Using ecology to inform physiology studies: implications of high population density in the laboratory

2015 ◽  
Vol 308 (6) ◽  
pp. R449-R454 ◽  
Author(s):  
Amy E. M. Newman ◽  
Nicholas B. Edmunds ◽  
Shannon Ferraro ◽  
Quentin Heffell ◽  
Gillian M. Merritt ◽  
...  
Keyword(s):  
Population Density ◽  
Immune Function ◽  
Body Condition ◽  
Natural Environment ◽  
Critical Factor ◽  
High Population Density ◽  
Animal Kingdom ◽  
Present Evidence ◽  
Natural Systems ◽  
Conspecific Density

Conspecific density is widely recognized as an important ecological factor across the animal kingdom; however, the physiological impacts are less thoroughly described. In fact, population density is rarely mentioned as a factor in physiological studies on captive animals and, when it is infrequently addressed, the animals used are reared and housed at densities far above those in nature, making the translation of results from the laboratory to natural systems difficult. We survey the literature to highlight this important ecophysiological gap and bring attention to the possibility that conspecific density prior to experimentation may be a critical factor influencing results. Across three taxa: mammals, birds, and fish, we present evidence from ecology that density influences glucocorticoid levels, immune function, and body condition with the intention of stimulating discussion and increasing consideration of population density in physiology studies. We conclude with several directives to improve the applicability of insights gained in the laboratory to organisms in the natural environment.

Managing Landscape Irrigation to Avoid Soil and Nutrient Losses

EDIS ◽  
2013 ◽  
Vol 2013 (11) ◽  
Author(s):  
George Hochmuth ◽  
Laurie Trenholm ◽  
Don Rainey ◽  
Esen Momol ◽  
Claire Lewis ◽  
...  
Keyword(s):  
Natural Environment ◽  
Management Practices ◽  
Root Zone ◽  
Irrigation Management ◽  
Critical Factor ◽  
Nutrient Losses ◽  
County Agents ◽  
The Right ◽  
Soil And Water

Proper irrigation management is critical to conserve and protect water resources and to properly manage nutrients in the home landscape. How lawns and landscapes are irrigated directly impacts the natural environment, so landscape maintenance professionals and homeowners must adopt environmentally-friendly approaches to irrigation management. After selecting the right plant for the right place, water is the next critical factor to establish and maintain a healthy lawn and landscape. Fertilization is another important component of lawn and landscape maintenance, and irrigation must be applied correctly, especially following fertilization, to minimize potential nutrient losses. This publication supplements other UF/IFAS Extension publications that also include information on the role of soil and the root zone in irrigation management. This publication is designed to help UF/IFAS Extension county agents prepare materials to directly address nutrient losses from lawns and landscapes caused by inadequate irrigation management practices. This 6-page fact sheet was written by George Hochmuth, Laurie Trenholm, Don Rainey, Esen Momol, Claire Lewis, and Brian Niemann, and published by the UF Department of Soil and Water Science, October 2013. http://edis.ifas.ufl.edu/ss586

Community based design approach as initial stage to promote urban composting from a Hill Station of the Philippines

2019 ◽  
Author(s):  
Marcelino Jr Lunag ◽  
Jessie C. Elauria ◽  
Juanito D. Burguillos
Keyword(s):  
Population Density ◽  
Community Involvement ◽  
The Philippines ◽  
Design Stage ◽  
High Population Density ◽  
Community Based ◽  
Hill Station ◽  
Initial Stage ◽  
Household Members ◽  
Community Based Design

This study confirms that lack of space due to high population density restricts household members and the barangay to comply with the existing law regarding composting. With these, community involvement in the design stage of compost bin as initial stage was done accordingly. The participants were voluntarily interviewed and were given questionnaires, which was endorsed and approved by barangay committee.

scholarly journals Recruitment sex ratios in gray-tailed voles (Microtus canicaudus) in response to density, sex ratio, and season

2003 ◽  
Vol 81 (8) ◽  
pp. 1306-1311 ◽  
Author(s):  
Monica L Bond ◽  
Jerry O Wolff ◽  
Sven Krackow
Keyword(s):  
Population Density ◽  
Sex Ratio ◽  
Resource Competition ◽  
Sex Ratios ◽  
Female Offspring ◽  
High Population ◽  
Reproductive Value ◽  
High Population Density ◽  
Adult Sex Ratio ◽  
Sex Ratio Adjustment

