scholarly journals Evidence for Edge Effects on Multiple Levels in Tallgrass Prairie

The Condor ◽  
2000 ◽  
Vol 102 (2) ◽  
pp. 256-266 ◽  
Author(s):  
Maiken Winter ◽  
Douglas H. Johnson ◽  
John Faaborg
Keyword(s):  
Tallgrass Prairie ◽  
Edge Effects ◽  
Fragment Size ◽  
Nest Survival ◽  
Forest Edge ◽  
Nesting Success ◽  
Forest Edges ◽  
Artificial Nests ◽  
Spiza Americana ◽  
Ammodramus Henslowii

Abstract We tested how edges affect nest survival and predator distribution in a native tallgrass prairie system in southwestern Missouri using artificial nests, natural nests of Dickcissels (Spiza americana) and Henslow's Sparrows (Ammodramus henslowii), and mammal track stations. Survival of artificial nests was lower within 30 m of forest edge. Nesting success of Dickcissels and Henslow's Sparrows was lower within 50 m to a shrubby edge than at greater distances, whereas fates of nests were not related to distances to roads, agricultural fields, or forests. Evidence from clay eggs placed in artificial nests indicated that mid-sized carnivores were the major predators within 30 m of forest edges. Furthermore, mid-sized carnivores visited track stations most frequently within 50 m of forest edges. Because proximity of woody habitat explained more variation in nest survival and mammal activity than did fragment size, it appears that edge effects were more pronounced than area effects. Edge effects appeared to be caused mainly by greater exposure of nests to mid-sized carnivores. We argue that, based on edge avoidance behavior, “grassland-interior” species such as the Henslow's Sparrow respond to edge effects mainly by a decrease in density, whereas habitat generalists such as the Dickcissel are affected mainly by a decrease in nesting success.

Predation rates of artificial nests in the edge and interior of a southern Victorian forest

2002 ◽  
Vol 29 (4) ◽  
pp. 341 ◽  
Author(s):  
Lainie Berry
Keyword(s):  
Small Mammals ◽  
Nest Predation ◽  
Forest Edge ◽  
Forest Edges ◽  
Artificial Nests ◽  
Avian Predators ◽  
Forest Interior ◽  
Grey Shrike ◽  
Predation Rates

Predation rates of nests at human-induced habitat edges may be greater than in forest interior due to differences in predator assemblages and predator activity. I compared the predation rates on 192 artificial nests containing plasticine eggs placed in forest edge and interior sites at Bunyip State Park, Victoria. The nest-predation rates at the forest edge sites were significantly greater (mean = 52–58%) than that at the forest interior sites (mean = 30–39%). The relative rates of predation by birds compared with mammals were significantly greater at forest edge sites (mean = 78–94%) than at forest interior sites (mean = 36–67%). Higher rates of nest predation at forest edges appeared to be due to greater densities of avian predators such as the grey shrike-thrush (Colluricincla harmonica), and/or lower abundances of small mammals. However, biases towards certain predator types may mask real, or create false, patterns in predation rates of artificial nests. A better understanding of how predators respond to artificial nests compared with natural nests is required. Until then, results of predation studies that use artificial nests should be interpreted with caution.

scholarly journals A Nest Predator's View of a Managed Forest: Gray Jay (Perisoreus Canadensis) Movement Patterns in Response to Forest Edges

The Auk ◽  
2004 ◽  
Vol 121 (1) ◽  
pp. 162-169 ◽  
Author(s):  
Jacques Ibarzabal ◽  
André Desrochers
Keyword(s):  
Coniferous Forest ◽  
Movement Patterns ◽  
Forest Edge ◽  
Early Summer ◽  
Forest Edges ◽  
Artificial Nests ◽  
Gray Jays ◽  
Perisoreus Canadensis ◽  
Mature Stands ◽  
Nest Predators

Abstract High nest-predation risk is often associated with forest edges. Most nest predators in boreal coniferous forests of North America are forest specialists living in mature stands. Nest predators have been studied mainly through use of artificial nests; knowledge of their behavior remains limited. We used radiotelemetry to examine movement patterns, relative to forest edge, of a forest nest predator, the Gray Jay (Perisoreus canadensis), in boreal coniferous forest. Each of 11 family groups of Gray Jays monitored in early summer exhibited a marked association with forest edges. Jays were found within 30 m of the forest edges more often than expected from random use of mature forest. Furthermore, jays traveled more slowly near forest edges than in the forest interior. Because forest edges apparently represent prime foraging habitat for Gray Jays, narrow forest strips left by logging could act as ecological traps for mature-stand songbirds before stands regenerate in adjacent clearcuts.

scholarly journals Life on the edge: behavioural and physiological responses of Verreaux's sifakas (<i>Propithecus verreauxi</i>) to forest edges

