scholarly journals Crypsis Decreases with Elevation in a Lizard

Diversity ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 236 ◽  
Author(s):  
Gregorio Moreno-Rueda ◽  
Laureano G. González-Granda ◽  
Senda Reguera ◽  
Francisco J. Zamora-Camacho ◽  
Elena Melero
Keyword(s):  
Local Adaptation ◽  
Sierra Nevada ◽  
Elevational Gradient ◽  
Bare Soil ◽  
High Elevation ◽  
Dorsal Skin ◽  
Se Spain ◽  
Psammodromus Algirus ◽  
Selection For ◽  
High Elevations

Predation usually selects for visual crypsis, the colour matching between an animal and its background. Geographic co-variation between animal and background colourations is well known, but how crypsis varies along elevational gradients remains unknown. We predict that dorsal colouration in the lizard Psammodromus algirus should covary with the colour of bare soil—where this lizard is mainly found—along a 2200 m elevational gradient in Sierra Nevada (SE Spain). Moreover, we predict that crypsis should decrease with elevation for two reasons: (1) Predation pressure typically decreases with elevation, and (2) at high elevation, dorsal colouration is under conflicting selection for both crypsis and thermoregulation. By means of standardised photographies of the substratum and colourimetric measurements of lizard dorsal skin, we tested the colour matching between lizard dorsum and background. We found that, along the gradient, lizard dorsal colouration covaried with the colouration of bare soil, but not with other background elements where the lizard is rarely detected. Moreover, supporting our prediction, the degree of crypsis against bare soil decreased with elevation. Hence, our findings suggest local adaptation for crypsis in this lizard along an elevational gradient, but this local adaptation would be hindered at high elevations.

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 Age structure of a lizard along an elevational gradient reveals nonlinear lifespan patterns with altitude

2019 ◽  
Vol 66 (4) ◽  
pp. 373-382 ◽  
Author(s):  
Mar Comas ◽  
Senda Reguera ◽  
Francisco J Zamora-Camacho ◽  
Gregorio Moreno-Rueda
Keyword(s):  
Life History ◽  
Sierra Nevada ◽  
Food Availability ◽  
Reproductive Investment ◽  
Elevational Gradient ◽  
Activity Time ◽  
Psammodromus Algirus ◽  
Limited Food ◽  
Main Components ◽  
Marginal Habitats

Abstract Lifespan is one of the main components of life history. Shorter lifespans can be expected in marginal habitats. However, in the case of ectotherms, lifespan typically increases with altitude, even though temperature—one of the main factors to determine ectotherms’ life history—declines with elevation. This pattern can be explained by the fact that a shorter activity time favors survival. In this study, we analyzed how lifespan and other life-history traits of the lizard Psammodromus algirus vary along a 2,200 m elevational gradient in Sierra Nevada (SE Spain). Populations at intermediate altitudes (1,200–1,700 m), corresponding to the optimal habitat for this species, had the shortest lifespans, whereas populations inhabiting marginal habitats (at both low and at high altitudes) lived longest. Therefore, this lizard did not follow the typical pattern of ectotherms, as it also lived longer at the lower limit of its distribution, nor did it show a longer lifespan in areas with optimal habitats. These results might be explained by a complex combination of different gradients along the mountain, namely that activity time decreases with altitude whereas food availability increases. This could explain why lifespan was maximum at both high (limited activity time) and low (limited food availability) altitudes, resulting in similar lifespans in areas with contrasting environmental conditions. Our findings also indicated that reproductive investment and body condition increase with elevation, suggesting that alpine populations are locally adapted.

scholarly journals Low genome-wide divergence between two lizard populations with high adaptive phenotypic differentiation

2021 ◽  
Author(s):  
Alejandro Llanos-Garrido ◽  
Javier Pérez-Tris ◽  
José Díaz
Keyword(s):  
Local Adaptation ◽  
Genetic Divergence ◽  
Elevational Gradient ◽  
Phenotypic Differentiation ◽  
Genome Wide ◽  
Isolation By Environment ◽  
Psammodromus Algirus ◽  
Low Levels ◽  
Two Populations ◽  
Degree Of Isolation

