Foraging and habitat relationships of the sibling species Willow Flycatcher (Empidonax traillii) and Alder Flycatcher (E. alnorum) in southern Ontario

1983 ◽  
Vol 61 (7) ◽  
pp. 1510-1516 ◽  
Author(s):  
Jon C. Barlow ◽  
W. Bruce McGillivray
Keyword(s):  
Sibling Species ◽  
Foraging Ecology ◽  
Habitat Preferences ◽  
Niche Overlap ◽  
Secondary Contact ◽  
Habitat Types ◽  
Sympatric Populations ◽  
Southern Ontario ◽  
Northward Expansion ◽  
A Site

A northward expansion of the range of Willow Flycatchers has resulted in regions of secondary contact with Alder Flycatchers. The foraging ecology of both species overlaps extensively for both mutually allopatric and sympatric populations. Willow Flycatchers choose a more xeric upland habitat in southwestern Ontario than they do farther north at a site of secondary contact near Stouffville, Ontario. Alder Flycatchers at both Stouffville and Ottawa show similar habitat preferences. Habitat types chosen by both species at Stouffville overlapped considerably. Despite the extensive niche overlap at Stouffville, no evidence of competition between the species was observed.

Habitat and dung preferences of scarab beetles of the subfamily Scarabaeinae: a case study in a tropical monsoon forest in Sri Lanka

2016 ◽  
Vol 36 (02) ◽  
pp. 97-105 ◽  
Author(s):  
Dishane K. Hewavithana ◽  
Mayuri R. Wijesinghe ◽  
Chandima D. Dangalle ◽  
H. A. S. Gayan Dharmarathne
Keyword(s):  
Sri Lanka ◽  
Habitat Preferences ◽  
Food Preferences ◽  
Niche Overlap ◽  
Dung Beetles ◽  
Individual Species ◽  
Habitat Types ◽  
Monsoon Forest ◽  
Tropical Monsoon ◽  
Tropical Monsoon Forest

AbstractWe studied the food and habitat preferences of beetles of the subfamily Scarabaeinae in a protected tropical monsoon forest, the Wasgomuwa National Park in Sri Lanka. While gaining an insight into the capacity of different resources to support dung beetles, we tested the hypothesis that, in a landscape with a mosaic of habitat types and a diversity of large mammals, specialization facilitates coexistence of the scarabs. Pitfall traps were laid in five distinct habitat types (forest, riverine, sandy banks, scrub and grassland), and baited with five dung types (leopard, cervid, elephant, bear and buffalo). Four hundred and fifty seven beetles of 22 species in seven genera were recorded. Significant differences were seen in the species richness and abundance of dung beetles between different habitats and dung types, indicating habitat and food preferences. The highest richness of scarabs was in the riverine habitat and in leopard dung. Niche breath values of the individual species indicated differences in the degrees of specialization, while niche overlap values indicated a greater sharing of dung beetle species between similar habitats and dung types than between dissimilar ones. These findings provide evidence that selectivity of habitat, and dung, may be important in promoting coexistence among the scarabs in a tropical environment.

scholarly journals The Evolutionary History, Diversity, and Ecology of Willows (Salix L.) in the European Alps

Diversity ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 146
Author(s):  
Natascha D. Wagner ◽  
Li He ◽  
Elvira Hörandl
Keyword(s):  
Habitat Preferences ◽  
Introgressive Hybridization ◽  
Ecological Factors ◽  
The Arctic ◽  
Secondary Contact ◽  
European Alps ◽  
Climatic Fluctuations ◽  
History Of ◽  
European Mountain ◽  
The Alps

The genus Salix (willows), with 33 species, represents the most diverse genus of woody plants in the European Alps. Many species dominate subalpine and alpine types of vegetation. Despite a long history of research on willows, the evolutionary and ecological factors for this species richness are poorly known. Here we will review recent progress in research on phylogenetic relationships, evolution, ecology, and speciation in alpine willows. Phylogenomic reconstructions suggest multiple colonization of the Alps, probably from the late Miocene onward, and reject hypotheses of a single radiation. Relatives occur in the Arctic and in temperate Eurasia. Most species are widespread in the European mountain systems or in the European lowlands. Within the Alps, species differ ecologically according to different elevational zones and habitat preferences. Homoploid hybridization is a frequent process in willows and happens mostly after climatic fluctuations and secondary contact. Breakdown of the ecological crossing barriers of species is followed by introgressive hybridization. Polyploidy is an important speciation mechanism, as 40% of species are polyploid, including the four endemic species of the Alps. Phylogenomic data suggest an allopolyploid origin for all taxa analyzed so far. Further studies are needed to specifically analyze biogeographical history, character evolution, and genome evolution of polyploids.

scholarly journals First records of Brachythemis impartita in peninsular Italy (Odonata: Libellulidae)

