scholarly journals The Discontinuous Elevational Distribution of an Ungulate at the Regional Scale: Implications for Speciation and Conservation

Animals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3565
Author(s):  
Kun Tan ◽  
De-Pin Li ◽  
Na Li ◽  
Yi-Hao Fang ◽  
Yan-Peng Li ◽  
...  
Keyword(s):  
Regional Scale ◽  
Elevation Gradient ◽  
Food Resource ◽  
Morphological Differentiation ◽  
Similar Species ◽  
Ecological Functions ◽  
Sheep Population ◽  
Blue Sheep ◽  
Conservation Values ◽  
Animal Communities

The elevational range where montane species live is a key factor of spatial niche partitioning, because the limits of such ranges are influenced by interspecies interaction, abiotic stress, and dispersal barriers. At the regional scale, unimodal distributions of single species along the elevation gradient have often been reported, while discontinuous patterns, such as bimodal distributions, and potential ecological implications have been rarely discussed. Here, we used extensive camera trap records to reveal the elevation distribution of Himalaya blue sheep (Pseudois nayaur) and its co-existence with other ground animal communities along a slope of Baima Snow Mountain, southwest China. The results show that Himalaya blue sheep exhibited a distinctive bimodal distribution along the elevation gradient contrasting the unimodal distributions found for the other ungulates in Baima snow mountain. A first distributional peak was represented by a population habituating in scree habitat around 4100 m, and a second peak was found in the dry-hot valley around 2600 m. The two distinct populations co-existed with disparate animal communities and these assemblages were similar both in the dry and rainy seasons. The extremely low abundance of blue sheep observed in the densely forested belt at mid-elevation indicates that vegetation rather than temperature is responsible for such segregation. The low-elevation population relied highly on Opuntia ficus-indica, an invasive cactus species that colonized the region six hundred years ago, as food resource. Being the only animal that developed a strategy to feed on this spiky plant, we suggest invasive species may have formed new foraging niche to support blue sheep population in lower elevation hot-dry river valleys, resulting in the geographic separation from the original population and a potential morphological differentiation, as recorded. These findings emphasize the important conservation values of role of ecological functions to identify different taxa, and conservation values of apparent similar species of different ecological functions.

scholarly journals REPTILES DEL BOSQUE SECO ESTACIONAL EN EL CARIBE COLOMBIANO: DISTRIBUCIÓN DE LOS HÁBITATS Y DEL RECURSO ALIMENTARIO

2016 ◽  
Vol 21 (2) ◽  
pp. 365-377
Author(s):  
Luis Eduardo Rojas Murcia ◽  
Juan E. Carvajal Cogollo ◽  
Javier Alejandro Cabrejo Bello
Keyword(s):  
Food Resource ◽  
Horizontal Distribution ◽  
Dry Forest ◽  
Caribbean Region ◽  
Homogeneous Distribution ◽  
Similar Species ◽  
Use Of Resources ◽  
Climatic Period ◽  
Wide Range ◽  
The Caribbean

