Consequences of forest fragmentation on territory quality of male Ovenbirds breeding in western boreal forests

2002 ◽  
Vol 80 (11) ◽  
pp. 1841-1848 ◽  
Author(s):  
Daniel F Mazerolle ◽  
Keith A Hobson
Keyword(s):  
Forest Fragmentation ◽  
Vegetation Structure ◽  
Boreal Forests ◽  
Prey Availability ◽  
Forest Fragments ◽  
Territory Quality ◽  
Seiurus Aurocapillus ◽  
Prey Biomass ◽  
Prey Composition ◽  
Territory Selection

We evaluated the effects of forest fragmentation caused by agriculture on arthropod prey biomass and vegetation structure found in territories of male Ovenbirds (Seiurus aurocapillus) breeding in the southern boreal mixed woods of Saskatchewan, Canada. The objective of this study was to determine if previously documented differences in pairing success of male Ovenbirds in contiguous forests and forest fragments in our study area were associated with differences in arthropod prey biomass and vegetation structure between contiguous and fragmented forests. A secondary objective was to examine the correspondence between vegetation and arthropods to evaluate whether vegetation cues could be useful for birds attempting to predict future arthropod biomass during territory selection. Our results indicate that both vegetation structure and arthropod prey composition in Ovenbird territories differed between fragmented and contiguous forests, whereas total arthropod biomass did not. Furthermore, the correspondence of vegetation with arthropod prey composition and total prey biomass was weak, a result that questions the use of vegetation structure by male Ovenbirds for predicting future prey availability during territory selection. Overall, the current extent of forest fragmentation in our study area is not likely reducing pairing success of territorial male Ovenbirds by lowering the biomass of arthropod prey. However, landscape differences in vegetation structure could influence pairing success of male Ovenbirds in forest fragments by reducing suitable microhabitats for nesting or by increasing habitat suitability for nest predators and Brown-headed Cowbird (Molothrus ater) parasites.

Irruptive White Ibis breeding is associated with use of freshwater crayfish in the coastal Everglades

The Condor ◽  
2021 ◽  
Vol 123 (1) ◽  
Author(s):  
Tasso C Cocoves ◽  
Mark I Cook ◽  
Jeffrey L Kline ◽  
Lori Oberhofer ◽  
Nathan J Dorn
Keyword(s):  
Prey Availability ◽  
Freshwater Crayfish ◽  
Seasonal Wetlands ◽  
Important Prey ◽  
Procambarus Alleni ◽  
Eudocimus Albus ◽  
Hydrologic Restoration ◽  
Prey Composition ◽  
White Ibis ◽  
Nesting Activity

Abstract As avian reproductive success is generally prey limited, identifying important prey types or sizes and understanding mechanisms governing prey availability are important objectives for avian conservation ecology. Irruptive White Ibis (Eudocimus albus) nesting at coastal colonies in the southern Everglades numbered over 100,000 nests in the 1930s. A century of drainage and altered hydrologic patterns reduced aquatic prey availability and eliminated large nesting events; nesting activity in recent decades has been typically less than 5% of historical peaks. Hydrologic restoration is expected to increase ibis nesting activity, but which prey types will support high nesting effort is less clear. In 2017 and 2018, we collected food boluses from White Ibis chicks at coastal colonies in Everglades National Park. We also monitored regional nesting activity from 1999 to 2018. In 2017, the region had 1,075 nests, typical of the past several decades; but in 2018, there were 30,420 nests, representing the highest recorded nesting activity in 87 yr. Prey composition varied between years; estuarine crabs dominated nestling boluses in 2017, while crayfish and fish were dominant prey in 2018. Crayfish, especially Procambarus alleni, were heavily exploited by ibis early in the 2018 breeding season, while fish were used more at the end. Crayfish abundances in wetlands near the colonies were higher prior to 2018, and more crayfish-producing short-hydroperiod wetlands remained available for ibis foraging in 2018. Our results support previous studies indicating that crayfish are important prey for breeding ibises and suggest that unprecedented, extensive flooding of seasonal wetlands promoted crayfish production and initiated the irruptive breeding in 2018. Our observations indicate that rehydration of the southern Everglades could restore ibis nesting activity at coastal colonies, but further investigations of hydrologic variation, crayfish production, and ibis foraging and nesting activity will be helpful to understand these dynamics and the importance of short-hydroperiod wetlands.

