scholarly journals Avian community structure and habitat use ofPolylepisforests along an elevation gradient

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3220 ◽  
Author(s):  
C. Steven Sevillano-Ríos ◽  
Amanda D. Rodewald
Keyword(s):  
Elevation Gradient ◽  
Elevational Gradient ◽  
Avian Community ◽  
Forest Patches ◽  
The Andes ◽  
High Conservation ◽  
Conservation Concern ◽  
High Elevations ◽  
Avian Community Structure ◽  
Landscape Attributes

BackgroundAs one of the highest forest ecosystems in the world,Polylepisforests are recognized both as center of endemism and diversity along the Andes and as an ecosystem under serious threat from habitat loss, fragmentation, and climate change due to human activities. Effective conservation efforts are limited, in part, by our poor understanding of the ecology and habitat needs of the ecosystem’s flora and fauna.MethodsIn 2014–2015, we studied bird communities and 19 associated local and landscape attributes within five forested glacial valleys within the Cordillera Blanca and Huascaran National Park, Peru. We surveyed birds during the dry (May–August) and wet (January–April) seasons at 130 points distributed along an elevational gradient (3,300–4,700 m) and analyzed our data using Canonical Correspondence Analysis (CCA).ResultsWe associated a total of 50 species of birds, including 13 species of high conservation concern, with four basic habitat types: (1)Polylepis sericeaforests at low elevations, (2)P. weberbaueriforests at high elevations, (3) Puna grassland and (4) shrublands. Four species of conservation priority (e.g., Microspingus alticola) were strongly associated with large forest patches (∼10-ha) ofP. sericeaat lower elevations (<3,800 m), whereas another four (e.g., Anairetes alpinus) were associated with less disturbed forests ofP. weberbaueriat higher elevations (>4,200 m).DiscussionResults suggest two key strategies form the cornerstones of conservation efforts: (a) protect large remnant (>10-ha)P. sericeaforests at lower elevations and (b) maintain all relicts ofP. weberbaueri, irrespective of size, at high elevations (>4,200 m).

scholarly journals Avian community structure and habitat use of Polylepis forests along an elevation gradient

2016 ◽  
Author(s):  
C Steven Sevillano-Rios ◽  
Amanda D. Rodewald
Keyword(s):  
Elevation Gradient ◽  
Elevational Gradient ◽  
High Elevation ◽  
Bird Diversity ◽  
Avian Community ◽  
Forest Patches ◽  
The Andes ◽  
High Conservation ◽  
Conservation Concern ◽  
High Elevations

Background. As one of the highest and most unique systems in the world, Polylepis forests are recognized both as center of endemism and diversity along the Andes and as a system under serious threat from human activities, fragmentation, and climate change. Effective conservation efforts are limited, in part, by our poor understanding of the habitat needs of the system’s flora and fauna. Methods. In 2014-2015, we studied bird communities and 19 associated local and landscape attributes within five forested glacial valleys within the Cordillera Blanca and Huascaran National Park, Peru. Birds were surveyed in dry (May-August) and wet (January-April) seasons at 130 points distributed along an elevational gradient (3,300-4,700 masl) and analyzed using Canonical Correspondence Analysis (CCA). Results. A total of 50 species of birds, including 13 species of high conservation concern, were associated with four basic habitat types: (1) Polylepis sericea forests at low elevations, (2) P. weberbaueri forests at high elevations, (3) Puna grassland and (4) shrublands. Four species of conservation priority (e.g., Poospiza alticola) were strongly associated with large forest patches (~10-ha) dominated by P. sericea at lower elevations (<3,800 masl), whereas another four (e.g., Anairetes alpinus) were associated with less disturbed forests of P. weberbaueri at upper elevations (>4,200 masl). Discussion. Results suggest that, in addition to conserving large (>10-ha) P. sericea forests at lower elevations as the cornerstone for maintaining bird diversity, any high elevation (>4,200 masl) relicts of P. weberbaueri, irrespective of size, should be prioritized for conservation.

scholarly journals Avian community structure and habitat use of Polylepis forests along an elevation gradient

2016 ◽  
Author(s):  
C Steven Sevillano-Rios ◽  
Amanda D. Rodewald
Keyword(s):  
Elevation Gradient ◽  
Elevational Gradient ◽  
High Elevation ◽  
Bird Diversity ◽  
Avian Community ◽  
Forest Patches ◽  
The Andes ◽  
High Conservation ◽  
Conservation Concern ◽  
High Elevations