<p>Con el fin de caracterizar la distribución horizontal (repartición de los hábitats) y la utilización del recurso alimentario (tipo y tamaño de las presas) del ensamblaje de reptiles del bosque seco estacional al norte de la región Caribe de Colombia, en el departamento del Cesar, se realizaron cinco salidas de campo con una duración de doce días cada una. Los muestreos se realizaron en jornadas diurnas y nocturnas, en un diseño de transectos replicados a lo largo de diferentes hábitats que incluyeron: pastizales, bordes e interiores de bosque. Se realizaron análisis descriptivos de uso de hábitat en un perfil de vegetación por cada época climática y análisis de amplitud y sobreposición de nicho. Se registraron 38 especies de 14 familias del orden Squamata. Las especies se distribuyeron de manera homogénea entre zonas abiertas y boscosas. Se encontraron registros de 31 categorías de presa en 109 estómagos de seis especies de serpientes (61 estómagos) y siete de lagartos (48 estómagos) con un porcentaje de estómagos vacíos de 38 %. Las presas de mayor importancia para los lagartos fueron Coleoptera y Araneae, y para las serpientes fueron los anfibios. La mayoría de las especies presentaron un amplio espectro de dieta y entre especies similares, como entre Anolis auratus y A. gaigei, se presentó uso de recursos similares. En síntesis, el ensamblaje de reptiles presentó una distribución homogénea en los hábitats evaluados (áreas abiertas y boscosas) y el recurso alimentario fue variado entre las diferentes especies; la estacionalidad de la zona presenta un papel fundamental en la estructura del ensamblaje de reptiles, presentándose menos abundancia durante la época seca, tanto en las áreas abiertas como en las boscosas.</p><p><strong>Reptiles from the Seasonal Dry Forest the Caribbean Region: Distribution of Habitat and use of Food Resource</strong></p><p><strong>ABSTRACT</strong></p><p>We assessed the horizontal distribution and use of the food resource of the reptile’s assemblage of the seasonal tropical dry forest in the North of the Caribbean region of Colombia, department of Cesar. Five fieldtrips of 12 days each were performed, sampling was diurnal and nocturnal, following a transect design replicated along different habitats including grasslands, edge and interior of forest. We performed descriptive analyzes of habitat use, using a profile of vegetation by each climatic period; we also did an analysis of amplitude and niche overlap. We recorded 38 species of 14 families of the Squamata order. Species distributed evenly between open and forested areas. Record of 31 categories of prey in 109 stomachs of six species snakes (61 stomachs) and seven of lizards (48 stomachs) with a percentage of empty stomachs of 38 % was found. The preys of greater importance for the lizards were Coleoptera and Araneae and for snakes, amphibians. Most of the species presented a wide range of diet and between similar species, such as Anolis auratus and A. gaigei, found a similar use of resources. In summary, the assembly of reptiles presented a homogeneous distribution in the habitats evaluated (forested and open areas) and the food resource varied among the different species; the seasonality of the area plays a fundamental role on the structure of this reptile assembly with less abundance during the dry season in both, open and forested habitats.</p>

scholarly journals Fire and Its Interactions With Other Drivers Shape a Distinctive, Semi-Arid ‘Mallee’ Ecosystem

2021 ◽  
Vol 9 ◽  
Author(s):  
Michael F. Clarke ◽  
Luke T. Kelly ◽  
Sarah C. Avitabile ◽  
Joe Benshemesh ◽  
Kate E. Callister ◽  
...  
Keyword(s):  
Regional Scale ◽  
Fire Regimes ◽  
Field Studies ◽  
Arid Ecosystems ◽  
Coarse Grained ◽  
Pest Species ◽  
Age Classes ◽  
Eastern Australia ◽  
Animal Communities ◽  
Semi Arid

Fire shapes ecosystems globally, including semi-arid ecosystems. In Australia, semi-arid ‘mallee’ ecosystems occur primarily across the southern part of the continent, forming an interface between the arid interior and temperate south. Mallee vegetation is characterized by short, multi-stemmed eucalypts that grow from a basal lignotuber. Fire shapes the structure and functioning of mallee ecosystems. Using the Murray Mallee region in south-eastern Australia as a case study, we examine the characteristics and role of fire, the consequences for biota, and the interaction of fire with other drivers. Wildfires in mallee ecosystems typically are large (1000s ha), burn with high severity, commonly cause top-kill of eucalypts, and create coarse-grained mosaics at a regional scale. Wildfires can occur in late spring and summer in both dry and wet years. Recovery of plant and animal communities is predictable and slow, with regeneration of eucalypts and many habitat components extending over decades. Time since the last fire strongly influences the distribution and abundance of many species and the structure of plant and animal communities. Animal species display a discrete set of generalized responses to time since fire. Systematic field studies and modeling are beginning to reveal how spatial variation in fire regimes (‘pyrodiversity’) at different scales shapes biodiversity. Pyrodiversity includes variation in the extent of post-fire habitats, the diversity of post-fire age-classes and their configuration. At regional scales, a desirable mix of fire histories for biodiversity conservation includes a combination of early, mid and late post-fire age-classes, weighted toward later seral stages that provide critical habitat for threatened species. Biodiversity is also influenced by interactions between fire and other drivers, including land clearing, rainfall, herbivory and predation. Extensive clearing for agriculture has altered the nature and impact of fire, and facilitated invasion by pest species that modify fuels, fire regimes and post-fire recovery. Given the natural and anthropogenic drivers of fire and the consequences of their interactions, we highlight opportunities for conserving mallee ecosystems. These include learning from and fostering Indigenous knowledge of fire, implementing actions that consider synergies between fire and other processes, and strategic monitoring of fire, biodiversity and other drivers to guide place-based, adaptive management under climate change.

