What factors affect the number of individuals in an animal group?

What factors affect the number of individuals in an animal group?

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Social animals can live in groups whose numbers vary greatly according to species (for instance wolves vs deer herds vs buffalo stampedes vs lemmings).

Is this number regulated only by environmental factors (resource abundance, position in the food web etc) or is there a genetic upper bound to this number which prevents overcrowding? Put in other words, would a species with endless food resources (but finite space) grow endlessly?

If the genetic regulation is common, then why humans don't seem to be subject to it?

this depends on what you mean by group.

If you mean population then it is mostly environmental factors, although part of the environment can be other member of your species, some groups have a minimum functional size, such as passenger pigeons and breeding in groups behavior, or have density controls(if you are too spread out you might never run into another member of your species to breed with) , these internal factors are fairly rare however compared to basic resources availability, things like food, water, territory, shelter, nutrients, ect.

If you mean size of individual packs, herds, ect, then it is a mix of both, behavior which is almost always genetic is the main cause. However this behavior can be alter or triggered by environmental factors and its ultimate evolution is strongly affected by those factors as well. for instance large herd behavior will never evolve if the environment cannot support it, and if the environment changes the behavior may stop being beneficial.

Population ecology

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population ecology, study of the processes that affect the distribution and abundance of animal and plant populations.

A population is a subset of individuals of one species that occupies a particular geographic area and, in sexually reproducing species, interbreeds. The geographic boundaries of a population are easy to establish for some species but more difficult for others. For example, plants or animals occupying islands have a geographic range defined by the perimeter of the island. In contrast, some species are dispersed across vast expanses, and the boundaries of local populations are more difficult to determine. A continuum exists from closed populations that are geographically isolated from, and lack exchange with, other populations of the same species to open populations that show varying degrees of connectedness.

Estimating MVP

Estimates of MVP have their greatest value in the field of conservation biology, which combines genetic and ecological theories to address global declines in biodiversity. One of the goals of conservation biology is to prevent extinction, which requires managing the small populations that are at greatest risk. To manage such endangered species over decades and centuries, researchers must identify the MVP necessary for the species’ long-term survival. Although ecologists have attempted to define a general MVP estimate that can be applied to numerous species for the purpose of simplifying ecological management, research shows that the MVP estimate for one species differs from that of another because of differences in reproductive rates, habitat requirements, and other factors.

The probability for long-term persistence of a species depends on whether the species can avoid the erosion of genetic variability that can occur in small populations. When genetic variation is reduced, the ability of a species to adapt to environmental change may become restricted. In small populations the genetic diversity of the gene pool may be reduced further by limited mating opportunities, such as when only low numbers of adults or adult members of one sex or the other are present. In these cases, genetic variability can be substantially reduced through inbreeding (mating between close relatives) and genetic drift (random changes in gene frequencies). Inbreeding and genetic drift both can result in an increased chance for the transmission of harmful traits to subsequent generations, which ultimately affects population and species viability (see population ecology).

One of the earliest attempts to define a minimum lower threshold that would prevent the loss of genetic variability in a species was made in 1980 by Australian geneticist Ian Franklin and American biologist Michael Soulé. They created the “ 50/500” rule, which suggested that a minimum population size of 50 was necessary to combat inbreeding and a minimum of 500 individuals was needed to reduce genetic drift. Management agencies tended to use the 50/500 rule under the assumption that it was applicable to species generally. Many experts, however, questioned its validity.

With advances in technology and mathematical theory throughout the 1970s and ’80s, a computer simulation model known as population viability analysis (PVA) was developed to estimate the MVP of a species. The method was later found to be useful for providing more-sophisticated estimates of extinction risk and long-term persistence. PVA can be customized by the researcher to incorporate various data related to a natural history of the species, including its reproduction and dispersal behaviour (movement of individuals among populations). Researchers can also incorporate into their PVA studies factors related to the current genetic context of a species (such as evidence of inbreeding depression, which is the overall decrease in ecological fitness as a result of inbreeding).

