Endangered and threatened species: American crocodile,

[Federal Register: March 24, 2005 (Volume 70, Number 56)]

[Proposed Rules]

[Page 15052-15063]

From the Federal Register Online via GPO Access [wais.access.gpo.gov]

[DOCID:fr24mr05-26]

[[Page 15052]]

DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

RIN 1018-AI41

Endangered and Threatened Wildlife and Plants; Reclassifying the American Crocodile Distinct Population Segment in Florida From Endangered to Threatened and Initiation of a 5-Year Review

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Proposed rule and initiation of a 5-year review.

SUMMARY: We, the U.S. Fish and Wildlife Service (Service), propose to reclassify the American crocodile (Crocodylus acutus) distinct vertebrate population segment (DPS) in Florida from its present endangered status to threatened status under the authority of the Endangered Species Act of 1973, as amended (Act). We believe that the endangered designation no longer correctly reflects the current status of this taxon within this DPS due to a substantial improvement in the species' status. Since its listing in 1975, the American crocodile population in Florida has more than doubled, and its distribution has expanded. Land acquisition has also provided protection for many important nesting areas. We have determined that the American crocodile in its range in Florida meets the criteria of a DPS as stated in our policy of February 17, 1996. If this proposal is finalized, the American crocodile DPS in Florida will continue to be federally protected as a threatened species. The American crocodile throughout the remainder of its range as described in our December 18, 1979, final rule would remain endangered. Because a status review is also required for the 5-year review of listed species under section 4(c)(2)(A) of the Act, we are electing to prepare these reviews simultaneously. We are seeking data and comments from the public on this proposal.

DATES: Comments from all interested parties must be received by May 23, 2005. Public hearing requests must be received by May 9, 2005.

ADDRESSES: Written comments and materials may be submitted to us by any one of the following methods:

  1. You may submit written comments and information to Cindy Schulz, U.S. Fish and Wildlife Service, 1339 20th Street, Vero Beach, FL 32960.

  2. You may hand-deliver written comments and information to our South Florida Ecological Services Office, at the above address, or fax your comments to (772) 562-4288.

  3. You may send comments by electronic mail (e-mail) to cindy_schulz@fws.gov. For directions on how to submit electronic filing of

comments, see the ``Public Comments Solicited'' section.

Comments and materials received, as well as supporting documentation used in the preparation of this proposed rule, will be available for public inspection, by appointment, during normal business hours at the above address.

FOR FURTHER INFORMATION CONTACT: Cindy Schulz, at the above address (telephone (772) 562-3909, extension 305, facsimile (772) 562-4288).

SUPPLEMENTARY INFORMATION:

Public Comments Solicited

We are requesting information for both the proposed rule and the 5- year review, as we are conducting these reviews simultaneously.

We intend that any final action resulting from this proposed reclassification will be as accurate and as effective as possible. Therefore, we solicit comments or suggestions from the public, other concerned governmental agencies, the scientific community, industry, or any other interested parties concerning this proposal. We particularly seek comments concerning:

(1) Biological, commercial trade, or other relevant data concerning any threat (or lack thereof) to this species;

(2) The location of any additional populations of the American crocodile within the extent of its range covered by this proposed rule;

(3) Additional information concerning the range, distribution, and population size of this species in Florida;

(4) Current management plans or anticipated plan development that incorporates actions that will benefit or impact the American crocodile in Florida;

(5) Current or planned activities within the geographic area addressed by this proposal and their potential impact on this species; and

(6) Whether the current status of this population of the American crocodile is more appropriately described as ``recovered,'' threatened due to similarity of appearance,'' or in some other way different than the proposal made here.

Please submit electronic comments in ASCII file format and avoid the use of special characters and encryption. Please also include ``Attn: [RIN 1018-AI41]'' and your name and return address in your e- mail message. If you do not receive a confirmation from the system that we have received your e-mail message, contact us directly by calling our South Florida Ecological Services Office (see ADDRESSES section).

