scholarly journals Interspecific differences among meiobenthic copepods in the use of microalgal food resources

1996 ◽  
Vol 143 ◽  
pp. 77-86 ◽  
Author(s):  
MC Pace ◽  
KR Carman
Keyword(s):  
Food Resources ◽  
Interspecific Differences

Morphologie bucco-linguale d'une guilde de canards barboteurs

1986 ◽  
Vol 64 (10) ◽  
pp. 2176-2180 ◽  
Author(s):  
Serge Tremblay ◽  
Richard Couture
Keyword(s):  
Resource Partitioning ◽  
Anas Platyrhynchos ◽  
Morphological Characters ◽  
Food Resources ◽  
Average Weight ◽  
Dabbling Ducks ◽  
Interspecific Differences ◽  
Interspecific Variations ◽  
Duck Species ◽  
Black Duck

Interspecific variations of bucco-lingual characteristics were measured in a guild of dabbling ducks and the influence of these characteristics on the use of food resources was studied. Morphological characters of the bill and tongue were measured in eight species of dabbling ducks of the genus Anas. Our results show that there are interspecific differences in the bucco-lingual characteristics of all species studied except for the Black Duck (Anas rubripes) and the Mallard (Anas platyrhynchos). There was a significant correlation between the density of bill lamellae and the weight of the species (r = −0.935, P < 0.01). In six species, the density of the lamellae was correlated with the volumetric index of the bill (r = −0.960, P < 0.01). These results indicate that in species with large bills the density of the lamellae is low, whereas in species with small bills, the number of lamellae is high. The volumetric index of the bill was significantly related to the average weight of each duck species (r = −0.905, P < 0.01). Dabbling ducks that filter benthic material can thus be classified on a scale based on lamellar density and bill volume. The differences in bucco-lingual morphlogical characters seem to reflect a mode of resource partitioning that diminishes competition.[Journal translation]

Brown Bear (Ursus arctos) Habitat Use and Food Resources on Elmendorf Air Force Base, Alaska

2007 ◽  
Author(s):  
Sean D. Farley ◽  
Herman Griese ◽  
Rick Sinnott ◽  
Jessica Coltrane ◽  
Chris Garner ◽  
...  
Keyword(s):  
Habitat Use ◽  
Air Force ◽  
Ursus Arctos ◽  
Brown Bear ◽  
Food Resources ◽  
Air Force Base

Long-term in vitro Storage Technique of Valuable Birch Genotypes and Plant Production on its Basis

2019 ◽  
pp. 57-67
Author(s):  
T.M. Tabatskaya ◽  
N.I. Vnukova
Keyword(s):  
Plant Production ◽  
High Survival ◽  
Ex Vitro ◽  
Regenerative Capacity ◽  
In Vitro Storage ◽  
Interspecific Differences ◽  
Regenerated Plants ◽  
Growing Conditions

A technique for the long-term (up to 27 years) in vitro storage of valuable birch genotypes under normal (25 °C, 2.0 klx, 16-h day and 8-h night) and low temperature (4 °C, 0.5 klx, 6-h day and 18-h night) growing conditions on hormone-free media has been described. The study explored for the first time the influence of different strategies to store the clones of Betula pubescens and B. pendula var. сarelica (6 genotypes) on the regenerative capacity of collection samples, adaptive potential of regenerated plants and plant production by the in vitro and ex vitro techniques. It was established that both storage strategies provided a persistently high survival rate (82-100%) and regenerative capacity of in vitro shoots (the multiplication coefficient of 4.2-6.3 and rhizogenic activity of 90-100%). The clones retained their characteristics of height growth under the in vitro and ex vitro conditions, and demonstrated intraclonal homogeneity and lack of signs of somaclonal variability. The plants showed substantial interspecific differences at the stage of multiplication and transfer to the greenhouse. The highest percentage of acclimated plants (75-98% depending on the clone genotype) was obtained after planting of micro plants straight in the greenhouse, which simplified the technology and made plant production less costly. long-term in vitro storage, birch, species, genotype, micropropagation, ex vitro adaptation, plant material

Altitudinal and Interspecific Differences in the Rehydration Abilities of Puerto Rican Frogs (Eleutherodactylus)

1982 ◽  
Vol 55 (2) ◽  
pp. 130-136 ◽  
Author(s):  
Fredrica Van Berkum ◽  
F. Harvey Pough ◽  
Margaret M. Stewart ◽  
Peter F. Brussard
Keyword(s):  
Puerto Rican ◽  
Interspecific Differences

scholarly journals Selective pollination by fungus gnats potentially functions as an alternative reproductive isolation among five Arisaema species

