Black Caiman Field Study
assist in caiman catching.
The Rupununi region currently hosts a rare, largely recovered population of Melanosuchus niger. Our village-based long-term study is an opportunity to understand the black caiman's ecological role and its physical and cultural context. Through this knowledge it may be possible to build a new consensus for its management from the local level on up.
Beyond its inherent value as a prime component of its ecosystem, an intact population may also serve as a sustainable resource for indigenous peoples, whether for hides, meat or ecotourism.
Developed and initiated in 2005 by Peter Taylor the black caiman research project based in Yupukari is a convergence of professional herpetology and local knowledge. Its immediate purpose is to develop a full understanding of black caiman natural history and ecology in Guyana, still a relatively neglected topic. This project is showing itself to be an excellent model and vehicle for indigenous capacity building, training and education: an immersion approach that transfers skills in wildlife study and monitoring.
These activities are the basis of linkages and activities that strengthen the community-development dimension of the project.
This has been an atypically short rainy season with little flooding: river, lakes and ponds were low early in the year, with early caiman nesting. Thanks to funding from IUCN Netherlands Ecoysystems Grant Program environmental monitoring has expanded to four projects: caiman monitoring; pit traps and transect walks; tree identification hikes, and "important bird areas" surveys. Out of 27 nights of "caimaning" to date, the team was joined on 11 of those nights by guests. We've sighted over 17 nests this year and surveyed eight. Our 500th caiman was caught on October 3rd 2009.
Basic goals of the study:
1. Conduct a detailed ecological study of the black caiman within its Rupununi environment and for comparison with populations elsewhere.
2. Recommend management protocols to resolve human/caiman conflicts.
3. Develop a cadre of indigenous naturalists to provide the basis for the continued study of crocodilian species, to educate local people on conservation and management issues, and to assist in the implementation of sound conservation practices.
4. Promote active discussion of black caiman issues at village and regional levels.
5. Enhance our knowledge of the natural history and biology of black caiman through scientific publications and other media.
The Yupukari Research Team would like to thank SeaWorld Busch Gardens Conservation Fund for their generous assistance of this season's efforts! And Peter Taylor for his years of effort to get us to this stage.
The First Two Seasons, 2005 - 2007
The active mark/recapture portion, and nest, egg, and hatchling study portions of the Yupukari project, from 24 September 2005 until 1 April 2007, required approximately 440 man days and over 4000 man hours in the field. This nocturnal work has been accomplished with four-man crews and a single boat for mark-recapture work. These seasons were directed by Peter Taylor.
Two or three man crews were used for nest and egg investigation work, exploring habitat and observing various diurnal patterns of caiman activity (e.g. basking behavior, maternal care of nests and young). From 4 November 2006 through 13 December 2006, 25 days (over 1000 man hours) were spent in the field locating nests and collecting data on a range of black caiman behaviors connected to reproduction.
Human capacity-building in the form of training local people was a critical development for the project. The identification of a key, local Guyanese counterpart (Ashley Holland) to act as Field Manager and assist the primary researcher greatly assisted to launch the project. In the first year, 11 men and 2 youths (age 14) from Yupukari worked on the project, and four more adults joined in the second season. They demonstrated dedicated work habits under often challenging conditions, and rapidly learned new field techniques needed to make the project work. Reciprocally, the primary researcher benefited greatly from the considerable ingenuity, skills, and local knowledge, possessed by Makushi men. The exchange of knowledge that continues to fuel the project goes hand in hand with its progress.
It should be mentioned that the organizing, training, and accomplishment required to perform the mark/recapture work with a perfect safety record was a major achievement in itself. Everyone involved, including the primary researcher, experienced a major learning curve in mastering the potentially very difficult and dangerous tasks of stalking, capturing, and safely handling hundreds of spiritedly resistant black caiman, often in moving river conditions, and always at night. The local participants deserve great credit in developing those skills to such a high level.
At this stage, independent indigenous teams lead by Ashley Holland, can safely and competently collect and record field data, fundamental steps toward monitoring and managing their own wildlife resources. As systematic inquiry goes forward, reactive fear is gradually being superseded by attitudes that support a better coexistence of mutual benefit to man and animal.
With each month spent in the field the crew has elevated their independent ability to achieve these milestones, summarized as follows:
1. Collection and handling of 317 marked, non-hatchling (.5 - 3.62 meters total length) caiman now in the study areas, yielding critical information on population structure as defined by age, size, sexual status, habitat use, also early feedback into growth rates, and survivorship of caiman.
2. A steadily increasing recapture rate, now averaging 10.1% (32 total). Recaptured individuals are beginning to supply critical feedback on the performance, and changes over time of black caiman in nature including movement and individual development.
3. Capture and data collection on 159 hatchlings from 11 clutches.
4. Location of over 50 nests, and complete description of 29 undisturbed black caiman nests containing a total 960 eggs have yielded a great deal of data. Findings show a mean of 33 eggs per nest. Black caiman eggs and hatchlings are exceptionally large. An important factor in wild nest performance entails heavy predation by tegu lizards in approximately 33% of observed nests. Gauging density of nests in study areas is critical to understanding reproductive patterns and capacity of black caiman.
5. Important confirmations of maternal behavior, protection of nests and hatchlings by female black caiman have been made. We have made collection of nest temperature data which may contribute to our understanding of "Temperature-Dependent-Sexual-Determination" (TSD).
6. Critical facilitation of research by visiting scientists. Three bioacoustic communication researchers from labs supported by Jean Monnet University, France were hosted at Caiman House Field Station. They were guided and assisted by locally trained crews to study mother caiman/hatchling relationships.
7. Collection of information on the other three species of caiman in the region (Caiman c. crocodiles, Paleosuchus palpebrosus, P. trigonatus), has been obtained helping to define their interactions with each other and with black caiman, their habitat preferences and more. Our constant contact with the broad environment of Melanosuchus has lead to the accumulation of information on other many other animals and plants with which black caiman share their environment, helping fill out the total ecological picture.
8. Interviews with locals can contribute to an important formulating data base on HCC (Human Crocodile Conflicts; as defined by the CSG (Crocodile Specialist Group); R. Ferguson coodinator). Information on at least 6 human fatalities and a greater number of caiman bites that have occurred over time (50 years) in the region have been obtained through local interviews and assimilation of reports using a developed format.
9. Accumulation of a large image bank; both still and video of the black caiman, and many aspects of its environment.