history in Florida. Bull. Fla. State Mus., Biol. Sci.
29(6):211-264.
02 Sykes, P.W., Jr. 1983. Snail kite use of the freshwater marshes
of South Florida. Florida Field Nat. 11:73-88.
03 Beissinger, S.R. 1981-1983. Personal communications. Dept.
Biological Science, Univ. of Michigan, Ann Arbor 48109.
04 Rodgers, J.A., Jr. 1981-1984. Personal communications. Wildlife
Res. Lab., Florida Game and Fresh Water Fish Comm., 4005 South Main
Street, Gainesville, FL 32601.
05 Wayne, A.T. 1985. Notes on the birds of the Wacissa and Aucilla
River regions of Florida. Auk 12:326-367.
06 Scott, W.E.D. 1881. On birds observed in Sumter, Levy, and
Hillsborough Counties, Florida. Bull. Nuttall Ornithol. Club
6:14-21.
07 Howell, A.H. 1932. Florida bird life. Fla. Dept. Game and Fresh
Water Fish Comm., Tallahassee, FL.
08 Stevenson, H.M. 1951. St. Marks, Florida Christmas bird count.
Audubon Field Notes 5:106-107.
09 Stevenson, H.M. 1951. Unusual records from the Tallahassee
region. Fla. Naturalist 24:60.
10 Stoddard, H.L., Sr. 1950. Wakulla County bird notes. Florida
Nat. 23:98-100.
11 Swann, H.K. 1934. Rostrhamus sociabilis plumbeus Ridgway,
northern Everglade kite. Page 249. IN: A monograph of the birds
of prey. Part 12. A. Wetmore, ed. Wheldon and Wesley, Ltd.,
London.
12 Boardman, G.A. 1884. Natural history -- birds notes. Forest and
Stream 22:203.
13 Grimes, S.A. 1944. Birds of Duval County (continuing). Florida
Naturalist 17:21-31.
14 Stevenson, H.M. 1955. Florida region. Audubon Field Notes
9:19-22.
References - 3