2020 ◽  
Author(s):  
Tetsuya K Matsumoto ◽  
Muneto Hirobe ◽  
Masahiro Sueyoshi ◽  
Yuko Miyazaki
Keyword(s):  
Reproductive Isolation ◽  
Altitudinal Gradient ◽  
Flowering Phenology ◽  
Altitudinal Distribution ◽  
Interspecific Differences ◽  
Flower Visitation ◽  
Fungus Gnats ◽  
Floral Visitor ◽  
Floral Visitors ◽  
Experimental Plots

Abstract Background and Aims Interspecific difference in pollinators (pollinator isolation) is important for reproductive isolation in flowering plants. Species-specific pollination by fungus gnats has been discovered in several plant taxa, suggesting that they can contribute to reproductive isolation. Nevertheless, their contribution has not been studied in detail, partly because they are too small for field observations during flower visitation. To quantify their flower visitation, we used the genus Arisaema (Araceae) because the pitcher-like spathe of Arisaema can trap all floral visitors. Methods We evaluated floral visitor assemblage in an altitudinal gradient including five Arisaema species. We also examined interspecific differences in altitudinal distribution (geographic isolation) and flowering phenology (phenological isolation). To exclude the effect of interspecific differences in altitudinal distribution on floral visitor assemblage, we established 10 experimental plots including the five Arisaema species on high- and low-altitude areas and collected floral visitors. We also collected floral visitors in three additional sites. Finally, we estimated the strength and contribution of these three reproductive barriers using the unified formula for reproductive isolation. Key Results Each Arisaema species selectively attracted different fungus gnats in the altitudinal gradient, experimental plots, and additional sites. Altitudinal distribution and flowering phenology differed among the five Arisaema species, whereas the strength of geographic and phenological isolations were distinctly weaker than those in pollinator isolation. Nevertheless, the absolute contribution of pollinator isolation to total reproductive isolation was weaker than geographic and phenological isolations, because pollinator isolation functions after the two early-acting barriers in plant life history. Conclusions Our results suggest that selective pollination by fungus gnats potentially contributes to reproductive isolation. Since geographic and phenological isolations can be disrupted by habitat disturbance and interannual climate change, the strong and stable pollinator isolation might compensate for the weakened early-acting barriers as an alternative reproductive isolation among the five Arisaema species.

scholarly journals An exploration of the relationship between recruitment communication and foraging in stingless bees

2021 ◽  
Author(s):  
Robbie I’Anson Price ◽  
Francisca Segers ◽  
Amelia Berger ◽  
Fabio S Nascimento ◽  
Christoph Grüter
Keyword(s):  
Stingless Bees ◽  
Sugar Content ◽  
Social Information ◽  
Food Resources ◽  
Food Sources ◽  
Foraging Strategies ◽  
High Quality ◽  
Recruitment Communication ◽  
Eusocial Bees ◽  
The Relationship

Abstract Social information is widely used in the animal kingdom and can be highly adaptive. In social insects, foragers can use social information to find food, avoid danger or choose a new nest site. Copying others allows individuals to obtain information without having to sample the environment. When foragers communicate information they will often only advertise high quality food sources, thereby filtering out less adaptive information. Stingless bees, a large pantropical group of highly eusocial bees, face intense inter- and intra-specific competition for limited resources, yet display disparate foraging strategies. Within the same environment there are species that communicate the location of food resources to nest-mates and species that do not. Our current understanding of why some species communicate foraging sites while others do not is limited. Studying freely foraging colonies of several co-existing stingless bee species in Brazil, we investigated if recruitment to specific food locations is linked to (1) the sugar content of forage, (2) the duration of foraging trips and (3) the variation in activity of a colony from one day to another and the variation in activity in a species over a day. We found that, contrary to our expectations, species with recruitment communication did not return with higher quality forage than species that do not recruit nestmates. Furthermore, foragers from recruiting species did not have shorter foraging trip durations than those from weakly-recruiting species. Given the intense inter- and intraspecific competition for resources in these environments, it may be that recruiting species favour food resources that can be monopolised by the colony rather than food sources that offer high-quality rewards.

scholarly journals Use of Formal and Informal Food Resources by Food Insecure Families in Lima, Peru: A Mixed-Methods Analysis

2021 ◽  
Author(s):  
J. D. Brewer ◽  
M. P. Santos ◽  
M. A. Lopez ◽  
V. A. Paz-Soldan ◽  
M. P. Chaparro
Keyword(s):  
Mixed Methods ◽  
Food Insecurity ◽  
Low Income ◽  
Food Resources ◽  
Food Assistance Programs ◽  
Assistance Programs ◽  
Food Security Status ◽  
Financial Need ◽  
June July ◽  
Food Insecure Households

