Endangered and Threatened Wildlife and Plants; Removal of the Monito Gecko (Sphaerodactylus micropithecus) From the Federal List of Endangered and Threatened Wildlife

AGENCY:

Fish and Wildlife Service, Interior.

ACTION:

Final rule.

SUMMARY:

We, the U.S. Fish and Wildlife Service (Service), are removing the Monito gecko (Sphaerodactylus micropithecus) from the Federal List of Endangered and Threatened Wildlife due to recovery. This determination is based on a thorough review of the best available scientific and commercial information, which indicates that this species has recovered and the threats to this species have been eliminated or reduced to the point that the species no longer meets the definition of an endangered species or a threatened species under the Endangered Species Act of 1973, as amended. Accordingly, the prohibitions and conservation measures provided by the Act will no longer apply to this species.

DATES:

This rule is effective November 4, 2019.

ADDRESSES:

The proposed and final rules, the post-delisting monitoring plan, and the comments received on the proposed rule are available on the internet at http://www.regulations.gov in Docket No. FWS-R4-ES-2017-0082 or https://ecos.fws.gov. Comments and materials we received, as well as supporting documentation we used in preparing this rule, are also available for public inspection by appointment, during normal business hours at: U.S. Fish and Wildlife Service, Caribbean Ecological Services Field Office, Road 301, Km. 5.1, Boquerón, Puerto Rico 00622; P.O. Box 491, Boquerón, Puerto Rico 00622; or by telephone (787) 851-7297.

FOR FURTHER INFORMATION CONTACT:

Edwin Muñiz, Field Supervisor, U.S. Fish and Wildlife Service, Caribbean Ecological Services Field Office (see ADDRESSES above). If you use a telecommunications device for the deaf (TDD), please call the Federal Relay Service at (800) 877-8339.

SUPPLEMENTARY INFORMATION:

Executive Summary

Purpose of Regulatory Action

The purpose of this action is to remove the Monito gecko from the Federal List of Endangered and Threatened Wildlife in title 50 of the Code of Federal Regulations (50 CFR 17.11(h)) (i.e., “delisting” it) based on its recovery.

Basis for Action

We may delist a species if the best scientific and commercial data indicate the species is neither a threatened species nor an endangered species for one or more of the following reasons: (1) The species is extinct; (2) the species has recovered; or (3) the original data used at the time the species was classified were in error (50 CFR 424.11). Here, we have determined that the species may be delisted based on recovery as follows:

• Rat predation, the threat suspected to be the main cause of an apparent population decline for the Monito gecko (factor C), was eliminated by August 1999 when the last rat eradication campaign was completed by the Puerto Rico Department of Natural and Environmental Resources (PRDNER). From August 1999 to May 2016, no rats or other potential exotic predators have been detected on Monito Island.
• The species' apparent small population size (factor E), noted as a threat at the time of listing, may have been an artifact of bias as surveys were conducted under conditions when the species was not easily detectable. The Monito gecko is currently considered abundant and widely distributed on Monito Island.
• The Monito gecko and its habitat have been and will continue to be protected under Commonwealth laws and regulations (factor D). These existing regulatory mechanisms are adequate to protect the Monito gecko now and in the future.

Despite potential climate change effects from a gradual warming trend for Puerto Rico, we expect the population to persist into the foreseeable future, especially with the current absence of other potential threats (e.g., habitat loss, disease, predation).

Previous Federal Actions

On October 15, 1982, we published a final rule in the Federal Register (47 FR 46090) listing the Monito gecko as an endangered species and designating the entire island of Monito as critical habitat. On March 27, 1986, we published the Monito Gecko Recovery Plan (USFWS 1986, 18 pp.). The 5-year review, which was completed on August 8, 2016 (USFWS 2016, 25 pp.), recommended delisting the species due to recovery. On January 10, 2018 (83 FR 1223), we published a proposed rule to delist the Monito gecko.

For additional details on previous Federal actions, see discussion under the Recovery section below. Also see http://www.fws.gov/endangered/species/us-species.html for the species profile for this reptile.

Summary of Comments and Recommendations

In the proposed delisting rule and draft post-delisting monitoring (PDM) plan published on January 10, 2018 (83 FR 1223), we requested that all interested parties submit written comments on the proposal and plan by March 12, 2018. We also contacted appropriate Federal and State agencies, scientific experts and organizations, and other interested parties and invited them to comment on the proposal. A newspaper notice inviting general public comments was published in Primera Hora (major local newspaper) and also announced using online and social media sources. We did not receive any requests for a public hearing.

Peer Review

In accordance with our policy published in the Federal Register on July 1, 1994 (59 FR 34270), and the Office of Management and Budget's Final Information Quality Bulletin for Peer Review, dated December 16, 2004, we solicited the expert opinions from five appropriate and independent specialists regarding the science in the proposed rule and the draft PDM plan. The purpose of such review is to ensure that we base our decisions on scientifically sound data, assumptions, and analyses. We sent peer reviewers copies of the proposed rule and the draft PDM plan immediately following publication of the proposed rule in the Federal Register. We invited peer reviewers to comment, during the public comment period, on the specific assumptions and conclusions regarding the proposed delisting rule and draft PDM plan. We received responses from one of the peer reviewers.

We reviewed all comments received from the peer reviewer for substantive issues and new information regarding the delisting rule and PDM plan for the Monito gecko. The peer reviewer generally concurred with our methods and conclusions and provided additional information, clarifications, and suggestions to improve the final delisting rule. Peer reviewer comments are summarized below and incorporated into the final rule as appropriate.

(1) Comment: The peer reviewer mentions that the evidence for the success of the Monito rat eradications is strong, but not compelling. The reviewer specified that, given the multiple trips to Monito Island with uniformly negative results, eradication success is the most likely explanation, but longer term monitoring would elevate confidence in this conclusion.

Our response: Since the rat eradication campaign in 1999, no rats have been detected on Monito Island. Based on the information available and consistent with the peer reviewer's interpretation of the evidence, is it highly unlikely there are still rats on Monito, unless there has been a reinvasion after May 2016, which is also unlikely. In addition, if rats had been present during our 2014 and 2016 trips we would likely have detected them, given the number of persons out at night searching for geckos, the relatively small size of the island, the rat detection devices used, and the scraps of food left out on purpose in the camp area. None of these methods produced even a suspicion of rats being present. Based on the best available information, the Service and its partners concluded that eradication was successful in 1998-1999.

(2) Comment: The peer reviewer mentioned that the gecko abundance estimate is based on a model that is reasonable but that has not been validated for this population. Several other commenters questioned the validity of the model used for the population estimate. They stated that the model was inaccurate and the estimated abundance was extremely biased and does not meet the assumptions of the model specified. Specifically, the model is intended for multi-temporal replication. Commenters explained that the Service is relying on just a single visit survey in its erroneous estimates that have overly broad confidence limits and high statistical error.