2021 ◽  
Vol 8 (1) ◽  
pp. 1-13
Author(s):  
Klara Dinter ◽  
Michael Heistermann ◽  
Peter M. Kappeler ◽  
Claudia Fichtel
Keyword(s):  
Edge Effects ◽  
Group Living ◽  
Forest Edge ◽  
Limiting Factor ◽  
Forest Edges ◽  
Activity Budgets ◽  
Propithecus Verreauxi ◽  
Edge Habitat ◽  
Forest Interior ◽  
Edge Site

Abstract. Forest edges change micro-environmental conditions, thereby affecting the ecology of many forest-dwelling species. Understanding such edge effects is particularly important for Malagasy primates because many of them live in highly fragmented forests today. The aim of our study was to assess the influence of forest edge effects on activity budgets, feeding ecology, and stress hormone output (measured as faecal glucocorticoid metabolite – fGCM – levels) in wild Verreaux's sifakas (Propithecus verreauxi), a group living, arboreal lemur. We observed five habituated groups: three living in the forest interior and two at an established forest edge. There was no difference in average daily temperatures between edge and interior habitats; however, within the edge site, the average daily temperature incrementally increased over 450 m from the forest edge towards the interior forest of the edge habitat, and the population density was lower at the edge site. Activity budgets differed between groups living in the two microhabitats, with individuals living near the edge spending more time travelling and less time feeding. Groups living near the edge also tended to have smaller home ranges and core areas than groups in the forest interior. In addition, edge groups had elevated average fGCM concentrations, and birth rates were lower for females living in the edge habitat. Combined with lower levels of fruit consumption at the edge, these results suggest that nutritional stress might be a limiting factor for Verreaux's sifakas when living near a forest edge. Hence, Verreaux's sifakas appear to be sensitive to microhabitat characteristics linked to forest edges; a result with implications for the conservation of this critically endangered lemurid species.

scholarly journals The effects of forest edge and nest height on nest predation in a U.K. deciduous forest fragment

2020 ◽  
Author(s):  
Noah Atkin ◽  
Cris Banks-Leite
Keyword(s):  
Edge Effect ◽  
Nest Predation ◽  
Deciduous Forest ◽  
Forest Edge ◽  
Forest Edges ◽  
Forest Fragment ◽  
Artificial Nests ◽  
Conservation Implications ◽  
Mixed Deciduous Forest ◽  
Nest Height

It has been previously hypothesised that nest predation is higher at forest edges. This has important conservation implications for the increasingly fragmented U.K. climax community. I aimed to test the generality of this edge effect in a mixed deciduous forest fragment which borders open grassland. Artificial nests containing a combination of quail and plasticine eggs were used, at ground and arboreal levels. I found an overall edge effect on nest predation rates, however this effect was not specifically seen in ground nests. Ground nests experienced significantly higher levels of predation than arboreal nests. I suggest this edge effect is due in part to the steep productivity gradient over the ecotone.

scholarly journals Nesting Success and Nest Predators in Forest Fragments: A Study Using Real and Artificial Nests

The Auk ◽  
2000 ◽  
Vol 117 (2) ◽  
pp. 445-454 ◽  
Author(s):  
Liana Zanette ◽  
Bert Jenkins
Keyword(s):  
Nest Predation ◽  
Agricultural Land ◽  
Fragment Size ◽  
Nesting Success ◽  
Forest Fragments ◽  
Artificial Nests ◽  
Area Sensitivity ◽  
Avian Nest ◽  
Nest Predator ◽  
Nest Predators

Abstract Area sensitivity in songbirds is commonly attributed to increased nest predation in forest fragments. In 1995 and 1996, we tested whether the nest predators and nesting success of an area-sensitive forest bird, the Eastern Yellow Robin (Eopsaltria australis), varied with fragment size, and we also conducted an artificial nest experiment. The study occurred in two small (55 ha) and two large (>400 ha) forest fragments in a matrix of agricultural land in New South Wales, Australia. Predation accounted for 95% of all failures of 282 robin nests, and the survival of robin nests was negatively correlated with how frequently we observed avian nest predators near nests (i.e. nest-predator activity). Of 461 artificial nests, 84% were depredated, nearly all (99%) by birds. Thus, birds were important predators of nests. The abundance, species richness, and activity of avian nest predators were not related to fragment size. Survival of robin nests averaged 19%; nests in small fragments had a 22% chance of producing at least one fledgling compared with 15% in large fragments, but the difference was not significant. Survival of artificial nests averaged 12% in both small and large fragments. Nest-predator activity accounted for the most variation (68%) in the fate of robin nests, followed by the cumulative density of open-cup nesters (16%). The placement of robin nests had no influence on nest fate. We conclude that nest predation was not area dependent and propose food supply as an alternative hypothesis to explain area sensitivity. We suggest that, rather than being related to fragment size, nest predation increases with decreasing forest cover in a landscape. Increased nest predation in fragmented compared with contiguous landscapes may lower the population viability of songbirds in a region, and hence regional numbers. Therefore, the spatial scale at which fragmentation influences nest predation and songbird populations must be considered carefully.

