Contracts

Population Status of the Monito gecko on Monito Island Prepared by Nicole F. Angeli

Project Report: The population status of the Monito Gecko, a U.S endangered species Background: Sphaerodactylus micropithecus Schwartz, 1977 (Sauria: Gekkonidae) is a small leaf litter gecko (adults 17-36 mm snout-vent length) that is grey with dark spotting. The geographic distribution is limited to 14.5 ha Monito Island, a small limestone island 5 km NW of Mona Island in the Mona Passage, and a land management unit of the Department of Environmental and Natural Resources of Puerto Rico. Based on its limited distribution and the risks from stochastic weather, the species was listed under the International Union for the Conservation of Nature as Endangered in 1996. The species was listed as Endangered by the U.S. Fish and Wildlife Service in 1982 and a recovery plan was established in 1986 with 11 action items. This project directly fulfilled action items including 1.1 ‘Survey existing population’, 1.2 ‘ Perform periodic surveys to determine population trends’, and 2.1 ‘Determine habitat preferences’. Overall, this project establishes a methodology and baseline to track the population status of geckos on Monito Island.

Methods: Surveys completed according to the Monito Gecko monitoring protocol (Angeli, 2016) were under the following safety, training, and sampling schedule.

Safety: Nothing in this project should create hazards outside of established conditions on Monito Island for volunteers. If a field site is too dangerous for humans to enter, it is considered inaccessible. Each team member (biologists, technicians, volunteers, etc.) should review relevant safety guidelines. Weather: Daily sampling should not be done if there is heavy rain after 7 PM or if the air temperature is cooler than 25°C. Training Procedures: Training to standardize data collection by observers should take place prior to each field trip to sample the species. Observer qualifications: Of the observers, multiple individuals had experience in identifying the species to implement the survey procedures detailed below. For additional observers with no prior knowledge of the species, training at a site to identify the species and observe its uninhibited movements was completed as stipulated herein:

In office training for the whole team.

1. Each observer read the entire document “Monitoring for occupancy of the Monito gecko on Monito Island”.
2. Each observer reviewed relevant safety guidelines.
3. All equipment was assembled and tested prior to entry into the field.

In field training:

1. All observers visited an area typical for the Monito Gecko together, carrying their datasheets and field gear (See Gear Checklist). Time was spent identifying the species and observing their movements.
2. During the training each observer actively searched for a gecko and alerted the whole team. Each observer used the codes in Data Codes and filled out the training datasheet for every gecko observed independently. After every 5 minutes or five observations, the team compared answers.
3. Geckos survey training continued until >90% of records matched between observers.

Sampling Schedule & Protocol: Four teams of observers worked in pairs (2 persons) to visit 40 sites pre-selected using a random selection function in ArcGIS. Days 2-4: Two sampling days are required to visit the following sites. Sites should be sampled to locate geckos present. Day 5: A final day is required for Data entry or as an additional sampling day if inclement weather occurs during the sampling period as detailed in Weather. Accessibility: Your handheld GPS should be programmed with the sites on the map below. If a site is inaccessible for a full survey, you should substitute the inaccessible site for a new site. Check-in with your field supervisor, communicate your location, and request to move onto to a new location.

Protocol when you arrive at the site:

1. Go to sites in the order specified by a field supervisor. Find a path to the selected sites. Get as close as possible to the site using trails.
2. Find the geographic coordinate centerpoint of the site determined with a handheld GPS unit. Using the handheld GPS unit, navigate off-trail until you arrive within 6 m of the geographic coordinates marking the centerpoint of the site.
3. When you arrive within the centerpoint, walk in six directions to mark a circle with a 20 m radius (1,260 m2), where the 8 m, 15 m, and 20 m radii are marked with field tape. Walk and clear trails connecting the flags at the 8 m and the 15 m concentric circle radii.
4. Wait to return to the site for at least five hours after marking and clearing to follow the sampling protocol for abundance.

Sampling protocol for abundance: 5. Each observer chooses to survey the 8 m or 15 m survey tract (see Figure 2). Walk to that tract using the estimated distance on the GPS unit and the marking tape. Quietly walk at a slow pace (15 min) within the site watching for geckos. Record any gecko that you see (Step 7, below). 6. Observers should wait to disclose any information on gecko sightings until the conclusion of all surveys. We need to ensure independence of the counts. 7. Classify each gecko as adult or juvenile based on size. Record the vegetation, substrate, and exposure at the animal’s position according to the codes in Data codes. 8. Store data daily as specified in Data Processing.

Sampling sites 9. When geckos present at the site after two 30 min. surveys (1 visit by 2 observers), then the site is ‘occupied’ and does not need to be surveyed again

Data Processing If 40 sites are surveyed four times, there will be between 80 and 160 datasheets. The datasheet should be secured in a weatherproof container. At the end of each field day, a photograph or scanned copy of the day’s data should be taken and uploaded to a computer drive. The completed datasheets should be entered in the Access database provided by the contractor. The Access database should be sent to contractor providing data analysis services. (nicoleangeli1@gmail.com) A copy of the electronic database and a *.pdf file of the photocopied datasheets should be the sent to all parties (federal, territorial, agency, institutions, contractors) involved in the project. The original datasheets should be stored at the Caribbean U.S. Fish and Wildlife Service headquarters.