Our response: The Service used abundance modeling based on repeated surveys across multiple days across multiple sites. Specifically, we observed 84 geckos during 96 surveys among 40 plots across two nights. The high numbers of geckos detected (84) during the 96 surveys during the 2016 site visit was the first systematic attempt to survey the Monito gecko population. Recommendations for future survey efforts have been noted; for example, marking plots more visibly (Island Conservation 2016). During the development of the model and survey methods, the Service wanted methods and models that can be replicated in order to adjust and improve the abundance estimates accordingly over time (i.e., validate). Per our Post-Delisting Monitoring Plan, we recommend conducting surveys every other year for the next 5 years.

For a complete review of the methods and results, a copy of Island Conservation (2016) report is available at http://www.regulations.gov in Docket No. FWS-R4-ES-2017-0082. In addition, the methods and a reproducible code set are freely available online at: https://github.com/nangeli1/Contracts.

Public Comments

(1) Comment: One commenter asked the Service to explain the process for finding independent specialists when soliciting expert opinion for peer review.

Our response: In accordance with our joint policy on peer review published in the Federal Register on July 1, 1994 (59 FR 34270) and our August 22, 2016, memorandum updating and clarifying the role of peer review of listing actions under the Act, we sought the expert opinions of seven reviewers. We are required by our peer review policy to find at least three peer reviewers, and we often choose more than three if they are available. In doing so, the Service looked for experts in the species, including its life history, habitat and threats that it may face. The experts cannot have been involved in the production of the draft rule.

(2) Comment: The peer reviewer stated that the Service does not have a population trajectory for this species, but rather only a single snapshot in time. Several other commenters also recommended that more surveys are needed to assess population trends before delisting, as well as more ecological studies.

Our response: Gecko detections during 2014 and the 2016 survey provide substantial evidence that the species is consistently abundant and widespread across the island. Further, our analysis of the listing factors shows how the Service determined that the Monito gecko should be delisted, and survey information is just one of the parameters used to make that determination. Ultimately, there is no indication that any of the threats are operating on the population at levels that meet an endangered or threatened species as defined under the Act. In addition, conducting ecological studies was considered in the species Recovery Plan (1986). However, based on the most recent observations, achievement of the most critical recovery actions (i.e., rat eradication and survey), and our 5-factor analysis, we have determined that no additional ecological studies are needed to determine the listing status for this species. Future needs for studies, status evaluations, and recommendations will be addressed with the Post-Delisting Monitoring Plan and its primary goal of monitoring to ensure the status of the species does not deteriorate and, if a substantial decline in the species population size or an increase in threats is identified, to enact measures to halt and reverse unfavorable trends.

(3) Comment: Several commenters specified that there is evidence-based support that climate change will impact S. micropithecus and provided scientific articles to support their claim.

Our response: In our proposed rule, we analyzed the potential effects of climate-related sea-level rise on the Monito gecko and determined that it was not a threat to the species because the topography of Monito Island will insulate the species from the effects of sea-level rise. We asked the public to provide any data or new information particularly on the possible effects of climate change to the Monito gecko. Based on the comments and information received, we evaluated new information and conducted a thorough review of the relevant literature. We continue to conclude that climate change does not constitute a threat to the species to the extent that it is endangered or threatened throughout all or a significant portion of its range (Refer to Factor E, below, for a discussion of the potential implications of climate change on the Monito gecko).

(4) Comment: One commenter opined that lack of genetic analysis hinders the Service's ability to assess effective population size, inbreeding rates, deleterious alleles, and any proactive genetic rescue plans.

Our response: The Service recognizes that this determination does not include a genetic analysis of the Monito gecko population but has determined that one is not needed. The fact that the species is found throughout Monito Island in the thousands, and that juveniles and gravid females were found (past and most current surveys), all demonstrate a large well-represented population with abilities to recover and adapt from disturbances. Thus, there do not seem to be any perceptible indications that a lack of genetic representation is causing species mortality or limiting the species' ability to adapt or reproduce. Still, any potential genetic rescue plan would need to consider that the Monito gecko population is endemic, closed to immigration from other Sphaerodactylus species, and has been isolated for millions of years.

(5) Comment: Several commenters request the Service recognize the severe vulnerability of Monito Island and its inhabitants to catastrophic events such as hurricanes and fires.

Our response: Catastrophic events such as fires or hurricanes were discussed under Factors A and E, respectively. Neither of these factors were found to be operating currently, or are expected to be found in the foreseeable future, on the Monito gecko population to require its continued listing under the Act. In addition, even though several hurricanes have potentially affected Monito Island in the past, the species remains abundant and widespread throughout the island. The recent Hurricane Maria (Sept. 2017), which caused extensive damage in Puerto Rico, did not cause significant damage to Monito Island.

Species Information

Biology and Life History

The Monito gecko, Sphaerodactylus micropithecus, (Schwartz 1977, entire) is a small lizard (approximately 36 millimeters (1.42 inches) snout-vent length) with an overall pale-tan body and dark-brown mottling on the dorsal surface. It is closely related to the Sphaerodactylus macrolepis complex of the Puerto Rican Bank, but variation in dorsal pattern and scale counts confirm the distinctiveness of the species; probably resulting from a single invasion to Monito Island and its subsequent isolation (Schwartz 1977, p. 990, Dodd and Ortiz 1984, p. 768). Little is known about the biology of this species, including its diet, reproduction, or potential predators. Other more common Sphaerodactylus species in Puerto Rico eat a diverse content of small invertebrates, such as mites, springtails, and spiders (Thomas and Gaa Kessler 1996, pp. 347-362). Out of the 18 individuals counted by Dodd and Ortiz (1983, p. 120), they found juveniles and gravid females suggesting that the species was reproducing. Dodd and Ortiz (1983, p. 121) suspected reproduction occurs from at least March through November as suggested by the egg found by Campbell in May 1974, by the gravid females found by Dodd and Ortiz (1982, p. 121) in August 1982, and the fact that Monito gecko eggs take 2 to 3 months to hatch (Rivero 1998, p. 89). During a plot survey in May 2016, two gravid females and several juveniles were found (USFWS 2016, p. 13). Potential natural predators of the Monito gecko may include the other native lizard Anolis monensis and/or the Monito skink (Spondilurus monitae).

Distribution and Habitat

The Monito gecko is restricted to Monito Island, an isolated island located in the Mona Passage, about 68 km (42.3 mi) west of the island of Puerto Rico, 60 km (37.3 mi) east of Hispaniola and about 5 km (3.1 mi) northwest of Mona Island (USFWS 1986, p. 2). Monito Island is a flat plateau surrounded by vertical cliffs rising about 66 m (217 ft) with no beach and is considered the most inaccessible island within the Puerto Rican archipelago (Garcia et al. 2002, p. 116). With an approximate area of 40 acres (c.a. 16 hectares) (Woodbury et al. 1977, p. 1), Monito Island is part of the Mona Island Reserve, managed for conservation by the PRDNER (no date, p. 2). The remoteness and difficulty of access to Monito Island make studying the Monito gecko difficult (Dodd 1985, p. 2).

