Interactions and relationships among organisms and their environment. This includes biotic and abiotic (non-living/environmental) factors that impact organisms.

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What is the difference between pianka's index and renkonen index? [on hold]

Why do Pianka's and renkonen indices give different results, even though they are both meant to measure overlap and similarities?
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42 views

Advantages of gregarious vs solitary behaviour?

I'm trying to explain why birds (specifically wildfowl) are gregarious during the winter and solitary during the summer. I think that in winter, birds are gregarious to reduce the risk of predation ...
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48 views

How far in can non-extremophiles live, in Earth?

I am a high school student. I'm doing a project where I need to find a planet in our galaxy that might be habitable. Then I need to create an organism that could live on that planet and justify ...
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76 views

What triggers the migration of robins?

I live in central Massachusetts, and have begun seeing robins, as we generally do in early March. The temperature is well below normal, though, and three feet of snow are covering the still-frozen ...
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9 views

What light conditions facilitate communication between birds with black and white plumage?

I'm studying two populations of birds: Population A and Population B Population A has a small white patch on its neck. Population B has a large white patch on its neck. See attached diagram. It is ...
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2answers
39 views

Does the biosphere have infinite resources and are they infinitely renewable?

Does biomass represent all of the resources of the biosphere and therefore it would be theoretically infinitely renewable (as long as we have the sun) since all the biomass is part of the carbon ...
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32 views

Literature that demonstrates organisms have a competitive advantage in numbers

I'm studying two bird populations that are competing against each other for a resource: Population A and Population B. Population A is present in much higher numbers than Population B, and as a ...
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2answers
71 views

What is the mechanism behind plants losing their leaves? [duplicate]

Do plants that lose their leaves (i.e., deciduous plants) do so because of external conditions (e.g., drought, cold), or because of an internal process? Another way of looking at it: if you take a ...
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32 views

Selection Pressure on Orca Whale Coloration

What is the proposed selection pressure that leads to the distinctive coloration of Orca whales? I can find nothing in the literature.
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63 views

Reconstruction of wildlife distribution based on poorly-sampled data [closed]

cross-posted to Signal Processing, Cross Validated, and World Building Stack Exchange Hi, I thought I'd also put this here in case there are any field biologists with ideas on the matter. Problem: ...
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54 views

What happens during kefir fermentation process?

I’ve found many sources about the positive effects of kefir for the digestive system. However I haven’t found any information about the fermenting process. What is the exact biology (chemistry?) ...
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1answer
57 views

(Why) are polar bears more common in Labrador than in southern Greenland?

The Labrador Sea is between Greenland, Labrador, and Qikiqtaaluk: Map source. A Greenlandic source on polar bears states: In Greenland the polar bear lives and breeds in the northernmost parts ...
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127 views

How big should the human population be, as predicted by body mass?

I would guess there is a theory in biology which states that the population size for a given species is inversely proportional to the body mass of individuals in that species. In other words, there ...
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1answer
115 views

Chaos theory and population cycles of odd periodicity

I have just begun to read about Chaos theory and have come across the statement that "Period three implies chaos." My question: Does any odd period imply chaos or only 3? If so, how can populations ...
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1answer
59 views

How does the ideal free distribution work?

I have recently completed a study on Brent Goose. I found that Brent Geese occupy high quality habitat first then once this is full of geese, they fill up low quality habitat. However, there were ...
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94 views

What is called the “area size that an animal usually lives in”?

What is called the "area size that an animal usually lives in" or "needs for a normal life"? Is there any specific term?
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133 views

Why are the fertility rates of large predators kept low?

Predators at the top of a food chain, like lions, seem to have a relatively low fertility rate, which fits well to the ecosystem and avoids overpredation. But what is the mechanism that keeps the ...
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2answers
102 views

Premise of life cycle synchronization between predator and prey

While reading about the predator satiation hypothesis of the periodical cicadas' 13/17 year life cycles, I started wondering about its premise. By the way, I understand the math behind the prime ...
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4answers
576 views

What prevents predator overpopulation?

I've often heard that a population, human or otherwise, will continue to grow as long as there is food available (assuming nothing else is killing them off). It makes sense: if you have food you can ...
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1answer
70 views

Why do the proportion of predators increase at mass extinction events?

Why does predation surge with mass extinction? It is caused by extreme selective pressures over resource competition that forces certain species to adapt to predatory niches?
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1answer
43 views

What fish (and/or shellfish) species with a multi-year life-cycle, besides salmon, die after spawning?

Most species of salmon die after spawning. Are there any other types of fish that spawn once and then die after a multi-year life-cylce? Is this a rare life history strategy among our human exploited ...
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1answer
140 views

Why are fly not scared when landing on a monitor with changing graphics?

I have been wondering why would insects in general, not be scared when important changes happen on your monitor where they have landed... If you move even just a finger, they are scared to death and ...
5
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1answer
74 views

How can we calculate the minimum sustainable number of the panda population?

I have a degree in Biology so I'm a little embarrassed that I never learned this, but... How do we know 1600 Pandas isn't enough? I know that we have historical numbers (although I couldn't find ...
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1answer
61 views

Almost philosophical question about controlling a pest/plague

Once in a math congress someone presented a paper on a mathematical model used to predict the impact of certain measures that could be taken in order to control some pest/plague. A guy in the audience ...
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1answer
41 views

In a typical population, what might the percentage of plants be to predators and everything inbetween?

I'm not sure if this will be a simple question that is almost a natural law for an ecologist, or a complex serious of assumptions. I vaguely remember from school that only 10% of the energy is ...
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22 views

Are there any viruses that are part of all land animals?