Our practice is to make all comments, including names and home addresses of respondents, available for public review during regular business hours. Individual respondents may request that we withhold their home address from the rulemaking record, which we will honor to the extent allowable by law. In some circumstances, we would withhold also from the rulemaking record a respondent's identity, as allowable by law. If you wish for us to withhold your name and/or address, you must state this prominently at the beginning of your comments. However, we will not consider anonymous comments. We will make all submissions from organizations or businesses, and from individuals identifying themselves as representatives or officials of organizations or businesses, available for public inspection in their entirety.

Background

The American crocodile is a large greenish-gray reptile. It is one of two native crocodilians (the other being the American alligator (Alligator mississippiensis)) that occur in the continental United States, and is limited in distribution in the United States to the southern tip of mainland Florida and the upper Florida Keys (Kushlan and Mazzotti 1989a). At hatching, crocodiles are yellowish-tan to gray in color with vivid dark bands on the body and tail. As they grow older, their overall coloration becomes more pale and uniform and the dark bands fade. All adult crocodiles have a hump above the eye, and tough, asymmetrical armor-like scutes (scale-like plates) on their backs. The American crocodile is distinguished from the American alligator by a relatively narrow, more pointed snout and by an indentation in the upper jaw that leaves the fourth tooth of the lower jaw exposed when the mouth is closed. In Florida, the American crocodile ranges in size from 26.0 centimeters (cm) (10.3 inches (in)) at hatching, to an upper length of 3.8 meters (m) (12.5 feet (ft)) (Moler 1991a). Larger specimens in Florida were reported in the 1800s (Moler 1991a), and individuals as large as 6 to 7 m (19.7 to 23.0 ft) have been reported outside the United States (Thorbjarnarson 1989).

The American crocodile occurs in coastal regions of both the Atlantic and Pacific coasts, in southern Mexico,

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Central America, and northern South America, as well as the Caribbean islands (Thorbjarnarson 1989). It reaches the northern extent of its range in the southern tip of Florida (Kushlan and Mazzotti 1989a, Thorbjarnarson 1989). The species occurs within the jurisdictional boundaries of many different governments in the western hemisphere, including Belize, Colombia, Costa Rica, Cuba, Dominican Republic, Ecuador, El Salvador, Florida (USA), Guatemala, Haiti, Honduras, Jamaica, Nicaragua, Mexico, Panama, Peru, and Venezuela.

The first documented occurrence of a crocodile in the United States resulted from the collection of a crocodile in 1869 in the Miami River off Biscayne Bay, though crocodiles were earlier suspected to occur there (Kushlan and Mazzotti 1989a). Within the United States, the historic core geographic range of crocodiles includes Miami-Dade, Broward, and Monroe Counties in Florida, but reports indicate that they occupied areas as far north as Indian River County on the east coast (Kushlan and Mazzotti 1989a). Crocodiles were probably never common on the west coast of Florida, but credible reports suggest that they occurred at least periodically as far north as Sanibel Island and Sarasota County (Kushlan and Mazzotti 1989a). The primary historic nesting area was on the mainland shore of Florida and Biscayne Bays, including many of the small islands near shore, in what is today Everglades National Park (Kushlan and Mazzotti 1989a). Nesting was also historically well-documented in the upper Keys from Key Largo south to Lower Matecumbe Key (Kushlan and Mazzotti 1989a). Reports of crocodile nests on Little Pine Key (Ogden 1978), and occurrences on Key West (Ogden 1978) suggest that crocodiles were once more common in the Keys than they are today.

In 1976, the American crocodile population in Florida was estimated to be between 200 and 300 individuals (40 FR 58308), with only 10 to 20 breeding females estimated in 1975 (40 FR 44149). Most of the remaining animals and known nesting activity during this time were concentrated in a small portion of their historic range in northeastern Florida Bay (Kushlan and Mazzotti 1989a).