The only life zone present on Monito Island is subtropical dry forest (Ewel and Whitmore 1973, p. 10). In this life zone, the Monito gecko has been found in areas characterized by loose rock sheets or small piles of rocks, exposed to the sun, and with little or no vegetation cover. Vegetation may or may not be associated with these areas. On Monito Island, such areas include small groves of Guapira discolor (barrehorno), Pithecellobium unguis-cati (escambrn colorado), or Capparis flexuosa (palo de burro) where some leaf litter is present; areas with loose rocks on the ground; or rock sheets that provide shady refuges, and numerous regions where large pieces of metal (remnant ordnance) lay on the ground (Ortiz 1982, p. 2). Being a small, ground-dwelling lizard, the Monito gecko, like other members of its genus, is usually found under rocks, logs, leaf litter, and trash (Rivero 1998, p. 89).

Population Size and Trends

When the species' recovery plan was completed in 1986, only two island-wide surveys had been completed (Dodd and Ortiz 1983, entire; Hammerson 1984, entire), with the higher count from Dodd and Ortiz (1983, p. 120) reporting a total of 18 geckos during a 2-day survey. During both of these surveys, all geckos were found during the day and under rocks. Subsequent surveys of variable length and area covered detected from 0 to 13 geckos during the day as well (PRDNER 1993, pp. 3-4; USFWS 2016, p. 9).

These previous attempts to survey for the Monito gecko are considered underestimates, because the surveys were done during the day when the species is more difficult to detect: It seems to be less active and mostly hiding under rocks, debris, crevices, or other substrates. Although geckos in the Sphaerodactylinae group are considered mostly diurnal or crepuscular (Rivero, p. 89; Pianka and Vitt 2003, p. 185), we suspect that the Monito gecko is more active at night and thus easier to detect during night surveys. This nocturnal behavior was confirmed during a May 2014 rapid assessment and a May 2016 systematic survey. During the May 2014 rapid assessment, at least one gecko was seen during each of the three nights of the trip; some encounters were opportunistic, and others occurred while actively searching for the species (USFWS 2016, p. 9). In fact, no geckos were seen during daylight hours. Geckos were seen on exposed substrates and not hidden under rocks or litter, although some were seen within leaf litter mixed with rocks under a Ficus citrifolia tree. Geckos were observed escaping into the cracks and solution holes of the limestone rock.

The May 2016 systematic gecko survey involved setting up of 40 random plots on Monito Island (USFWS 2016, p. 10). Each plot was 20 m × 20 m (400 m²), so that the survey covered a total of 16,000 m² or approximately 11 percent of Monito Island. Four two-person teams visited 10 plots each. Each observer surveyed each plot independently. All sites were surveyed at least twice, and all took place during the night. A total of 84 geckos were observed during 96 surveys among the 40 plots, most on exposed rock. Only 8 out of the 84 counted were found under a rock or other substrate; all others were out during the night. Only two geckos were opportunistically found during the day while observers were turning rocks and dry logs.

Gecko occupancy and abundance were estimated using a standard mathematical population model accounting for the abundance and detection bias that allows individuals to go unseen during surveys (Island Conservation (IC) 2016, p. 5). Occupancy of the geckos on Monito Island was determined to be 27.8 percent (confidence interval 11.3-68.6 percent). The mean number of geckos per plot was 73.3 (Range: 1-101). The abundance model indicates a total of 1,112 geckos present within the surveyed plots (95 percent confidence interval: 362-2,281). Extrapolated across the entire island, Monito Island hosts approximately 7,661 geckos (50 percent confidence interval: 5,344-10,590).

Recovery and Recovery Plan Implementation

Section 4(f) of the Act directs us to develop and implement recovery plans for the conservation and survival of threatened and endangered species unless we determine that such a plan will not promote the conservation of the species. Recovery plans are not regulatory documents and are instead intended to establish goals for long-term conservation of a listed species, define criteria that are designed to indicate when the threats facing a species have been removed or reduced to such an extent that the species may no longer need the protections of the Act, and provide guidance to our Federal, State, and other governmental and nongovernmental partners on methods to minimize threats to listed species. There are many paths to accomplishing recovery of a species, and recovery may be achieved without all recovery criteria being fully met. For example, one or more criteria may have been exceeded while other criteria may not have been accomplished or become obsolete, yet the Service may judge that, overall, the threats have been minimized sufficiently, and the species is robust enough, to reclassify the species from endangered to threatened or perhaps delist the species. In other cases, recovery opportunities may have been recognized that were not known at the time the recovery plan was finalized. These opportunities may be used instead of methods identified in the recovery plan.

Likewise, information on the species may subsequently become available that was not known at the time the recovery plan was finalized. The new information may change the extent that criteria need to be met for recognizing recovery of the species. Recovery of species is a dynamic process requiring adaptive management that may, or may not, fully follow the guidance provided in a recovery plan.

The following discussion provides a brief review of recovery planning and implementation for the Monito gecko, as well as an analysis of the recovery criteria and goals as they relate to evaluating the status of the taxon.

The Monito Gecko Recovery Plan (Plan) was approved on March 27, 1986 (USFWS 1986, entire). The objective of the Plan was to conduct a systematic status survey and ecological study of the species, and to reevaluate the species' status and formulate a quantitative recovery level and specific recovery actions (USFWS 1986, p. 7). This Plan is considered outdated and does not contain recovery criteria that could lead to delisting the Monito gecko. However, the Plan does provide recovery objectives that, when accomplished, would aid in developing such criteria. No quantitative recovery level was defined due to the lack of data on historical population levels, population trends, and apparent historical population size. The objectives were accomplished as follows:

Recovery Actions

The Plan identifies five primary recovery actions:

(1) Determine the status of the present population;

(2) Conduct basic ecological studies;

(3) Determine extent, if any, of predation and competition by rats and other native lizards (see Factor C);

(4) Update the Plan; and

(5) Continue protection of the present population.

The following discussion provides specific details for each of these actions.

Recovery action 1: Determine the status of the species.

From 1982 to 1993, several Monito gecko surveys were conducted (USFWS 2016, p. 9). However, some of these surveys were either done before the Plan was completed (USFWS 1986) or did not provide enough information to answer the population objectives of the Plan, and current information (see Population Size and Trends above) suggests that surveys underestimated the number of geckos. Data from the 2014 rapid assessment and the 2016 systematic plot survey show that, overall, the Monito gecko is abundant across the whole island and numbers in the thousands, indicating a large healthy population, as specified in the Species Information section above.

