Gamebird vulnerability to forest fragmentation: patch occupancy of the crested guineafowl (<i>Guttera edouardi</i>) in Afromontane forests

Lawes, Michael J.; Fly, S.; Piper, S. E.

doi:10.1111/j.1469-1795.2005.00006.x

Cited by 12 publications

(10 citation statements)

References 35 publications

(48 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The result that patch size is the best single predictor for capercaillie occurrence is paralleled by other studies of forest‐dwelling species (Blake and Karr 1984, Rolstad 1991, Lawes et al 2006). Being a forest‐interior species, capercaillie appears to be very sensitive to area effects.…”

Section: Discussionsupporting

confidence: 66%

Quantitative predictions for patch occupancy of capercaillie in fragmented habitats

Bollmann¹,

Graf²,

Suter³

2010

Ecography

View full text Add to dashboard Cite

A major conclusion of studying metapopulation biology is that species conservation should favor regional rather than local population persistence. Regional persistence is tightly linked to size, spatial configuration and quality of habitat patches. Hence it is important for the management of endangered species that priority patches can be identified. We developed a predictive model of patch occupancy by capercaillie, a threatened grouse species, based on a single snapshot of data. We used logistic regression to predict patch occupancy as a function of patch size, isolation, connectivity, relative altitude, and biogeographical area. The probability of a patch being occupied increased with patch size and increasing altitude, and decreased with increasing distance to the next occupied patch. Patch size was the most important predictor although occupied patches varied considerably in size. Our model only uses data on the number, size and spatial configuration of habitat patches. It is a useful tool to designate priority areas for conservation, i.e. large core patches with high resilience in habitat quality, smaller island‐patches that still have high probability of being inhabited or becoming recolonised, and patches functioning as “stepping stones”. If capercaillie is to be preserved, habitat suitability needs to be maintained in a functional network of patches that account for size and inter‐patch distance thresholds as found in this study. We suggest that similar area‐isolation relationships are valid for almost any region within the distribution range of capercaillie. The thresholds for occupancy are however likely to depend on characteristics of the respective landscape. The outcome of our study emphasises the need for future investigations that explore the relationship between patch occupancy, matrix quality and its resistance to dispersing individuals.

show abstract

Section: Discussionsupporting

confidence: 66%

Quantitative predictions for patch occupancy of capercaillie in fragmented habitats

Bollmann¹,

Graf²,

Suter³

2010

Ecography

View full text Add to dashboard Cite

show abstract

“…For example, a comparison of species numbers in nine small forest fragments with that in a larger forest site in the east Usambara mountains, Tanzania, showed that understorey species were absent from the former (Newmark 1991). Forest sensitive species such as the Crested Guineafowl Guttera edouardi are more likely to occur in larger fragments although isolation may be relatively unimportant (Lawes et al . 2006).…”

Section: Discussionmentioning

confidence: 99%

“…For example, a com-parison of species numbers in nine small forest fragments with that in a larger forest site in the east Usambara mountains, Tanzania, showed that understorey species were absent from the former (Newmark 1991). Forest sensitive species such as the Crested Guineafowl Guttera edouardi are more likely to occur in larger fragments although isolation may be relatively unimportant (Lawes et al 2006). A comparison of the avifauna communities in mature forest and adjacent disturbed forest in the Tanzania-Malawi mountains showed that there were more species in disturbed than undisturbed forest owing to the presence of edge species in the former (Fjeldsa 1999).…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

The effects of edge, fragment size and degree of isolation on avian species richness in highly fragmented forest in West Africa