Today, the population of American crocodiles in Florida has grown to an estimated 500 to 1,000 individuals, not including hatchlings (P. Moler, Florida Fish and Wildlife Conservation Commission (FWC), personal communication 2004; F. Mazzotti, University of Florida (UF), personal communication 2004). This estimate, developed by two established American crocodile experts, is based on a demographic characteristic that has proven true for both Nile crocodiles and American alligators. The characteristic is based on a generality from crocodilian research, that breeding females make up 4 to 5 percent of the non-hatchling population size. This estimate exhibits a large range, because the researchers used a range of 40 to 50 crocodile nests existing in Florida to do their calculations (P. Moler, FWC, personal communication 2004; F. Mazzotti, UF, personal communication 2004). We believe this is a reasonable but conservative estimate, because as stated below nesting has increased to 61 documented nests in 2003 and not all mature females breed and nest each year.

The nesting range has also expanded on both the east and west coasts of the State, and crocodiles are frequently being seen throughout most of their historical range. Nesting has extended back into Biscayne Bay on Florida's east coast, and now commonly occurs at the Turkey Point Nuclear Plant (Brandt et al. 1995, Gaby et al. 1985). During 2003, 61 crocodile nests were discovered in south Florida (S. Klett, Service, personal communication 2003; M. Cherkiss, personal communication 2003; J. Wasilewski, Natural Selections Inc., personal communication 2003), and nesting has been increasing for several years (Ogden 1978, Brandt et al. 1995, Kushlan and Mazzotti 1989b, Moler 1991b, Mazzotti et al. 2000, Mazzotti and Cherkiss 2001, and Mazzotti et al. 2002). Approximately 75 percent of reproductively mature females breed and nest each year (F. Mazzotti, personal communication 2001), suggesting that the actual number of nesting females may be higher than the 61 nests recorded. Surveys detect approximately 80 to 90 percent of nests (F. Mazzotti, personal communication 2001; J. Wasilewski, personal communication 2002), and surveyors are generally unable to distinguish those nests that contain more than one clutch of eggs from different females without researchers excavating the nests. We believe this situation lends to a possible underestimation of nests or females, because on occasion 2 females lay eggs in the same nest.

The breeding range of the American crocodile today is still restricted relative to its reported historic range (Kushlan and Mazzotti 1989a), with most breeding occurring on the mainland shore of Florida Bay between Cape Sable and Key Largo (Mazzotti et al. 2002). Crocodiles no longer regularly occur in the Keys south of Key Largo (P. Moler, personal communication 2002, Jacobsen 1983), though individuals have occasionally been observed in the lower Keys in recent years. An American crocodile was also observed for the first time near Fort Jefferson in the Dry Tortugas in May 2002 (O. Bass, Everglades National Park, personal communication 2002). We believe that these occasional observations may indicate that crocodiles are expanding their range back into the Keys, but Key Largo is the only nesting area currently known in the Florida Keys.

Crocodiles live primarily in the sheltered, fresh, or brackish waters of mangrove-lined bays, mangrove swamps, creeks, and inland swamps (Kushlan and Mazzotti 1989b). Prolonged exposure to salinities similar to that of seawater (35 parts per thousand (ppt) of sodium) may lead to reduced growth rates, particularly for young crocodiles (Dunson 1982, Dunson and Mazzotti 1989, Mazzotti et al. 1986). Availability of fresh water is a primary factor affecting growth and survival in young crocodiles (Dunson and Mazzotti 1989).

American crocodiles are shy and secretive, and remain solitary for most of the year (Mazzotti 1983); however, they are usually tolerant of other crocodiles in the same general area. Individuals may travel widely throughout their range, but they are generally concentrated around the major nesting areas (Kushlan and Mazzotti 1989b, Mazzotti 1983). Prior to nesting season, males become more territorial, and dominant males may mate with several females (Thorbjarnarson 1989).

