Habitat Distribution of Canary Chaffinches Among Islands: Competitive Exclusion or Species-Specific Habitat Preferences?

1992 ◽  
Vol 19 (4) ◽  
pp. 383 ◽  
Author(s):  
Luis M. Carrascal ◽  
Jose L. Telleria ◽  
Alfredo Valido
Keyword(s):  
Competitive Exclusion ◽  
Habitat Preferences ◽  
Habitat Distribution ◽  
Species Specific

scholarly journals Subterranean Species in Washington, D.C.: Spatial Analysis, Habitat Preferences, & Urban Conservation Implications

2018 ◽  
Vol 1 ◽  
Author(s):  
Jenna Keany
Keyword(s):  
Competitive Exclusion ◽  
Habitat Preferences ◽  
Shallow Groundwater ◽  
Soil Morphology ◽  
Chemical Parameters ◽  
Species List ◽  
Environmental Preferences ◽  
Small Water ◽  
Conservation Implications ◽  
Subterranean Species

Washington, D.C. is home to a remarkable assemblage of troglomorphic amphipods and isopods living in shallow groundwater habitats, the hypotelminorheic. Groundwater from the hypotelminorheic emerges on the surface into low-flowing seepage springs, or “seeps”, which are categorized as having blackened leaves, an underlain layer of clay, a drainage area of less than 10,000 m2, and are situated in slight topographical depressions. Stygobiotic species found in D.C.’s seeps include Crangonyx and Stygobromus amphipods and Caecidotea isopods. One species, Stygobromus hayi, is on the endangered species list and is endemic to the district; however, little is known about their habitat preferences or their distribution. All small water bodies, including rainwater puddles and seepage springs were sampled in national park lands in Southeast D.C. for hypotelminorheic fauna, soil morphology, and water quality indicators such as nitrates, phosphates, radon, pH, DO, and conductivity. Comparing sites with and without stygobionts, all phsysico-chemical parameters were statistically insignificant except for conductivity, which was able to distinguish between stygobiont-rich and stygobiont-poor seeps using logistic regression. Spatially, Crangonyx and Stygobromus amphipods rarely inhabit the same seepage spring, with only three occasions of cohabitation and an expected occurrence of ten. Caecidotea, however, is found in habitats with both amphipods. These results can be explained by either competitive exclusion or the presence of chemical differences in their habitats; however, even if there were some slight differences in their habitats, that still does not exclude competitive exclusion as an explanation. This study highlights new and important findings into the environmental preferences of D.C.’s most cryptic and rare species, and the importance of continued exploration of D.C.’s lesser known park lands.

scholarly journals The Role of Plasticity and Adaptation in the Incipient Speciation of a Fire Salamander Population

Genes ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 875
Author(s):  
Joana Sabino-Pinto ◽  
Daniel J. Goedbloed ◽  
Eugenia Sanchez ◽  
Till Czypionka ◽  
Arne W. Nolte ◽  
...  
Keyword(s):  
Gene Expression ◽  
Phenotypic Plasticity ◽  
Local Adaptation ◽  
Habitat Preferences ◽  
Genetic Change ◽  
Incipient Speciation ◽  
Expression Of Genes ◽  
Species Specific ◽  
Reciprocal Transfer ◽  
High Degree

Phenotypic plasticity and local adaptation via genetic change are two major mechanisms of response to dynamic environmental conditions. These mechanisms are not mutually exclusive, since genetic change can establish similar phenotypes to plasticity. This connection between both mechanisms raises the question of how much of the variation observed between species or populations is plastic and how much of it is genetic. In this study, we used a structured population of fire salamanders (Salamandra salamandra), in which two subpopulations differ in terms of physiology, genetics, mate-, and habitat preferences. Our goal was to identify candidate genes for differential habitat adaptation in this system, and to explore the degree of plasticity compared to local adaptation. We therefore performed a reciprocal transfer experiment of stream- and pond-originated salamander larvae and analyzed changes in morphology and transcriptomic profile (using species-specific microarrays). We observed that stream- and pond-originated individuals diverge in morphology and gene expression. For instance, pond-originated larvae have larger gills, likely to cope with oxygen-poor ponds. When transferred to streams, pond-originated larvae showed a high degree of plasticity, resembling the morphology and gene expression of stream-originated larvae (reversion); however the same was not found for stream-originated larvae when transferred to ponds, where the expression of genes related to reduction-oxidation processes was increased, possibly to cope with environmental stress. The lack of symmetrical responses between transplanted animals highlights the fact that the adaptations are not fully plastic and that some level of local adaptation has already occurred in this population. This study illuminates the process by which phenotypic plasticity allows local adaptation to new environments and its potential role in the pathway of incipient speciation.

The ecology of bats in south-east Australian forests and potential impacts of forestry practices: a review

1995 ◽  
Vol 2 (4) ◽  
pp. 363 ◽  
Author(s):  
Bradley S. Law
Keyword(s):  
Species Richness ◽  
Radio Telemetry ◽  
Habitat Preferences ◽  
Structural Complexity ◽  
Current Evidence ◽  
Mature Trees ◽  
Long Distance ◽  
Forestry Practices ◽  
High Conservation ◽  
Species Specific

