U.S. Fish & Wildlife Service

Ecological Services

Southeast Region


Featured Species: Coquí Llanero



A coqui on a leaf looks over its shoulder
A coquí llanero. Photo: Jan Paul Zegarra, USFWS.

Domain: Eukaryotic

Kingdom: Animalia

Phylum: Cordata

Subphylum: Vertebrata

Class: Amphibia

Subclass: Lissamphibia

Order: Anura

Family: Leptodactylidae

Subfamily: Eleutherodactylinae

Genus: Eleutherodactylus

Wetland plant
Wetland plants. Photo: USFWS.
Wetland plants labeled by name
Wetland plants with labels. Photo: USFWS.
Wetland plant
Wetlands. Photo: USFWS.
  • Listing Classification: Endangered range-wide
  • Listing Date: October 4, 2012
  • Effective Listing Date: November 5, 2012


Taxonomy and Species Description

In 2007, the coquí llanero was described as a new species of the genus Eleutherodactylus, family Leptodactylidae. The coquí llanero is the smallest and only known herbaceous wetland specialist within the genus Eleutherodactylus in Puerto Rico (Ríos-López and Thomas 2007, p. 62). It has a mean snout-vent length of 0.58 inches (in) (14.7 millimeters (mm)) in males and 0.62 in (15.8 mm) in females. The nares (nasal passages) are prominent and a ridge connects them behind the snout tip, giving the tip a somewhat squared appearance. The species has well-developed glands throughout its body; its dorsal coloration is yellow to yellowish brown with a light, longitudinal, reversed comma mark on each side; and its mid-dorsal zone is broadly bifurcated (divided into two branches) (Ríos-López and Thomas 2007, p. 55).

The species' communication call consists of a series of short, high-pitched notes, with call duration varying from 4 to 21 seconds. The advertisement call has the highest frequency among all Puerto Rican Eleutherodactylus, between 7.38 and 8.28 kilohertz (Ríos-López and Thomas 2007, p. 61). The calling activity starts at approximately 4:30 p.m. and decreases significantly before midnight.

Mouse over the players below and click play to hear the sounds of the coqui:

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Ths is the call of the coquí llanero and it was created by © Luis J. Villanueva-Rivera, who edited the coquí llanero community sound recorded by Neftalí Ríos, PhD to isolate and amplify the voice of the coquí llanero. This material is provided for educational purposes/noncommercial use only. No derivatives allowed without explicit consent and credit from Luis J. Villanueva-Rivera.

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This file was recorded by species expert, Neftalí Ríos, PhD., and it shows all of the sounds you hear when you walk into the only wetland where coquí llanero is found. The voice of the coquí is barely recognizable because of its high pitch and the presence of much louder species living in the same community. This material is provided for educational purposes only. No derivatives allowed without explicit permission and credit to Neftalí Ríos, PhD.


Population Status

Species experts estimate the frog’s population within its wetland habitat is about 192 individuals per acre.  This estimate is based on population counts performed on five transects of 90 square meters each, and individuals are not evenly distributed throughout the wetland.  



The primary threat to the species is from habitat modification in the form of urban development and ongoing threats of habitat destruction and modification. Predation may also present a current threat to the coquí llanero, particularly at the dryer edges of the wetland, and its isolation makes it particularly susceptible to disease and predation.  The inadequacy of existing regulatory mechanisms is currently a threat because no legal protection is in place for the species.  Other natural or manmade factors affecting its continued existence, particularly its specialized ecological requirements, also may be threats to the species.  All these factors pose imminent threats to the species because they are currently occurring.  Other potential threats to the species include, water and soil pollution, the use of herbicides and climate change. 


Critical Habitat

The Act requires the Service to designate critical habitat at the time of listing unless it is not prudent or not determinable. 

The Service has determined that designating the location where the coquí llanero is currently known to exist is a necessary conservation measure.  The designated critical habitat is a herbaceous wetland located within the former Sabana Seca Naval Base in Toa Baja, Puerto Rico.  This site is comprised of 615 acres of a palustrine herbaceous wetland with ferns, bulltongue arrowhead, flatsedges, spike rushes, vines and grasses. 


Activities Affected by Listing and Critical Habitat Designation

Activities that kill or harm the coquí llanero would be in violation of section 9 of the Act and thus illegal, unless a permit or incidental take statement is issued.  We believe the following activities, unless authorized by a permit or incidental take statement, would result in section 9 violations.  This list is not all inclusive.

(1) Killing, collecting, handling, or harassing individual of coquí llanero at any life stage;

(2) Selling or offering to sell coquí llanero in addition to delivering, receiving, carrying, transporting, or shipping in interstate or foreign commerce any coquí llanero;

(3) Destroying or altering the species habitat (e.g., discharging fill material, dredging, removing vegetation, (ferns, bulltongue arrowhead, flatsedges, spike rushes, vines, and grasses) could alter the hydrology or plant composition of the wetland.  In addition, the discharge of fill material may kill or injure individual coquí llanero or the plants that the coquí llanero needs;

 (5) Discharging or dumping toxic chemicals or other pollutants into the wetland may threaten the plant composition of the wetland.

(6)Using insecticides or herbicides within the designated critical habitat.


Conservation Actions

First, adding the coquí llanero to the Threatened and Endangered Species list raises awareness of the species’ vulnerability.  Agencies and groups use this list to help prioritize their funding and management.  Secondly, for every listed species the Service must prepare a recovery plan that outlines and prioritizes actions necessary to restore the species.  Recovery plans are also used by agencies and groups to help guide their funding and conservation activities.  Third, grants are available specifically for listed species conservation.  The Service would be able to grant funds to the government of Puerto Rico for coquí llanero conservation.  Lastly, listing the coquí llanero provides it with the strength of a federal law that prohibits its “taking” and prohibits federal agencies from jeopardizing its existence. 