Females do not become reproductively active until they reach a total length of approximately 2.3 m (7.4 ft) (Mazzotti 1983), and this generally corresponds to an age of 10 to 13 years (LeBuff 1957, Moler 1991a). Females construct earthen nests (mounds or holes) on elevated, well-drained sites near the water, such as ditch-banks and beaches. Nests have been reported in sand, marl, and organic peat soils, and the nests constructed in these different soils may be susceptible to different environmental conditions and different threats (Lutz and Dunbar-Cooper 1984, Moler 1991b). Female crocodiles will only nest one time per year and may not nest every year after they reach sexual maturity. They lay an average of 38 eggs (Kushlan and Mazzotti 1989b), which will hatch after an incubation period of approximately 90 days (Mazzotti 1989). Flooding, over-drying, and raccoon predation all pose threats to nests and developing eggs (Mazzotti et al. 1988, Mazzotti 1999), and suitable nest sites

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that are protected from these threats may be limited. The reported percent of nests from which eggs successfully hatch in any one year range from 33 to 78 percent (Ogden 1978, Kushlan and Mazzotti 1989b, Moler 1991b, Mazzotti et al. 2000, Mazzotti and Cherkiss 2001). Typically, a nest was considered successful if at least one hatched eggshell or hatchling crocodile was documented. However, Moler (19991b) classified a nest as successful if ``it appeared to have been opened by an adult crocodile. In all but one case, hatchling crocodiles were tagged near each successful nest.''

Unlike alligators, female crocodiles do not defend nest sites (Kushlan and Mazzotti 1989b). However, females remain near their nest sites and must excavate young from the nest after hatching (Kushlan and Mazzotti 1989b). Kushlan (1988) reported that females may be very sensitive to disturbance at the nest site; most females that were disturbed near their nests did not return to excavate their young after hatching. Female crocodiles show little parental care, and young are generally independent shortly after hatching. Hatchlings disperse from nest sites to nursery habitats that are generally more sheltered, have lower salinity (1 to 20 ppt), shallower water (generally), and more vegetation cover, shortly after hatching, where they remain until they grow larger. Growth during the first year can be rapid, and crocodiles may double or triple in size (Moler 1991a). Growth rates in hatchling crocodiles depend primarily on the availability of fresh water and food in the nursery habitat they occupy and may also be influenced by temperature (Mazzotti et al. 1986).

Adult crocodiles have few natural enemies, but hatchlings and young crocodiles are regularly eaten by a variety of wading birds, crabs, mammals, and reptiles, including larger crocodiles. As crocodiles grow, their former predators become prey. The diet of American crocodiles at all ages is varied, and crocodiles forage opportunistically. Fish, crabs, snakes, turtles, and a variety of other small prey compose the majority of their diet. Crocodiles are usually active at night, which is the primary time when they pursue prey.

Land acquisition efforts by many agencies have continued to provide protection for crocodile habitat in south Florida. Crocodile Lake NWR was acquired in 1980 to provide over 2,205 ha (5,000 acres) of crocodile nesting and nursery habitat. In 1980, Everglades National Park established a crocodile sanctuary in northeastern Florida Bay. A total of 46 public properties (including Crocodile Lake NWR and Everglades National Park), owned and managed by Federal, State, or county governments, as well as 3 privately-owned properties (including Turkey Point Nuclear Power Plant) are managed at least partially or wholly for conservation purposes and contain potential crocodile habitat within the coastal mangrove communities in south Florida. For example, in the early 1980s, Everglades National Park plugged canals which allowed crocodiles to begin nesting on the canal berms. In 1976 the C-107 canal was completed and provides habitat for crocodiles at the Turkey Point Nuclear Power Plant. Approximately 95 percent of nesting habitat for crocodiles in Florida is under public ownership (F. Mazzotti, personal communication 2001).

Previous Federal Action

We proposed listing of the United States population of the American crocodile as endangered on April 21, 1975 (40 FR 17590). The proposed listing stated that only an estimated 10 to 20 breeding females remained in Florida, mostly concentrated in northern Florida Bay. The primary threats cited included development pressures, lack of adequate protection of crocodiles and their habitat, and the risk of extinction inherent to a small, isolated population. Comments on the proposed rule were received from 14 parties including representatives of the State of Florida, and all supported listing the American crocodile as endangered in Florida. We published a final rule on September 25, 1975, listing the United States population of the American crocodile as endangered (40 FR 44149).

On December 16, 1975, we published a proposal to designate critical habitat for the American crocodile (40 FR 58308). The proposed critical habitat included portions of Biscayne Bay south of Turkey Point, northeast Florida Bay, including the Keys, and the mainland extending as far west as Flamingo. We published a final rule designating critical habitat on September 24, 1976 (41 FR 41914). The final rule expanded the critical habitat to include a portion of Everglades National Park and northern Florida Bay to the west of the previously proposed area. The additional area lies entirely within Everglades National Park.