scholarly journals Close species of rodent superfamily Muroidei in the fauna of Ukraine: taxonomy, biogeography, diagnostics, and ecomorphology

2020 ◽  
Vol 2020 (19) ◽  
pp. 3-26
Author(s):  
Igor Zagorodniuk ◽  
Keyword(s):  
Morphological Differentiation ◽  
Steppe Zone ◽  
Sympatric Species ◽  
The Other ◽  
Similar Species ◽  
Large Species ◽  
Forest Zone ◽  
Wood Mice ◽  
The Carpathians ◽  
Common Voles

The results of the revision of the species composition and related knowledge of taxonomy, biogeography, diagnostics, variability and ecomorphology of polytypic groups of murine rodents, superfamily Muroidei, are presented. These are 5 former "large" species: "wood mice", "common mice", water voles, "shrub voles" and "common voles". Each of these groups is represented in the fauna of Ukraine and neighboring countries by 2–3 species. The two most difficult for revision and for background monitoring of fauna are "forest mice" and "common voles", each of which is represented in the fauna of the region by three morphologically very similar species of different kinship, among which one (the most genetically distant) is widely sympatric to the other two species that are allospecies. Among "forest mice", such species are Sylvaemus uralensis (= microps) against the pair S. sylvaticus + S. witherbyi (= S. falzfeini), and among the "common voles" it is Microtus levis (= rossiaemeridionalis) against the pair M. arvalis + M. obscurus. The other three pairs of species are generally more diverged (at least in terms of habitats and ecology, and in some cases morphology) and clearly less sympatric species. In the group of "common" mice, Mus "musculus" (s.l.), there is a pair of synanthropic and exanthropic forms — M. musculus and M. spicilegus (= M. sergii), which usually do not interact in nature, and therefore poorly diverged in morphology. In the group of "water voles" there is an allopatric pair, represented by the Carpathian-Roztochchian (essentially mountainous, associated with meadows) as well as plain hydrophilic forms, Arvicola scherman and A. amphibius (= A. terrestris). In the group of "shrub voles" there is a sympatric pair of species, one of them has limited distribution in the Carpathians (Terricola tatricus), but the other (T. subterraneus), being sympatric to the first in the Carpathians, also forms numbered populations in lowland forests, as in the forest zone as in the bairak steppe zone. Morphological differentiation between them is generally high, but the Eastern Carpathian form of Terricola tatricus is the smallest in a row of mountain forms of Terricola (multiplex, tatricus, zykovi), which was the reason for its long-term non-recognition in the fauna of Ukraine. For all species, descriptions are presented, including 5 standard parts for this series of publications: general remarks, taxonomy (including nomenclature), distribution (including biotopes), diagnostics (including variability), ecomorphology.Key words: small mammals, habitats, dominance, abundance of species.

scholarly journals Bemovi, software for extracting BEhaviour and MOrphology from VIdeos.

2014 ◽  
Author(s):  
Frank Pennekamp ◽  
Nicolas Schtickzelle ◽  
Owen L. Petchey
Keyword(s):  
Image Analysis ◽  
Video Processing ◽  
Morphological Differentiation ◽  
Machine Learning Algorithms ◽  
Community Genetics ◽  
Supervised Machine Learning ◽  
Similar Species ◽  
Multiple Traits ◽  
Experimental Conditions ◽  
Movement Trajectories

