Albertine Rift

Methods Development

Inadequate methods are not often thought of as a challenge or threat to conservation. Yet the inability to monitor conservation targets, for instance, provides a severe limitation on the capacity of a protected area authority to assess whether its interventions are succeeding or to adapt to changes in threats in their landscapes. WCS has been developing several methods to improve monitoring and management which are highlighted here together with links to more details about the methods.

Surveying Primates

Estimating primate population numbers is usually made with line transect surveys. Andy Plumptre, WCS’s Albertine Rift Program Director, has been improving these methods together with Steve Buckland at the University of St Andrews.  Initially this involved devising a survey method for chimpanzees that avoids the need to calculate nest decay rates for the night nests constructed by chimpanzees. Decay rates are very variable and can strongly affect the estimate of a survey and they should be calculated across a study region but rarely are. As a result avoiding calculating decay rate can offer a significant advantage in a survey. The method uses repeated surveys of the same transects counting new nests that appear over time and is called the ‘marked nest count method’. This method was published as a paper:

Plumptre, A. & Reynolds, V. (1996) Censusing chimpanzees in the Budongo forest.  International Journal of Primatology 17, 85-99

Some subsequent papers also provided additional information on nest construction rates and the power to detect changes in animal numbers:

Plumptre, A.J. & Reynolds, V. (1997) Nesting behavior of chimpanzees:implications for censuses. International Journal of Primatology 18, 475-485

Plumptre, A.J. (2000) Monitoring mammal populations with line transect techniques in African forests. Journal of Applied Ecology 37, 356-368.

More recently two papers have been published that critique a common but flawed method use to survey primates in the scientific literature and to provide a summary of how primate population densities should be estimated:

Buckland, S.T., Plumptre, A.J., Thomas, L. and Rexstad, E. 2010. Line transect surveys of primates:can animal-to-observer distance methods work? International Journal of Primatology, 31, 485-499

Buckland, S.T., Plumptre, A.J., Thomas, L. and Rexstad, E. 2010. Design and analysis of line transect surveys for primates. International Journal of Primatology 31,833-847.


Aerial survey methods

Aerial surveys are commonly used to survey large mammal populations in savannas. The basic method used was published by Mike Norton Griffiths in 1978  and hasn’t changed greatly since that time. However, the technology available has changed greatly and we now have better aircraft systems, GPS units as well as software for planning surveys that can ensure that the method is rigorously followed. WCS Albertine Rift Program has been working with the WCS flight program over the past 10 years to undertake surveys of wildlife as well as mapping of habitat. David Moyer who managed the WCS flight program teamed up with Howard Fredricks who has been improving aerial survey methods and data management within the Tanzania Wildlife Research Institute (TAWIRI). Howard was contracted to develop an aerial survey manual which, rather than cover the statistics of the methods used in Mike Norton Griffiths publication, covers the basics of planning a survey, setting up the plane, training and calibrating observers and actually carrying out the survey.  The two publications are intended to be complimentary and be used together.

Ranger-based monitoring

Rangers in parks and reserves are going on patrols on a daily basis and, as a result, see what is happening and where it is taking place. Protected area managers do not get out as often because of other management commitments and so usually don’t know so well where the latest threats are occurring. Traditionally, rangers would communicate anything new or unusual in daily or monthly reports to the protected area headquarters. However, this leaves the onus on the ranger to decide what to report and what is ‘unusual’.  In the late 1990s a GTZ supported project to the Uganda Wildlife Authority (UWA) started to develop a software program that would enable rangers to collect data while on patrols, enter the data in a computer easily, and provide simple analyses of the data useful for protected area managers. This software was called Management Information System (MIST). It was piloted in the Murchison Falls National Park in the Murchison-Semliki Landscape. At the end of the GTZ project the software was partially working but had several bugs that caused problems with its use. Since 2001, the WCS Albertine Rift Program has been working with UWA and the software developer (Ecological Software Solutions) to fix the bugs in MIST and roll out its implementation to all of the protected areas managed by UWA in Uganda. The program has been successfully used at most sites in Uganda and is used to create:

1.       Monthly patrol maps that show protected area managers where patrols have been

2.       Maps of sightings of key species and illegal activities in the protected area

3.      Encounter rates of sightings of key species and illegal activities corrected for patrol effort

4.       Trends in encounter rates of key species or illegal activities over time.

The data entry is designed to be simple and can be done by a trained ranger freeing wardens to be able to analyse the data and use the results. The analyses listed above are easily produced and can also be generated by a trained ranger.

The success of the program led to it being adopted in all the national parks in Rwanda, in four parks in DRC and it is now being established in Burundi, Gabon, at all MIKE sites across Africa where the monitoring of the illegal killing of elephants takes place, and it is now being adopted in some countries in Asia such as Thailand and Cambodia.

WCS has more recently engaged other international NGOs to work together to create the next generation of software that will replace MIST in due course. Called SMART, this software will be open source and will aim to improve the analysis of ranger-collected data which is inherently biased and hence is difficult to analyse.


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Albertine Rift Program
Plot 802 Kiwafu Rd, Kansanga, PO Box 7487, Kampala, Uganda

Key Staff

Deo Kujirakwinja
Director Eastern DRC Projects
Andrew Plumptre
Director Albertine Rift Program
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Partners Include

Institut Congolais pour la Conservation de la Nature
Uganda Wildlife Authority
The John D. and Catherine T. MacArthur Foundation
Use of this image and link does not imply endorsement by the U.S. Fish & Wildlife Service.