Do yellow-faced honeyeater (Lichenostomus chrysops) nests experience higher predation at forest edges?

2003 ◽  
Vol 30 (2) ◽  
pp. 119 ◽  
Author(s):  
Rebecca L. Boulton ◽  
Michael F. Clarke
Keyword(s):  
Bird Species ◽  
Exposure Period ◽  
Forest Edge ◽  
Ecological Trap ◽  
Forest Edges ◽  
Artificial Nests ◽  
Fragmented Habitat ◽  
Avian Predators ◽  
Negative Edge ◽  
Nestling Period

We tested the hypothesis that predation rates increase near habitat edges and can cause low reproductive success in forest bird species living in a fragmented habitat. We constructed artificial yellow-faced honeyeater (Lichenostomus chrysops) nests and placed them 5 m, 20 m, 50 m and 200 m from the forest edge. We also monitored natural yellow-faced honeyeater nests at varying distances from the forest edge. Artificial nests experienced 43% predation over the 14-day exposure period, while natural yellow-faced honeyeater nests experienced 28% during the incubation period and 47% during the nestling period. No negative edge effect was detected for artificial or natural nests. In fact, natural nests experienced higher nest success closer to the forest edge. There was no increase in the number of avian predators recorded at the forest edge, even though birds were identified as the main predators at artificial nests (49%). The lack of support for both the 'ecological trap' and 'predator influx' hypotheses contributes to a growing body of evidence that suggests that not all species surviving in highly fragmented environments are negatively affected by edge effects.

scholarly journals Urbanization Impacts on Mammals across Urban-Forest Edges and a Predictive Model of Edge Effects

PLoS ONE ◽  
2014 ◽  
Vol 9 (5) ◽  
pp. e97036 ◽  
Author(s):  
Nélida R. Villaseñor ◽  
Don A. Driscoll ◽  
Martín A. H. Escobar ◽  
Philip Gibbons ◽  
David B. Lindenmayer
Keyword(s):  
Predictive Model ◽  
Edge Effects ◽  
Urban Forest ◽  
Forest Edges

scholarly journals Studies of Ant-Following Birds North of the Eastern Amazon

1972 ◽  
Vol 2 (2) ◽  
pp. 127-151 ◽  
Author(s):  
Yoshika Oniki ◽  
Edwin O. Willis
Keyword(s):  
Forest Edge ◽  
Forest Edges ◽  
Army Ants ◽  
Forest Interior ◽  
Second Growth

Abstract Birds that prey on arthropods flushed by army ants north of the eastern Amazon were studied at Serra do Navio and Reserva Ducke (Brazil) and at Nappi Creek and Bartica (Guyana). Regular ant-followers are two medium-sized antbirds (Percnostola rufifrons and Gymnopithys rufigula) and two smaller ones (Pithys albifrons and Hylophylax poecilonota), plus five woodcreepers of differing sizes (from very large Hylexetastes perrotti through Dendrocolaptes picumnus, D. certhia, and Dendrocincla merula to medium-sized Dendrocincla fuliginosa). Four other regular ant-followers occur in the region but were not found at the study areas. Forty-five species of casual or nonprofessional ant-followers, including 16 antbirds, 5 woodcreepers, and 5 manakins, also were recorded. Percnostola rufifrons tends to be at the forest edge or in second growth. Pithys albifrons works around Gymnopithys rufigula, Hylophylax poecilonota peripheral to both, in the forest interior. The large Dendrocolaptes picumnus and medium-large Dendrocincla merula often capture prey near the ground, like antbirds. Unlike antbirds, which use vertical or horizontal slender perches, the woodcreepers use thick vertical perches. Dendrocolaptes certhia and Dendrocincla fuliginosa also tend to capture prey high over the ground-foraging antbirds. The woodcreepers tend to forage lower at midday. Hylexetastes perrotti is rare, and overlaps strongly with D. picumnus. There is fairly large overlap among the 9 professional ant-followers, and large ones chase away smaller ones. Nonprofessional birds tend to forage briefly or peripherally when or slightly after the professional species are active. They also forage above the antbirds and below or above the woodcreepers, and concentrate at forest edges or in second growth. The guild of ant-following birds in this region differs fairly widely from guilds in Panamá and at Belém, Brazil; the absence of large antbirds and the predominance of large woodcreepers north of the Amazon are the major differences.

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