Recovery action 2: Conduct basic ecological studies.

Besides the population survey efforts, no basic ecological studies have been conducted for the Monito gecko. Conducting ecological studies, as described in the Plan (USFWS 1986, pp. 7-8), is not crucial to further assess the species' listing status. There is no indication that ecological factors such as habitat preferences (species occurs throughout the island) and fluctuations in reproductive biology or activity patterns (both unknown), are critical for the species' listing status. The adjustment of surveys from diurnal to nocturnal was a key factor for researchers to discover in order to obtain reliable data and provide optimal population information. We will further discuss any possible needs of ecological evaluations in relation to post-delisting monitoring with our partners, but we will likely not need detailed research on the gecko's ecology based on the status of threats in its native habitat on Monito Island.

Recovery action 3: Determine the extent, if any, of predation and competition by rats and native reptiles.

At the time of listing, the presence of rats on Monito Island was identified as the main threat to the Monito gecko. This threat was suspected to be the main cause of an apparent population decline for the Monito gecko, since rats are effective predators and are known to feed on both lizards and lizard eggs (Dodd and Ortiz 1983, p. 120; Case and Bolger 1991, pp. 273-278). However, the net effect, if any, of the potential rat predation on the geckos is debatable. For example, in comments quoted in the final listing rule (47 FR 46091, October 15, 1982), Dr. H. Campbell indicated that the scarcity of the Monito geckos was an artifact of the intense predation by black rats (Rattus rattus), while Dr. A. Schwartz expressed doubts that rats could have any effect on the gecko or its eggs. Dodd and Ortíz (1983, p. 121) also explained that, during their surveys, predator pressure on the gecko could not be proven and that more studies were needed to determine if rats or other predators do affect the Monito gecko. The potential effect of rats on two other relatively common small geckos (Sphaerodactylus monensis and Sphaerodactylus levinsi) on nearby Mona and Desecheo Islands (respectively) is also unknown. Nevertheless, there is ample evidence that the Monito gecko would fare better without rats (Case and Bolger 1991, entire; Towns et al. 2006, entire; Jones et al. 2016, entire; Thibault et al. 2017, entire).

In October 1992, the PRDNER began a black rat eradication and survey project on Monito Island to benefit native and endemic species on that Island (García et al. 2002, p. 116). The eradication campaign continued in March 1993 with poisoning (rodenticide) and snap traps to assess changes in the rat population. A second eradication campaign started in October 1998, with three eradication events at 4-month intervals, and again using, in addition to snap traps, chew blocks (i.e., soft wood pieces soaked in canola oil) as a monitoring tool.

García et al. (2002, pp. 117-118) evaluated the status of the rat population seven times during the first campaign and five times during the second campaign. Since the completion of the second eradication campaign (August 1999), no rats have been detected on Monito Island. García et al. (2002, p. 118) concluded that in order to be certain that eradication had been achieved, it was essential to continue an appropriate rat monitoring program on the island, and recommended using chew blocks. However, no systematic rat monitoring has been implemented on the island since September 1999. Nonetheless, during a seabird blood sampling trip in August 2000, Anderson and Steeves (2000, p. 1) reported not seeing any rats on Monito Island, as did subsequent PRDNER bird survey trips in 2003.

On May 2014, the Service organized an expedition to Monito Island with the PRDNER in order to confirm the eradication of black rats from the island, and to evaluate the status of and threats to the Monito gecko. The Service and the PRDNER placed 27 snap traps and 70 chew blocks distributed along transects covering 870 meters in length (USFWS 2016, p. 7). In addition, some food items (i.e., watermelon, left-over canned food) were intentionally left exposed and available for rats. No signs of rats were detected on these available sources during this 4-day/3-night trip. During surveys conducted in May 2016, the Service and the PRDNER also placed 80 chew blocks, two within each gecko sampling plot (USFWS 2016, p. 10). No rats were seen or detected with the chew blocks during this 5-day/4-night trip. This is a marked contrast from when the species was listed in 1982, when rats were observed island-wide at all times during a 2-day expedition (47 FR 46090, October 15, 1982).

In short, although it cannot be ascertained when the last rat died, Monito Island appears to have been rat free since August-September 1999. Thus, the suspected main threat to the species has not been present for at least the past 18 years.

Other lizards (i.e., Anolis monensis and Spondilurus monitae, formerly Mabuya mabouya sloani) that naturally occur on the Island may also prey on the Monito gecko. These other species are considered diurnal (active during the day), while the Monito gecko is considered nocturnal (active during the night). Determining the extent of these potential predator-prey interactions would be challenging. However, this should no longer be necessary, as the species has persisted despite potential predatory threats.

Recovery action 4: Update Recovery Plan.

Because of the information on threats and recovery progress that is provided in the Monito gecko 5-year review (USFWS 2016) and this final rule, the Monito gecko no longer meets the definition of an endangered or threatened species. Therefore, a formal update of the 1986 Plan is not needed.

Recovery action 5: Continue protection of the present population.

Monito Island has been protected by the PRDNER as a nature reserve since 1986 (PRDNER, no date, p. 2). There are no permanent human residents on Monito Island and access is allowed only under special permits issued by the PRDNER, which also maintains a ranger detachment and biologist on nearby Mona Island. Monito Island is also visited by illegal immigrants. The frequency of these events varies from year to year, and illegal immigrants are evacuated fairly quickly by the U.S. Coast Guard. Furthermore, the impacts of these visitations seem to be minimal (see discussion below).

Summary of Factors Affecting the Species

Section 4 of the Act and its implementing regulations (50 CFR part 424) set forth the procedures for listing, reclassifying, or removing species from the Federal List of Endangered and Threatened Species. “Species” is defined by the Act as including any species or subspecies of fish or wildlife or plants, and any distinct vertebrate population segment of fish or wildlife that interbreeds when mature (16 U.S.C. 1532(16)). Once the species is determined, we then evaluate whether that species may be an endangered species or a threatened species because of any of one or a combination of the five factors described in section 4(a)(1) of the Act:

(A) The present or threatened destruction, modification, or curtailment of its habitat or range;

(B) Overutilization for commercial, recreational, scientific, or educational purposes;

(C) Disease or predation;

(D) The inadequacy of existing regulatory mechanisms; or

(E) Other natural or manmade factors affecting its continued existence.

We must consider these same five factors in reclassifying or delisting a species. In other words, for species that are already listed as endangered or threatened, the analysis for a delisting due to recovery must include an evaluation of the threats that existed at the time of listing, the threats currently facing the species, and the threats that are reasonably likely to affect the species in the foreseeable future following the delisting or downlisting and the removal of the Act's protections.

The following discussion examines the factors that were believed to affect the Monito gecko at the time of its listing, are currently affecting it, or are likely to affect the Monito gecko within the foreseeable future.

