scholarly journals How to Become a Generalist Species? Individual Niche Variation Across Habitat Transformation Gradients

2020 ◽  
Vol 8 ◽  
Author(s):  
Dan Liang ◽  
Shengnan Yang ◽  
Emilio Pagani-Núñez ◽  
Chao He ◽  
Yang Liu ◽  
...  
Keyword(s):  
Habitat Type ◽  
Bird Species ◽  
Niche Width ◽  
Natural Habitats ◽  
Generalist Species ◽  
Niche Expansion ◽  
Habitat Transformation ◽  
Niche Dynamics ◽  
Niche Variation ◽  
Niche Variation Hypothesis

Species in transformed habitats, frequently labeled as environmental generalists, tend to show broader niches than species in natural habitats. However, how population niche expansion translates into changes in the niches of individual organisms remains unclear, particularly in the context of habitat transformation. Niche expansion could be a product of individuals having broader niches, greater distances among individuals’ niches, or a combination of both processes. This would challenge the traditional conceptions on niche dynamics, which emphasize the role played by individual specialization (IS). Here, using stable isotopes, we computed total niche width (TNW), its within- and between-individual components (WIC and BIC), and IS (the ratio WIC/TNW), in 13 populations of 6 bird species and 8 populations of 3 frog species in natural and transformed habitats. We confirmed that species had broader niche width in transformed than in natural habitats, yet population niche expansion across habitats was mainly a product of increased distance between individuals. Within each habitat type, increases in TNW were linked to increases in WIC for all habitat types, while relationships between TNW and BIC were found in transformed but not in natural habitats. Hence, both increased individual niche width and increased distance among individuals were apparent within habitats, particularly in transformed ones, where increases in WIC dominated. Neither across or within habitats was niche expansion associated with increasing IS. Therefore, our results overturn traditional conceptions associated with the niche variation hypothesis and illustrate that niche expansion is not invariably associated with increased IS, because the distance between individual’s niches (BIC) can increase, as well as the breadth of those niches (WIC).

scholarly journals Habitat use by the critically endangered Blue Swallow in KwaZulu-Natal, South Africa

Bothalia ◽  
2018 ◽  
Vol 48 (1) ◽  
Author(s):  
James Wakelin ◽  
Carl G. Oellermann ◽  
Amy-Leigh Wilson ◽  
Colleen T. Downs ◽  
Trevor Hill
Keyword(s):  
Home Range ◽  
Agricultural Land ◽  
Bird Species ◽  
Past Research ◽  
Critically Endangered ◽  
Strong Impact ◽  
Local Conservation ◽  
Natural Habitats ◽  
Habitat Requirement ◽  
Habitat Transformation

Background: Habitat loss and fragmentation continue to threaten the survival of many species. One such species is the Blue Swallow Hirundo atrocaerulea, a critically endangered grassland specialist bird species endemic to sub-Saharan Africa.Objectives: Past research has shown a serious decline in range and abundance of this species, predominantly because of habitat transformation and fragmentation.Method: The influence of land cover on Blue Swallow habitat and foraging home range, in both natural and transformed habitats, was investigated by radio tracking adult birds.Results: Results showed that tracked birds spent over 80% of their forage time over grasslands and wetland habitats, and preferentially used these ecotones as forage zones. This is likely owing to an increase in insect mass and abundance in these habitats and ecotones. There was reduced selection and avoidance of transformed habitats such as agricultural land, and this is a concern as transformed land comprised 71% of the home range with only 29% of grassland and wetland mosaic remaining for the Blue Swallows to breed and forage in, highlighting the importance of ecotones as a key habitat requirement. The results indicate that management plans for the conservation of Blue Swallows must consider protecting and conserving natural habitats and maintaining mosaic of grassland and wetland components to maximise ecotones within conserved areas.Conclusion: To this end, the stewardship programme spearheaded by local conservation agencies, which aims to formally conserve privately owned patches of untransformed grassland and other natural habitats, may have a strong impact on the long-term persistence of Blue Swallow populations.

scholarly journals Range Shifts of Overwintering Birds Depend on Habitat Type, Snow Conditions and Habitat Specialization

2022 ◽  
Author(s):  
Laura Bosco ◽  
Yanjie Xu ◽  
Purabi Deshpande ◽  
Aleksi Lehikoinen
Keyword(s):  
Snow Cover ◽  
Habitat Type ◽  
Bird Species ◽  
Habitat Specialization ◽  
Range Shifts ◽  
Habitat Types ◽  
Climatic Niche ◽  
Generalist Species ◽  
Distribution Shifts ◽  
Snow Conditions

