3 research outputs found
Habitat characteristics of wintering Wood Warbler Phylloscopus sibilatrix in the Centre Region of Cameroon: conservation implications
Populations of many Afro-Palearctic birds have declined, with those wintering in sub-Saharan Africa, such as Wood Warbler Phylloscopus sibilatrix, particularly affected. In this study we investigated the relationship between habitat characteristics and Wood Warbler presence/absence in the Centre Region of Cameroon. A total of six transects were established in three habitat types (forest, forest–savanna transitional zone and savanna). Call playback surveys were conducted monthly from November 2015 to April 2016 to determine Wood Warbler presence/absence. Detailed habitat measurements were also recorded in each transect. A total of 86 responses were recorded: 33 (mean 6.6 ± 2.3) in forest habitat, 47 (mean 9.4 ± 3.36) in the forest–savanna transitional zone, and 6 (mean 2 ± 1.1) in savanna habitat. Wood Warbler presence increased significantly with the number of trees between 3 and 7 m in height, and decreased significantly with the number of shrubs between 0.5 and 3 m in height. Anthropogenic disturbance such as the agricultural cycle and burning were not found to have an effect on Wood Warblers presence/absence. We conclude that Wood Warblers overwinter in all three habitat types with probability of detection greatest in the forest–savanna transitional habitat with a relatively low canopy and an open understorey. Forest clearance in sub-Saharan Africa potentially threatens wintering habitat for Wood Warblers
Quantifying the scale and socioeconomic drivers of bird hunting in Central African forest communities
Global biodiversity is threatened by unsustainable exploitation for subsistence and commerce, and tropical forests are facing a hunting crisis. In Central African forests, hunting pressure has been quantified by monitoring changes in the abundance of affected species and by studying wild meat consumption, trade and hunter behaviour. However, a proportion of offtake is also discarded as bycatch or consumed by hunters when working, which can be overlooked by these methods. For example, remains of hornbills and raptors are found regularly in hunting camps but relatively few birds are consumed in households or traded in markets. Hornbill and raptor populations are sensitive to small increases in mortality because of their low intrinsic population growth rates, however, the scale and socioeconomic drivers of the cryptic hunting pressure affecting these species have not been quantified. We used direct and indirect questioning and mixed-effects models to quantify the socioeconomic predictors, scale and seasonality of illegal bird hunting and consumption in Littoral Region, Cameroon. We predicted that younger, unemployed men with low educational attainment (i.e. hunters) would consume birds more often than other demographics, and that relative offtake would be higher than expected based on results from village and market-based studies. We found that birds were primarily hunted and consumed by unemployed men during the dry season but, in contrast to expectations, we found that hunting prevalence increased with educational attainment. Within unemployed men educated to primary level (240 of 675 respondents in 19 villages), we estimated an average of 29 hornbills and eight raptors (compared with 19 pangolins) were consumed per month during the study period (Feb–Jun 2015) in a catchment of c.1135 km2. We conclude that large forest birds face greater hunting pressure than previously recognised, and birds are a regular source of protein for men during unemployment. Offtake levels may be unsustainable for some raptors and hornbills based on life history traits but in the absence of sufficient baseline ecological and population data we recommend that a social-ecological modeling approach is used in future to quantify hunting sustainability
Modeling the potential distribution of the threatened Grey-necked Picathartes Picathartes oreas across its entire range
Understanding the distribution and extent of suitable habitats is critical for the conservation of endangered and endemic taxa. Such knowledge is limited for many Central African species, including the rare and globally threatened Grey-necked Picathartes Picathartes oreas, one of only two species in the family Picathartidae endemic to the forests of Central Africa. Despite growing concerns about land-use change resulting in fragmentation and loss of forest cover in the region, neither the extent of suitable habitat nor the potential species’ distribution is well known. We combine 339 (new and historical) occurrence records of Grey-necked Picathartes with environmental variables to model the potential global distribution. We used a Maximum Entropy modelling approach that accounted for sampling bias. Our model suggests that Grey-necked Picathartes distribution is strongly associated with steeper slopes and high levels of forest cover, while bioclimatic, vegetation health, and habitat condition variables were all excluded from the final model. We predicted 17,327 km2 of suitable habitat for the species, of which only 2,490 km2 (14.4%) are within protected areas where conservation designations are strictly enforced. These findings show a smaller global distribution of predicted suitable habitat forthe Grey-necked Picathartes than previously thought. This work provides evidence to inform a revision of the International Union for Conservation of Nature (IUCN) Red List status, and may warrant upgrading the status of the species from “Near Threatened” to “Vulnerable”