Factor A. The Present or Threatened Destruction, Modification, or Curtailment of Its Habitat or Range

At the time of listing (47 FR 46090, October 15, 1982), the destruction, modification, or curtailment of its habitat was not considered a threat to the Monito gecko. In 1940, the U.S. Government acquired Monito Island, and the entire island was used by the Air Corps/U.S. Air Force as a high-level radar bombing and gunnery range (Parsons Corp. 2010, pp. 2-5). In 1961, Monito Island was declared surplus and was returned to the Commonwealth of Puerto Rico in September 1965 (Parsons Corp. 2010, pp. 2-5). Monito Island is managed by the PRDNER for conservation as part of the Mona Island Reserve (PRDNER, no date, p. 2). The final listing rule indicated that there were no plans to continue to use Monito Island for bombing practices at the time, and any major alteration of the island could be detrimental to the continued survival of the Monito gecko. In fact, the large amount of scattered debris on Monito Island suggests significant historical habitat modification from bombing activities (USFWS 1986, p. 5).

A Monito Island site inspection was conducted in August 2009 (Parsons Corp. 2010, entire). A qualitative reconnaissance and munitions constituents sampling was performed to confirm the range location and to evaluate the potential presence of munitions and explosives of concern (Parsons Corp. 2010, p. ES-1). Although unexploded ordnance (UXO) and munitions debris was found on Monito Island, immediate munitions removal actions were not warranted.

The potential for future UXO detonation activities may have an effect on the Monito gecko and its critical habitat. Since Monito Island is a natural reserve, all activities must be coordinated with the PRDNER. The Service has been conducting informal consultations with the U.S. Army Corps of Engineers in order to develop species-specific standard operating procedures (SOPs) for the Monito gecko and other federally listed species that occur on Monito Island. These site-specific SOPs would be considered the appropriate conservation measures required to avoid and minimize potential adverse effects on the species or its critical habitat. Based on the current consultation, the magnitude of threat of these future U.S. Army Corps of Engineers' actions on the Monito gecko is considered minimal and non-imminent (USCOE 2017).

Monito Island receives illegal immigrants, usually from the western islands of Cuba and Hispaniola, that are trying to enter U.S. territory. The PRDNER has stated that illegal immigrants sometimes light fires on Monito Island in order to be detected and rescued. This information was documented during the May 2016 trip, where two recent fire pits were found, along with a small pile of firewood cuttings, on the south-southeast side of the island on exposed rock with no vegetation in the immediate vicinity. The presence of fire pits on Monito Island had not been documented in the past. At least for the two fire pits found in May 2016, their placement and construction demonstrates these were controlled fires and their intention was not of criminal nature. Although there is no information available on the frequency and damage these fires may be causing, based on what was documented in May 2016, the potential effects of such fires may also be considered minimal. To date, there is no indication that any potential fires have spread throughout the Island.

Factor B. Overutilization for Commercial, Recreational, Scientific, or Educational Purposes

The final listing rule (47 FR 46091, October 15, 1982) mentioned that, because of the rarity of the Monito gecko, removal of specimens could be detrimental. At present, we are not aware of any individuals taken after listing for commercial, recreational, scientific, or educational purposes. The remoteness and difficult access of Monito Island limits any collecting efforts. In addition, access is only allowed under special permits issued by the PRDNER, mostly for research, security, or management purposes. Furthermore, the Monito gecko's apparent rarity may have been an artifact of sampling bias, because surveys from 1982 to 1993 were done during daylight hours when the species is mostly hiding and the species has a low detection probability (see Species Information section).

Factor C. Disease or Predation

The final listing rule (47 FR 46091, October 15, 1982) indicates that the presence of large numbers of introduced black rats was thought to be the major factor in the precarious state of the Monito gecko because, although predation by black rats on this species has not been confirmed, rats are predaceous and are known to feed on both lizards and lizard eggs (Dodd and Ortiz 1983, p. 120; Case and Bolger 1991, pp. 273-278). Thus, predation by rats was considered a possible cause of population decline for the Monito gecko (USFWS 1986, p. 5). As previously explained above under Recovery Action 3, Monito Island has been rat free since August-September 1999. Thus, the main threat to the species has not been present for at least the past 18 years.

Although Monito Island is currently rat free, there is still the possibility that rats could reach the island again. Rats may be transferred from Mona Island by floating debris or more likely by human means. In addition to illegal immigrants, as discussed above, there is limited evidence of public use of Monito Island for recreational or unknown purposes. Although it is logistically difficult to disembark on the island and prohibited because of unexploded ordinances from the previous military activities, these disembarking events could increase the chance of invasion and establishment of rats or other exotic species. However, this possibility is considered very low. The rat eradication campaign was completed in 1999, and 18 years later, no rats have been found.

Ortiz (1982, p. 7) included the endemic Monito skink Spondilurus monitae (formerly Mabuya mabouya sloani) as a potential predator of the Monito gecko. Other species of Mabuya feed primarily on small invertebrates, but the diversity of prey types in stomach contents, including small vertebrates, indicates that some skink species (such as M. bistriata) most likely feed on any moving animal of the appropriate size (Vitt and Blackburn 1991, p. 920). Mabuya mabouya live in places where Sphaerodactylus abound (Rivero 1998, p. 106) and it is probable that geckos constitute an important food item for this skink. During the 2016 trip, biologists observed one adult skink active at night within the same exposed rock habitat used by the Monito gecko (i.e., exposed karst rock with lots of crevices and holes). It is also highly probable that another native lizard, Anolis monensis, will prey on the Monito gecko as well, except that Anolis are considered diurnal. The Monito gecko's trait of tail autotomy (tail loss) is certainly an effective predator defense mechanism (Pianka and Vitt 2003, p. 76). During our May 2014 site visit, 2 out of the 8 geckos captured for measurements were missing the tips of their tails, and during May 2016, only 5 geckos out of the 84 seen had missing tail parts. Although difficult to determine, this suggests natural predation pressure from the two other native lizard species mentioned above is low.

Factor D. The Inadequacy of Existing Regulatory Mechanisms

When the Monito gecko was listed (47 FR 46091; October 15, 1982), the species did not have any other statutory or regulatory protections. Now, territorial laws and regulations protect the Monito gecko. In 1999, the Commonwealth of Puerto Rico enacted Law No. 241-1999, known as the New Wildlife Law of Puerto Rico (Nueva Ley de Vida Silvestre de Puerto Rico). The purpose of this law is to protect, conserve, and enhance both native and migratory wildlife species; declare property of Puerto Rico all wildlife species within its jurisdiction; provide provisions to issue permits; regulate hunting activities; and regulate exotic species, among other actions. In 2004, the PRDNER approved Regulation 6766—to regulate the management of threatened and endangered species in Puerto Rico (Reglamento 6766—Reglamento para Regir el Manejo de las Especies Vulnerables y en Peligro de Extinción en el Estado Libre Asociado de Puerto Rico), including the Monito gecko, which was listed as endangered. Article 2.06 of this regulation prohibits collecting, cutting, removing, among other activities, listed animals within the jurisdiction of Puerto Rico. There is no evidence that either the law or the regulation is not being adequately implemented.