scholarly journals Forest fragmentation in the landscape in the Atlantic Forest Biome: A systematic review of the literature

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Stephany Diolino Cunha ◽  
Bruna Sampaio Crivilin ◽  
Matheus da Silva Araújo ◽  
Luís Antônio Coimbra Borges
Keyword(s):  
Systematic Review ◽  
Landscape Ecology ◽  
Forest Fragmentation ◽  
Atlantic Forest ◽  
Forest Fragments ◽  
Review Of The Literature ◽  
Search Terms ◽  
High Degree ◽  
Forest Biome ◽  
Degree Of Fragmentation

Forest fragmentation is defined as the process by which a continuous area of habitat is reduced in size and divided between spaces. Therefore, due to the increase in these areas, this study aimed to conduct a systematic review of the literature on forest fragments in the Atlantic Forest biome in order to verify their main characteristics and landscape ecology. Publications in search platforms referring to the period from 2000 to 2020 were analyzed such as: SciELO, Google academic and CAPES journals portal. The search terms entered were: “Studies of forest fragments in the Atlantic Forest biome” and “Landscape ecology in forest fragments”. A total of 15 articles were selected from among the works found, and 5 of these were chosen to be evaluated in the present study. Four of the five works were carried out in the state of Espírito Santo, close to basins and sub-basins, and only one work was carried out in a state park. Thus, the evaluated works with the theme, study of fragmentation and ecology of the landscape showed a high degree of fragmentation, meaning that they have fragments smaller than 5 hectares; in addition, all fragments have an irregular edge effect. Therefore, measures aimed at the conservation of biodiversity are needed in all places so that there is ecological restoration of the landscape and conservation of fauna and flora in the Atlantic Forest biome. 

scholarly journals Effect of Land Cover Change on Atlantic Forest Fragmentation in Rio Largo, Al, Brazil

2020 ◽  
pp. 102-114
Author(s):  
Lucas Galdino da Silva ◽  
Arthur Costa Falcão Tavares ◽  
Carlos Frederico Lins E. Silva Brandão ◽  
João Pedro dos Santos Verçosa ◽  
Raquel Elvira Cola ◽  
...  
Keyword(s):  
Land Cover ◽  
Land Cover Change ◽  
Forest Fragmentation ◽  
Atlantic Forest ◽  
Pearson Correlation ◽  
Aerial Images ◽  
Forest Fragments ◽  
Case Scenario ◽  
Worst Case ◽  
Digital Format

This study's objective was to analyze the effect of land cover change, between 1965 and 2018, using statistical metrics and geoprocessing tools. And consequently, to provide information of area (ha) and spatial fragmentation of the Atlantic Forest in the municipality of Rio Largo/AL, Brazil. The samples were collected and transferred by CECA, CADEH, and INCRA, between November 2019 and April 2020. The basic materials used in this work were multi-temporal aerial images in digital format, derived from the 1965 aerophotogrametric survey on the scale 1:25000, belonging to the collection of the Engineering and Agrarian Sciences Campus - UFAL, and images of Landsat satellites (5 and 8) processed and made available by the Mapbiomas Project. The statistic landscape metrics were calculated using Landscape ecology Statistics (LECOs), a QGIS plugin. The analysis of forest fragmentation areas over the 53 years showed a reduction between 32.17% (1965) and 12.04% (2018) concerning the total extension of the municipality. In 1965, the average area obtained from 49 fragments was 201.13 ha. The values show a higher distance of forest fragments between 1965 and 1989, and disappearance by 2018.The Pearson correlation coefficient for 1965 and 2018 presented the value of r = -0.525, indicating a moderate and negative correlation between the mean values of areas (ha) of forest fragments and the number of forest fragments. The worst-case scenario for the maintenance of native forests occurred in 1989, where the reduction of continuous forest areas had 10.87 ha for forest area average, being spaced in 327 fragments. In the period 1986 and 1996, there was a decrease in fragmentation, reaching 200 fragments. In 1996 and 1997, there was an imbalance in forest maintenance, again increasing the number of fragments to 250 areas, and being explained by the loosening of surveillance in previous years, followed by deforestation.

