Report submitted by Ernst Rupp, Grupo Jaragua
Ricord´s Iguana (Cyclura ricordii) is considered Critically Endangered by the IUCN Red List of Threatened Species. Three subpopulations are found within the Jaragua-Bahoruco-Enriquillo Biosphere Reserve in the Dominican Republic. Since 2003, Grupo Jaragua has been involved in Ricord´s Iguana conservation and has monitored the two most vulnerable populations: one in the Pedernales area and the other on the southern shore of Lake Enriquillo. The main goal of this project is to ensure the long-term survival of C. ricordii throughout its natural range by protecting, maintaining, restoring a diversity of high quality native habitats, and establishing community-based management for wild C. ricordii populations with the key components described below.
Nest monitoring activities within key habitats in Pedernales. Nesting locations of Cyclura ricordii around Pedernales are concentrated in so-called “fondos”, which are depressions filled with soil within the limestone rocks. Fondos are a very limited vital resource for the species and the reproduction and survival of the population in Pedernales depends on them completely. Constant monitoring, especially during the reproductive season, is therefore necessary.
Nest monitoring activity consists of weekly visits by the monitoring team to register nests and nesting success to acquire long-term data on reproductive trends of the Ricord’s population in the Perdernales area. Additionally, the fondos are inspected to avert major cattle concentration, detect and prevent poaching activities, prevent illegal land invasion, or appearance of exotic predators (see below on invasives control).
Nest and hatching monitoring has continued every year since 2004. The local team, Jose Luis Castillo and Jairo Isaa Matos, were in charge of this important activity in 2016 and marked 207 nests, taking GPS coordinates. Of these nests, only four were not found again during follow-up, and no emergence holes were found for an additional three. The remaining 200 marked nests showed emergence holes by the end of the hatching season, indicating total hatching success at 96.6%. During the hatching season, an additional 124 non-marked emergence holes were found, bringing the total number of nests hatched in 2016 up to 324 – representing an increase of 16 nests over 2015.
From 2012–2014, we saw significant decreases in the number of hatched nests every year, reflecting the impact of feral dogs. In 2015, we applied intensive dog control measures during the nesting season and saw a turnaround, with 308 nests hatched in 2015 and 324 nests in 2016. These control measures halted the massacre of gravid female iguanas and allowed nesting activity without major disturbance. For 2017, we are planning to repeat dog control measures.
To supplement the existing fondo nesting sites, 6.3 hectares of agricultural land directly adjacent to Fondo La Tierra was bought in 2012 (Mayin property). A restoration process was initiated to plant Alpargata cactus (Consolea moniliformis), a major food item for Ricord´s Iguana. Within the property limits, eight Ricord’s nests were found in 2012, 12 in 2013, 13 in 2014, 16 in 2015, and 19 this year (plus an additional Cyclura cornuta nest). This upward trend of nests in Mayin´s property is likely attributed to invasive control measures — our original land investment is paying off with more iguanas nesting every year.
Monitoring for illegal activities in Pedernales and the southern shore of Lake Enriquillo. Two teams, one in Pedernales and the other on the southern shore of Lake Enriquillo, are monitoring to detect illegal activities like slash and burn agriculture, land occupation, charcoal production, charcoal trafficking, iguana poaching, as well as any other disturbance that might affect the iguana population. The teams report directly to the local Ministry´s office (Pedernales and Jimani) to initiate, coordinate, and follow-up on corrective measures.
The southern shore of Lake Enriquillo holds the biggest and most important population of C. ricordii and has been plagued by charcoal burning. Anibal Volquez and Jelbin Volquez have worked for several years now revising the zone to detect charcoal production onslaughts, and their effort is paying off. Whereas 2011 and 2012 the whole area was mined by charcoal kilns, 2016 was very quiet. Only two kilns were detected and reported. In Pedernales, agricultural encroachment had been a major threat. Land purchase and monitoring over the last few years has been an effective barrier preventing conversion of iguana land to agricultural use. Monitoring by Jose Luis Castillo and Jairo Isaa Matos did not reveal any disturbance in 2016.
Restoring degraded Ricord’s habitat in Pedernales and the south shore of Lake Enriquillo. Large areas of iguana habitat on the southern shore of Lake Enriquillo and in Pedernales have been destroyed by charcoal production and agricultural activities. The cactus Alpargata (Consolea moniliformis) has been particularly decimated by these activities. Iguanas rely heavily on this cactus for food, especially during the dry season when they can be seen climbing the spiny trunks to eat the juicy fruits growing on the cladodes of the plant. These fruits not only constitute nourishment, but are the only source of water when the rest of the vegetation is withered and dry. Iguanas seem to be the only native animal that eats these fruits and therefore are the sole seed distributor for C. moniliformis. Since the cactus is no longer present in degraded areas, only with human help can this cactus be re-established by harvesting and planting cladodes.
In 2016, we continued restoration of degraded areas in Pedernales and the south shore of Lake Enriquillo by planting cladodes of C. monoliformis. After a drought-stricken 2015, weather conditions were more favorable in 2016 and establishing new Alpargata plantations was successful. We planted 6,740 cladodes in Pedernales and 4,220 on the southern shore of Lake Enriquillo. About 70% of the planted cladodes have survived to date. Based on studies of preferred iguana food by Dr. Stesha Pasachnik, we are looking at additional plant species to add to the restoration to achieve higher diversity. This is challenging because only a few seedlings may survive in the extreme dry climate and young plants are vulnerable to hungry free-roaming ungulates like horses, cows, and goats. We have started to experiment with seeds of Lignum vitae or Guayacán (Guayacaum officinalis) since our observations show that ungulates avoid eating leaves of this species. 9,400 seeds were sown in different plots on the southern shore in April and July, but despite some rain in April and May, no germination has been detected so far.