Additionally, the PRDNER has managed Monito Island as a natural reserve since 1986, protecting its wildlife and vegetation. Monito Island is managed for conservation because it harbors one of the largest seabird nesting colonies in the Caribbean, in addition to other endemic and federally listed species like the Higo chumbo cactus (Harrisia portoricensis) and the yellow-shouldered blackbird (Agelaius xanthomus). No human permanent residents live on the island, and public access is prohibited. The best available information indicates that Monito Island will remain permanently protected as a nature reserve and managed for conservation. In addition, Monito Island harbors additional species protected by the ESA and the Migratory Bird Treaty Act. Any potential future federal actions on Monito Island will still require consultation with the USFWS for those species (e.g., Harrisia cactus, Yellow-shouldered black bird), thereby potentially also benefiting the Monito gecko from conservation measures developed for those other species.

Factor E. Other Natural or Manmade Factors Affecting Its Continued Existence

In listing the Monito gecko, we considered as a factor the species' extremely small population size (47 FR 46090, October 15, 1982). As previously explained in Species Information and Recovery and Recovery Plan Implementation, the Monito gecko is a small and cryptic species and difficult to detect, especially during the day. However, all of the historical surveys documented (USFWS 2016, p. 9) were done during daylight hours, when the species is apparently less active, safely hiding from diurnal native reptile predators, and/or exhibiting behavioral adaptations to avoid the hot temperatures within its xeric dry forest environment. As discussed above (see Population Size and Trends), these and other biases cause us to question the validity of these historical surveys. In contrast, as also discussed above (see Population Size and Trends), the best available population estimate for the species, completed during the May 2016 systematic plot survey, shows that the Monito gecko is widely distributed throughout Monito Island and gecko abundance appears to number in the thousands, indicating a large well-represented population (IC 2016, pp. 5-6). Our post-delisting monitoring will demonstrate the continued recovery of this species. In general, lizard populations remain fairly stable and are influenced by predation and amount of resources available, and predation and competition usually result in populations existing below their carrying capacity (Pianka and Vitt 2003, p. 64). Based on the May 2014 and 2016 observations and results, there is no indication that limited resources are acting on the population to warrant listing under the Act.

Potential sea level rise as a result of climate change is not a threat to this species or its habitat, because the Monito gecko is found only on Monito Island, which is 66 m (217 ft) above sea level and has no beach areas. The current rate of sea level rise in the Caribbean is 10 cm (3.9 inches) per century, with more specific sea level rise estimates for Puerto Rico ranging from 0.07 to 0.57 meters (m) (0.20 to 1.87 feet) above current sea level by the year 2060 and between 0.14 to 1.70 m (0.40 to 5.59 feet) by the year 2110 (Puerto Rico Climate Change Council 2013, p. 64). Thus, the habitat occupied by the Monito gecko will remain well above the area of Monito Island predicted to be affected by sea-level rise in the foreseeable future.

Hurricanes, such as the recent Hurricanes Irma and Maria are not considered a threat to the Monito gecko in part because the island is 66 m above sea level. The vegetation on the island is short and therefore hurricane impacts are expected to be minimal. Additionally, the Monito gecko is adapted to living under cover mostly during the day when the species seems to be less active. Typical forms of cover include rocks, debris, crevices, or other substrates.

We further evaluated the potential effects of the predicted scenario of a gradual trend toward a dryer and hotter climate for Puerto Rico (Henareh et al. 2016, p. 265; Bhardwaj et al. 2018, pp. 133-134). To a certain extent, evaluating the vulnerability of the Monito gecko to climate change would require linking the magnitude of changes (i.e., temperature and humidity) with the physiological response of the species to those changes (Deutsch et al. 2008, p. 6668; Huey et al. 2009, p. 1; Glick et al. 2011, pp. 39-43; Pacifici et al. 2015, p. 215). For example, the fact that Sphaerodactylus are particularly vulnerable to overheating and desiccation is an important criterion to evaluate.

Based on the available information, the Monito gecko should have low evaporative water loss rates, with behavioral adaptions similar to other Sphaerodactylus (or other lizards) that exploit arid microhabitats (Snyder 1979, p. 110; Dunson and Bramham 1981, pp. 257-258; Nava 2001, pp. 461-463; López-Ortiz and Lewis 2004, p. 438; Nava 2004, pp. 18-26; Steinberg et al. 2007, pp. 334-335; Turk et al. 2010, pp. 128-129; Bentz et al. 2011, pp. 46-47; Allen and Powell 2014, pp. 594-596). Research suggests that these tiny lizards have behavioral and physiological traits that allow them to acclimate to and survive under each particular local environment and climate. In the case of the Monito gecko, the species usually hides and is undetectable during the day (unless an active search of turning rocks and debris is conducted) and shifts to a more active and detectable lifestyle during the night. This is consistent with microhabitat selection and activity patterns exhibited by other Sphaerodactylus lizards to minimize exposure to physiologically challenging diurnal conditions of lower humidity and higher temperatures. Cover during the day not only provides insulation from higher temperatures, but also protection from predators such as the relatively abundant Anole lizard on Monito Island. In addition, Sphaerodactylus eggs are considered extremely resistant to dessication (Dunson and Bramham 1981, p. 255).

Without any specific climate change studies for the Monito gecko, it is difficult to predict with certainty how the Monito gecko will respond to predicted climate change scenarios and how they might affect the species' fitness and viability. Some researchers suggest that climate change will increase the thermal stress on tropical lizards, suggesting a detrimental effect on the basic physiological functions of these ectotherms (Deutsch 2008, entire; Tewksbury 2008, entire; Huey et al. 2009, entire). However, with the current absence of other potential threats (e.g., habitat loss, disease, rat predation, etc.) and the perpetual legal protection of the species and its habitat as a nature reserve, the Monito gecko should have the best opportunity to survive and adapt well past the foreseeable future. Thus, we do not expect the Monito gecko to be endangered nor threatened currently or in the foreseeable future by potential climate change effects.

Determination of Species Status

Under section 4(a)(1) of the Act, we determine whether a species is an endangered species or threatened species because of any one or a combination of the following: (A) The present or threatened destruction, modification, or curtailment of its habitat or range; (B) Overutilization for commercial, recreational, scientific, or educational purposes; (C) Disease or predation; (D) The inadequacy of existing regulatory mechanisms; or (E) Other natural or manmade factors affecting its continued existence. The Act defines an endangered species as any species that is “in danger of extinction throughout all or a significant portion of its range” and a threatened species as any species “which is likely to become an endangered species within the foreseeable future throughout all or a significant portion of its range.”