On April 6, 1977, we published a proposed rule to list as endangered all populations of the American crocodile with the exception of those in Florida and all populations of the saltwater (estuarine) crocodile (Crocodylus porosus) due to their similarity in appearance to the American crocodile in Florida (42 FR 18287). Under the similarity of appearance clause of Section 4 of the Act, a species may be treated as endangered or threatened for the purposes of commerce or taking if it so closely resembles an endangered species that law enforcement personnel will be unable to distinguish between the listed and unlisted species. We did not finalize this proposed rule.

On February 5, 1979, we provided notice in the Federal Register that a status review was being conducted for the American crocodile (outside of Florida) and the saltwater crocodile (Crocodylus porosus). The notice specified that we had information to suggest that the American crocodile and the saltwater crocodile may have experienced population declines and extensive habitat loss during the previous decade (44 FR 7060).

On July 24, 1979, we published a proposed rule (44 FR 43442) that recommended listing the American and saltwater crocodiles as endangered throughout their ranges outside of Papua New Guinea, citing widespread loss of habitat and extensive poaching for their hides. The Florida population of the American crocodile was not included because it was previously listed as endangered. Saltwater crocodiles were not listed within the jurisdictional boundaries of Papua New Guinea due to strict government control of crocodile farming and assurances that wild populations there were not being threatened.

We listed the American crocodile, with the exception of the previously-listed population in Florida, and the saltwater crocodile throughout its range, with the exception of the Papua New Guinea population, as endangered on December 18, 1979 (44 FR 75074). This action provided protection to these crocodilians worldwide.

Since the Florida population of the American crocodile was listed as endangered, we have conducted numerous consultations under section 7 of the Act for actions that may affect crocodiles. Most potential conflicts have been resolved early in the informal consultation process, resulting in our concurrence with a determination of ``not likely to adversely affect.''

One Federal prosecution occurred in the late 1970s for a dredge- and-fill permit violation that affected crocodile habitat on Key Largo within the boundaries of the then-proposed Crocodile Lake National Wildlife Refuge (U.S. v. Joseph R. Harrison, Jr. Civil Action No. 84- 1465, Judge E.B. Davis, Final Consent Judgment on September

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22, 1984). This case was settled prior to trial.

Distinct Vertebrate Population Segment Analysis

The Act defines ``species'' to include ``* * * any distinct population segment of any species of vertebrate fish or wildlife which interbreeds when mature.'' On February 7, 1996, we published in the Federal Register our Policy Regarding the Recognition of Distinct Vertebrate Population Segments (DPS Policy) (61 FR 4722). For a population to be listed under the Act as a distinct vertebrate population segment, three elements are considered--(1) The discreteness of the population segment in relation to the remainder of the species to which it belongs; (2) the significance of the population segment to the species to which it belongs; and (3) the population segment's conservation status in relation to the Act's standards for listing (i.e., is the population segment endangered or threatened?). The best available scientific information supports recognition of the Florida population of the American crocodile as a distinct vertebrate population segment. We discuss the discreteness and significance of the DPS within this section; the remainder of the document discusses the species' status within the Florida DPS.

Discreteness: The DPS policy states that vertebrate populations may be considered discrete if they are markedly separated from other populations of the same taxon as a consequence of physical, physiological, ecological, or behavioral factors; and/or they are delimited by international governmental boundaries within which significant differences exist in control of exploitation, management of habitat, conservation status, or regulatory mechanisms.