1. Microbes are critical components of ecosystems and vital to the services they provide. The essential role of microbes is due to high levels of functional diversity, which are, however, not always mirrored in morphological differentiation hampering their taxonomic identification. In addition, the small size of microbes hinders the measurement of morphological and behavioural traits at the individual level, as well as interactions between individuals. 2. Recent advances in microbial community genetics and genomics, flow cytometry and digital image analysis are promising approaches, however they miss out on a very important aspect of populations and communities: the behaviour of individuals. Video analysis complements these methods by providing in addition to abundance and trait measurements, detailed behavioural information, capturing dynamic processes such as movement, and hence has the potential to describe the interactions between individuals. 3. We introduce bemovi, a package using R–the statistical computing environment–and the free image analysis software ImageJ. Bemovi is an automated digital video processing and analysis work flow to extract abundance and morphological and movement data for numerous individuals on a video, hence characterizing a population or community by multiple traits. Through a set of functions, bemovi identifies individuals present in a video and reconstruct their movement trajectories through space and time, merges measurements from all treated videos into a single database to which information on experimental conditions is added, readily available for further analysis in R. 4. We illustrate the validity, precision and accuracy of the method for experimental multi-species communities of protists in aquatic microcosms. We show the high correspondence between manual and automatic counts of individuals and illustrate how simultaneous time series of abundance, morphology and behaviour are constructed. We demonstrate how the data from videos can be used in combination with supervised machine learning algorithms to automatically classify individuals according to the species they belong to, and that information on movement behaviour can substantially improve the predictive ability and helps to distinguish morphologically similar species. In principle, bemovi should be able to extract from videos information about other types of organism, including microbes, so long as the individuals move relatively fast compared to their background.

scholarly journals Niche expansion leads to small-scale adaptive divergence along an elevation gradient in a medium-sized passerine bird

2008 ◽  
Vol 275 (1647) ◽  
pp. 2155-2164 ◽  
Author(s):  
John E McCormack ◽  
Thomas B Smith
Keyword(s):  
Gene Flow ◽  
Regional Scale ◽  
Elevation Gradient ◽  
Passerine Bird ◽  
High Elevation ◽  
Adaptive Divergence ◽  
Small Scale ◽  
Niche Expansion ◽  
Aphelocoma Ultramarina ◽  
Pine Cones

Niche expansion can lead to adaptive differentiation and speciation, but there are few examples from contemporary niche expansions about how this process is initiated. We assess the consequences of a niche expansion by Mexican jays ( Aphelocoma ultramarina ) along an elevation gradient. We predicted that jays at high elevation would have straighter bills adapted to feeding on pine cones, whereas jays at low elevation would have hooked bills adapted to feeding on acorns. We measured morphological and genetic variation of 95 adult jays and found significant differences in hook length between elevations in accordance with predictions, a pattern corroborated by analysis at the regional scale. Genetic results from microsatellite and mtDNA variation support phenotypic differentiation in the presence of gene flow coupled with weak, but detectable genetic differentiation between high- and low-elevation populations. These results demonstrate that niche expansion can lead to adaptive divergence despite gene flow between parapatric populations along an elevation gradient, providing information on a key precursor to ecological speciation.

scholarly journals Food resource partitioning among species of Astyanax (Characiformes: Characidae) in the Lower Iguaçu River and tributaries, Brazil

2019 ◽  
Vol 17 (4) ◽  
Author(s):  
Suelen F. R. Pini ◽  
Milza C. F. Abelha ◽  
Elaine A. L. Kashiwaqui ◽  
Rosilene L. Delariva ◽  
Sergio Makrakis ◽  
...  
Keyword(s):  
Resource Partitioning ◽  
Paired Comparison ◽  
Food Resource ◽  
Similar Species ◽  
Species Introduction ◽  
Terrestrial Plant ◽  
Food Overlap ◽  
A Minor ◽  
Iguaçu River ◽  
Food Resource Partitioning

ABSTRACT Resource partitioning allows for interspecific coexistence and is frequently reported for similar species. Here, we predicted the existence of resource partitioning among species of Astyanax that co-occur in the Low Iguaçu River and tributaries in Brazil. A total of 848 stomachs of five species of Astyanax were analyzed. Algae, terrestrial plant and fruit/seed were the most consumed resources. Astyanax bifasciatus and A. dissimilis had predominantly herbivorous diets, A. gymnodontus and A. lacustris were omnivorous, and A. minor was mainly algivorous. Permutational analysis of variance showed the species had different diets, and similarity percentage analysis indicated that fruit/seed and terrestrial plant contributed the most to this differentiation. A paired comparison indicated that the trophic breadth of A. gymnodontus differed from that of other species. The food overlap was low for 55% of Astyanax pairs. These results showed alignment with the niche theory, in which differentiation in the use of food resources facilitates the coexistence of species and minimizes competition. These adjustments to coexistence become relevant in the context of endemic species in a highly isolated basin under intense threat (dams, species introduction, deforestation, and pollution) as is the case for the Iguaçu River basin.