In general, the results of PVA modeling indicate that species with high reproductive capacities, such as arthropods and rodents, can accommodate lower MVPs than species with lower reproductive capacities, such as redwood trees and large mammals and some birds. High MVPs typically are found for species that are sedentary (e.g., trees), that do not breed until individuals are several years old, that have mating behaviours in which only a few individuals account for most of the mating, or that show high levels of inbreeding (such as elephants, California condors, and cheetahs).

The PVA model also incorporates environmental and demographic stochasticity. Environmentally stochastic events are random events, such as severe weather, floods, fires, and other ecological disturbances. Demographically stochastic events are random fluctuations in population variables, such as sex ratios and number of births or deaths. Depicting such events with PVA has the effect of increasing the model’s MVP estimate, because both types of phenomena have the potential for reducing population size, either by increasing the death rate or increasing the annual variability with respect to the birth rate.

Estimating MVP with PVA allows scientists to determine which biological parameters (e.g., hunting pressure, disease, habitat loss, inbreeding) will have the greatest impact on the extinction probability of a given species. This information can provide environmental managers with a set of quantitative targets for the minimum critical area required to support a viable population.

One major limitation of PVA is that it requires large amounts of data to make realistic predictions. Therefore, some researchers argue that using a single, universal MVP (such as the 50/500 rule) would streamline conservation efforts. Others, however, maintain that MVPs must be carried out in a case-by-case fashion, because the circumstances that characterize extinction risk differ among species.

Related Biology Terms

  • Community – A group consisting of various species, which interact with each other directly or passively, in a common location.
  • Species – A group of physically similar individuals, which are capable of reproducing with the outcome of fertile offspring.
  • Gene pool – The set of genes present within a population or species.
  • Speciation – The formation of new, distinct species.

1. Which of the following scenarios best fits the definition of a population?
A. Five species of frog living in a swamp.
B. All of the sharks swimming off the west coast of Australia.
C. All the individual mountain gorillas living in the dense forest of four national parks in Africa.
D. The birds, bats and monkeys, which live in the rainforest of Ecuador.

2. A population bottleneck occurs when:
A. The numbers of individuals in a group becomes too high.
B. An event causes a significant loss of individuals in a population.
C. Species migrate away from their native population.
D. Two populations merge together to form a new population.

3. Small populations are more vulnerable than large ones because:
A. They are more likely to be predated on.
B. They are vulnerable to change because they have a smaller gene pool.
C. They cannot keep each other warm.


Animal popularity

The top five characteristics that were listed as ‘liked’ by the majority of the sample population were ‘active’, ‘easy to see’, ‘intelligent’, ‘bright colours’ and ‘the ability to hold objects’. The bottom five characteristics that were listed as ‘dislike’ by many of the sample population were ‘smelly’, ‘slimy’, ‘bites or stings’, ‘bald/little hair’ and ‘venomous/poisonous’ (Table 2). Characteristics that scored close to 0 (e.g. thin, sharp claws and teeth, dull coloured) represent those features that were neither likeable nor dislikeable (‘don't mind’) by the population or could be those characters that may be liked by half of the population but the positive score cancels out owing to the other half that dislike the characteristics. Some paired characters were both positive features but ‘exotic’ and ‘rare’ were more popular than ‘lives in Britain’ and ‘common’. Another observation to note is that ‘small’ scored more popular than ‘large’ when considering the size of an animal.

Table 3 shows that primates were the most popular group of mammals, whilst ‘hippos’, ‘aardvarks’, ‘cavy-like rodents’ and ‘insectivores’ scored relatively low. ‘Passerines’ and ‘parrots’ were the two highest scoring bird groups whilst the ‘frogmouths and nightjars’ ranked lowest. With regard to the reptiles and amphibians the ‘iguanas’ and ‘frogs and toads’ were the two highest scoring, with ‘crocodiles and alligators’, ‘caecilians’ and the venomous snake groups scoring the lowest.

Zoo popularity

The zoos that scored as the top five collections based upon the popularity of their collections were Chester, Paignton, London, Edinburgh and Twycross. The five lowest scoring collections were New Forest Wildlife Conservation Park, Highland Wildlife Park, Knowsley, Shaldon and The Living Rainforest (Table 4). Despite the fact that visitor number figures cannot be stated (for confidentiality reasons), it may be noted that there are some unexpected results within the rankings. Markedly the following collections scored relatively low (popularity scores shown below in brackets) in comparison with their visitor number figures: Knowsley (111.36), Flamingo land (298.46), Woburn (235.39) and West Midlands (200.99).