2017 ◽  
pp. 133-136
Author(s):  
Emanuele Guido Condello ◽  
Edoardo Razzetti ◽  
Cristiano Liuzzi ◽  
Vittoria D’Agostino ◽  
Fabio Mastropasqua
Keyword(s):  
Habitat Preferences ◽  
Artificial Lake ◽  
Northward Expansion ◽  
First Time ◽  
Two Populations

Two populations of Brachythemis impartita (Karsch, 1890) are here reported in peninsular Italy. The species was found for the first time in 2015 in Calabria in the area of the Angitola artificial lake (Maierato and Monterosso Calabro municipalities) not far from the Tyrrhenian coast. In 2016 the species was also observed in southern Apulia, along the banks of two artificial lagoons in the municipality of Ugento. Information are provided that confirm the habitat preferences of the species and a northward expansion.

scholarly journals Temporal Variation in the Niche Partitioning of Lake Michigan Salmonines as it Relates to Alewife Abundance and Size Structure.

2021 ◽  
Author(s):  
Benjamin A. Turschak ◽  
Charles R. Bronte ◽  
Sergiusz J. Czesny ◽  
Brandon S. Gerig ◽  
Austin Happel ◽  
...  
Keyword(s):  
Ecological Niche ◽  
Lake Michigan ◽  
Nitrogen Isotopes ◽  
Size Structure ◽  
Prey Availability ◽  
Habitat Preferences ◽  
Niche Partitioning ◽  
Niche Overlap ◽  
Isotopic Niche ◽  
Resource Gradient

Stable isotope analyses offer a useful means for quantifying ecological niche dimensions, though few studies have examined isotopic response of an ecological community with respect to resource gradients such as fluctuations in prey availability. Stable carbon and nitrogen isotopes were measured for Lake Michigan salmonines and their prey collected from 2014 to 2016. Bayesian ellipse and mixing model analyses were used to quantify isotopic niche characteristics and diets, respectively, among species and years. During the three-year study period, abundance and size structure of preferred alewife prey changed substantially and offered an opportunity to explore predator isotopic niche response and diet shifts along a prey resource gradient. Results suggested increased reliance on alewives, especially small alewives, over the study period and were consistent with greater availability of this prey. However, differential use of alewife size classes and alternative prey sources by salmonine predators was apparent, which suggested possible resource partitioning. Characterization of ecological niche overlap using stable isotopes likely requires consideration of shared resource availability as well as specific prey and habitat preferences.

Light intensity as a factor in the choice of an oviposition site by Drosophila pseudoobscura and Drosophila persimilis

1983 ◽  
Vol 25 (4) ◽  
pp. 370-377 ◽  
Author(s):  
Dennis J. Wogaman ◽  
Marvin B. Seiger
Keyword(s):  
Light Intensity ◽  
Genetic Variability ◽  
Sibling Species ◽  
Light Response ◽  
Drosophila Pseudoobscura ◽  
Isofemale Lines ◽  
Sympatric Populations ◽  
Allopatric Populations ◽  
Behavioral Differentiation ◽  
Drosophila Persimilis

Light preferences for ovipositing of the sibling species Drosophila pseudoobscura and D. persimilis were measured in a multichoice chamber. Behavioral differentiation was found among sympatric populations of D. pseudoobscura and D. persimilis and between allopatric populations of D. pseudoobscura. Differences among isofemale lines within populations indicated genetic variability for the behavior. Both D. pseudoobscura populations were less fecund in a uniform light environment than in the multichoice environment while D. persimilis showed no difference in fecundity in the two environments. The patterns for general photoresponse and ovipositional light response were shown to be different for each population. Thus, the motivation to oviposit may affect photopreference differentially in each population.

Corrigendum to: Distribution and relative abundance of forest duikers in Dassioko Sud Forest Reserve (coastal Côte d'Ivoire)

2018 ◽  
Vol 45 (2) ◽  
pp. 194
Author(s):  
K. A. Yao ◽  
E. A. Bitty ◽  
K. B. Kassé ◽  
Y. C. Kouakou ◽  
K. H. Yaokokoré-Beibro ◽  
...  
Keyword(s):  
Relative Abundance ◽  
Habitat Preferences ◽  
Habitat Type ◽  
Distribution Patterns ◽  
Encounter Rate ◽  
Line Transect ◽  
Habitat Types ◽  
Anthropogenic Pressures ◽  
Forest Reserve ◽  
Encounter Rates