The Florida population segment represents the northernmost extent of the American crocodile's range (Kushlan and Mazzotti 1989a, Thorbjarnarson 1989). It is spatially separated by approximately 90 miles of open ocean from the nearest adjacent American crocodile population in Cuba (Kushlan 1988). The Gulf Stream, or the Florida Current (the southernmost leg of the Gulf Stream), flows through this 90-mile gap. This strong current makes it unlikely that crocodiles would regularly, or even occasionally, move between Florida and Cuba. Behaviorally, American crocodiles are not predisposed to travel across open ocean. They prefer calm waters with minimal wave action, and most frequently occur in sheltered, mangrove-lined estuaries (Mazzotti 1983). No evidence is available to suggest that crocodiles have crossed the Florida Straits. There are no other American crocodile populations in close proximity to Florida (Richards 2003) that would allow direct interaction of animals. The Florida DPS is effectively isolated from other American crocodile populations and functions as a single demographic unit. Consequently, we conclude that the Florida population of American crocodiles is separated from other American crocodile populations as a consequence of physical or behavioral factors.

The genetic makeup of the Florida population of the American crocodile also is recognizably distinct from populations in other geographic areas within its range (M. Forstner, Southwest Texas State University, unpublished data), despite reported evidence of the introduction of genetic material from foreign crocodile populations (M. Forstner, personal communication 2002). Analysis of mitochondrial DNA suggests that the Florida DPS may be genetically more closely related to American crocodile populations in Central and South America than to those in Cuba and the Bahamas (M. Forstner, unpublished data). However, the Florida DPS remains genetically distinct and geographically distant from American crocodiles in central and south America.

In addition to the effective spatial isolation of the Florida population, the regulatory mechanisms providing protection for the crocodile and the level of enforcement of protections are substantially different outside of Florida, across international government boundaries. The first listing of the American crocodile under the Act only included the Florida population, and protection under the Act was extended to populations outside of the United States several years later (see ``Previous Federal Actions'' section). Florida supports the only population of the American crocodile that is subject to the full jurisdiction of the Act. Though the American crocodile is protected from international commerce by the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), other countries have distinctly different regulatory mechanisms in place that do not provide the same level of protection from exploitation, disturbance, or loss of habitat within their jurisdictional boundaries for the American crocodile. Cuban laws provide protection to both crocodiles and crocodile habitat (Soberon 2000), and enforcement of those laws is reported to be good (P. Ross, International Union for the Conservation of Nature, Crocodile Specialists Group, personal communication 2002). However, the threats to crocodiles in Cuba are different than in the United States, with most human-caused mortality resulting from subsistence hunting due to a depressed economy. In the Dominican Republic, Jamaica, and Haiti, a wide variety of threats, conservation regulations, and levels of enforcement make the level of protection within these countries difficult to quantify or evaluate. Threats to American crocodile populations vary substantially throughout their range in Central and South America, with threats including malicious killing, illegal subsistence hunting in areas with a depressed economy, incidental mortality during legal caiman hunting, killing by fishermen, and incidental mortality in fishing nets (Ross 1998, Soberon 2000, Platt and Thorbjarnarson 2000, P. Ross personal communication, 2002). Therefore, significant differences do exist in control of exploitation, management of habitat, conservation status, or regulatory mechanisms in areas of the American crocodile's range outside of Florida.

Significance: The DPS policy states that populations that are found to be discrete will then be examined for their biological or ecological significance. This consideration may include evidence that the loss of the population would create a significant gap in the range of the taxon. The Florida population of the American crocodile represents the northernmost portion of its range in the world (Kushlan and Mazzotti 1989a, Thorbjarnarson 1989) and the only U.S. population. Loss of this population would result in a significant reduction of the extent of the species' range. Maintaining a species throughout its historic and current range is important to ensure its genetic diversity and population viability. While it is difficult to determine to what degree the Florida population of the American crocodile contributes substantially to the security of the species as a whole, the apparent isolation and evidence of genetic uniqueness (M. Forstner, Southwest Texas State University, unpublished data) suggest that the Florida population substantially contributes to the overall diversity within the species and is biologically or ecologically significant.

Recovery Accomplishments

The first recovery plan for the American crocodile was approved on February 12, 1979 (Service 1979). The recovery plan was revised on February

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2, 1984 (Service 1984). The recovery plan for the American crocodile was revised again and included as part of the South Florida Multi- Species Recovery Plan (MSRP) (Service 1999). The recovery plan for the crocodile in the MSRP, which was approved in May 1999, represents the current recovery plan for this species.