We tested predictions associated with three widely used hypotheses for facultative sex-ratio adjustment of vertebrates using eight enclosed populations of gray-tailed voles, Microtus canicaudus. These were (i) the population sex ratio hypothesis, which predicts that recruitment sex ratios should oppose adult sex-ratio skews, (ii) the local resource competition hypothesis, which predicts female-biased recruitment at low adult population density and male-biased recruitment at high population density, and (iii) the first cohort advantage hypothesis, which predicts that recruitment sex ratios should be female biased in the spring and male biased in the autumn. We monitored naturally increasing population densities with approximately equal adult sex ratios through the spring and summer and manipulated adult sex ratios in the autumn and measured subsequent sex ratios of recruits. We did not observe any significant sex-ratio adjustment in response to adult sex ratio or high population density; we did detect an influence of time within the breeding season, with more female offspring observed in the spring and more male offspring observed in the autumn. Significant seasonal increases in recruitment sex ratios indicate the capacity of female gray-tailed voles to manipulate their offspring sex ratios and suggest seasonal variation in the relative reproductive value of male and female offspring to be a regular phenomenon.

scholarly journals Quantitative effects of defaunation on rumen fermentation and digestion in sheep

1985 ◽  
Vol 54 (1) ◽  
pp. 105-119 ◽  
Author(s):  
J. B. Rowe ◽  
A. Davies ◽  
A. W. J. Broome
Keyword(s):  
Organic Matter ◽  
Population Density ◽  
Volatile Fatty Acids ◽  
Rumen Fluid ◽  
Dietary Carbohydrate ◽  
High Population Density ◽  
Irreversible Loss ◽  
Faecal Excretion ◽  
Carbon And Nitrogen ◽  
End Products

1. Studies on the quantitative significance of protozoa on carbon and nitrogen digestion and metabolism in the rumen were carried out in sheep given a diet of pelleted concentrate (500 g/d) and chopped hay (500 g/d).2. Measurements were made of apparent digestibility; flows of organic matter and dietary and microbial non-ammonia N (NAN) (using 15NH+4) to the duodenum; and rates of production, interconversion and metabolism of the major C fermentation end-products (from mathematical modelling of 14C isotope values).3. The population density of bacteria in the rumen increased as a result of defamation (28.6 compared with 8.2 x 10° organisms/ml). This high density was associated with greater utilization of volatile fatty acids (VFA) within the rumen.4. The rate of irreversible loss (IL) of bicarbonatefcarbon dioxide from the rumen was greater in the defaunated animals (98.5 v. 57.2 g C/d) but the IL from the blood was greater in the faunated group (138.6 v. 106.1 g C/d). This is consistent with the hypothesis that the high population density of bacteria found in the rumen fluid of defaunated animals may result in increased fermentation of rumen VFA and digestible dietary carbohydrate, thereby increasing the output of CO2 from the rumen and reducing the quantity of VFA (hence energy) available to the host.5. There was no difference in the flow of organic matter (OM) to the duodenum but there was a higher faecal excretion of OM in defaunated animals (apparent OM digestibility: 0.72 in faunated, 0.67 in defaunated).6. Defamation did not significantly increase the flow of NAN to the duodenum, the percentage of duodenal NAN of bacterial origin or the quantity of microbial NAN synthesized/g organic matter fermented. Faecal excretion of NAN was higher in defaunated animals (5.3 v. 3.6 g N/d).

Ecological Selves and Organizational Leadership Values that Matter

2014 ◽  
Vol 3 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Katrina S. Rogers
Keyword(s):  
Seventeenth Century ◽  
Soil Erosion ◽  
Knowledge Base ◽  
Human Activity ◽  
Natural Environment ◽  
Western Europe ◽  
Industrial Revolution ◽  
Striking Feature ◽  
Natural Systems ◽  
Body Of Knowledge

One striking feature in the sweep of history is the extent to which humans have manipulated the natural environment to serve our needs and our desires. In the early written record, there are tales of deforestation and soil erosion (Plato, 360 BCE). As early as the seventeenth century, natural historians compared the grasslands around villages to inhabited areas and speculated on the consequences of human activity on natural systems ( Goudie, 2006 , p. 3). The onset of the industrial revolution in Western Europe combined with a growing understanding and knowledge base of science has rendered a circumstance of uncontrolled manipulation of the ecosystems and ever finer ways to measure these consequences. This article is an invitation to challenge us as scholars and practitioners to seek understanding as companies and other organizations take up their roles in a world that we are transforming irrevocably. Why does it matter, after all, that we seek to build a body of knowledge around corporate functioning? It is my intention that this article helps us ponder and reflect on that question.

