vertebrate in forest plot

Vertebrate Monitoring



The ForestGEO Vertebrate Program gathers information on the presence and abundance of vertebrates in and around the ForestGEO research sites. The program focuses on groups that are relatively easy to survey in a standardized manner. The surveys are done according to detailed protocols to ensure standardization, which is crucially important for comparison of data between sites across the network, and across years within sites.

Active Survey Programs

  • Camera trap survey of terrestrial mammals and birds, according to two different protocols. 

Survey Programs in Pilot Stage

  • Line - and point - transect counts for birds 
  • Transect counts of hunting signs

Future Survey Programs

  • Acoustic monitoring of birds, bats and amphibians
  • iDNA sampling of vertebrate communities
  • Live trapping of small mammals and their parasites and pathogens

Vertebrates are of special interest to ForestGEO because they strongly influence the vital rates of trees in numerous ways, such as through pollination of flowers, dispersal and predation of seeds, browsing of juveniles trees, soil disturbance, and ecosystem engineering. Which vertebrates occur in a forest, and how many, influences how successful tree species produce seedlings that develop into new adult trees. Positive and negative influences of vertebrates vary dramatically among tree species. Some tree species entirely depend on particular vertebrates for on certain services. Others are kept in check by seed - and plant - eating vertebrates. In tropical forests, up to 90% of tree species depend on fruit-eating birds and mammals for seed dispersal, a vital step in their life cycle. Over time, plant-vertebrate interactions thus affect the tree species composition of the forest.

This becomes clear in forests that have lost their larger birds and mammals, sometimes called ‘empty forests’. Here, many animal-dispersed tree species have trouble to recruit (Harrison et al. 2013). The seedling community of such forests may get dominated by wind-dispersed trees and lianas, and by species whose seeds and seedlings preferred food to plant-eating vertebrates (Wright et al. 2007). If such shifts persist until the adult phase of trees, they may alter the ecosystem functions that the forest fulfills. Examples are the storage of carbon and the production of timber and other forest products.

Vertebrates are sensitive to anthropogenic disturbance. Bushmeat hunting, collection for pet trade and habitat fragmentation may dramatically alter vertebrate communities within timespans or just years or even months. Climate change may have a major effect on vertebrates over longer timespans. By measuring and monitoring the abundance of vertebrates, ForestGEO seeks to understand and forecast changes of forest communities and ecosystem functions.


Harrison, R. D., Tan, S., Plotkin, J.B., Silk, J. F., Davies, S. J., Brenes-Arguedas, T., Itoah, A., and Detto, M. 2013. Consequences of defaunation for a tropical tree community. Ecology Letters, 16:1-8 (PDF)

Wright, S. J., Hernandez, A., and Condit, R. 2007. The bushmeat harvest alters seedling banks by favoring lianas, large seeds, and seeds dispersed by bats, birds, and wind. Biotropica, 39:363-371. John Wiley & Sons. (PDF)

The ForestGEO camera trapping program uses grids of camera traps to survey terrestrial mammals and birds at the sites. The camera traps take series of photographs whenever an animal passes in front and triggers the infrared motion sensor, creating a vouchered observation. They allow collection data even on secretive species that are rarely encountered. Repeating surveys allows detecting abundance trends.

We use two protocols. The first is the ForestGEO protocol, which is aimed at the 1 km² area that contains the Forest Dynamics Plots. The second is the TEAM Protocol, which is aimed at the surrounding 120 km². In both protocols, all camera sites are unbaited and off-trail, so that observations are random with respect to movement of the animals. Sites can borrow equipment from ForestGEO to run these protocols.

Click here to view our camera trapping database.

The goal of the ForestGEO camera trapping protocol is to record presence and abundance of terrestrial mammals that potentially interact with the plants that are being monitored in the Forest Dynamics Plots. 

Each survey consists of running an unbaited camera trap for at least 20 days at each of 49-50 points, yielding 1000+ survey days. The points are organized in a grid that cover 1 km², and includes the Forest Dynamics Plot.

The placement of the camera traps as well as the processing of the images is highly standardized as to achieve the best possible level of comparability across the sites. We also have procedures to calibrate the view of the cameras so that images are suitable for computer-aided image processing. 

Images are stored and processed using the custom-made ForestGEO camera-trapping database. This online tool facilitates efficient and standardized processing of the thousands of images that each survey yields, and safely stores images and data in a secured environment.


ForestGEO has a number of camera-trapping kits that sites can borrow to conduct a survey. Each kit consists of a case containing 14 high-end camera traps + accessories, with which the ForestGEO camera trap protocol can be run in four survey over three months. The kits are based in Panama, USA and the Netherlands. 

ForestGEO sites can borrow a kit under the conditions that the protocol is precisely followed and that the images and data are made available to other users via the ForestGEO camera trapping databases. Write to Patrick Jansen ( for more information.   

Patrick Jansen, PI Vertebrate Program (Coordination, STRI, Panama & Wageningen University, The Netherlands)
Bill McShea, PI Camera Trapping Program (Coordination, Smithsonian Conservation Biology Institute, USA)
Doug Robinson, PI Bird Surveys (Coordination, STRI, Panama & Oregon State University, USA)
Yorick Liefting, Technical Assistant (Coordination, STRI, Panama & Wageningen University, The Netherlands)
Stephen Blake, Camera Trapping (Max Planck Institute for Ornithology)
Jonathan Myers, Camera Trapping (Washington University in St. Louis, USA)
Tavis Forrester, Camera Trapping (Smithsonian Conservation Biology Institute, USA)
Claudio Monteza, camera trapping (ForestGEO, Panama)
Santiago Espinosa, Camera Trapping (Pontificia Universidad Catolica de Ecuador, Ecuador)
Jan den Ouden, Camera Trapping (Wageningen University, The Netherlands)
Kelly Boekee, Camera Trapping (Wageningen University, The Netherlands)
Lazarus Njoh Agwetang, Camera Trapping (World Wildlife Fund, Cameroon)
Hadrien Vanthomme, Camera Trapping (Smithsonian Conservation Biology Institute, USA)
Zhishu Xiao, Camera Trapping (Institute of Zoology, China)
  • Sites: China (Multiple Sites)
Ahimsa Campos-Arceiz, Camera Trapping (University of Nottingham, Malaysia)
  • Sites: China (Multiple Sites)