Vallée de Mai Nature Reserve

Coco der mer nuts were previously heavily exploited in Vallée de Mai, and it was clear that harvesting at those levels could not be maintained indefinitely. It was recommended that a set of sustainable harvesting and replanting strategies should be implemented to increase the regeneration rate and long-term sustainability of the site (Rist et al., 2010; Fleischer-Dogley et al., 2011). Based on these recommendations, SIF has initiated an incentive-driven stewardship scheme to ensure that a minimum number of 20% of nuts remain in the forest (SIF, 2018; Pinto-Rodrigues 2021). Poaching of coco de mer nuts has substantially decreased due to increased surveillance (SIF, 2021) but it remains a long-term threat to the integrity of the World Heritage site (IUCN Consultation, 2017). In 2018 higher patrol procedures were introduced, which lead to the year of lowest poaching compared to previous years with poaching on the decline since 2014 (SIF, 2019).

The main Praslin road passes through the Praslin National Park, adjacent to the Vallée de Mai. The effects of disturbance and noise on the site's fauna are unknown.

The threat of invasive alien species is high in the site since they can lead to changes in species composition and habitats (Ketterer, 2010). This threat has decreased in terms of invasive plant species (which have been controlled for the last six years with excellent progress made in removing several invasive plant species entirely from the site and a biosecurity plan developed), but other high priority species have been identified. Clidemia hirta and Diffenbachia sp. are spreading fast and have significant impact on native plant diversity (Dine & Senterre 2021). The threat from invasive animals has only partially decreased, with new species posing as potential threats. The Indian ring-necked parakeet (Psittacula krameri) has been successfully eradicated from Mahé island seemingly without having transferred the deadly PBFD (Psittacene Beak and Feather Disease) virus to the black parrot population on Praslin island (Fogell et al., 2018). Another success is currently seen on the highly invasive yellow crazy ant (Anoplolepis gracilipes), which is impacting upon black parrot nests, and threaten much of the native biodiversity of the site. The number and abundance of several endemic arboreal species was lower in invaded areas (Kaiser-Bunbury et al., 2014b). The expansion of the A. gracilipes, which in October 2018 had reached its peak with 100% cover of the site (SIF, 2018), has been under control after an emergency assistance request was granted (World Heritage Committee, 2019) with the latest research showing a decrease to a 60% coverage of the site (SIF, 2019). By 2021, the Vallée de Mai was free of A. gracilipes apart from small incursions in the buffer zone (SIF 2021). Rats remain a problem, but have been controlled locally around black parrot nests during their breeding season as well throughout the entire site since the introduction of the invasive species management team Inva'Ziles before the start of the black parrot breeding season in October 2017 (SIF, 2017). Besides a few brown rats (Rattus norvegicus), mainly black rats (Rattus rattus) were trapped successfully from 2017 onwards, resulting in parrot breeding with seemingly no rat disturbances (SIF, 2018a, unpubl. report). Tenrecs potentially pose a threat to the ground fauna and therefore trapping was introduced in 2017. This trapping and dissection of the animal could not yet reveal their impact on native wildlife due to a lack of specified staff (SIF, 2018a, unpubl. report). However, the report points out that there is likely to be an impact of feral cats (Felis catus) within the site and across Praslin and the impacts of this additional invasive alien species on black parrots and their nesting success is not yet known (SIF, 2018a, unpubl. report). In 2021, the common myna (Acridotheres tristis) were surveyed in the Vallée de Mai. The invasive bird has increasing significantly in presence and abundance between 2018 and 2021, rapidly encroaching the entire forest- Mynas pose a threat to native wildlife as e.g. potentially competing with black parrots for nesting sites and predation of parrot eggs and chicks (SIF, 2021). Climate change may also create novel areas that are suitable for invasives plants and animals that are currently not occupied (Seychelles Assessment Workshop, 2025). While the management response has been exemplary, long-term commitment will be essential.