The influences of climate, habitat and fire on the distribution of cockatoo grass (Alloteropsis semialata) (Poaceae) in the Wet Tropics of northern Australia

2011 ◽  
Vol 59 (4) ◽  
pp. 315 ◽  
Author(s):  
Brooke L. Bateman ◽  
Christopher N. Johnson
Keyword(s):  
Prescribed Burning ◽  
Regional Scale ◽  
Food Resource ◽  
Grass Species ◽  
High Survival ◽  
Themeda Triandra ◽  
Management Actions ◽  
Litter Cover ◽  
Scale Modelling ◽  
Wet Tropics

Cockatoo grass [Alloteropsis semialata (R.Br.) A. Hitchc.] is considered a keystone species in northern Australian ecosystems as it provides a food resource for many species, including several endangered vertebrates. This study examined both local and regional environmental factors influencing cockatoo grass distribution and abundance in the Wet Tropics of north Queensland, Australia. Local distribution and abundance were investigated in the sclerophyll ecotone between open woodland and tall open forest, because little is known about cockatoo grass distribution within this habitat; also, the endangered northern bettong (Bettongia tropica) is restricted to this habitat and depends on cockatoo grass for its survival. Regional-scale modelling of distribution was undertaken to examine the climatic tolerances of cockatoo grass in Queensland. Density of cockatoo grass was negatively related to litter cover, soil moisture, and the presence of two dominant grass species, Themeda triandra [Forssk.(R.Br.) Stapf] and Cleistochloa subjuncea (C.E.Hubb.). Soil nutrients (N, C, S, and C : N ratio) were positively related to density of cockatoo grass. A late dry season experimental burn demonstrated that cockatoo grass had high survival to fire, with increased density and flowering in response to fire. Regional-scale modelling using climate variables indicated that cockatoo grass is more suited to the drier end of the sclerophyll habitat range. Cockatoo grass in the woodland-forest ecotone in the Wet Tropics appears to be influenced by several environmental features associated with the ground layer. The species benefits from the reduction in litter cover and competing grass species that result from management actions such as prescribed burning. Understanding of the factors limiting this species, both at a local and regional scale, can be used to guide management of this ecotone habitat for both cockatoo grass and the survival of other species that depend on it.

An attempt to explain the distribution of the tree species composing the riparian forests of Lake Duparquet, southern boreal region of Quebec, Canada

2000 ◽  
Vol 77 (12) ◽  
pp. 1744-1755 ◽  
Author(s):  
Bernhard Denneler ◽  
Yves Bergeron ◽  
Yves Bégin
Keyword(s):  
Tree Species ◽  
Elevation Gradient ◽  
Great Part ◽  
Morphological Differentiation ◽  
Basal Area ◽  
Stepwise Logistic Regression ◽  
Minor Importance ◽  
Rock Outcrops ◽  
Data Set ◽  
Boreal Region

The objective of this study was to evaluate the most important environmental factors determining the distribution of tree species within the riparian zone of Lake Duparquet, located in the southern boreal region of Quebec, Canada. Occurrence and relative basal area of 10 species were recorded within an altitudinal range of 200 cm above mean water level along 95 transects. Stepwise logistic regression and canonical correspondence analyses were performed on the overall data set as well as separately for the five geomorphological shore types distinguished (depositional flats, floodplains, beaches, terraces, and rock outcrops). The elevation gradient, representing seasonal floodings, is the main factor determining the distribution of the species. The differences between the geomorphological shore types with respect to composition and arrangement of the arborescent vegetation along the elevation gradient are at least partially explained by surficial substratum, topography, aspect, and fire. Exposure to wave activity seems to be of minor importance only. However, since they are the driving force of erosion and sedimentation, the waves are to a great part responsible for the morphological differentiation of the shoreline. The distribution of the tree species along a characteristic physiographic cross-section is illustrated for each geomorphological shore type.

Sign in / Sign up

Export Citation Format

Share Document