Monito Gecko--Determination of Status Throughout All of Its Range

As required by section 4(a)(1) of the Act, we conducted a review of the status of this species and assessed the five factors to evaluate whether it is in danger of extinction currently or likely to become so in the foreseeable future throughout all of its range. The Monito gecko is endemic to Monito Island, a small island (approx. 40 acres; 16.2 hectares) off the west coast of Puerto Rico, and it has not been introduced elsewhere. There are no landscape barriers within Monito Island that might be of biological or conservation importance. The most recent survey found that the species occurs across most of the Island. The basic ecological components required for the species to complete its life cycle are considered present throughout Monito Island. We found that Monito gecko populations are persistent with an estimate of approximately 7,661 geckos (50 percent confidence interval: 5,344-10,590). During our analysis, we found that impacts thought to be threats at the time of listing (primarily predation by rats, factor C) are either not as significant as originally anticipated or have been eliminated or reduced since listing, and we do not expect any of these conditions to substantially change post-delisting and into the foreseeable future, nor do we expect climate change to affect this species in the foreseeable future. We conclude that the previously recognized impacts (i.e., rat predation, small population size) to the Monito gecko no longer threaten the species, such that the species is no longer in danger of extinction throughout all of its range now or in the foreseeable future. In order to make this conclusion, we analyzed the five threat factors used in making Endangered Species Act listing (and delisting) decisions. This analysis indicates that the Monito gecko is not in danger of extinction throughout all of its range, nor is it likely to become so in the foreseeable future.

Monito Gecko--Determination of Status Throughout a Significant Portion of Its Range

Under the Act and our implementing regulations, a species may warrant listing if it is in danger of extinction or likely to become so in the foreseeable future throughout all or a significant portion of its range (SPR). Where the best available information allows the Services to determine a status for the species rangewide, that determination should be given conclusive weight because a rangewide determination of status more accurately reflects the species' degree of imperilment and better promotes the purposes of the Act. Under this reading, we should first consider whether the species warrants listing “throughout all” of its range and proceed to conduct a “significant portion of its range” analysis if, and only if, a species does not qualify for listing as either an endangered or a threatened species according to the “throughout all” language.

Having determined that the Monito gecko is not in danger of extinction now or likely to become so in the foreseeable future throughout all of its range, we now consider whether it may be in danger of extinction or likely to become so in the foreseeable future in an SPR. The range of a species can theoretically be divided into portions in an infinite number of ways, so we first screen the potential portions of the species' range to determine if there are any portions that warrant further consideration. To do the “screening” analysis, we ask whether there are portions of the species' range for which there is substantial information indicating that: (1) The portion may be significant; and (2) the species may be, in that portion, either in danger of extinction or likely to become so in the foreseeable future. For a particular portion, if we cannot answer both questions in the affirmative, then that portion does not warrant further consideration and the species does not warrant listing because of its status in that portion of its range. We emphasize that answering these questions in the affirmative is not a determination that the species is in danger of extinction or likely to become so in the foreseeable future throughout a significant portion of its range—rather, it is a step in determining whether a more detailed analysis of the issue is required.

If we answer these questions in the affirmative, we then conduct a more thorough analysis to determine whether the portion does indeed meet both of the SPR prongs: (1) The portion is significant and (2) the species is, in that portion, either in danger of extinction or likely to become so in the foreseeable future. Confirmation that a portion does indeed meet one of these prongs does not create a presumption, prejudgment, or other determination as to whether the species is an endangered species or threatened species. Rather, we must then undertake a more detailed analysis of the other prong to make that determination. Only if the portion does indeed meet both SPR prongs would the species warrant listing because of its status in a significant portion of its range.

At both stages in this process—the stage of screening potential portions to identify any portions that warrant further consideration and the stage of undertaking the more detailed analysis of any portions that do warrant further consideration—it might be more efficient for us to address the “significance” question or the “status” question first. Our selection of which question to address first for a particular portion depends on the biology of the species, its range, and the threats it faces. Regardless of which question we address first, if we reach a negative answer with respect to the first question that we address, we do not need to evaluate the second question for that portion of the species' range.

For Monito gecko, we chose to evaluate the status question (i.e., identifying portions where the Monito gecko may be in danger of extinction or likely to become so in the foreseeable future) first. To conduct this screening, we considered whether the threats are geographically concentrated in any portion of the species' range at a biologically meaningful scale. If a species is not in danger of extinction or likely to become so in the foreseeable future throughout all of its range and the threats to the species are essentially uniform throughout its range, then the species would not have a greater level of imperilment in any portion of its range than it does throughout all of its range and therefore no portions would qualify as an SPR.

We examined the following threats: The destruction and modification of habitat by humans and exotic foreign species introduced to the Monito Island, such as rats and mice, including cumulative effects. We found no concentration of threats in any portion of the Monito gecko's range at a biologically meaningful scale. Since we found no portions of the species' range where potential threats are significantly concentrated or substantially greater than in other portions of its range, we did not identify any portions where the species may be in danger of extinction or likely to become so in the foreseeable future. Therefore, no portions warrant further consideration through a more detailed analysis, and the species is not in danger of extinction or likely to become so in the foreseeable future in any significant portion of its range. Our approach to analyzing SPR in this determination is consistent with the court's holding in Desert Survivors v. Department of the Interior, No. 16-cv-01165-JCS, 2018 WL 4053447 (N.D. Cal. Aug. 24, 2018).

Our review of the best available scientific and commercial information indicates that the Monito gecko is not in danger of extinction nor likely to become an endangered species within the foreseeable future throughout all or a significant portion of its range. Therefore, we find that listing the Monito gecko as an endangered species or a threatened species under the Act is not warranted at this time.

Conclusion and Determination

The Monito gecko has demonstrated the ability to persist despite changing environmental conditions over time from both anthropogenic and natural disturbances. Although the Monito gecko population is considered to have low redundancy (i.e., one population endemic to Monito Island), no risk of extirpation was identified and no other populations outside of Monito Island are needed for its recovery. In addition, the fact that the species was found throughout the Island, gecko abundance is in the thousands, and past and current occurrence of juveniles and gravid females, indicates a large, well-represented population with demonstrated abilities to recover and adapt from disturbances.

Because the Monito gecko population is considered self-sustaining, contains a large number of individuals, and has demonstrated high resilience and viability, we expect this population to persist into the future. The species is considered abundant within its habitat, which consists of adequate area and quality to maintain survival and reproduction in spite of disturbances. Thus, the Monito gecko appears to have highly resilient population attributes (e.g., habitat generalist, potential high adult survival rate) that allow at least some degree of disturbance within a harsh xeric environment.

