Forest edges and habitat selection in birds: a functional approach

Abstract

Edge effects encompass a complex panoply of biotic and biotic phenomena across woodlan borders. I identify four main explanations which have been proposed to explain avian habital selection with respect to forest edges: 1) individualistic resource and patch use. 2) biotic interactions: 3) microclimate modification 4) changes in vegetation structure. In relates nest site location in woodlands relative to the edge to the proximity of food resources. It is shown that all other things being equal birds which are wholly dependent on resources found within woodlands will tend to avid forest edges. Woodland species dependent upon resources found in adjacent habitats will tend to be found near to edges to enable their exploitation. 2) identifies competition predation and brood parasitism as factor which have the potential to influence bird habitat selection near edges. 3) identifies microclimate modification as a potential influence which may are directly on nesting success or indirectly through its effects on food supply: 4) relates the activities of birds such as nesting feeding or Research on edge effects of birds in woodland has provided few practical recommendations to conservation managers. Forest edge management needs to take into account the multiple cause and defects which influence habitat selection at the edge and to target species of conservation concern.

Integrated effects of urban morphology on birdsong loudness and visibility of green areas

“…Because of the effects of edges on bird habitats (e.g., feeding, foraging, and nest selection), as noted in several studies (Hansson, 1994;D McCollin, 1998;Huhta et al, 1999), and because deciduous trees are most widely planted in green areas and along the local streets in Assen (Gemeente Assen, 2006;Gemeente Assen, 2009), sources that are localised on the boundaries of green areas were considered along with uniformly distributed sources throughout the green areas. Therefore, as shown in Figure 2, four different types of sound source distributions were examined, including an idealised situation of full distribution of sound sources in rectangular arrays (RF), random distribution of 50% sound sources in rectangular arrays (RR), full distribution of sound sources along green area boundaries (BF), and a random distribution of 50% sound sources along green area boundaries (BR).…”

Effects of structural and functional habitat gaps on breeding woodland birds: working harder for less

“…For birds and other wildlife, small patches, whether rural or urban, may constitute sub-optimal habitat. For example, small patches may lack food resources and be more exposed to poor weather conditions and certain predators (Andrén 1992; Burke and Nol 1998;McCollin 1998). In urban parkland, structural patchiness can be exacerbated by functional patchiness due to high proportions of exotic plant species which may support relatively few invertebrates, reducing the foraging opportunities for birds (Mills et al 1989;Reichard et al 2001, Stauss et al 2005.…”

Little evidence of temporal changes in edge-use by woodland birds in southern England

“…Many species associated with the edges of woods in fragmented landscapes are not obligate edge species but are early successional species that often find their habitat requirements at the edges of woodland fragments (Fuller and Warren 1991, McCollin 1998, Imbeau et al 2003. The classification of species by habitat used here is based on the occurrence rates of species in edge habitats rather than their functional associations with edges, as this is more relevant to questions concerning changes in rates of edge-use due to changing ecological conditions.…”

“…Vegetation structure, microclimate, food availability and predation rates can differ from the woodland interior (Paton 1994, McCollin 1998. Bird species may have different responses to the characteristics of habitat present at the edges of patches, depending upon how these habitats meet their functional requirements (McCollin 1998, Flaspohler et al 2001. Edges are avoided by some species but are often prime habitat for others as they offer resources that may be scarce in the interior (Fuller & Warren 1991), although nest predation rates are often higher at edges (Paton 1994, Andrén 1995.…”

“…Vegetation structure, microclimate, food availability and predation rates can differ from the woodland interior (Paton 1994, McCollin 1998. Bird species may have different responses to the characteristics of habitat present at the edges of patches, depending upon how these habitats meet their functional requirements (McCollin 1998, Flaspohler et al 2001.…”