AbstractThe goal of this study was to measure food insecurity among families with children in a low-income district of Lima, Peru and to identify the formal and informal food resources available to them that may affect their food security status. In June-July 2019, we collected data from 329 randomly selected households in Villa El Salvador (Lima, Peru). Following a mixed methods approach, we found that the percentage of households using food assistance programs (FAPs) increased with increasing levels of food insecurity, but two FAPs were heavily used by households regardless of food (in)security. The main reasons for using FAPs included financial need, already being signed up in the program, and believing that the food was of nutritional value; the main reasons for non-use were finding the program unnecessary, dislike or poor perceived quality of the food, and not being able to sign up for the program. Similarly, informal food resources, such as buying food on credit or receiving food from someone outside the household, were incrementally used with increased levels of food insecurity. Our study clarifies the relationship between level of household food insecurity and FAP use – FAPs more commonly used by food insecure households were used because of financial need, whereas the FAPs most commonly used by food secure households were those with automatic enrollment. At a programmatic level, our research highlights the need for making nutritious and preferred foods available in FAPs and standardizing the application of enrollment criteria.

scholarly journals Landscape condition influences energetics, reproduction, and stress biomarkers in grizzly bears

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Abbey E. Wilson ◽  
Dan Wismer ◽  
Gordon Stenhouse ◽  
Nicholas C. Coops ◽  
David M. Janz
Keyword(s):  
Protein Expression ◽  
Physiological Function ◽  
A Priori ◽  
Food Resources ◽  
Information Criteria ◽  
Complement C3 ◽  
Grizzly Bears ◽  
Theoretic Approach ◽  
Protein Food ◽  
The Impact

AbstractEnvironmental change has been shown to influence mammalian distribution, habitat use, and behavior; however, few studies have investigated the impact on physiological function. This study aimed to determine the influence of landscape condition on the expression of target proteins related to energetics, reproduction, and stress in grizzly bears. We hypothesized that changes in landscape condition explains protein expression. Skin biopsies were collected from free-ranging grizzly bears in Alberta, Canada from 2013–2019 (n = 86 individuals). We used an information theoretic approach to develop 11 a priori candidate generalized linear mixed models to explain protein expression. We compared models using Akaike Information Criteria (AICc) weights and averaged models with ΔAICc < 2 for each protein. Food resources, represented by increased distance to coal mines and decreased crown closure, positively influenced energetic proteins (adiponectin and alpha-1-acid glycoprotein). Proteins related to reproduction (ceruloplasmin and serpin B5) were positively associated with increased wetland and upland food resources in addition to movement, but negatively associated with increased distance to roads. One stress related protein, complement C3, was positively influenced by increased percent conifer. Given the need to detect emerging threats to wildlife, we suggest the assessment of physiological function will lead to improved monitoring of species in rapidly changing landscapes.

scholarly journals Bark traits, decomposition and flammability of Australian forest trees

2017 ◽  
Vol 65 (4) ◽  
pp. 327 ◽  
Author(s):  
Saskia Grootemaat ◽  
Ian J. Wright ◽  
Peter M. van Bodegom ◽  
Johannes H. C. Cornelissen ◽  
Veronica Shaw
Keyword(s):  
Forest Tree ◽  
Remarkable Feature ◽  
Interspecific Differences ◽  
Eucalypt Plantations ◽  
Physical Traits ◽  
Key Driver ◽  
Multiple Species ◽  
Species Specific ◽  
First Time ◽  
Different Tissues

Bark shedding is a remarkable feature of Australian trees, yet relatively little is known about interspecific differences in bark decomposability and flammability, or what chemical or physical traits drive variation in these properties. We measured the decomposition rate and flammability (ignitibility, sustainability and combustibility) of bark from 10 common forest tree species, and quantified correlations with potentially important traits. We compared our findings to those for leaf litter, asking whether the same traits drive flammability and decomposition in different tissues, and whether process rates are correlated across tissue types. Considerable variation in bark decomposability and flammability was found both within and across species. Bark decomposed more slowly than leaves, but in both tissues lignin concentration was a key driver. Bark took longer to ignite than leaves, and had longer mass-specific flame durations. Variation in flammability parameters was driven by different traits in the different tissues. Decomposability and flammability were each unrelated, when comparing between the different tissue types. For example, species with fast-decomposing leaves did not necessarily have fast-decomposing bark. For the first time, we show how patterns of variation in decomposability and flammability of bark diverge across multiple species. By taking species-specific bark traits into consideration there is potential to make better estimates of wildfire risks and carbon loss dynamics. This can lead to better informed management decisions for Australian forests, and eucalypt plantations, worldwide.

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