Investigation of the Common Green Iguana (Iguana iguana) wild population in the Bani area and work on control measures with the Dominican Wildlife Department. Common Green Iguanas were first imported into the Dominican Republic in the 1990s as pets. Being aware of a possible threat to the island´s biodiversity by this invasive species, the Dominican Ministry of the Environment issued a resolution in 2010 that prohibited the importation, commercialization, and breeding of this iguana species. However, no control measures were taken. Pasachnik et al. 2012, gave evidence of the installations of “iguanarios”, ongoing breeding, and escapes as well as planned releases of Common Green Iguanas into the wild. Establishing a monitoring program on Green Iguanas was recommended.
In 2015, we were able to prove the existence of a Green Iguana wild population around the town of Bani and drew a map based on encounters and reports. We calculated that Green Iguanas occupy an area of about 200 to 400 square km around Bani. During March, April, and May 2016, we worked to find Green Iguana nesting areas with the help of iguaneros (iguana hunters) and students. We found many nests concentrated along the beach, west of the town of Paya, and at some distance inland within open sandy areas. Nests were even found within the town of Paya in open, sandy terrain. Control measures must be planned and initiated to avoid a major disaster. Paya also seems to be a hotspot for trade with Green Iguanas. We heard from iguaneros that they are receiving orders from animal traders as far as Santiago; they are also selling directly to travelers at rest stops in Paya.
We have approached the Wildlife Department of the Ministry of Environment to seek cooperation in this matter. Both entities agreed to join forces and work on this problem in order to develop a control program, or if still possible to eradicate the species from the island. Additional measures involve educating the general public to understand the problem posed by this dangerous invasive species. A detailed program is being developed and will be made public shortly.
Control of feral dogs, cats, and mongooses in the Pedernales area. During the 2012–2014 nesting seasons, feral dogs had a strong negative impact on nesting females, reducing their numbers significantly. In 2015, we contracted four local hunters who placed 50 units of steel wire snares, as well as 10 Tomahawk cage traps within Ricord´s nesting areas. After five weeks of intensive hunting and trapping, a total of 21 dogs had been eliminated. However, dog tracks were still seen after this period, so we decided to continue with control measures in 2016. With less funds available for this activity, we hired only three hunters who worked for a total of 23 days (April 1–11 and May 3–14). Thirty snares and 10 Tomahawk cage traps were opened. The hunters were also equipped with three shotguns (two 16 gauge and one 20 gauge). A total of nine dogs were eliminated: six adult males, one juvenile male, and two adult females. Four of the animals were shot while five of them were trapped in the snares.
During the 2015 hatching season, Dr. Stesha Pasachnik had used Tomahawk cage traps to eliminate feral cats and mongooses from her study site. We repeated this activity in 2016 using a variety of baits: salami, butter, smoked herring, fresh fish, and sardines in oil. From July 5 to August 4, ten traps were placed in the Fondo de la Tierra and four in Malagueta. Traps were checked daily, early in the morning and evening. One cat was caught using salami as bait, while the smoked herring lured two Rhinoceros Iguanas into the traps. Fresh fish trapped one cat, one mongoose, and one Rhinoceros Iguana. Sardines in oil were most attractive to Ricord´s Iguanas, catching four. The butter did not attract any animal at all. All iguanas were released unharmed; the cats and mongoose were euthanized. Cats are eaten in Pedernales, especially for Haitian citizens, so this meat was not wasted.
Control measures on feral cats and mongooses cannot be directly correlated to iguana conservation since at present we have no measure to estimate survival rates of hatchlings on a large scale. We hope to note an increase of young adult females, as they reach nesting age in three to four years’ time.
Support community of Baitoa in establishing alternative income sources. The small rural town of Baitoa has been the community most highly involved in charcoal production and trafficking in the past, due to high levels of poverty and little opportunities for other income. For several years, Grupo Jaragua has been trying to develop alternative incomes in this community. Last year, we were able to establish bee colonies for five families, and the hives are working well. Technical follow-up for the bee project is led by the NGO Lemba, an organization run by the Catholic Church.
We also have been working on getting people interested in agroforestry. One focus is on Caribbean Oregano (Lippia micromera), a highly-priced product collected from the wild. Last year we initiated the first demonstration plot, and this year added a second one with more to follow. The first plot has been harvested three times already and the second plot harvested for the first time last month. Oregano plants can produce for several years if well managed. The original investment is low, maintenance is not very complicated, and it is well-adapted to dry climates. Interest in planting this species is growing in the community and we hope to establish more plots. We are also integrating other native dry climate-adapted plants into the existing plots to diversify the systems. We are now also growing Anón (Anona squamosa), a native fruit, and Canelilla (Pimenta haitiensis), an endemic which produces aromatic leaves with high demand in the local markets. Canelilla grows naturally only within a small area inside the Jaragua National Park close to Pedernales, and is presently illegally harvested and sold. Our efforts to establish ex-situ plantations of this species may take pressure off the wild plants, which have dwindled heavily over the years.
For the future, we envision the following activities:
• Continue nest monitoring in Pedernales
• Continue general monitoring in Pedernales and Southern Shore of Lake Enriquillo
• Continue control of feral dogs, cats, and mongooses in Pedernales
• Purchase of land suitable for nesting in Pedernales
• Continue restoration of degraded lands with more diversified vegetation
• Initiate translocation of hatchlings within Southern Shore of Lake Enriquillo to repopulate restored areas formerly inhabited by C. ricordii
• Intensify community outreach in Baitoa and other communities which are affecting populations of Ricord´s Iguana
• Execute control measures (extermination, if possible) of Common Green Iguanas, in cooperation with the Ministry of Environment
• Work in Haiti to conserve small Ricord´s population in Anse-à-Pitres