Woodland habitat quality prevails over fragmentation for shaping butterfly diversity in deciduous forest remnants

2015 ◽  
Vol 357 ◽  
pp. 171-180 ◽  
Author(s):  
Inge van Halder ◽  
Jean-Yves Barnagaud ◽  
Hervé Jactel ◽  
Luc Barbaro
Check List ◽  
2012 ◽  
Vol 8 (3) ◽  
pp. 432 ◽  
Author(s):  
Joydeb Majumder ◽  
Rahul Lodh ◽  
B. K. Agarwala

Quantification of butterfly diversity and species richness is of prime importance for evaluating the status of protected areas. Permanent line transect counts were used to record species richness and abundance of butterfly communities of different habitat types in Trishna wildlife sanctuary. A total of 1005 individuals representing 59 species in 48 genera belonging to five families were recorded in the present study. Of these, 23 species belonged to the family Nymphalidae and accounted for 38.98% of the total species and 45.20% of the total number of individuals. Mature secondary mixed moist deciduous forest showed the maximum diversity and species richness, while exotic grassland showed minimum diversity and species richness. Out of 59 species, 31 are new records for Tripura state, while 21 are unique species and nine are listed in the threatened category. This study revealed that mature secondary forests are more important for butterfly communities, while exotic grasslands have a negative impact on species composition.


2009 ◽  
Vol 93 (1) ◽  
pp. 31-37 ◽  
Author(s):  
Erik Öckinger ◽  
Åse Dannestam ◽  
Henrik G. Smith

Oryx ◽  
2020 ◽  
pp. 1-9
Author(s):  
Elaine Rios ◽  
Philip J. K. McGowan ◽  
Nigel J. Collar ◽  
Maíra Benchimol ◽  
Gustavo R. Canale ◽  
...  

Abstract Large ground-dwelling Neotropical gamebirds are highly threatened by habitat loss and hunting, but conservationists rarely attempt to distinguish between these two threats in the management of populations. We used three different types of species records to determine the status (i.e. persistence level) of the Endangered red-billed curassow Crax blumenbachii in 14 forest remnants in north-east Brazil, as either persistent, precarious or extirpated. We related these persistence levels to variables measured in a 2-km buffer radius, including variables associated with habitat quality (proportion of forest cover, length of rivers, patch density, distance from rivers) and hunting pressure (proportion of cacao agroforests and farmlands, length of roads, total area occupied by settlements, distance from roads and from settlements). Curassows were more persistent in forest patches located (1) more distant from settlements, (2) in landscapes with few settlements, (3) in landscapes with a high incidence of roads, (4) in a mosaic with a high proportion of forest, shaded cacao agroforest and farmland, and (5) more distant from other forest patches. Hunting pressure potentially exerts more influence on persistence than habitat quality: (1) hunting pressure submodels had a higher explanatory power than habitat quality submodels, (2) final models comprised four hunting pressure variables but only two habitat quality variables, and (3) hunting pressure variables appeared in all models whereas habitat quality variables appeared in only one final model. If hunting pressure is driving declines in curassows, regions with low human presence and a high proportion of forest cover are recommended for establishing new reserves.


2018 ◽  
Vol 6 (2) ◽  
pp. 133-143
Author(s):  
Carlos R. Lehn ◽  
Marcelo D. Arana ◽  
Marcelo L. Bueno ◽  
Edmilson Bianchini

2021 ◽  
Author(s):  
Suman Attiwilli ◽  
Nitin Ravikanthachari ◽  
Krushnamegh Kunte

Long-term monitoring programmes have revealed catastrophic population declines that are contributing to biodiversity loss. These discoveries and the underlying programmes have been possible because of standardised methods of counting butterflies. Butterflies have been monitored using modified line transects, known in butterfly monitoring schemes as Pollard walks. However, line transects are not feasible in many tropical and mountainous habitats. To tackle this problem, we devised time-constrained (30-min) counts and compared butterfly diversity as estimated through this method with that estimated through line transects (500 m, 10 min) in three tropical habitats in India (evergreen forest, dry deciduous forest and an urban woodland). We tested the efficacy of the two methods to sample species richness and abundance, as well as numbers of rare, endemic and specialist butterflies. We observed greater species richness, and more species of habitat specialists and endemics per sample in time-constrained counts when compared with line transects in evergreen forest, but not in the other two habitats. Thus, time-constrained counts were more efficient at detecting species than line transects in the species-rich evergreen habitat. Apart from this difference, the two sampling methods captured similar levels of species richness and other measures of diversity. Time-constrained counts may thus be viewed as a feasible alternative to line transects to carry out butterfly surveys in tropical and mountainous landscapes. This method is particularly suited for biodiversity assessments and mapping involving citizen science initiatives, which has considerable potential in populous and tech-ready countries such as India.