Usually, adaptive phenotypic differentiation is paralleled by genetic divergence between locally adapted populations. However, adaptation can also happen in a scenario of non-significant genetic divergence due to intense gene flow and/or recent differentiation. While this phenomenon is rarely published, findings on incipient ecologically-driven divergence or isolation by adaptation are relatively common, which could confound our understanding about the frequency at which they actually occur in nature. Here, we explore genome-wide traces of divergence between two populations of the lacertid lizard Psammodromus algirus separated by a 600 m elevational gradient. These populations seem to be differentially adapted to their environments despite showing low levels of genetic differentiation (according to previously studies of mtDNA and microsatellite data). We performed a search for outliers (i.e. loci subject to selection) trying to identify specific loci with FST statistics significantly higher than those expected on the basis of overall, genome-wide estimates of genetic divergence. We find that local phenotypic adaptation (in terms of a wide diversity of characters) was not accompanied by genome-wide differentiation, even when we maximized the chances of unveiling such differentiation at particular loci with FST-based outlier detection tests. Instead, our analyses confirmed the lack of differentiation on the basis of more than 70,000 SNPs, which is concordant with a scenario of local adaptation without any degree of isolation by environment. Our results add evidence to previous studies in which local adaptation does not lead to any kind of isolation (or early stages of ecological speciation), but maintains phenotypic divergence despite the lack of a differentiated genomic background.

scholarly journals The Within-Population Formation of the Upper Range Limit in a Songbird

2021 ◽  
Author(s):  
Martin Grüebler ◽  
Johann von Hirschheydt ◽  
Fränzi Korner-Nievergelt
Keyword(s):  
Environmental Gradients ◽  
Elevational Gradient ◽  
High Elevation ◽  
Range Limit ◽  
Apparent Survival ◽  
Breeding Sites ◽  
Factors Affecting ◽  
Mobile Species ◽  
Random Dispersal ◽  
High Elevations

Abstract The formation of the upper distributional range limit of species at mountain slopes is often based on environmental gradients resulting in changing demographic rates towards high elevations. However, we still lack an empiric 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 lower elevations 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 Odonata (Insecta) communities along an elevational gradient in the Atlantic forest of southeastern Brazil, with the description of the female of Heteragrion mantiqueirae Machado, 2006

2021 ◽  
Vol 24 ◽  
pp. 178-196
Author(s):  
G. Stefani-Santos ◽  
W.F. Ávila Jr ◽  
M.A. Clemente ◽  
N.R. Henriques ◽  
A.S.B. Souza ◽  
...  
Keyword(s):  
Atlantic Forest ◽  
Elevational Gradient ◽  
High Elevation ◽  
Minas Gerais ◽  
Southeastern Brazil ◽  
Lack Of Information ◽  
Minas Gerais State ◽  
Environmental Protection Area ◽  
Protection Area ◽  
High Elevations

Despite the important role of the order Odonata in ecosystems, there is a lack of information about dragonfly communities in several regions, high elevation sites, and environmentally protected areas in Minas Gerais State, Brazil. Our objective was to assess the abundance and richness of dragonfly and damselfly communities along an elevational gradient in the Atlantic Forest,southeastern Brazil. This study was conducted in the Fernão Dias Environmental Protection Area,Mantiqueira Mountain region, Gonçalves, Minas Gerais State, in sites covered by Seasonal Semideciduous and mixed forests. This is the first study of Odonata communities in the region. Samplings were carried out on 17 days from October 2019 to March 2020 at three elevation ranges (low,mid, and high). A total of 293 specimens, distributed in 39 species and 9 families, were sampled. Elevation did not influence the richness or abundance of dragonflies but altered community composition. Some species were found to be exclusive to high-elevation sites, such as Heteragrion mantiqueirae Machado, 2006, which was recorded for the first time in Minas Gerais and we provide a description and diagnosis of the single female collected in tandem. A novel species of the genus Brechmorhoga was found to occur at mid and high elevations. The composition of dragonfly communities depends on the degree of preservation and extension of forest areas. Therefore, conservation of forests in Gonçalves is crucial for preserving Odonata diversity in Minas Gerais State.

scholarly journals Life-history characteristics influence physiological strategies to cope with hypoxia in Himalayan birds

2016 ◽  
Vol 283 (1843) ◽  
pp. 20162201 ◽  
Author(s):  
S. Barve ◽  
A. A. Dhondt ◽  
V. B. Mathur ◽  
Z. A. Cheviron
Keyword(s):  
Life Histories ◽  
Haemoglobin Concentration ◽  
Elevational Gradient ◽  
High Elevation ◽  
Blood Oxygen ◽  
Migration Patterns ◽  
Migratory Patterns ◽  
Physiological Stressor ◽  
Migratory Strategy ◽  
High Elevations