The MSRP identifies 10 primary recovery actions for the American crocodile. Species-focused recovery actions include: (1) Conduct surveys to determine the current distribution and abundance of American crocodiles; (2) protect and enhance existing colonies of American crocodiles; (3) conduct research on the biology and life history of crocodiles; (4) monitor the south Florida crocodile population; and (5) inform the public about the recovery needs of crocodiles. Habitat- focused recovery actions include: (1) Protect nesting, basking, and nursery habitat of American crocodiles in south Florida; (2) manage and restore suitable habitat of American crocodiles; (3) conduct research on the habitat relationships of the American crocodile; (4) continue to monitor crocodile habitat; and (5) increase public awareness of the habitat needs of crocodiles. All of these primary recovery actions have been initiated since the 1999 MSRP.

American crocodile nest surveys and subsequent hatchling crocodile surveys around nest sites are conducted in all areas where crocodiles nest (Mazzotti et al. 2000, Mazzotti and Cherkiss 2003). Nest monitoring has been conducted nearly continuously at each of the primary nesting areas since 1978. Without these data, we would have little evidence to support reclassification. In addition, detailed surveys and population monitoring have been conducted annually since 1996 throughout the American crocodile's range in Florida. These surveys documented distribution, habitat use, population size, and age class distribution of crocodiles. During both crocodile surveys and nest monitoring, crocodiles of all age classes are captured and marked (Mazzotti and Cherkiss 2003). These marked individuals continue to provide information on survival, longevity, growth, and movements (Mazzotti and Cherkiss 2003). All captured individuals are marked by clipping tail scutes in a prescribed manner so that each crocodile is given an individual identification number (Mazzotti and Cherkiss 2003). In addition, hatchlings at Turkey Point are marked with microchips placed under the skin.

Several ecological studies have been initiated or continued in recent years. Study has continued on the effects of salinity on growth rate and survival of American crocodiles in the wild. Previous laboratory studies provided a general relationship, but field data have improved our understanding of this relationship. In addition, analysis of contaminants in crocodile eggs has been conducted recently at Rookery Bay, and these analyses contribute to a record of contaminants data as far back as the 1970s.

Protection and enhancement of nesting habitat within each of the three primary American crocodile nesting areas has also been ongoing for many years. Turkey Point Nuclear Plant has implemented management actions to minimize disturbance to crocodiles and their nesting habitat. This includes the designation of nesting ``sanctuaries'' where access and maintenance activities are minimized. Habitat management in these areas includes exotic vegetation control and encouraging the growth of low-maintenance native vegetation. On Crocodile Lake National Wildlife Refuge, management has focused on maintaining suitable nesting substrate. The organic soils that compose the nesting substrate have subsided over time, leading to the potential for increased risk of flooding or unfavorable microclimate. Nesting substrate has been augmented near nesting areas. Encroaching vegetation in nesting areas has also been removed. In Everglades National Park, management has included minimizing disturbance to crocodiles resulting from public use, and relocation of crocodile nests that were placed in recently- excavated spoil material subject to disturbance and inhospitable environmental conditions.

Signs have been in place for several years along highways to alert motorists to the presence of crocodiles in the areas where most crocodile road kills have occurred. Fences were also erected along highways to prevent crocodiles from crossing, although several of these fences were later removed because they were ineffective. The remaining sections of fence are intended to funnel crocodiles to culverts where they can cross underneath roads without risk. Other efforts to reduce human-caused mortality include law enforcement actions and signs that inform the public about crocodiles in areas where crocodiles and people are likely to encounter each other, such as at fish cleaning stations along Biscayne Bay.

The FWC established a standard operating protocol in 1988 to manage crocodile-human interactions. This protocol established a standard procedure that included both public education to encourage tolerance of crocodiles and translocation of crocodiles in situations that may threaten the safety of either crocodiles or humans. While the protocol has led to the successful resolution of many complaints, many of the large crocodiles that have been translocated under the protocol have shown strong site fidelity and have returned to the areas from which they were removed (Mazzotti and Cherkiss 2003). Translocation appears to be effective with small crocodiles (generally

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