2019 ◽  
Vol 12 (2) ◽  
pp. 67-72 ◽  
Author(s):  
Michał Glądalski ◽  
Iwona Cyżewska ◽  
Mirosława Bańbura ◽  
Adam Kaliński ◽  
Marcin Markowski ◽  
...  

The vegetation structure surrounding nest sites is a crucial component of habitat quality and may have large effects on avian breeding performance. Habitat quality reflects the extent to which the environmental characteristics of an area correspond to the preferred habitat characteristics of the species. The concentration of haemoglobin is considered a simple biochemical indicator of nestling body condition. We present results concerning the effects of variation in habitat characteristics on the concentration of haemoglobin in the blood of 14-day-old nestlings and breeding success of European Pied Flycatchers ( Ficedula hypoleuca) in a mature mixed deciduous forest in central Poland. The haemoglobin concentration of nestlings was higher when there were more native oaks and deciduous, native trees on the territory. Breeding success was reduced by the number of alien oak (the Red Oak, Quercus rubra) and other alien deciduous trees, but increased by the number of native oaks in the territory. This study was conducted on only one site so further research is needed to examine the broader applicability of our results. Our data support the idea that haemoglobin concentration may serve as a simple indicator of body condition in nestlings and is useful in field ecophysiology studies of European Pied Flycatchers.


2012 ◽  
Vol 52 (8) ◽  
pp. 707 ◽  
Author(s):  
B. Bolívar-Cimé ◽  
S. Gallina

Modelling wildlife habitat availability for animal species has important implications for explaining the distribution of the animals in the wild, their effective management and conservation. In this study we evaluated an Optimal Habitat Model based on the Habitat Suitability Index (HSI) for the white-tailed deer (Odocoileus virginianus) in central Veracruz, Mexico. We generated a GIS-based model from the main habitat requirements that influence the presence of white-tailed deer. Six variables were used for modelling the optimal habitat. With these data layers we calculated the HSI for deer in the study area. Two strip transects (500 by 2 m) were set up at 18 sites where all signs of white-tailed deer were recorded. The HSI for the study area ranged from –0.667 to 0.905, with the lowest values associated with poor habitat quality. Eighty-six percent of the study area’s surface was habitat of intermediate and low quality. Seventy percent of the deer signs were found in intermediate habitat quality. White-tailed deer frequently used oak forest, tropical deciduous forest and pastures. A Classification Tree Analysis indicated that temperature and aspect were the main habitat features influencing white-tailed deer presence. Although anthropogenic pressure in the region is high, forest patches help maintain some suitable habitat for small populations of this species. Conservation and restoration of the vegetation cover is recommended to promote the recovery of deer populations in central Veracruz, Mexico.


2020 ◽  
Vol 150 ◽  
Author(s):  
Constance Fastré ◽  
Diederik Strubbe ◽  
José A. Balderrama ◽  
Jennifer R.A. Cahill ◽  
Hannes Ledegen ◽  
...  

Montane forests worldwide are known centers of endemism and biodiversity but are highly threatened by fragmentation processes. Using data collected in 15 Polylepis forest remnants covering 2000 hectares, we investigated how bird species richness and bird community composition, particularly for species of conservation concern, are influenced by habitat quality and topography in the Tunari National Park in the High Andes of Bolivia. Bird species richness was highest in topographically complex, low-elevation Polylepis patches located in areas with a high potential to retain rainwater. Bird communities differed strongly between Polylepis lanata and P. subtusalbida remnants, each supporting different threatened and endemic species. Within the P. subtusalbida forest, high-elevation fragments characterized by high amounts of sunlight and low anthropogenic disturbance were more likely to contain threatened species. Surprisingly, we found no effect of fragment size on the diversity or composition of bird communities or the presence of bird species of conservation concern. The presence of exotic plantations (Pinus and/or Eucalyptus spp.) in or outside forest remnants was negatively associated with the number of bird species as well as with occurrence of the endangered Cochabamba-mountain finch (Compsospiza garleppi). To support the different communities found in Polylepis forests, these results suggest that conservation efforts should be directed towards both forest types (P. subtusalbida and P. lanata) present in the area. For an efficient management of avian diversity, exotic plantations should be established away from native remnants while existing patches should be managed to maintain or increase habitat quality. Finally, the importance of local topography in determining avian species richness and community composition in forest fragments, mainly through topographic controls on moisture distribution and the amount of sunlight received by the fragments, should be considered when planning conservation and reforestation schemes.


2009 ◽  
Vol 156 (2) ◽  
pp. 159-171 ◽  
Author(s):  
Aristide C. Adomou ◽  
Akpovi Akoègninou ◽  
Brice Sinsin ◽  
Bruno de Foucault ◽  
Laurentius J.G. van der Maesen

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