scholarly journals Vegetation structure and decreased moth abundance limit the recolonisation of restored habitat by the European Nightjar

2018 ◽  
Vol 3 ◽  
pp. 25-39 ◽  
Author(s):  
Nathalie Winiger ◽  
Pius Korner ◽  
Raphaël Arlettaz ◽  
Alain Jacot
Keyword(s):  
Vegetation Structure ◽  
Habitat Restoration ◽  
Stand Structure ◽  
Prey Availability ◽  
Population Declines ◽  
Major Transitions ◽  
Slowing Down ◽  
Open Forest ◽  
Mineral Soils ◽  
Management Recommendations

Woodland ecosystems of Europe have undergone major transitions in the last centuries. Changes in land use and the loss of natural forest dynamics have often led to structurally poor, uniform and dense stands. Not surprisingly, open forest species relying on a heterogeneous stand structure have suffered dramatic population declines. The European Nightjar Caprimulguseuropaeus, a nocturnal insectivorous bird, has undergone such a decline in its main Swiss stronghold in Valais. Despite the species’ potential to colonize new sites and habitat restoration measures implemented since 2001, recolonisation of restored sites has not taken place, suggesting problems with the current habitat restoration strategy. In order to refine management recommendations, we compared habitat structure and moth abundance, a key Nightjar food source, at sites that are still occupied and at sites that had been abandoned but have recently been restored. Vegetation structure was more heterogeneous and moth abundance greater at occupied than at abandoned sites. More specifically, occupied sites harboured a greater coverage of bare ground, while abandoned sites exhibited a higher amount of regeneration and intermediate shrub layer. The occurrence of natural perches was also higher in occupied sites. Abandoned sites are thus characterised by lower prey abundance and denser vegetation cover, the combination of which is likely to lead to lower prey availability for hunting Nightjars. Restoration action would benefit from maintaining snags and dead branches and by targeting unproductive habitats characterised by mineral soils, thereby slowing down regeneration and shrub regrowth. For future successful management of Nightjar habitats, it seems thereby essential trying to find the balance between actions that allow opening the lower and mid-strata of the forest while sustaining high moth populations.

Effects of forest fragmentation on neotropical fauna: current research and data availability

1995 ◽  
Vol 3 (2) ◽  
pp. 191-211 ◽  
Author(s):  
Holly L. Offerman ◽  
Virginia H. Dale ◽  
Scott M. Pearson ◽  
Robert V. O'Neill ◽  
Richard O. Bierregaard Jr.
Keyword(s):  
Forest Fragmentation ◽  
Amazon Basin ◽  
Data Availability ◽  
Forest Fragments ◽  
Forest Patches ◽  
Neotropical Fauna ◽  
Using Data ◽  
Spatially Explicit Data ◽  
Biological Dynamics

Tropical deforestation often produces landscapes characterized by isolated patches of forest habitat surrounded by pasture, agriculture, or regrowth vegetation. Both the size and the distribution of these forest patches may influence the long-term persistence of faunal species. There is, therefore, a pressing need to understand faunal responses to patterns of forest fragmentation in tropical systems. The Biological Dynamics of Forest Fragments Project (BDFFP) provides a wealth of autecological information and spatially explicit data describing habitat use and movement of fauna between Amazonian forest fragments. Using data from the BDFFP and other studies in the Amazon Basin, this paper reviews the information available on tropical insects, frogs, birds, primates, and other mammals that can be used to identify and classify species most at risk for extirpation in fragmented forests.Key words: Amazonia, habitat fragmentation, rainforest, fauna, Biological Dynamics of Forest Fragmentation Project.

