Ricardo F. de Lima

Reassessing the conservation status of the shrew Crocidura thomensis , endemic to São Tomé Island

The shrew Crocidura thomensis is a little-known species endemic to Sao Tome Island. We review its distribution, ecology and conservation status based on nine published and 23 new records. The species has a wide distribution across Sao Tome, preferring rugged forested areas with high rainfall. The location of new records coincides with that of historical records but the proportion of records in plantations has declined, possibly as a result of agricultural intensification, increased use of pesticides, and presence of exotic species. The shrew is restricted to a single island, its extent of occurrence is 2 and its habitat is declining in extent and quality, and thus its categorization as Endangered on the IUCN Red List remains appropriate. It is important to gain a better knowledge of population trends, ecological preferences and sensitivity to potential threats, but the effective protection of Sao Tome Obo Natural Park and surrounding forests is the most important measure to ensure the long-term survival of this mammal.

Factors influencing the distribution and abundance of endemic pigeons on São Tomé Island (Gulf of Guinea)

Understanding the factors that determine habitat use and abundance of exploited species is essential to develop effective conservation strategies. We studied the four forest pigeons on Sao Tome Island to assess the species’ distribution and abundance patterns. We determined ecological factors likely to be associated with each species’ use of habitats and numbers, as well as the influence of hunting pressure. In total, 35 km of line transects were surveyed in the rainy season and at the start of the dry season. Pigeons differed in their use of habitats; there were also strong seasonality effects. The most abundant species was the Lemon Dove Columba simplex , the only non-hunted species. The Sao Tome Green Pigeon Treron sanctithomae and Maroon Pigeon Columba thomensis were less abundant and had more restricted ranges. Both species were strongly associated with old-growth forests. In contrast, the Bronze-naped Pigeon Columba malherbii was relatively abundant and widespread; this species favours human-altered habitats such as shade forests and non-forested areas. Fruit availability measured within the different habitats was linked with the distribution and abundance of the three hunted species. Potential human predation pressure on all species was determined from hunting signs found along the surveyed transects. There was a significant negative correlation between the abundance of two of the hunted species and hunting pressure. Our results indicate the importance of adequately protecting old-growth and secondary forests as core habitats for the survival of viable populations of all pigeon species in the island. However, control of hunting is also crucial.

Land flatworms (Platyhelminthes, Geoplanidae) of São Tomé: a first account on their diversity, with the description of five new species

The present contribution provides the first faunistic and taxonomic account of six species of land flatworm from the island of São Tomé, including five new species of the genus Othelosoma Gray, 1869 and the introduced Bipalium kewense Moseley, 1878. One of the new species represents the first African land flatworm that has specks on its dorsal body surface, instead of stripes or a more or less uniform colouration. At least two of the new species were observed to prey on snails. The study details the fourth record of a sclerotic spermatophore in a species of land flatworm, and discusses the definition and homology of double female genital canals in African and Indian species of the genus Othelosoma.

Can REDD+ help the conservation of restricted-range island species? Insights from the endemism hotspot of São Tomé.

REDD+ aims to offset greenhouse gas emissions through “Reduced Emissions from Deforestation and forest Degradation”. Some authors suggest that REDD+ can bring additional benefits for biodiversity, namely for the conservation of extinction-prone restricted-range species. Here, we assess this claim, using São Tomé Island (Democratic Republic of São Tomé and Príncipe) as a case study. We quantified the abundance of bird and tree species, and calculated the aboveground carbon stocks across a gradient of land-use intensity. We found a strong spatial congruence between carbon and the presence and abundance of endemic species, supporting the potential of REDD+ to protect these taxa. We then assessed if REDD+ could help protect the forests of São Tomé and Príncipe. To do so, we used OSIRIS simulations to predict country-level deforestation under two different REDD+ designs. These simulations showed that REDD+ could promote the loss of forests in São Tomé and Príncipe through leakage. This happened even when additional payments for biodiversity were included in the simulations, and despite São Tomé and Príncipe having the fourth highest carbon stocks per land area and the second highest biodiversity values according to the OSIRIS database. These results show weaknesses of OSIRIS as a planning tool, and demonstrate that the benefits that REDD+ might bring for biodiversity are strongly dependent on its careful implementation. We recommend that payment for ecosystem services programmes such as REDD+ develop safeguards to ensure that biodiversity co-benefits are met and perverse outcomes are avoided across all tropical countries. In particular, we advise specific safeguards regarding the conservation of extinction-prone groups, such as island restricted-range species.