Abstract Climatic warming is forcing numerous species to shift their ranges poleward, which has been demonstrated for many taxa across the globe. Yet, the influence of habitat types on within- and among-species variations of distribution shifts has rarely been studied, especially so for the non-breeding season. Here, we investigated habitat specific shift distances of northern range margins and directions of the center of gravity based on a long-term dataset of overwintering birds in Finland. Specifically, we explored influences of habitat type, snow cover depths, species’ climatic niche and habitat specialization on range shifts from 1980’s to 2010’s in 81 bird species. Birds overwintering in farmlands shifted significantly more often northwards than birds of the same species in rural and forest habitats, while the northern range margin shift distances did not significantly differ among the habitat types. Snow cover was negatively associated with the eastward shift direction across all habitats, while we found habitat specific relations to snow cover with northward shift directions and northern range margins shift distances. Species with stronger habitat specializations shifted more strongly towards north as compared to generalist species, whereas the climatic niche of bird species only marginally correlated with range shifts, so that cold-dwelling species shifted longer distances and more clearly eastwards. Our study reveals habitat specific patterns linked to snow conditions for overwintering boreal birds and highlights importance of habitat availability and preference in climate driven range shifts.

scholarly journals Principles of niche expansion

2018 ◽  
Vol 285 (1893) ◽  
pp. 20182603 ◽  
Author(s):  
Henrik Sjödin ◽  
Jörgen Ripa ◽  
Per Lundberg
Keyword(s):  
General Theory ◽  
Evolutionary Model ◽  
Resource Acquisition ◽  
Short Term ◽  
Trade Off ◽  
Niche Expansion ◽  
Niche Variation ◽  
Wide Range ◽  
Niche Variation Hypothesis ◽  
Resource Diversity

Niche expansion is attained by adaptations in two generalized phenotypical traits—niche position and niche width. This gives room for a wide range of conceptual ways of niche filling. The niche variation hypothesis reduces the range by predicting that expansion occurs by increasing variation in niche position, which has been debated on empirical and theoretical grounds as also other options seem possible. Here, we propose a general theory of niche expansion. We review empirical data and show with an eco-evolutionary model how resource diversity and a trade-off in resource acquisition steer niche evolution consistent with observations. We show that the range can be reduced to a discrete set of two orthogonal ways of niche filling, through (1) strict phenotypical differentiation in niche position or (2) strict individual generalization. When individual generalization is costly, niche expansion undergoes a shift from (2) to (1) at a point where the resource diversity becomes sufficiently large. Otherwise, niche expansion always follows (2), consistent with earlier results. We show that this either–or response can operate at both evolutionary and short-term time scales. This reduces the principles of niche expansion under environmental change to a notion of orthogonality, dictated by resource diversity and a resource-acquisition trade-off.

Niche Expansion and the Niche Variation Hypothesis: Does the Degree of Individual Variation Increase in Depauperate Assemblages?

2008 ◽  
Vol 172 (6) ◽  
pp. 868-877 ◽  
Author(s):  
Gabriel C. Costa ◽  
Daniel O. Mesquita ◽  
Guarino R. Colli ◽  
Laurie J. Vitt
Keyword(s):  
Individual Variation ◽  
Niche Expansion ◽  
Niche Variation ◽  
Niche Variation Hypothesis

Trophic niche width increases with bill-size variation in a generalist passerine: a test of niche variation hypothesis

2013 ◽  
Vol 83 (2) ◽  
pp. 450-459 ◽  
Author(s):  
Yu-Cheng Hsu ◽  
Pei-Jen Shaner ◽  
Chun-I Chang ◽  
Linhua Ke ◽  
Shuh-Ji Kao
Keyword(s):  
Size Variation ◽  
Trophic Niche ◽  
Niche Width ◽  
Niche Variation ◽  
Niche Variation Hypothesis

Distribution and habitat preference of protected reindeer lichen species (Cladonia arbuscula, C. mitis and C. rangiferina) in the Balaton Uplands (Hungary)

2021 ◽  
Vol 53 (3) ◽  
pp. 271-282
Author(s):  
Mónika Sinigla ◽  
Erzsébet Szurdoki ◽  
László Lőkös ◽  
Dénes Bartha ◽  
István Galambos ◽  
...  
Keyword(s):  
Vascular Plants ◽  
Management Practices ◽  
Soil Depth ◽  
Habitat Preferences ◽  
Habitat Type ◽  
Canopy Cover ◽  
Lichen Species ◽  
Oak Forests ◽  
Natural Habitats ◽  
Cladonia Rangiferina