Nocturnally constrained foraging of a lotic minnow (Rhinichthys cataractae)

1989 ◽  
Vol 67 (8) ◽  
pp. 2008-2012 ◽  
Author(s):  
Joseph M. Culp
Keyword(s):  
Seasonal Changes ◽  
Prey Availability ◽  
Diel Periodicity ◽  
Foraging Activity ◽  
Light Levels ◽  
Prey Composition ◽  
Rhinichthys Cataractae ◽  
Nocturnal Foraging ◽  
Gut Fullness ◽  
Foraging Pattern

Diel periodicity in foraging activity of the longnose dace (Rhinichthys cataractae) was determined by measuring dace activity over the stream bed, gut fullness, and the digestive state of prey items. Although most species of minnows are either diurnally or crepuscularly active, dace began foraging within 1 h after sunset with light levels near 10 lx and ceased before sunrise throughout the ice-free period. During the day few prey were taken as the dace remained under the shelter of stones. This nocturnal foraging pattern did not appear to be affected by spawning or seasonal changes in prey composition. Nocturnal foraging in dace is not likely a response to prey availability, but may be a response to avoid diel periods when salmonid competitors or visual predators are active.

The diet of a forest-dependent frog species, Odorrana morafkai (Anura: Ranidae), in relation to habitat disturbance

2020 ◽  
Vol 41 (1) ◽  
pp. 29-41
Author(s):  
Duong Thi Thuy Le ◽  
Jodi J.L. Rowley ◽  
Dao Thi Anh Tran ◽  
Huy Duc Hoang
Keyword(s):  
Rainy Season ◽  
Prey Availability ◽  
Feeding Strategy ◽  
Habitat Disturbance ◽  
Habitat Modification ◽  
Prey Composition ◽  
Frog Species ◽  
Disturbed Habitats ◽  
The Impact ◽  
Prey Items

Abstract While deforestation is one of the greatest drivers of biodiversity loss, our understanding of the effects of habitat modification on species is limited. We investigated the diet of a forest-dwelling frog species, Morafka’s frog (Odorrana morafkai), in a highland forest in Vietnam in relation to habitat disturbance, sex and season. We surveyed the species at 45 sites in forest of varying disturbance and examined its diet using stomach flushing, estimating prey availability via trapping. We detected significantly fewer O. morafkai in highly disturbed habitats compared to moderately disturbed or non-disturbed habitats. We revealed that O. morafkai is a dietary generalist, identifying 28 prey types, primarily invertebrates. Prey composition, the number of prey items per stomach and prey volume per stomach did not vary between disturbance levels. Diet did not vary significantly between sexes, except that females had a higher prey volume. Prey composition in the species varied between seasons, with Coleoptera and Orthoptera dominating the diet in the rainy season and Lepidoptera in the dry season. The number of prey items per stomach and prey volume were significantly higher in the rainy season. There was a significant correlation between prey availability and diet composition. The low number of O. morafkai detected in highly disturbed habitats suggests that this habitat may not be optimal for the species, despite having a generalist feeding strategy and presumed high mobility. This study provides a window into the impact of an increasing threat, habitat disturbance, on forest-dependent amphibian species.

Distance effect from cloud forest fragments on plant community structure in abandoned pastures in Veracruz, Mexico

2006 ◽  
Vol 22 (4) ◽  
pp. 431-440 ◽  
Author(s):  
Miguel Angel Muñiz-Castro ◽  
Guadalupe Williams-Linera ◽  
José María Rey Benayas
Keyword(s):  
Species Richness ◽  
Vegetation Structure ◽  
Forest Restoration ◽  
Cloud Forest ◽  
Distance Effect ◽  
Basal Area ◽  
Woody Species ◽  
Primary Forest ◽  
Forest Fragments ◽  
Forest Region

Secondary succession was studied in a Mexican cloud forest region along a chronosequence of 15 abandoned pastures (0.25–80 y). Our objective was to determine the effects of distance from the forest border on successional vegetation structure and woody species richness along the chronosequence. Vegetation structure similar to that of mature forests recovered over 40–50 y, both close to (0–10 m) and away from (40–50 m) the border. Total woody species richness was similar for both distances but species composition differed significantly. When primary forest species were analysed separately, basal area, height, abundance and richness were all significantly higher close to the forest border. Primary species such as Quercus spp. (barochorous-synzoochorous) and Carpinus caroliniana (anemochorous) had lower basal area, density and height away from the border than close to it. Secondary species such as Lippia myriocephala (anemochorous) and Myrsine coriacea (endozoochorous) did not differ in their rate of colonization between distances. The limitation of seed dispersal and establishment for primary woody species away from forest borders suggests that propagules need to be introduced to accelerate forest restoration.

Sign in / Sign up

Export Citation Format

Share Document