Distribution and habitat associations of the critically endangered bird species of São Tomé Island (Gulf of Guinea)

São Tomé holds 20 endemic bird species, including the little known and ‘Critically Endangered’ Dwarf Olive Ibis Bostrychia bocagei, São Tomé Fiscal Lanius newtoni and São Tomé Grosbeak Neospiza concolor. We conducted a systematic survey of the core forest area, performing 1,680 point counts and compiling occasional observations, which enabled the identification of new areas of occurrence for the target species. MaxEnt distribution modelling suggested that the ibis and fiscal have roughly half of the potential area of occurrence that had been assumed (127 and 117 km2, respectively), while it more than doubled that of the grosbeak (187 km2). The south-west central region of the island, most of which is included in the São Tomé Obô Natural Park, has the highest potential for the Critically Endangered birds. We confirmed the association of all target species with native forest. The ibis preferred high tree density, while the fiscal selected low tree density and intermediate altitudes. Despite very restricted ranges, population sizes seem to be larger than previously assumed. These results suggest that the fiscal and grosbeak might be better classified as ‘Endangered’, while the ibis should maintain its status under different criteria, due to a very restricted range during the breeding season. This work provides vital ecological knowledge to support conservation action focusing on these species and their habitats, highlighting the need to improve the effectiveness of the São Tomé Obô Natural Park in protecting its unique biodiversity.

New hope for the critically endangered São Tomé Grosbeak Neospiza concolor and an alert to protect Obô Natural Park surroundings

The São Tomé Grosbeak Neospiza concolor is critically endangered, with an area of occurrence smaller than 16 km2 and an adult population under 50 individuals. It was previously thought to be restricted to old-growth forest in the southern lowlands of the island, but here we describe its presence at altitude over a long period, using young secondary forests and feeding on plants characteristic of disturbed areas. By extending the grosbeaks area of occurrence and what is known about its ecology, these observations raise new hope for the survival of this threatened bird. However, this new site lies outside the Ôbo Natural Park, São Tomés only protected area, for which we alert the need to better protect its surroundings, which are relevant for many of the islands endemic species.

São Tomé Island Endemic Treefrogs (Hyperolius spp.) and Land-Use Intensification: A Tale of Hope and Caution:

Forest degradation is a major driver of the global biodiversity declines. However, responses to forest degradation vary greatly between taxa and are predominantly understudied. This study investigates the effects of land-use change on the endemic amphibian fauna of São Tomé Island (Central Africa), where a fast-growing human population increases pressure on forest resources. We sampled acoustic data on reed frog (Hyperolius spp.) abundance at eight transects in each of four land-use categories, representing different levels of forest degradation: old-growth forest, secondary forest, agroforest, and horticulture. While Hyperolius molleri was most abundant in secondary forest and horticulture, Hyperolius thomensis was almost exclusively found in agroforest. We interpret these differences based on reproductive traits, since both species deposit terrestrial eggs and have aquatic larvae, but reproduce in different microhabitats. H. molleri utilizes open water bodies bordered by vegetation for calling and oviposition, which human disturbance has made available in secondary forest and horticulture. In contrast, H. thomensis breeds in water-filled tree holes (phytotelmata), which predominantly occurred in agroforest, often within coral trees (Erythrina spp.). This first study on Santomean amphibian abundances revealed that H. molleri and H. thomensis males exhibit distinct nonlinear responses to forest degradation and may reap some benefit from human habitat alteration. However, despite their apparent tolerance to some anthropogenic disturbance, further land-use intensification may reduce overall habitat suitability for these and other endemic species.

Drivers of bird diversity in an understudied African centre of endemism: The Angolan Central Escarpment Forest

Natural habitats are being rapidly lost due to human activities. It is therefore vital to understand how these activities influence biodiversity so that suitable guidelines can be established for conservation. This is particularly important in understudied, high biodiversity, areas such as the Angolan Escarpment. Here we examine which habitat characteristics drive bird diversity and endemic species presence at Kumbira Forest, a key site in the Central Escarpment Forest. Bird diversity was sampled by 10 min bird point counts, whereas habitat characteristics were measured by a combination of ground-based vegetation surveys and remotely sensed data modelling of Landsat images. GLM, multi-model inference and model averaging were used to determine the most important variables driving species richness and the presence of endemics. The remote sensing variables performed poorly in predicting presence of Red-crested Turaco Tauraco erythrolophus and Gabela Bushshrike Laniarius amboimensis but they contributed significantly to explain species richness and Gabela Akalat Sheppardia gabela presence, both of which were associated with greater canopy cover. Liana density and elevation were also important explanatory variables in certain cases. Conservation actions at Kumbira should focus on increasing canopy cover and maintaining forest integrity (as measured by liana density), as these actions are likely to have the most positive outcomes for the avifauna.

The Role of Science in Society: Challenges in a Time of Global Changes

What is the role of science in society? Is science improving our ability of living in a sustainable way? Does science communicate effectively with society? In a societal point of view, science should provide solutions to our daily problems, as well as to technical and philosophical issues [1]. Science should enhance the quality level of responses provided to society. On the other hand, science requires a high level of support from society. The financial support is perhaps the most visible, and of course, a critical issue in managing science. However, science also needs to engage in communication with society. Feedback and understanding from the common citizen is essential to improve science and to protect the natural environment [2]. Nevertheless, communication between scientists, managers and policy makers still represents a major challenge.