Second, designating critical habitat helps ensure that the biological and ecological factors of the wetland designated as critical habitat, will not be destroyed or adversely modified by projects with federal funds or permits.

We notified various Federal, State, and local agencies about the listing of the coquí llanero and critical habitat designation.  In the event that if there are federal actions that may affect the coquí llanero, they would consult with the appropriate Federal Agency and be compliant with sections 7 and 10 of the ESA.

Third, we will continue to work within an informal network of partners in academia and non-profit organization to further understand the coquí llanero and its habitat.  Professors and biologists from different campuses of the University of Puerto Rico (Río Piedras, Humacao, and Mayagüez) have conducted studies on the species.  In addition, non-governmental organizations have been searching other areas similar to the one the coquí llanero is found in an effort to locate other extant populations and to identify possible suitable habitats.  The Service conducted acoustical surveys in a recent documented location using a digital recording system.  With assistance from a research group –Automated Remote Biodiversity Monitoring Network (ARBIMON), the recordings were analyzed to verify the presence of the coquí by its call frequency (very high frequency).  The Service provides technical assistance on various projects on the presence of the coquí llanero and increases public awareness on this endangered species.


Recovery Strategy

Similar habitat (freshwater wetland and specific vegetation composition) is very limited in Puerto Rico.  Furthermore, searches for the species in these areas have not been successful locating coquí llanero. At present time, there is only one limited area that contains the known species.

Because of the very limited distribution of the coquí llanero, our initial recovery strategy will be to work with partners to maintain and protect the only known population and known occupied habitat. In addition, we would include work to better understand the species and species dynamics.  Our next step will be to protect coquí llanero habitat and characterize and monitor the freshwater wetland to better understand the dynamics of that ecosystem.  As we work to find out more about this species, we are going to continue our work in understanding the threats it faces in the known location so we can reduce the threats and enhance its habitat.  We would evaluate the use of captive propagation to introduce the species into other similar protected areas if deemed appropriate.  We are also going to expand our efforts to increase public awareness of this frog as another unique species that we are working to recover.


Initial Action Plan

Anticipated Recovery Actions in relation to our recovery strategy described above:

  1. Conduct basic research to determine the life history characteristics of coquí llanero and integrate results into recovery actions and protection for the species.
  2. Conduct basic research on environmental requirements associated with the reproductive biology of the species.
  3. Conduct research on the carrying capacity of the wetland.
  4. Conduct habitat studies on the distribution and habitat use in the wetland.
  5. Conduct studies on population size and home range; on dispersal barriers; on the effects of the leachetes on the species; on sex ratios; and on disease and predation.
  6. Monitor the species’ status and its habitat conditions in designated long term stations.
  7. Develop sound strategies to protect habitat integrity (physical habitat) and water quality in the wetland that currently support the coquí llanero.
  8. Conduct a hydrologic study of the wetland to better understand features such as water flows, groundwater, connectivity, drainage patterns. 
  9. Develop and implement a program to educate the public on the need and benefit of coquí habitat management and involve the public in coquí llanero recovery efforts.
  10. Control habitat modifying invasive non-native plant species.
  11. Monitor success of management actions and use results to adapt management actions.
  12. Investigate the potential need and feasibility of coquí llanero translocation into unoccupied similar habitat.
  13. Develop a fire prevention plan for the area.
  14. Monitor the landfill operation to avoid and prevent additional effects on the coquí habitat.


Recovery Plan Underway

The Service will prepare a recovery plan for the coquí llanero that includes objective and measurable criteria which, when met, will ensure the conservation of the species.  Recovery criteria will address all meaningful threats to the species, as well as estimate the time and the cost to achieve recovery.  The recovery planning effort will be led by the Caribbean Ecological Services Field Office in coordination with an informal network of experts and knowledgeable interested parties.  These partners should be experts in amphibians and capable of sharing information on recovery population thresholds and short and long term actions important to the coquí llanero recovery.  These will include State and Federal agencies, industrial and agricultural groups, universities, and conservation organizations.  Different stakeholders are currently cooperating in on-going conservation planning within the area of the coquí llanero, including the municipality of Toa Baja and the United States Navy. 

The Recovery Plan will provide a blueprint for what is needed to recover the coquí llanero.  Recover plans are advisory only and do not have any regulatory authority. However, many state and federal agencies are guided by recovery plans when making decisions about land management and other actions. Recovering a species take a great deal of collaboration among agencies and landowners but with cooperation and dedication, species can be recovered.


Additional Information

If you have questions or would like more information, please see our website at http://www.fws.gov/es/coquillanero.html.  You can also contact Carlos Pacheco or Maritza Vargas at the U.S. Fish and Wildlife Service, Caribbean Ecological Services Field Office 787-851-7297



  • Department of Natural and Environmental Resources. 2007a. Designación del coquí llanero Eleutherodactylus juanariveroi como especie en peligro crítico de extinción. San Juan, Puerto Rico.  11 pp.
  • Department of Natural and Environmental Resources. 2007b. Designación del hábitat crítico esencial del coquí llanero. San Juan, Puerto Rico. 48 pp.
  • Ríos-López, N. and R. Thomas. 2007. A new species of palustrine Eleutherodactylus (Anura: Leptodactylidae) from Puerto Rico. Zootaxa 1512: 51-64.