Context Duikers play a vital role in maintaining forest ecosystems, as both seed dispersers and prey. In West Africa, duikers are also an important source of food and income; however, it is likely that some species are now being hunted at unsustainable levels. So as to contribute to duiker conservation, we used line-transect data and additional information on dung and track counts to estimate relative abundance and establish distribution patterns of forest duikers in Côte d'Ivoire's Dassioko Sud Forest Reserve (DSFR), a poorly known, remnant coastal rainforest. We also collected basic information on hunting pressure. Methods Forest duiker counts were made twice per month from July 2013 to March 2014 on six line transects of varying lengths (5.6–6.7km) and in different regions of the DSFR, representing different habitat types. The number of sightings per kilometre walked, defined as ‘encounter rate', was used to compute an index of relative abundance. We recorded all evidence of poachers and used these data to generate a poaching index (# poaching signs per kilometre) for different habitat types. Key results The DSFR has lost three of seven total forest duiker species and populations of the four remaining species are declining. Encounter rates were greatest for Philantomba maxwellii (0.46 indices km–1) and accounted for 68% of total encounters. Cephalophus niger, C. dorsalis and C. silvicultor were encountered at similar (0.07 indices km–1) but much lower rates. For all species, mean encounter rates were highest in degraded forest (0.38–0.73 indices km–1), followed by secondary (0.2–0.44 indices km–1) and primary (0.19–0.44 indices km–1) forest. Conclusions Of the four forest duiker species still present in the DSFR, the black, bay and yellow-backed duikers are the most affected by anthropogenic pressures. Duiker abundance in the DSFR varies with habitat type. This variation is apparently influenced by differences in forest structure, poaching pressure and proximity to villages. Implications The study provides baseline data for future managing of ungulate populations in the DSFR. We recommend that a biomonitoring study of duiker populations be initiated immediately to help determine population trends, investigate habitat preferences, and help curb illegal hunting activities in this important forest reserve.

scholarly journals Habitat preferences of tigers Panthera tigris in the Sundarbans East Wildlife Sanctuary, Bangladesh, and management recommendations

Oryx ◽  
2007 ◽  
Vol 41 (4) ◽  
pp. 463-468 ◽  
Author(s):  
M. Monirul H. Khan ◽  
David J. Chivers
Keyword(s):  
Habitat Preferences ◽  
Panthera Tigris ◽  
Wildlife Sanctuary ◽  
Habitat Types ◽  
Transect Sampling ◽  
Management Recommendations ◽  
The Sundarbans

AbstractWe examined the habitat preferences of tigers Panthera tigris in four habitat types in the Sundarbans East Wildlife Sanctuary, Bangladesh. Transect sampling was used to count tiger signs. Mean densities of signs of feeding, resting, defaecation and interaction were significantly different between the four main habitat types (mangrove woodlands, grasslands, sea beaches and transitional areas), whereas movement, scratch-scent-urinal and other signs were not significantly different. This indicates that tigers have habitat preferences for at least some activities. Similar patterns were found in the densities of movement and feeding signs, as well as of resting and defaecation signs, across the four different habitat types. Tigers were found to use soft-barked trees for scratching more often than other types.

scholarly journals Variation in hierarchical guild structure between two bird assemblages of a wetland in the Mexican Pacific

2017 ◽  
Vol 65 (4) ◽  
pp. 1540 ◽  
Author(s):  
Mateo Donald Ruiz Bruce Taylor ◽  
José Luis Rangel Salazar ◽  
Paula Enríquez ◽  
Jorge L. León-Cortés ◽  
Carlos García-Estrada
Keyword(s):  
Habitat Preferences ◽  
Species Abundance ◽  
Bird Species ◽  
Ecological Groups ◽  
Trophic Guilds ◽  
Guild Structure ◽  
Habitat Types ◽  
Species Identity ◽  
Mexican Pacific ◽  
Bird Assemblages

Neotropical wetlands comprise contrasting habitats with highly diverse avifauna, including herbivores, insectivores and carnivores, of both terrestrial and aquatic species. Therefore, comparisons between wetland bird assemblages based only on species identity may disregard turnover within ecological groups, and eclipse important variations between habitat types. We studied bird assemblages from mangrove and estuary habitat types from a coastal lagoon system in Oaxaca, Mexico. For this, we used 640 point counts to obtain data on bird species using those habitats between October 2009 and May 2012. We ascertained guild structure by classifying 139 species in a scalar hierarchy of two-levels: 17 key-resource guilds nested within seven trophic guilds. To evaluate variation in guild structure between habitat types, we contrasted richness and diversity across trophic guilds and tested for variation in abundance within key-resource guilds. We exposed a tendency of greater diversity within terrestrial guilds in mangrove and within aquatic guilds at the estuary. However, these differences were compensatory and neither richness nor diversity varied between habitat types in comparisons across the sets of trophic guilds. Parallel analyses at two hierarchical levels supported the theoretical prediction of greater change at lower levels. Herpetofauna, wood invertebrates, aquatic invertebrates and seeds emerged as dietary components that may explain the distribution of abundance in key-resource guilds. Although the guilds from mangrove and estuary produced comparable sets of richness and diversity values, the actual identity of guilds with high values varied between habitats. On the other hand, species abundance comparisons within guilds pinpointed specific associations with habitat types and this method represents a suitable strategy for identifying habitat preferences in complex wetland bird assemblages.

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