Field mission to French Guiana

As part of the research work carried out at the Muséum National d’Histoire Naturelle de Paris (MNHN) (Mathieu JORON’s team), a field mission to French Guiana was organised with 4 members of the team (Mathieu JORON, Lise FREZAL, Robert JONES and Jérôme BARBUT).

Works of which some of my results were published in the journal Nature/Heredity (25 March 2015): to read here.

It took place in 2 stages:

  • Kaw Mountains (7 days)
  • Nuragu Station (10 days)

caption id=”attachment_223″ align=”alignleft” width=”300″]Location of different prospecting sites in French Guiana Location of different prospecting sites in French Guiana (Google Earth)[/caption]

The objective was to collect biological material. This consisted in taking butterflies of the genus Heliconius from the environment, packaging them in a certain way in order to preserve, on the one hand, the wings and their colouring, and on the other, the body and its DNA.

The interest is to obtain a representative sample of genetic diversity for each species. The DNA studies, carried out in Paris, will make it possible to understand and highlight the structure, diversity and movements of the genes at the origin of wing colouring in populations and species (for more information).

Reserve de Kaw

The Kaw-Roura Marsh Nature Reserve (see photo album) is located a few kilometers southeast of Cayenne, between the towns of Roura and Regina. Because of its surface, it is the 3rd French reserve (94 700ha) and the largest wetland area in France. It was created by decree on 13 March 1998.

caption id=”attachment_332″ align=”alignright” width=”300″]Map of French Guiana Map of French Guiana (Source lonelyplanet.fr)[/caption]

Marshes, essentially composed of floating savannah to Cypeus sp. and Aracées, are bordered by the Atlantic Ocean to the northeast and by 2 rivers: the Mahury and the Approuague, and are fed by the Angélique creek and the Kaw river.

The Kaw mountain is the first relief encountered by the trade winds coming from the sea, which makes it one of the rainiest areas of Guyana.

The region is known for its high biodiversity and endemism.
There are 4 species of caimans: the red caiman (Paleosuchus palpebrosus), the grey caiman (Paleosuchus trigonatus), the spectacled caiman (Caïman crocodilus) and the black caiman (Melanosuchus niger) for whom the reserve is one of the latter. Visit Kaw Reserve

La station des Nouragues

The Nouragues (see photo album) is a scientific station of the CNRS (UPS 2561), located in the heart of the primary rainforest, in the heart of the Nouragues nature reserve. Its mission is to promote scientific research in a site as far away as possible from the direct influence of human activities.

It is a privileged place to study the functioning of tropical forests and their biodiversity. The station hosts scientists from national and international research organizations. Scientific equipment is made available to allow permanent measurements, maintained and operated by the station’s technical staff.

In order to limit environmental disturbances through excessive use of the site, the station can only accommodate a limited number of scientists, sufficient to develop research and thus have a global vision of the ecosystem but also to make the structure profitable. This is why the resort is not an establishment open to the public, except in exceptional cases.

The station is composed of 2 permanent camps, 8km away (3h walk!).
  • the Inselberg site < suitable for studies on tropical forest vegetation and is a reference point for the study of mammals and other animals due to zero hunting pressure.
  • le site Pararé installé au bord de la rivière, est adapté aux études des forêts riveraines et des communautés de rivière.

The station is open all year round. It can thus host scientific missions lasting from a few days to several months. Sleeping books, electricity, refrigerators and drinking water are available. Communication is via satellite telephone and internet.

Geography and environment

The station is located on the watershed of the Arataye, a tributary of the Approuague, where the relief does not exceed 120m altitude. The Balanfois mountain range, which crosses the region, culminates at 460m. Inselberg lies at the base of a 430m high granitic inselberg (Def : rocky, steep residual relief dominating a plain).

Vegetation is typical of large low-lying primary forest. In addition there are palm swamps Euterpe (Pinoptières), vine forests and cambrouzes (vine bamboos). On the leached soil of the top of the inselberg, where the granitic rock outcrops, only a few plant species manage to develop as Clusia and Pitcairnia. Near the summit grows a forest rich in Myrtaceae and endemic plants.

The climate is tropical humid, so 3 000mm of annual rainfall, spread over 280 days. One dry season is between September and November, and another during March, also called “small summer of March”.
The maximum monthly average temperature is 33.5°C (32.1-35.6) and the minimum monthly average is 20.3°C (19.7-21).

Recommendation of books on this theme:

Guide encyclopédique de Guyane




Benoît GILLES
Chargé de recherche – Entomologiste chez Cycle Farms