Bats are important contributors to Australia's mammal diversity and are ecologically diverse, feeding on insects, fish, small vertebrates, nectar, pollen and fruit. As such they are likely to play key ecological roles as regulators of invertebrate populations and pollinators of forests. Although somewhat contradictory, current evidence suggest that logging impacts on the species richness and activity of insectivorous bats when forest structural complexity and the number of available roosting hollows are reduced. Inconsistent results concerning impact on species richness stem from methodological problems with bat surveys. "Rare" species are often recorded in low numbers, preventing habitat preferences and disturbance impacts from being determined. Radio-telemetry has demonstrated that roosts in hollows of mature trees are a critical resource for many species of bats due to species specific requirements. However, it is not yet possible to state whether bat populations are directly limited by the availability of hollows in areas where a mosaic of logged and unlogged forest exists. Although data on foraging areas are extremely limited, some species appear to be flexible, capable of flying across open areas and exploiting those rich in invertebrates. Some species (e.g., Vespadelus) show a high degree of site attachment, possibly indicating a susceptibility to logging, however, the extent of site fidelity for most species is unknown. As pollinators, megachiropteran bats are likely to play a key role in maintaining the genetic diversity currently present in eucalypts by facilitating long-distance movement of pollen. Areas that are productive in nectar and pollen have a high conservation value for these bats and many other nectarivores, however, the age at which important nectar-producing trees flower is generally not known. The extent to which wildlife prescriptions, such as habitat trees and mosaics of small reserves, mitigate these impacts on bat species requires urgent research.

scholarly journals Occurrence Patterns, Photoperiod and Dispersion Ability of the Non-Marine Ostracoda (Crustacea) in Shallow Waters

2020 ◽  
Vol 21 (02) ◽  
pp. 73-85
Author(s):  
Okan Külköylüoğlu ◽  
Mehmet Yavuzatmaca ◽  
Derya Akdemir
Keyword(s):  
Habitat Preferences ◽  
Sampling Time ◽  
Shallow Waters ◽  
Species Occurrence ◽  
Natural Habitats ◽  
Effective Factor ◽  
Species Pairs ◽  
Occurrence Pattern ◽  
Species Specific ◽  
Occurrence Patterns

Patterns of species occurrence, dispersion ability, habitat preferences and sampling time can be important factors on the species composition. To understand effective roles of these factors on non-marine ostracods, samples were collected from 98 different shallow aquatic bodies from Osmaniye and Kilis provinces in Turkey. Total of 16 and 12 species were identified from the two provinces, respectively. All species are reported new for these provinces. Three species (Heterocypris incongruens, Ilyocypris inermis, I. bradyi) demonstrated the most frequent occurrences and abundances in up to seven different habitats. Species diversity and abundance were at least two times higher in natural habitats (streams, creeks) than artificial habitats (reservoirs, troughs). Numbers of species with and without swimming setae on the second antenna was not significantly different between lentic and lotic habitats. A positive co-occurrence pattern was found between Neglecandona neglecta and I. inermis while the rest of the species pairs exhibited random co-occurrences to each other. Canonical Correspondence Analysis showed 80.8% of correlation between species and environmental variables when water temperature was the major effective factor (P<0.05) on species occurrence. Sampling time did not make difference on the numbers of species between morning (06:30-11:58 a.m.) and after noon (12:05-19:52 p.m.). Results suggest that species occurrence seems to be related to species-specific characteristics in its n-dimensional niche where species deals with several other factors.

scholarly journals Species‐specific habitat preferences do not shape the structure of a crested newt hybrid zone ( Triturus cristatus  x  T. carnifex )

2019 ◽  
Vol 9 (22) ◽  
pp. 12446-12458 ◽  
Author(s):  
Zdeněk Mačát ◽  
Martin Rulík ◽  
Daniel Jablonski ◽  
Antonín Reiter ◽  
Lenka Jeřábková ◽  
...  
Keyword(s):  
Hybrid Zone ◽  
Habitat Preferences ◽  
Triturus Cristatus ◽  
Crested Newt ◽  
Species Specific

scholarly journals Reconciling single-chamber Mg / Ca with whole-shell δ<sup>18</sup>O in surface to deep-dwelling planktonic foraminifera from the Mozambique Channel

2015 ◽  
Vol 12 (8) ◽  
pp. 2411-2429 ◽  
Author(s):  
J. Steinhardt ◽  
C. Cléroux ◽  
L. J. de Nooijer ◽  
G.-J. Brummer ◽  
R. Zahn ◽  
...  
Keyword(s):  
Planktonic Foraminifera ◽  
Habitat Preferences ◽  
Balance Model ◽  
Surface Mixed Layer ◽  
Single Specimen ◽  
Single Chamber ◽  
Mozambique Channel ◽  
Shallow Habitat ◽  
Neogloboquadrina Dutertrei ◽  
Species Specific

Abstract. Most planktonic foraminifera migrate vertically through the water column during life, meeting a range of depth-related conditions as they grow and calcify. For reconstructing past ocean conditions from geochemical signals recorded in their shells, it is therefore necessary to know vertical habitat preferences. Species with a shallow habitat and limited vertical migration will reflect conditions of the surface mixed layer and short-term and mesoscale (i.e. seasonal) perturbations therein. Species spanning a wider range of depth habitats, however, will contain a more heterogeneous, intra-specimen variability (e.g. Mg / Ca and δ18O), which is less for species calcifying below the thermocline. Obtained single-chamber Mg / Ca ratios are combined with single-specimen δ18O and δ13C of the surface-water inhabitant Globigerinoides ruber, the thermocline-dwelling Neogloboquadrina dutertrei and Pulleniatina obliquiloculata, and the deep dweller Globorotalia scitula from the Mozambique Channel. Species-specific Mg / Ca, δ13C and δ18O data combined with a depth-resolved mass balance model confirm distinctive migration and calcification patterns for each species as a function of hydrography. Whereas single-specimen δ18O rarely reflects changes in depth habitat related to hydrography (e.g. temperature), measured Mg / Ca of the last chambers can only be explained by active migration in response to changes in temperature stratification. Foraminiferal geochemistry and modelled depth habitats shows that the single-chamber Mg / Ca and single shell δ18O are in agreement with each other and in line with the changes in hydrography induced by eddies.

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