Background. As one of the highest and most unique systems in the world, Polylepis forests are recognized both as center of endemism and diversity along the Andes and as a system under serious threat from human activities, fragmentation, and climate change. Effective conservation efforts are limited, in part, by our poor understanding of the habitat needs of the system’s flora and fauna. Methods. In 2014-2015, we studied bird communities and 19 associated local and landscape attributes within five forested glacial valleys within the Cordillera Blanca and Huascaran National Park, Peru. Birds were surveyed in dry (May-August) and wet (January-April) seasons at 130 points distributed along an elevational gradient (3,300-4,700 masl) and analyzed using Canonical Correspondence Analysis (CCA). Results. A total of 50 species of birds, including 13 species of high conservation concern, were associated with four basic habitat types: (1) Polylepis sericea forests at low elevations, (2) P. weberbaueri forests at high elevations, (3) Puna grassland and (4) shrublands. Four species of conservation priority (e.g., Poospiza alticola) were strongly associated with large forest patches (~10-ha) dominated by P. sericea at lower elevations (<3,800 masl), whereas another four (e.g., Anairetes alpinus) were associated with less disturbed forests of P. weberbaueri at upper elevations (>4,200 masl). Discussion. Results suggest that, in addition to conserving large (>10-ha) P. sericea forests at lower elevations as the cornerstone for maintaining bird diversity, any high elevation (>4,200 masl) relicts of P. weberbaueri, irrespective of size, should be prioritized for conservation.

scholarly journals Aposematic Coloration of Moths Decreases Strongly along an Elevational Gradient in the Andes

Insects ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 903
Author(s):  
Konrad Fiedler ◽  
Gunnar Brehm
Keyword(s):  
Light Trap ◽  
Elevational Gradient ◽  
Montane Forest ◽  
Taxonomic Composition ◽  
Tropical Andes ◽  
Tropical Mountains ◽  
Aposematic Coloration ◽  
The Andes ◽  
High Elevations ◽  
Trap Catches

On tropical mountains, predation pressure decreases with elevation. Accordingly, one expects an elevational decay in the prevalence of costly defensive traits such as aposematic coloration. Using light-trap catches of Arctiinae moths (353 species, 4466 individuals), assembled along a forested gradient in the megadiverse tropical Andes of southern Ecuador, we show that the incidence of aposematic coloration decreases strongly between 1040 and 2670 m asl. While over 60% of Arctiinae moths were warningly colored at lowest sites, this fraction decreased to less than 20% in montane forest, yet increased slightly again at the highest sites in the very open Purdiaea nutans forest. In parallel, the incidence of hymenopteran mimics and of species that mimic chemically defended beetles decreased with elevation. Hymenopteran mimics accounted for less than 5% of Arctiinae moths at sites above 2100 m, and beetle mimics were essentially lacking at high elevations. These patterns coincide with a change in gross taxonomic composition of Arctiinae ensembles and with an increase in average body size towards higher elevations. Representatives of Euchromiina and Ctenuchina became scarce with altitude, whereas the prevalence of Lithosiinae increased. Our findings suggest that the variable selective pressures along the elevational gradient favor warning coloration primarily at lower sites, whereas cryptic appearance of adult moths dominates in the tropical upper montane forest.

Functional evenness of bird communities varies along the elevational gradient in Europe: Conservation implications

2019 ◽  
Author(s):  
Federico Morelli ◽  
Yanina
Keyword(s):  
Species Richness ◽  
Elevation Gradient ◽  
Bird Species ◽  
Elevational Gradient ◽  
Negative Association ◽  
Bird Communities ◽  
Breeding Bird ◽  
Bird Species Richness ◽  
Large Spatial Scale ◽  
Functional Evenness

ContextThe negative association between elevation and species richness is a well-recognized pattern in macro-ecology. ObjectivesThe aim of this study was to investigate changes in functional evenness of breeding bird communities along an elevation gradient in Europe. MethodsUsing the bird data from the EBCC Atlas of European Breeding Birds we estimated an index of functional evenness which can be assumed as a measure of the potential resilience of communities.ResultsOur findings confirm the existence of a negative association between elevation and bird species richness in all European eco regions. However, we also explored a novel aspect of this relationship, important for conservation: Our findings provide evidence at large spatial scale of a negative association between the functional evenness (potential community resilience) and elevation, independent of the eco region. We also found that the Natura2000 protected areas covers the territory most in need of protection, those characterized by bird communities with low potential resilience, in hilly and mountainous areas.ConclusionsThese results draw attention to European areas occupied by bird communities characterized by a potential lower capacity to respond to strong ecological changes, and, therefore, potentially more exposed to risks for conservation.

scholarly journals Ecological drivers of avian community assembly along a tropical elevation gradient