For the Monito gecko, we determined that a foreseeable future of 20 to 30 years is reasonable. Based on the available information, making threat projections beyond this time frame increases speculation. For example, although rats could potentially reinvade Monito Island, the probability of rats reinvading is considered low since rats have not been detected after the eradication effort was completed in 1999. In addition, lifespan data for almost all of the Sphaerodactylus species is not available. One species from Martinique in the West Indies, Sphaerodactylus vicenti ronaldi, estimated longevity did not exceed 4 years (Leclair and Leclair 2011). Assuming the Monito gecko would have a similar lifespan, a foreseeable future of 20 to 30 years would allow for multiple generations and detection of any population changes. The Monito gecko has been listed since 1982, has persisted apparent mayor threats (i.e. bombing effects, rat predation), and is currently well represented. Further, we do not anticipate significant impacts in the foreseeable future from climate change factors. Therefore, without no immediate risk of extinction, we have a baseline to continue assessing how the Monito gecko population may respond in the foreseeable future.

We carefully assessed the best scientific and commercial information available regarding the threats faced by the Monito gecko in developing the proposed rule and this final rule. The Service finds that the present or threatened destruction, modification, or curtailment of its habitat (factor A) is not a threat to the continued existence of the Monito gecko, and we do not expect it to be a threat in the future. We also conclude that overutilization (factor B) and disease (factor C) are not a threat to the Monito gecko. Natural predation by other native lizards may occur, but this activity is considered a low-magnitude threat because the Monito gecko has persisted despite potential predation and there is no indication that the magnitude of an undetermined natural predation pressure significantly affects the gecko's survival. No rats have been detected on Monito Island since August 1999. Therefore, we conclude that predation (factor C) is no longer a threat to the Monito gecko.

The species' apparent small population size (factor E), noted at the time of listing, may have been an artifact of bias as surveys were conducted under conditions when the species was not easily detectable. There are no known potential climate change effects (i.e., sea level rise or changes in air temperature) (factor A) that negatively affect the Monito gecko. No other natural or manmade factors are considered threats (factor E). The Monito gecko and its habitat have been and will continue to be protected under Commonwealth laws and regulations (factor D), and these existing regulatory mechanisms are adequate to protect the Monito gecko now and in the future. The information indicates that this species is no longer at risk of extinction, nor is it likely to experience reemergence of threats and associated population declines in the foreseeable future. Based on the analysis above and after considering the best available scientific and commercial information, we conclude that the Monito gecko does not currently meet the Act's definition of either an endangered or threatened species throughout all or a significant portion of its range.

Effects of This Rule

This final rule revises 50 CFR 17.11(h) to remove the Monito gecko from the Federal List of Endangered and Threatened Wildlife. The prohibitions and conservation measures provided by the Act would no longer apply to the Monito gecko. Federal agencies will no longer be required to consult with us under section 7 of the Act to ensure that any action authorized, funded, or carried out by them is not likely to jeopardize the gecko's continued existence. The prohibitions under section 9(a)(1) of the Act will no longer make it illegal for any person subject to the jurisdiction of the United States to import or export, transport in interstate or foreign commerce, or take, possess, sell, deliver, carry, transport, or ship Monito geckos. Finally, this rule will also remove the Federal regulations related to the Monito gecko listing: The critical habitat designation at 50 CFR 17.95(c).

Post-Delisting Monitoring

Section 4(g)(1) of the Act requires us to implement a system in cooperation with the States to monitor effectively for not less than 5 years the status of all species that are delisted due to recovery. Post-delisting monitoring (PDM) refers to activities undertaken to verify that a species delisted due to recovery remains secure from the risk of extinction after the protections of the Act no longer apply. The primary goal of PDM is to ensure that the species' status does not deteriorate, and if a decline is detected, to take measures to halt the decline so that proposing it as threatened or endangered is not again needed. If at any time during the PDM period, data indicate that protective status under the Act should be reinstated, we can initiate listing procedures, including, if appropriate, emergency listing. At the conclusion of the PDM period, we will review all available information to determine if re-listing, the continuation of monitoring, or the termination of monitoring is appropriate.

Section 4(g) of the Act explicitly requires cooperation with the States (which includes Territories such as Puerto Rico) in development and implementation of PDM programs. However, we remain responsible for compliance with section 4(g) and, therefore, must remain actively engaged in all phases of PDM. We also seek active participation of other entities that are expected to assume responsibilities for the species' conservation after delisting. In April 2017, the PRDNER and the Service agreed to be cooperators in the PDM for the Monito gecko.

We have prepared a PDM Plan for the Monito gecko (USFWS 2017). The plan is designed to detect significant declines in the Monito gecko with reasonable certainty and precision, and detect possible new or reoccurring threats (i.e., presence of rats). The plan:

(1) Summarizes the species' status at the time of delisting;

(2) Defines thresholds or triggers for potential monitoring outcomes and conclusions;

(3) Lays out frequency and duration of monitoring;

(4) Articulates monitoring methods including sampling considerations;

(5) Outlines data compilation and reporting procedures and responsibilities; and

(6) Proposes a PDM implementation schedule including timing and responsible parties.

It is our intent to work with our partners towards maintaining the recovered status of the Monito gecko.

Required Determinations

National Environmental Policy Act

We have determined that we do not need to prepare an Environmental Assessment or Environmental Impact Statement, as defined in the National Environmental Policy Act of 1969 (42 U.S.C. 4321 et seq.), in connection with regulations adopted pursuant to section 4(a) of the Endangered Species Act. We published a notice outlining our reasons for this determination in the Federal Register on October 25, 1983 (48 FR 49244).

Government-to-Government Relationship With Tribes

In accordance with the President's memorandum of April 29, 1994, “Government-to-Government Relations with Native American Tribal Governments” (59 FR 22951), Executive Order 13175, and the Department of the Interior's manual at 512 DM 2, we readily acknowledge our responsibility to communicate meaningfully with recognized Federal Tribes on a government-to-government basis. We have determined that no tribal lands are affected by this proposal.

References Cited

A complete list of references cited is available on http://www.regulations.gov under Docket Number FWS-R4-ES-2017-0082.

Author

The primary authors of this document are the staff members of the Caribbean Ecological Services Field Office.

List of Subjects in 50 CFR Part 17

• Endangered and threatened species
• Exports
• Imports
• Reporting and recordkeeping requirements
• Transportation

Regulation Promulgation

Accordingly, we amend part 17, subchapter B of chapter I, title 50 of the Code of Federal Regulations, as set forth below:

PART 17—ENDANGERED AND THREATENED WILDLIFE AND PLANTS

1. The authority citation for part 17 continues to read as follows:

Authority: 16 U.S.C. 1361-1407; 1531-1544; and 4201-4245, unless otherwise noted.

2. Amend § 17.11(h) by removing the entry “Gecko, Monito” under “Reptiles” from the List of Endangered and Threatened Wildlife.

3. Amend § 17.95(c) by removing the entry for “Monito Gecko ( Sphaerodactylus micropithecus)”.