Hypobaric hypoxia at high elevation represents an important physiological stressor for montane organisms, but optimal physiological strategies to cope with hypoxia may vary among species with different life histories. Montane birds exhibit a range of migration patterns; elevational migrants breed at high elevations but winter at low elevations or migrate further south, while high-elevation residents inhabit the same elevation throughout the year. Optimal physiological strategies to cope with hypoxia might therefore differ between species that exhibit these two migratory patterns, because they differ in the amount time spent at high elevation. We examined physiological parameters associated with blood-oxygen transport (haemoglobin concentration and haematocrit, i.e. the proportion of red blood cells in blood) in nine species of elevational migrants and six species of high-elevation residents that were sampled along a 2200 m (1000–3200 m) elevational gradient. Haemoglobin concentration increased with elevation within species regardless of migratory strategy, but it was only significantly correlated with haematocrit in elevational migrants. Surprisingly, haemoglobin concentration was not correlated with haematocrit in high-elevation residents, and these species exhibited higher mean cellular haemoglobin concentration than elevational migrants. Thus, alternative physiological strategies to regulate haemoglobin concentration and blood O 2 carrying capacity appear to differ among birds with different annual elevational movement patterns.

Thermoregulation in the lizard Psammodromus algirus along a 2200-m elevational gradient in Sierra Nevada (Spain)

2015 ◽  
Vol 60 (5) ◽  
pp. 687-697 ◽  
Author(s):  
Francisco Javier Zamora-Camacho ◽  
Senda Reguera ◽  
Gregorio Moreno-Rueda
Keyword(s):  
Sierra Nevada ◽  
Elevational Gradient ◽  
Psammodromus Algirus

Effects of gravidity on the locomotor performance and escape behaviour of two lizard populations: the importance of habitat structure

Behaviour ◽  
2010 ◽  
Vol 147 (1) ◽  
pp. 133-150 ◽  
Author(s):  
José Díaz ◽  
Camila Monasterio ◽  
Pablo Iraeta ◽  
Alfredo Salvador
Keyword(s):  
Habitat Structure ◽  
High Elevation ◽  
Laying Date ◽  
Locomotor Performance ◽  
Before And After ◽  
Psammodromus Algirus ◽  
Effects Of Temperature ◽  
Selection For ◽  
Gravid Females ◽  
Two Populations

AbstractIn lizards, locomotor costs of gravidity may depend on habitat structure and refuge availability. We compared the locomotor performance and escape tactics in the laboratory, before and after oviposition, of two populations of Psammodromus algirus separated by 700 m altitude. When gravid, females escaped using a larger number of slower and shorter runs, and had lower temperatures at the time of trial, than after oviposition. Some of these effects differed between populations: when gravid, but not after oviposition, low-elevation females ran shorter distances at a slower average speed than high-elevation ones. Low-elevation females laid their clutches earlier than high-elevation ones, which conditioned their lower speed when gravid in simultaneous running trials. However, their escape distances were still shorter after controlling for the effects of temperature and laying date. In the field, refuge availability was lower at the low-elevation site, where females spent more time inside refuges and perching above ground. The shorter escape distance of low-elevation females may, thus, represent a behavioural response to minimize detectability, especially if predator avoidance depends primarily on whether or not the lizard is seen by the predator. Such behavioural adjustments might inhibit selection for evolutionary shifts in the performance of gravid females.

Comparative demography of a temperate anuran, Rana chensinensis, along a relatively fine elevational gradient

2006 ◽  
Vol 84 (12) ◽  
pp. 1789-1795 ◽  
Author(s):  
Xin Lu ◽  
Bin Li ◽  
Juan Juan Liang
Keyword(s):  
Life History ◽  
Northern China ◽  
Elevational Gradient ◽  
High Elevation ◽  
Life History Strategies ◽  
Adult Males ◽  
Rana Chensinensis ◽  
Demographic Traits ◽  
Comparative Demography ◽  
High Elevations

Rana chensinensis (David, 1875) is a temperate anuran endemic to northern China. We examined differences in demographic traits of the populations from three elevations (1400, 1700, and 2000 m) along a montane river in 2002. We found that frogs from higher elevations had delayed maturity, a larger size at maturity, and slower growth rates compared with frogs at lower elevations. This life-history model is similar to observations of other amphibians living in montane areas. However, discordance with the expected model occurred between neighboring populations and the variation was sex-specific. Mid-elevation adult males were significantly older and larger than their low-elevation congeners, but they were statistically similar in age and size to frogs from high elevations; females from mid elevations were not statistically different in age and size from females from our low-elevation site, but they were significantly younger and smaller than high-elevation females. These variations may be related to sexual differences in life-history strategies, which might not covary systematically when elevational gradients are set at a finer scale. At each elevation, the sex ratio was skewed towards females; females also matured later, lived longer, and were larger. Age was a major factor related to size, but other factors played a role in shaping size differences both between populations and between sexes.

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.

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