Ecography ◽  
2020 ◽  
Author(s):  
Flavia A. Montaño‐Centellas ◽  
Bette A. Loiselle ◽  
Morgan W. Tingley
Keyword(s):  
Community Assembly ◽  
Elevation Gradient ◽  
Avian Community

scholarly journals New glacier evidence for ice-free summits during the life of the Tyrolean Iceman

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Pascal Bohleber ◽  
Margit Schwikowski ◽  
Martin Stocker-Waldhuber ◽  
Ling Fang ◽  
Andrea Fischer
Keyword(s):  
Elevation Gradient ◽  
Ice Age ◽  
Detailed Knowledge ◽  
New Approach ◽  
Radiocarbon Age ◽  
Alpine Glaciers ◽  
The Alps ◽  
Tyrolean Iceman ◽  
High Elevations ◽  
Age Constraints

AbstractDetailed knowledge of Holocene climate and glaciers dynamics is essential for sustainable development in warming mountain regions. Yet information about Holocene glacier coverage in the Alps before the Little Ice Age stems mostly from studying advances of glacier tongues at lower elevations. Here we present a new approach to reconstructing past glacier low stands and ice-free conditions by assessing and dating the oldest ice preserved at high elevations. A previously unexplored ice dome at Weißseespitze summit (3500 m), near where the “Tyrolean Iceman” was found, offers almost ideal conditions for preserving the original ice formed at the site. The glaciological settings and state-of-the-art micro-radiocarbon age constraints indicate that the summit has been glaciated for about 5900 years. In combination with known maximum ages of other high Alpine glaciers, we present evidence for an elevation gradient of neoglaciation onset. It reveals that in the Alps only the highest elevation sites remained ice-covered throughout the Holocene. Just before the life of the Iceman, high Alpine summits were emerging from nearly ice-free conditions, during the start of a Mid-Holocene neoglaciation. We demonstrate that, under specific circumstances, the old ice at the base of high Alpine glaciers is a sensitive archive of glacier change. However, under current melt rates the archive at Weißseespitze and at similar locations will be lost within the next two decades.

scholarly journals High turn-over rates at the upper range limit and elevational source-sink dynamics in a widespread songbird

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Martin U. Grüebler ◽  
Johann von Hirschheydt ◽  
Fränzi Korner-Nievergelt
Keyword(s):  
Environmental Gradients ◽  
Elevational Gradient ◽  
High Elevation ◽  
Range Limit ◽  
Apparent Survival ◽  
Breeding Sites ◽  
Mobile Species ◽  
Source Sink ◽  
Turn Over ◽  
High Elevations

AbstractThe formation of an upper distributional range limit for species breeding along mountain slopes is often based on environmental gradients resulting in changing demographic rates towards high elevations. However, we still lack an empirical understanding of how the interplay of demographic parameters forms the upper range limit in highly mobile species. Here, we study apparent survival and within-study area dispersal over a 700 m elevational gradient in barn swallows (Hirundo rustica) by using 15 years of capture-mark-recapture data. Annual apparent survival of adult breeding birds decreased while breeding dispersal probability of adult females, but not males increased towards the upper range limit. Individuals at high elevations dispersed to farms situated at elevations lower than would be expected by random dispersal. These results suggest higher turn-over rates of breeding individuals at high elevations, an elevational increase in immigration and thus, within-population source-sink dynamics between low and high elevations. The formation of the upper range limit therefore is based on preference for low-elevation breeding sites and immigration to high elevations. Thus, shifts of the upper range limit are not only affected by changes in the quality of high-elevation habitats but also by factors affecting the number of immigrants produced at low elevations.

scholarly journals Phylogeography of two Andean frogs: Test of vicariance versus elevational gradient models of diversification

2019 ◽  
Author(s):  
Daria Koscinski ◽  
Paul Handford ◽  
Pablo L. Tubaro ◽  
Peiwen Li ◽  
Stephen C. Lougheed
Keyword(s):  
Sequence Data ◽  
Environmental Gradients ◽  
Spatial Scales ◽  
Elevational Gradient ◽  
Northwestern Argentina ◽  
Dna Sequence Data ◽  
The Andes ◽  
Common Causes ◽  
History Of ◽  
Historical Range

