Countryside biogeography: Use of human-dominated habitats by the avifauna of southern Costa Rica

Ecological Applications (Impact Factor: 4.09). 01/2000; 11. DOI: 10.1890/1051-0761(2001)011[0001:CBUOHD]2.0.CO;2
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    • "Cushman and McGarigal 2003; Fahrig 2003; O ¨ ckinger and Smith 2006). Other studies have considered the biodiversity benefits provided by 'countryside elements' such as gardens, hedgerows and field margins, but often these have been focussed at the local scale without incorporating all the interactions from the wider landscape (e.g. Green et al. 1994; Daily et al. 2001; Mayfield and Daily 2005; Gardiner 2007). Recently, it has been recognised that methods encompassing both the spatial landscape pattern and the composition of the surrounding matrix provide a more detailed understanding of how species respond in wooded-agricultural landscapes (e.g. "
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    ABSTRACT: Context: Landscape heterogeneity (the composition and configuration of matrix habitats) plays a major role in shaping species communities in wooded-agricultural landscapes. However, few studies consider the influence of different types of semi-natural and linear habitats in the matrix, despite their known ecological value for biodiversity. Objectives: To investigate the importance of the composition and configuration of matrix habitats for woodland carabid communities and identify whether specific landscape features can help to maintain long-term populations in wooded-agricultural environments. Methods: Carabids were sampled from woodlands in 36 tetrads of 4 km2 across southern Britain. Landscape heterogeneity including an innovative representation of linear habitats was quantified for each tetrad. Carabid community response was analysed using ordination methods combined with variation partitioning and additional response trait analyses. Results: Woodland carabid community response was trait-specific and better explained by simultaneously considering the composition and configuration of matrix habitats. Semi-natural and linear features provided significant refuge habitat and functional connectivity. Mature hedgerows were essential for slow-dispersing carabids in fragmented landscapes. Species commonly associated with heathland were correlated with inland water and woodland patches despite widespread heathland conversion to agricultural land, suggesting that species may persist for some decades when elements representative of the original habitat are retained following landscape modification. Conclusions: Semi-natural and linear habitats have high biodiversity value. Landowners should identify features that can provide additional resources or functional connectivity for species relative to other habitat types in the landscape matrix. Agri-environment options should consider landscape heterogeneity to identify the most efficacious changes for biodiversity.
    Landscape Ecology 07/2015; DOI:10.1007/s10980-015-0244-y · 3.50 Impact Factor
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    • "Production landscapes containing natural habitats can harbour a substantial proportion of the regional bird species [17-20]. Natural windbreaks are one such habitat that may be critical for the persistence of birds in production landscapes. "
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    ABSTRACT: Windbreaks often form networks of forest habitats that improve connectivity and thus conserve biodiversity, but little is known of such effects in the tropics. We determined bird species richness and community composition in windbreaks composed of remnant native vegetation amongst tea plantations (natural windbreaks), and compared it with the surrounding primary forests. Fifty-one, ten-minute point counts were conducted in each habitat type over three days. Despite the limited sampling period, our bird inventories in both natural windbreaks and primary forests were nearly complete, as indicated by bootstrap true richness estimator. Bird species richness and abundance between primary forests and windbreaks were similar, however a difference in bird community composition was observed. Abundances of important functional groups such as frugivores and insectivores did not vary between habitat types but nectarivores were more abundant in windbreaks, potentially as a result of the use of windbreaks as traveling routes, foraging and nesting sites. This preliminary study suggests that natural windbreaks may be important habitats for the persistence of bird species in a production landscape. However, a better understanding of the required physical and compositional characteristics for windbreaks to sustain bird communities is needed for effective conservation management.
    PLoS ONE 07/2013; 8(7):e70379. DOI:10.1371/journal.pone.0070379 · 3.23 Impact Factor
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    • "habitat types harbor similar bird communities and if birds frequently pass habitat boundaries when foraging, tropical farmlands may buffer species loss caused by forest destruction to a certain degree (Daily et al. 2001; Hughes et al. 2002). Hence, from a conservation perspective it is important to assess the value of tropical farmlands for the maintenance of tropical bird diversity (Hughes et al. 2002; Sekercioglu et al. 2007). "
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    ABSTRACT: The conversion of forest into farmland has resulted in mosaic landscapes in many parts of the tropics. From a conservation perspective, it is important to know whether tropical farmlands can buffer species loss caused by deforestation and how different functional groups of birds respond to land-use intensification. To test the degree of differentiation between farmland and forest bird com-munities across feeding guilds, we analyzed stable C and N isotopes in blood and claws of 101 bird species comprising four feeding guilds along a tropical forest-farmland gradi-ent in Kenya. We additionally assessed the importance of farmland insectivores for pest control in C 4 crops by using allometric relationships, C stable isotope ratios and esti-mates of bird species abundance. Species composition differed strongly between forest and farmland bird com-munities. Across seasons, forest birds primarily relied on C 3 carbon sources, whereas many farmland birds also assimilated C 4 carbon. While C sources of frugivores and omnivores did not differ between forest and farmland communities, insectivores used more C 4 carbon in the farmland than in the forest. Granivores assimilated more C 4 carbon than all other guilds in the farmland. We estimated that insectivorous farmland birds consumed at least 1,000 kg pest invertebrates km -2 year -1 . We conclude that tropical forest and farmland understory bird communities are strongly separated and that tropical farmlands cannot compensate forest loss for insectivorous forest understory birds. In tropical farmlands, insectivorous bird species provide a quantitatively important contribution to pest control.
    Oecologia 07/2012; 171(2). DOI:10.1007/s00442-012-2422-9 · 3.09 Impact Factor
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