Synergistic Population Density and Environmental Effects on Deer Body Condition

2020 ◽  
Vol 84 (5) ◽  
pp. 938-947
Author(s):  
Pascale Ayotte ◽  
Mael Le Corre ◽  
Steeve D. Côté
Keyword(s):  
Population Density ◽  
Body Condition ◽  
Environmental Effects

Can differences between continental and insular habitats influence the parasites communities associated with the endemic frog Haddadus binotatus?

2020 ◽  
Vol 94 ◽  
Author(s):  
A. Aguiar ◽  
D.H. Morais ◽  
F.H. Yamada ◽  
L.A. dos Anjos ◽  
L.A.F. da Silva ◽  
...  
Keyword(s):  
Population Density ◽  
Parasite Transmission ◽  
Helminth Parasites ◽  
High Population Density ◽  
Geographic Isolation ◽  
Transmission Success ◽  
Parasite Richness ◽  
Continental Islands ◽  
Colonization Process ◽  
The Mean

Abstract Habitats characterized by geographic isolation such as islands have been studied using different organisms as models for understanding the dynamic and insular patterns of biodiversity. Determinants of parasite richness in insular host populations have been conducted mainly with mammals and birds, showing that parasite richness decreases in insular areas. In the present study, we predicted that the type of environment (insular or continental) can influence the richness, diversity and abundance of parasites associated with the endemic frog Haddadus binotatus (Spix, 1824). We sampled frogs in two insular and two mainland fragments to survey their helminth parasites. The total richness was composed of 15 taxa of Nematoda and two of Acanthocephala, and the community composition of the two islands had more similarities between them than the two mainland localities. The insular effect was positive for richness and abundance of helminths, and no significant effect was observed on helminth diversity – even the mean diversity presented high numbers for the islands. We presumed that insular hosts could have lost some parasites in the colonization process when these continental islands were separated from the mainland, approximately 11,000 years ago. However, the high richness and abundance on islands can be explained by an epidemiological argument, which considers high population density due to insularity and other features of the host as factors that increase parasite transmission success among individuals.

Aggregations of masked shrews ( Sorex cinereus ): density-related mating behavior? / Agrégation de musaraignes masquées ( Sorex cinereus ): accouplement relatif à la densité de la population?

Mammalia ◽  
2006 ◽  
Vol 70 (1-2) ◽  
Author(s):  
Thomas J. Maier ◽  
Katherine L. Doyle
Keyword(s):  
Population Density ◽  
Mating Behavior ◽  
High Population ◽  
High Population Density ◽  
Genetic Analyses ◽  
Highly Active ◽  
Sorex Cinereus

AbstractLarge aggregations of shrews have been reported and various explanations offered for this seemingly rare behavior; however, there has been little evidence to support any particular interpretation. We observed two small aggregations of highly active vocalizing Sorex cinereus while performing wildlife surveys in forested habitats in central Massachusetts, USA. These observations, in conjunction with a review of other reports, including genetic analyses, strongly suggest that such aggregations of adult Sorex are associated with mating behavior, more readily observed during periods of high population density. Published accounts of such behavior may be rare because primarily large aggregations have been reported; however, smaller breeding aggregations may be common.

scholarly journals Sex-Related Natal Dispersal of White Storks (Ciconia Ciconia) in Poland: How Far and Where to?

The Auk ◽  
2006 ◽  
Vol 123 (4) ◽  
pp. 1103-1109 ◽  
Author(s):  
Nikita Chernetsov ◽  
Wiesław Chromik ◽  
Pawel T. Dolata ◽  
Piotr Profus ◽  
Piotr Tryjanowski
Keyword(s):  
Regression Analysis ◽  
Population Density ◽  
Interannual Variation ◽  
Natal Dispersal ◽  
High Population Density ◽  
Ciconia Ciconia ◽  
Nesting Sites ◽  
White Storks ◽  
Population Indices ◽  
Dispersal Distances

Abstract Distance and direction of natal dispersal were studied in a Polish White Stork (Ciconia ciconia) population on the basis of 25 years of banding and resighting data. Multiple regression analysis showed a significant sex-linked bias (females settled farther from the natal sites than males) and effect of banding year, in that dispersal distances were decreasing toward the end of the study period. Population indices in the hatching year and the presumed recruitment year did not help to explain the variance. The birds showed a trend toward settling southeast of the natal site, but this was significant only in individuals that settled within 50 km of the natal site. We suggest that when returning from winter sites in the southeast, young White Storks settle before they reach their presumed migratory target in the vicinity of the natal site. This is only possible if, in spite of a relatively high population density, many breeding areas and potential nesting sites remain vacant. This might also explain our failure to find density dependence in the interannual variation of dispersal distances.

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