An article on I Fucking Love Science (linked to below) got me thinking, are there any viruses that have been so successful that they have spread to all land animals similar to Toxoplasmosis which has ...
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1answer
40 views

Coniferous trees in temperare rain forests

In temperate rainforest, the dominant plant form is often coniferous trees (source). However, coniferous trees are also the dominant plant form in a very different climate and form a different biome ...
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1answer
27 views

Is there a risk of localised die-off when plants bud too early?

I've been taking a few walks in the countryside in Scotland and England this winter (end of December 2014). Some parts of England haven't had any frosts yet, which is very unusual, and it's been ...
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1answer
64 views

Speciation and Phylogeny of Lactobacillus

The lactobacillus, also called Döderlein's bacillus is a genus of facultative aerobic bacteria. There are several species such as Lactobacillus acidophillus and Lactobacillus reuteri. I have several ...
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1answer
184 views

Deciduous trees in tropical rainforest

Some books says the dominant plant form in tropical rainforest biome is broad leaved evergreen trees. Other books say it is broad leaved evergreen trees and deciduous trees. What is the most accepted ...
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2answers
83 views

What is Environmental Robustness? Is it different from plasticity?

Hansen (2006) in his review uses the concept of environmental robustness independently of the other concepts of robustness (at pages 139 and 140) without defining ...
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0answers
35 views

Native vs Immigrant plants [closed]

Is this statement applicable to any known plant/region combinations? Plant species X, Y, and Z are truly indigenous to region R. Other "immigrant" species can be destroyed by drought or harsh ...
4
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1answer
61 views

Do plants have preference for the form of nitrogen as nutrient?

In the nitrogen cycle (ecology), it is usually described that plants can use nitrogen in the form of ammonium (NH4+) and nitrate (NO3-). Do plants prefer one form of nitrogen over the other?
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1answer
229 views

Body size, what are the evolutionary trade-offs?

Background Considering just the "Kingdom Animalia" branch of organisms. It is clear that bigger does not necessarily mean better - there is large variation in body size... From the 94 µm long ...
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1answer
28 views

Can plants directly use sulfuric acid?

In the explanation of the sulfur cycle, it is often said that sulfur moves from the atmosphere to the ground by acid rain in the form of sulfuric acid. Can plants directly use sulfuric acid to ...
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1answer
65 views

Examples of genes involved in plastic responses

Adaptive plasticity involves sensing the environment and responding adaptively to it. Intuitively, I would think that this process may ask for a more or less complex genetic machinery of regulation of ...
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1answer
43 views

Do invasive species survive in the long run?

If an invasive species preys on native species, spreads widely and becomes dominant, should it not become extinct soon enough because of a lack of food?
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1answer
168 views

Energy flow in an ecosystem

What are the mistakes in here? The image below shows a part of the energy flow diagram in an ecosystem. 1. Part P of the biomass of the primary producers does not get consumed. Give a concrete ...
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1answer
19 views

Determining break/border of movement

A population given inhabiting an area. I can trace every individual and I've got the hypothesis there is a break in distribution like individuals born in the upper half of the area will rarely move to ...
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21 views

Classification of degree of infested areas by pine processionary moth on regions

I'm making a thesis about pine processionary moth distribution on the regions of algeria! i'm making tests about if there are spatial autocorrelation of this insects on the regions. and i'm doing ...
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0answers
14 views

Can different strains of Rhizobium share an infection thread or symbiosome?

Rhizobium infection can be triggered at root hairs of legumes, creating infection threads. Can these infections threads be colonized by more than one type of Rhizobium (e.g. Fixing and non-fixing)? ...
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1answer
76 views

To what extent is immature eggs in insects (beetles) a good approximation for maximum fecundity?

To what extent is the number of immature eggs from dissected, newly emerged individuals a reasonable approximation for maximum/potential fecundity in insects (more specifically beetles)? I know that ...
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3answers
220 views

Why are there no tree-like plants that grow in lakes?

Looking at aerial photos of boreal forests, with dense woods clear-cut by quiet lakes, I wondered why exactly are the woods so clear-cut at the edge of water? Why won't trees develop adaptations that ...
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3answers
64 views

Are there organisms that have incorporated plastic into their lives?

Are there organisms that have incorporated (manmade) plastic into their lives in any way? Either in their diet, or as a part of their body?
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3answers
142 views

Are there any known mutual symbiotic relationships that has more than two agents?

We are all familiar with the examples of symbiotic relationships in nature consisting of two agents, like lichen or the co-evolvement between certain birds and flowering plants. Do we know of any ...
3
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1answer
49 views

Confusion regarding niches in evolution theory

This is the definition of a niche from Crash Course: An area of the environment that requires a special set of skills or traits to extract food and reproduce. Obviously, this version of the ...
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31 views

Using Canonical Correspondence Analysis on matrices with missing data

I have a matrix of sites where not all the environmental variables I want to assess were sampled. In other words, there are sites with the whole set of variables sampled, and there are other sites ...
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1answer
72 views

Can “human exclusion zones” in national parks for preserving Wolves and Grizzlies be a good idea?

There are National Preserves in the National Parks where some human activities are permitted. But can it make sense to create "exclusion zones" so no human would be permitted in a certain area, not ...
11
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1answer
115 views

Vaccination and population dynamics of an epidemic

I'm trying to figure out how should a vaccination model be built to correlate with population density, and I'm having problems to understand meanings of the results I receive when I apply theory on ...
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1answer
120 views

Effects of selection on effective population size

Background The effective population size ($N_e$) is a central concept of evolutionary biology and is influenced by several parameters. For example: sex ratio bias affects $N_e$ $\left(N_e = ...