Preliminary findings from the first-ever comprehensive Biodiversity Survey conducted on Rugezi Marsh in Rwanda that were released by the Rwanda Wildlife Conservation Association (RWCA), on September 20, showed that 638 different species were documented. They include 433 new ones that had not been previously documented.

The research effort reveals new insights into the unique ecosystem of Rugezi Marsh, an internationally recognised and Ramsar-protected site.

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Rugezi Marsh, covering an area of 6,736 hectares, is a Ramsar-protected site located in the north of Rwanda (in Burera District), renowned for its rich biodiversity and the crucial ecosystem services it provides. The marsh feeds Burera and Ruhondo lakes. The List of Wetlands of International Importance, also known as the Ramsar List, is considered the world&039;s largest network of protected areas.

The survey covered different biodiversity groups, including plants, mammals, birds, reptiles, amphibians, fish, and insects.

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Below are eight key findings from the Rugezi Marsh biodiversity survey.

Plants: 197 species documented

The survey recorded 197 plant species of which 109 were newly documented in Rugezi Marsh. The researchers recorded eight species that are endemic to the Albertine Rift, including Trifolium purseglovei and Vaccinium stanleyi, as well as three globally threatened species - Bothriocline glomerate (Endangered), Afroligusticum runsorricum (Vulnerable) and Oenanthe mildbraedii (Vulnerable).

At least 149 species of arthropods

For arthropods, the survey recorded at least 149 species – and this number is likely to increase as further analysis is conducted – according to RWCA. This includes 49 different species of butterflies.

Arthropods are invertebrates with segmented bodies or jointed legs. They include spiders, crabs, ants, and butterflies.

An aquatic moth ‘never heard of’ in Rwanda before

As per the survey, 82 aquatic macroinvertebrate species were recorded, including 29 species that are indicators of good water quality. The aquatic moth Paraponyx dimunitalis was recorded for the first time in Rwanda.

A fish species first documented in Rwanda’s wetland habitat

Another result from the survey are three fish species including Enteromius alberti and Pseudocrenilabrus multicolor documented for the first time in Rugezi Marsh.

Additionally, it was the first time that Enteromius alberti was recorded in the wetland habitat of Rwanda. The third fish species found in Rugezi Marsh is Clarias liocephalus, which is also the most abundant.

Eight newly documented species of amphibians

Concerning amphibians, the survey recorded 14 species in Rugezi Marsh, including eight newly documented. All recorded species are not globally threatened based on the IUCN Red List of Threatened Species.

However, two species namely Afrixalus orophilus and Ptychadena chrysogaster are categorised as Endangered at the national level, while Hyperolius lateralis is also categorised as Vulnerable at national level. Four species are endemic to the Albertine Rift, namely Leptopelis kivuensis, Afrixalus orophilus, Phrynobatrachus bequaerti and Ptychadena chrysogaster.

Ten newly documented reptile species

Reptile population in Rugezi Marsh comprise 13 species, according to the survey which showed that they include chameleons, snakes, and lizards, with 10 newly documented. The five-toed skink (Leptosiaphos graueri) is classified as endangered on the IUCN Red List of Threatened Species, it was indicated.

Twenty-eight newly documented bird species

The survey recorded 127 bird species recorded, with 28 newly documented for Rugezi Marsh – adding that, with these new records, the total number of bird species so far recorded in and around Rugezi Marsh has now been increased to 222.

The recorded species include the Endangered Grey Crowned Crane (Balearica regulorum), and the emblematic, yet Vulnerable Albertine Rift Endemic Grauer’s Swamp Warlber (Bradypterus graueri). Other notable species recorded during this study include the Lake Victoria endemics, namely Carruther’s Cisticola (Cisticola carruthersi) and Papyrus Yellow Warbler (Calamonastide gracilirostris).

The latter was believed to have disappeared from the marsh due to the extensive destruction of its habitat. Among the newly documented species is the Rwenzori Nightjar (Caprimulgus ruwenzorii), an Albertine Rift endemic bird whose observation in this study marks the first documented record of its distribution beyond the montane rainforests (in Rwanda).

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The survey did not record other papyrus-dependent species, namely, the Papyrus Gonolek (Laniarius mufumbiri), Papyrus Canary (Crithagra koliensis) and the White-winged Swamp Warlber (Bradypterus carpalis) which were known to inhabit Rugezi Marsh.

The absence of these species calls for enforced regulation of papyrus cutting as well as the restoration of papyrus stands within the marsh and continued landscape conservation interventions for the persistence of globally threatened birds (three species) and the endemic birds (six species) that call Rugezi Marsh home.

Mammals: 51 species newly documented

Another interesting result from the survey is that 53 species of mammals were recorded, including 51 newly documented for Rugezi Marsh. Within this total, 22 bat species were recorded, representing 40 per cent of known bat species in Rwanda. Mammals such as jackals, genets, serval cats, otters, and mongoose were documented, as well as a wide variety of rodents for which RWCA said further laboratory analysis is currently conducted to identify specific species.

Some key records that are already known include the Harrison’s giant mastiff bat (Otomops harrisoni) which is globally threatened (Vulnerable) based on the IUCN Red List of Threatened Species.

Then there are two species of otters Aonyx congicus and Hydrictis maculicollis that are classified as Near Threatened and one species of rodent; Delany’s swamp mouse (Delanymys brooksi) classified as vulnerable.