AbstractThe maintenance of protected lichen species and their biodiversity in general depends on good management practices based on their distribution and habitat preferences. To date, 10 of the 17 protected lichen species of Hungary have been recorded in the Bakony Mts including the Balaton Uplands region. Habitat preferences of three protected Cladonia species (C. arbuscula, C. mitis and C. rangiferina) growing on underlying rocks of red sandstone, basalt, Pannonian sandstone and gravel were investigated by detailed sampling. We recorded aspect, underlying rock type, soil depth, pH and CaCO3 content, habitat type (as defined by the General National Habitat Classification System Á-NÉR), all species of lichen, bryophyte and vascular plants as well as percentage cover of exposed rock, total bryophytes, lichens, vascular plants and canopy, degree of disturbance and animal impacts. Sporadic populations of these species mostly exist at the top of hills and mountains in open acidofrequent oak forests, but they may occur in other habitats, such as closed acidofrequent oak forests, slope steppes on stony soils, siliceous open rocky grasslands, open sand steppes, wet and mesic pioneer scrub and dry Calluna heaths. Cladonia rangiferina was found to grow beneath higher canopy cover than either C. arbuscula or C. mitis in the Balaton Uplands. Furthermore, there were significant differences in canopy cover between occupied and unoccupied quadrats in the case of all three species. Cladonia rangiferina is a good indicator species of natural habitats in Hungary due to its restricted distribution and low ecological tolerance. These results may lead to the adoption of effective conservation methods (e.g. game exclusion, artificial dispersal) in the future.

scholarly journals Conservation, Restoration, and Sustainable Use of Biodiversity Based on Habitat Quality Monitoring: A Case Study on Jeju Island, South Korea (1989–2019)

Land ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 774
Author(s):  
Hyun-Jung Hong ◽  
Choong-Ki Kim ◽  
Hyun-Woo Lee ◽  
Woo-Kyun Lee
Keyword(s):  
South Korea ◽  
Habitat Quality ◽  
Sustainable Use ◽  
Habitat Type ◽  
Biodiversity Loss ◽  
Well Being ◽  
Jeju Island ◽  
Natural Habitats ◽  
Invest Model ◽  
Aichi Biodiversity Targets

Biodiversity loss is progressing despite biodiversity being essential for human survival, prosperity, and well-being. Conservation, restoration, and sustainable use of the habitat, given that its change is the most prominent factor causing the deterioration of biodiversity, represents a highly effective way of securing biodiversity. Therefore, we assessed and monitored habitat quality as a proxy for biodiversity with habitat quantity in Jeju Island, South Korea. We used an InVEST model with data on the habitat type, suitability, sensitivity, accessibility, and threat factors. Natural habitats throughout Jeju had rapidly decreased in area by 24.9% from 1989 to 2019, and this change contributed to the degradation of habitat quality by 15.8%. We provided significant evidence on the critical degradation of habitat for a long period of over 30 years and highlighted the urgent need for policies and behaviors that enhance biodiversity. We proposed appropriate strategies to prompt people to conserve better, restore effectively, and use biodiversity sustainably. We expect that our findings will provide scientific and evidence-based guidance for policy-making on biodiversity enhancement and will further support achievement of the Sustainable Development Goals and Aichi Biodiversity Targets, in addition to compliance with the New Deal for Nature and People.

Bird community structure in natural and urbanized habitats along an altitudinal gradient in Pauri district (Garhwal Himalaya) of Uttarakhand state, India

Biologia ◽  
2012 ◽  
Vol 67 (4) ◽  
Author(s):  
Archana Naithani ◽  
Dinesh Bhatt
Keyword(s):  
Community Structure ◽  
Altitudinal Gradient ◽  
Diversity Index ◽  
Bird Species ◽  
Bird Community ◽  
High Elevation ◽  
Base Line ◽  
Natural Habitats ◽  
Forest Habitat ◽  
Rarefaction Analysis

