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Conclusions:Owls avoided agricultural lands (due to prey availability), used grass-forb areas for foraging, and avoided croplands and grazed pasture. 95% of all movements occurred within 600 meters of the nest burrows.Thresholds/Learnings:At a minimum, a 600m radius should be maintained around burrowing owl nests in order to ensure the survival of burrowing owls
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Conclusions: Although there was not a detectable decrease in bird communitiy species richness resulting from experimental forest fragmentation, community structure was altered, and maintaining connections between fragments significantly mitigated these effects. Thresholds/Learnings: Synopsis: This study examined the effects of forest fragmentation on the richness, diversity, turnover, and abundance of breeding bird communities in old boreal mixed-wood forest by creating experimental forest fragments of 1, 10, 40, and 100 ha. Connected fragments were linked by 100 m wide buffer strips. The study detected no significant change in species richness as a result of forest harvesting, except in the 1 ha connected fragments...
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Synopsis: To date, there is a lack of well-controlled field experiments that disentangle the effects of the intervening matrix from other landscape variables (e.g., patch geography or quality) that might influence animal dispersal among patches. We performed a field experiment to investigate how the movement of a delphacid planthopper (Prokelisia crocea) among discrete patches of prairie cordgrass (Spartina pectinata) is affected by the composition of the matrix (mudflat, native nonhost grasses, and the introduced grass smooth brome [Bromus inermis]). Within each matrix type, marked planthoppers were released onto experimental cordgrass patches that were made identical in size, isolation, and host plant quality....
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Conclusions: Results offer support for the use of land cover as an indicator of biotic integrity estimated by both vegetation and bird communities. Strong, significant predictions of IBI scores in plant and bird communities were achieved using land cover data from every spatial extent. Plant-based IBI scores were best predicted using data from 100 m buffers and bird-based IBI scores were best predicted using data extracted from 500 m buffers. Road density and measures of the proportion of disturbed land were consistent predictors of IBI score, suggesting their universal importance to plant and bird communities. Thresholds/Learnings: Road effects on bird communities were most pronounced at the 500m spatial extent....
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Conclusions: Edge structure affects movement patterns in chickadee flocks. Flocks tend to move parallel to forest edges. Thresholds/Learnings: Synopsis: During a two-year study of chickadee flocks in a fragmented agricultural landscape near Edmonton, Alberta, researchers tested the degree to which flocks responded to forest boundaries based on changes in vegetation, foraging sites, and edge structure near these boundaries. The results indicate that sharp forest boundaries (edges) acted strongly as movement corridors for birds, encouraging flocks to move parallel (within 75 m) to forest edges.
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Conclusions: Marten capture rates were negatively correlated with increasing proximity of open areas and increasing extent of high-contrast edges. Forested landscapes were unsuitable for martens when the average nearest-neighbor distance between open, non-forested patches was <100m. Thresholds/Learnings: Synopsis: This study aimed to determine whether American marten abundance changed with incremental increases in habitat fragmentation caused by the combined effects of natural openings and timber clearcuts. Researchers evaluated differences in marten capture rates in 18 study sites with different levels of fragmentation. Martens appeared to respond negatively to low levels of habitat fragmentation, even with remaining...
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Synopsis: This study examined the reluctance of different birds species to cross habitat gaps in a fragmented forest landscape. Researchers induced birds in the post-fledging period to cross gaps of varying widths and to choose between routes through woodland or across open areas by attracting them with recorded chickadee mobbing calls. Overall, birds were twice as likely to travel through 50 m of woodland than they were to travel through 50 m of open gap areas to reach the recording. When given a choice of traveling through woodland or across a gap, the majority of birds preferred woodland routes, even when they were three times longer than shortcuts in the open. Birds did not just use movement corridors, but strongly...
Conclusions:Bird and medium sized mammal population densities were affected by the arrangement and density of exurban housing developments, with both species groups avoiding developments up to 180 away. The composition of native wildlife is altered in the vicinity of exurban housing developments.Thresholds/Learnings:Avian densities were altered up to 180m away from homes on the perimeter of ex-urban developments.
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Conclusions: In response to logging, songbirds demonstrated “habitat compensation” by moving into different adjacent habitats across a fragmented landscape. Thresholds/Learnings: Synopsis: This study investigates the degree to which species respond differently to logging across different scales in Alberta’s boreal mixed-wood forests. Researchers tracked changes in the composition and abundance of songbirds at the patch-level and landscape level, finding significant variation between the two spatial scales. The results suggest that predictions of organism response based on the island biogeographic model are limited, and that—while responses varied across species—songbirds demonstrated “habitat compensation” by moving...
Conclusions:Unsuitable habitat surrounding a patch of suitable habitat creates islands of high species density from which successful dispersion becomes difficult. Therefore, habitat surrounding a patch, rather than the quality of the patch itself, may be a more important determining factor of species abundance.Thresholds/Learnings:
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Synopsis: The study examined the effects of road networks on suburbanizing ecosystems, using grassland bird distribution to explore the relative ecological importance of variables relative to linear disturbances and the effect of road traffic volumes. The study found that roads primarily affect ecological variables for 1) distance from road and 2) habitat patch size. The study also found that road traffic volumes are correlated to avian distribution, suggesting that traffic volumes have an ecological effect. The research suggests that traffic noise is the primary ecological effect of roads and that roads with higher traffic volumes extend the road effect zone outwards of 100 m and up to 1,200 m. Given the ecological...
    map background search result map search result map The influence of forest fragmentation and landscape pattern on American martens. Are boreal birds resilient to forest fragmentation? An experimental study of short-term community responses. Understanding avian responses to forest boundaries: a case study with chickadee winter flocks. Fragments are not islands: patch vs landscape perspectives on songbird presence and abundance in a harvested boreal forest. Gap crossing decisions by forest songbirds during the post-fledgling period. Road traffic and nearby grassland bird patterns in a suburbanizing landscape. The accuracy of land cover-based wetland assessments is influenced by landscape extent. Matrix composition affects the spatial ecology of a prairie planthopper. Understanding avian responses to forest boundaries: a case study with chickadee winter flocks. Are boreal birds resilient to forest fragmentation? An experimental study of short-term community responses. Fragments are not islands: patch vs landscape perspectives on songbird presence and abundance in a harvested boreal forest. Road traffic and nearby grassland bird patterns in a suburbanizing landscape. The accuracy of land cover-based wetland assessments is influenced by landscape extent. The influence of forest fragmentation and landscape pattern on American martens. Gap crossing decisions by forest songbirds during the post-fledgling period. Matrix composition affects the spatial ecology of a prairie planthopper.