Manu

Peach

Cresswell

2007

Ibis

View full text Add to dashboard Cite

Almost nothing is known of the effects of forest fragmentation on bird diversity within the heavily degraded and fragmented forest remnants in West Africa. We examined the effects of edge, fragment size and isolation on bird species richness in southwestern Nigeria where forest fragmentation is pronounced. In total, 122 km of line transects were used to survey birds and vegetation within 45 forest patches between January 2000 and March 2002: 197 species were recorded. Avian species number and total counts in forest patches were unrelated to fragment area (within the observed range of 14–445 ha), but were negatively influenced by degree of isolation and increasing distance from the edge. As the total area of forested land within 15 km of a patch fell from 4 to 0%, so 21% of species were lost. In total, six and zero species (of 154 recorded more than once) were consistently recorded in the larger and smaller forest fragments, respectively, and four and two bird species were consistently recorded in unisolated and isolated forest fragments, respectively, suggesting that the addition of ‘edge’ species did not compensate for loss of species sensitive to fragmentation. Diversity index was not affected by either fragment area or degree of isolation, but decreased with distance from the edge. When individual species counts were considered, 68% of species (n = 62) showed no significant effect of distance to edge. Of those 20 species which showed an effect, 12 were less common close to the edge. Most species (65%) did not respond significantly to increasing isolation but of those 22 species that did, 20 were less common in more isolated fragments. Ninety‐seven per cent of species showed no significant response to area. As avian diversity and species composition, but not species number, were apparently insensitive to forest fragmentation, our findings suggest that fragmentation reduces the probability of occurrence of a wide range of West African bird species, rather than a subset of fragmentation‐sensitive species. The greater apparent sensitivity of present‐day West African forest bird communities to fragmentation rather than patch size might reflect previous extinctions of area‐sensitive species. Minimizing further forest fragmentation might be the most effective means of conserving avian diversity in current West African landscapes where most remaining forest patches are small (i.e. < 500 ha).

show abstract

“…The fitted detection function reflects both the decrease in detectability with distance and the lower proportion of animals that are potentially detectable (Buckland et al 2001). For each sighting, we recorded the number of birds and habitat type (according to Kikula 1980;Caro 1999), but because of small sample size we pooled habitat types into two categories, closed habitat (woodlands and bushlands) and open habitat (grasslands, wooded grasslands, bushed grasslands and cultivated lands).…”

Section: Questionnaire Datamentioning

confidence: 99%

Does illegal hunting affect density and behaviour of African grassland birds? A case study on ostrich (Struthio camelus)

et al. 2008

View full text Add to dashboard Cite

Widespread bushmeat hunting represents one of the major threats to many mammals and birds in Africa. We studied the influence of illegal bushmeat hunting on large grassland birds in the Serengeti National Park (SNP) and adjoining protected areas, by using the ostrich (Struthio camelus) as a case study. First, we documented illegal hunting of both small and large birds by using a questionnaire in the villages on the western and eastern side of the SNP. Second, we studied the effect of illegal hunting on density by driving 4,659 km of transects inside SNP and on the adjacent protected areas, where the data were analysed by DISTANCE sampling. Last, we used flight initiation distance (FID, i.e. the distance between an approaching predator (human) and prey when flight is started), to assess possible impacts on behaviour from illegal hunting. We found that people from the western side of the SNP admitted to hunting both small and large grassland birds, and collect ostrich feathers and eggs. Although the Maasai also hunted small birds, only ostrich feathers and eggs of the large grassland birds were used. Surprisingly, we found no significant differences in densities between the SNP and adjoining partially protected areas, but ostriches had longer FID to an approaching human outside the SNP. Currently illegal hunting does not appear to affect the ostrich population, but given the extensive use of birds for consumption more awareness educational programs accompanied by provision of agricultural incentives within the protected areas are needed.

show abstract

Gamebird vulnerability to forest fragmentation: patch occupancy of the crested guineafowl (Guttera edouardi) in Afromontane forests

Cited by 12 publications

References 35 publications

Quantitative predictions for patch occupancy of capercaillie in fragmented habitats

Quantitative predictions for patch occupancy of capercaillie in fragmented habitats

The effects of edge, fragment size and degree of isolation on avian species richness in highly fragmented forest in West Africa

Does illegal hunting affect density and behaviour of African grassland birds? A case study on ostrich (Struthio camelus)

Contact Info

Product

Resources

About