AbstractIn the Indian subcontinent there is hardly any study that compares the bird community structure of urban/suburban areas with those of forest habitat. The present survey identified diverse assemblages of birds in the Pauri district at different elevations. A total of 125 bird species belonging to 40 families including two least count species (Lophura leucomelanos and Pucrasia marcolopha) were recorded during this survey in the forest and urbanized habitats of Pauri District (Garhwal Hiamalaya) of Uttarakhand state, India. The high elevation (Pauri 1600–2100 m a.s.l.), mid elevation (Srikot-Khanda 900–1300 m a.s.l.) and low elevation (Srinagar 500–900 m a.s.l.) contributed 88.8%, 63.2% and 58.4% of the total species respectively. Rarefaction analysis and Shannon diversity index showed that the high elevation forest habitat had highest bird species richness (BSR) and bird species diversity (BSD) followed by the mid and then the low elevation forests. BSR and BSD fluctuated across seasons at all elevations but not across habitat types. Present study provides a base line data about avian community composition in urbanized and natural habitats along altitudinal gradient in the study area. This information may be useful to the conservation biologists for the better management and conservation of the avifauna in the Western Himalaya, a part of one of the hot biodiversity spots of the world.

scholarly journals An assessment of the distribution, population size and conservation status of the Santa Marta Foliage-gleaner Automolus rufipectus: a Sierra Nevada de Santa Marta endemic

2015 ◽  
Vol 25 (4) ◽  
pp. 451-465 ◽  
Author(s):  
ESTEBAN BOTERO-DELGADILLO ◽  
NICHOLAS BAYLY ◽  
CAMILA GÓMEZ ◽  
PAULO C. PULGARÍN-R. ◽  
CARLOS ANDRÉS PÁEZ
Keyword(s):  
Population Size ◽  
Sierra Nevada ◽  
Forest Cover ◽  
Conservation Status ◽  
Bird Species ◽  
Environmental Niche ◽  
Coffee Plantations ◽  
Habitat Transformation ◽  
Elevation Range ◽  
Area Of Occupancy

SummaryThe Santa Marta Foliage-gleaner Automolus rufipectus is one of 19 endemic bird species found in the Sierra Nevada de Santa Marta (SNSM) in northern Colombia but until recently it was considered a sub-species of the Ruddy Foliage-gleaner Automolus rubiginosus. Consequently, published information on its distribution and ecology is lacking, and while it is classified as near- threatened, this designation was based on limited quantitative data. To improve our knowledge of the Santa Marta Foliage-gleaner’s geographical distribution, elevation range, population density, habitat use and conservation status, we analysed both historical and recent site locality records and carried out variable distance transects within forested habitats and shade coffee plantations. We modelled the environmental niche of the species and subsequently estimated its extent of occurrence and area of occupancy, as well as population size. Our results consistently showed that the distribution of the Santa Marta Foliage-gleaner is more restricted than previously considered, both geographically and by elevation (we redefine elevation range as 600–1,875 m). This suggests that the species is more at risk of habitat transformation and combined with our estimates of population size (< 10,000 individuals), it is likely that the species will be uplisted to a higher threat category. More positively, and contrary to published accounts, we found that approximately 40% of the species’ range lies within protected areas. Nevertheless, we recommend the implementation of strategies to maintain forest cover on the western flank of the SNSM and further research to better define the species’ habitat needs and population dynamics.

Habitats for large branchiopods in the agricultural landscape of the Mureş Floodplain Natural Park: how long will they last?

Crustaceana ◽  
2021 ◽  
Vol 94 (7) ◽  
pp. 775-795
Author(s):  
Alfred-Ştefan Cicort-Lucaciu ◽  
Gabriel-Lucian Herlo
Keyword(s):  
Agricultural Landscape ◽  
Habitat Type ◽  
Natural Habitats ◽  
Natural Landscape ◽  
Large Branchiopods ◽  
Natural Park ◽  
Black Spots ◽  
Chirocephalus Diaphanus ◽  
Floodplain Area ◽  
Large Branchiopod

Abstract In the last two hundred years, the Mureş River Floodplain has suffered major changes caused by dike constructions, meander cutting, and by the transformation of the natural landscape into an agricultural one. In this environmental context, we wanted to find out the degree to which large branchiopod species still survive in the Mureş Floodplain area. Every stagnant aquatic habitat encountered in 2019 in the Mureş Floodplain Natural Park was sampled. For the habitats where more species co-occur, urgent preservation actions must be taken. Most of the species prefer open habitats and have survived in the wheel ruts on agricultural lands. In the absence of natural habitats, the importance of this habitat type becomes a major one. The forest advantages species related to shady habitats, such as Chirocephalus diaphanus. We have found several individuals in the park that showed black spots on their bodies, characteristic of the black disease of fairy shrimp. The presence of the disease only in the populations from wheel ruts suggests that vehicles which make these ruts, could be the carriers of the disease.

Sign in / Sign up

Export Citation Format

Share Document