ABSTRACTThe tropical and subtropical Andes have among the highest levels of biodiversity in the world. Understanding the forces that underlie speciation and diversification in the Andes is a major focus of research. Here we tested two hypotheses of species origins in the Andes: 1. Vicariance mediated by orogenesis or shifting habitat distribution. 2. Parapatric diversification along elevational environmental gradients. We also sought insights on the factors that impacted the phylogeography of co-distributed taxa, and the influences of divergent species ecology on population genetic structure. We used phylogeographic and coalescent analyses of nuclear and mitochondrial DNA sequence data to compare genetic diversity and evolutionary history of two frog species: Pleurodema borellii (Family: Leiuperidae, 130 individuals; 20 sites), and Hypsiboas riojanus (Family: Hyllidae, 258 individuals; 23 sites) across their shared range in northwestern Argentina. The two showed concordant phylogeographic structuring, and our analyses support the vicariance model over the elevational gradient model. However, Pleurodema borellii exhibited markedly deeper temporal divergence (≥4 Ma) than H. riojanus (1-2 Ma). The three main mtDNA lineages of P. borellii were nearly allopatric and diverged between 4-10 Ma. At similar spatial scales, differentiation was less in the putatively more habitat-specialized H. riojanus than in the more generalist P. borellii. Similar allopatric distributions of major lineages for both species implies common causes of historical range fragmentation and vicariance. However, different divergence times among clades presumably reflect different demographic histories, permeability of different historical barriers at different times, and/or difference in life history attributes and sensitivities to historical environmental change. Our research enriches our understanding of the phylogeography of the Andes in northwestern Argentina.

Evidence of sodium limitation in ants and termites in a Neotropical savanna

2022 ◽  
pp. 1-8
Author(s):  
Natalie A. Clay ◽  
Donald B. Shepard ◽  
Adrian A. Garda ◽  
Daniel O. Mesquita ◽  
Alexandre Vasconcellos
Keyword(s):  
Mass Loss ◽  
Strong Evidence ◽  
Decomposition Rate ◽  
Nutritional Ecology ◽  
Neotropical Savanna ◽  
Nacl Concentration ◽  
Neotropical Savannas ◽  
High Conservation ◽  
Type Water ◽  
Conservation Concern

Abstract Nutritional ecology of ropical ecosystems like Neotropical savannas, which are of high conservation concern, is understudied. Sodium is essential for heterotrophs but availability often falls short relative to plant consumer requirements. Savanna plant consumers like ants and termites should be sodium-limited due to high temperatures, nutrient-poor soils, and lack of oceanic sodium deposition. We tested the hypothesis that Neotropical savanna ants and termites are sodium-limited. Termites were tested by supplementing 0.25 m2 plots with H2O (control), 0.1%, 0.5%, or 1.0% NaCl and measuring termite presence and artificial substrate mass loss after 1 week. Ants were tested by collecting ants that recruited to H2O (control), 0.1%, 0.5%, and 1.0% NaCl and 1.0%, 10%, and 20% sugar baits on paired diurnal–nocturnal transects. Termites were 16 times more likely to occur on 1% NaCl than H2O plots and wood-feeding termites were most frequent. However, the decomposition rate did not differ among treatments. Ant bait use increased with increasing NaCl concentration and 1% NaCl usage was similar to sugar bait usage. Ants were 3.7 times more active nocturnally than diurnally, but contrary to predictions bait type (water, sugar or NaCl) usage did not differ between day and night. Together, these results provide strong evidence of sodium limitation in Neotropical savannas.

Altavelia, a new genus of Neotropical Veliinae (Heteroptera: Gerromorpha: Veliidae), with a key to species and descriptions of four new species from Colombia

Zootaxa ◽  
2019 ◽  
Vol 4585 (2) ◽  
pp. 295 ◽  
Author(s):  
DAN A. POLHEMUS ◽  
FREDY MOLANO ◽  
IRINA MORALES ◽  
FELIPE FERRAZ FIGUEIREDO MOREIRA ◽  
CARLA FERNANDA BURGUEZ FLORIANO
Keyword(s):  
New Species ◽  
Body Shape ◽  
New Genus ◽  
Antennal Segment ◽  
Andes Mountains ◽  
Key To Species ◽  
The Andes ◽  
High Elevations ◽  
Female Abdomen

The new genus Altavelia Polhemus & Moreira (Heteroptera: Gerromorpha: Veliidae) includes seven species previously contained in the inveruglas group of Paravelia Breddin, 1898 and four new species from Colombia: A. altoandina Molano & Morales, A. antioquia Molano & Morales, A. montana Molano & Morales, and A. quindiana Molano & Morales. Additionally, A. amoena (Drake, 1957) is synonymized with A. flavomarginata (Hungerford, 1930). The genus is characterized by prominent setal tufts or sclerotized wing-like processes on the male proctiger; elongate body shape with long, slender legs; uniformly blackish forewings; antennal segment I longest; and the female abdomen with tergum VIII deflexed. Species in this genus occur at high elevations in the Andes Mountains with records from 1500 to 3600 m. A key is provided to all 11 species in the genus and new distributional records are presented for A. boliviana (Breddin, 1898), A. columbiensis (Hungerford, 1930), and A. flavomarginata.  

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