Tourism numbers continue to increase annually at this small site (Seychelles Islands Foundation, 2021c), and although tourism management is conducted (via paths and guided tours, off-peak activities, and tourist visitor app), the impacts of 100,000 tourists a year in a 19.5-ha site require effective management. So far the trail infrastructure has been improved substantially to limit erosion of trails (SIF 2021). It is also important to monitor noise levels and disturbance to black parrot nests to better understand possible impacts (IUCN Consultation, 2020) and carry out research on the impact of tourists on the ecosystem.

The thick palm leaf litter of the Vallée de Mai is a hugely important part of the ecosystem and trampling/disturbance of this substrate is likely to have unpredictable effects on leaf litter fauna and possibly also nutrient recycling. Walking off-path through the Vallée de Mai by staff is controlled. More work needs to be done to raise awareness of and limit these impacts (IUCN Consultation, 2017).

Vallee de Mai is a small site supporting several unique animal species. Relatively little is known about the populations of most these species, including endemic reptiles, amphibians and molluscs. However, their presumably small populations makes them vulnerable to a variety of threats, including extreme climate events, fire, deomographic stochasticity and invasive species. This vulnerability became very clear during the recent outbreak of yellow crazy ant, when populations of endemic molluscs (Filicaulis ( = Vaginula) seychellensis) were visibly reduced. For example, the formerly abundant endemic slug was nowhere to be seen (IUCN Consultation, 2020). Strengthening the management of the surrounding areas of Lodoicea forest will be important for reducing the constant threat posed by small populations.

Illegal collection of coco de mer nuts in Vallée de Mai has long posed a threat due to the high value of its nuts and kernels, with the total economic value of the species estimated at $2.89 million for 2018 (SIF 2019). Poachers often climb the palms and cut off all infructescences with mature and immature nuts, an impact which appears to negatively affect reproduction in female trees for up to 3–5 years (Rist et al., 2010). Poaching primarily targets the kernel of both mature nuts, sold as an aphrodisiac in the Chinese medicine market, and of immature nuts, as a delicacy for local consumption (Kaiser-Bunbury et al., 2014a). Despite legal protection under Seychelles’ law and international regulations, poaching still jeopardises the future of this iconic species and all that depend on it. Since 2014 a decline in poaching has been observed and the illegal collection of coco de mer nuts has substantially decreased due to increased surveillance by the management authority (SIF 2019), but remains a long-term threat to the integrity of the site (IUCN Consultation, 2020).

There have been cases of illegal wildlife poaching observed, e.g. on the endemic giant bronze gecko in 2018 and according to media reports, illegal trade of the giant bronze gecko and Seychelles tiger chameleon is ongoing and their value on the black market is high (Magnan, 2021). The endemic giant bronze geckos are regarded as "holy grails" amongst reptile collectors and are consequently being traded for around 20,000€ each (CITES 2018), online and at international reptile fairs with an estimated more than 2% of the global population of this gecko poached in one year (Nature Seychelles, 2018). The wildlife trade also impacts native fauna and flora by introduced/escaped 'pets' (including freshwater fish) being competitors and vectors of infectious disease, e.g. Psittacine Beak and Feather Diseas (PBFD) in introduced ringed-neck parakeets on Mahé (Fogell et al., 2018); ranaviruses affecting reptiles and amphibians (Wirth et al., 2018; Price at al., 2017), and several fungal diseases including nannizziomycosis, and ophidiomycosis (reptiles), and chytridiomycosis (amphibians), all of which are global problems and could prove catastrophic to the endemic herpetofauna (Greenberg & Palen, 2019; Shilliger et al., 2023). The Cabinet of Ministers has approved new regulations to protect two reptiles endemic to Seychelles from exploitation and trafficking. The cabinet approved regulations for the giant bronze gecko and the Seychelles tiger chameleon in 2021. On the same date, the cabinet approved the drafting of the Trade in Wild Fauna and Flora Bill, 2020. The bill would allow for the protection of specified wild animal and flora and would prohibit the capture, possession, or trade in these species (Magnan, 2021).