Reliability of assigning characteristics

There was a significant positive relationship found between the ranks of the sample list given to the keeping staff (n = 7) and the rankings generated by the authors (Spearman's rank correlation: n = 22 rs = 0.591 P = 0.01). The use of Spearman's rank was used here as n = 7 and being non-parametric was more applicable on a sample of this size.

Multivariate analysis

Demographic variables are linked together but with slight variations with the loadings. The admission costs for adults and children were grouped together with loadings that are almost identical. There is also a correlation with admission costs and the popularity scorings of the zoos.

Data containing actual demographic figures

The first PCA looking at popularity scores, admission costs and total populations compresses the six variables into three. The first factor of the initial FA was loaded mostly with the total populations and was accountable for 39.3% of the variation. The second factor was loaded mostly with admission prices and a minor contribution from the popularity rating and was responsible for 34.2% of the variation. A third factor was composed mostly of the popularity rating but was responsible for just 16% of the variation. The communalities for each variable all lay above 82%, which suggests they are all well represented with the three factors. The first factor may be termed ‘total population’, the second can be termed ‘zoo success’ whilst the third may be termed ‘zoo popularity’.

The above result was almost identical for each of the PCAs and FAs for the data that included demographics of age structure, household composition and economic activity. Each one resulted in just three factors being extracted with all demographic factors being loaded onto the first factor, whilst admission costs are the main loadings on the second factor, with a minor contribution from the popularity scoring. The third factor, which only accounts for a small amount of the data variation, is mainly composed of the popularity scoring for the zoos. The main difference being that over 80% of the variation in the data was retained within the first factor (‘demographics’).

Data containing proportions of the total population

The PCAs determined that five factors would best represent the data as >90% of the variation would be retained. Each of the following FAs had five factors extracted with a varimax rotation.

At the 15 and 40 mile (c. 24 km and c. 63 km) distances four of the factors were loaded mainly with demographic variables. However, it was also observed that one factor was comprised mostly of admission costs and the popularity scoring on the same factor.

The 75 mile (c. 121 km) distance displayed the first three factors containing the various demographic variables. The fourth factor was loaded with admission costs, with a minor contribution from the popularity scoring. The final factor, which only accounts for a small amount of the data variation, was mainly composed of the popularity scoring for the zoos.

Factor comparisons with visitor numbers

Visitor numbers displayed a positive correlation with both admission costs (for adults and children) and also with the generated popularity scores. There was no relationship to suggest that demographic factors related to a zoo's visitor numbers. When visitor numbers were compared with the first factor from the first FA no correlation was found (Pearson correlation: n = 34, r = 0.268, P = 0.126 Fig. 1). Visitor numbers were positively correlated with both factors two (Pearson correlation: n = 34, r = 0.496, P = 0.003 Fig. 2) and three (Pearson correlation: n = 34, r = −0.430, P = 0.011 Fig. 3). Pearson's correlation is used here as n = 34 and a parametric analysis is applicable.


The distribution of the zoos is clustered around larger cities with higher populations (e.g. London, Birmingham and the northwest) or towards areas of high tourism, such as the southwest, coastal areas and the Lake District (Fig. 4). There are differences between zoos situated in coastal regions and those situated within city areas in relation to the demographic factors within their local areas.

Age structure

The maps relating to age structure show that the younger age groupings are relatively widely distributed amongst all zoos. The zoos with higher proportions of 30–44 year old age groupings tend to be found within larger cities whilst zoos with higher proportions of older age groupings tend to be found around coastal areas but are very low within major cities.

Economic activity

The zoos that have a higher proportion of economically active people within their buffer zones can be found in and around London, whilst economic inactivity and unemployment levels are much higher around zoos located in coastal areas and the northwest of England.

Household composition

Zoos within inner city areas have a larger proportion of single-parent households whilst zoos with higher proportions of couples with children are situated surrounding city areas. Zoos in coastal areas have higher proportions of couples without children.

5. Situational Factors of Personality

Situational factors of personality also have a complete share in the formation of personality of an individual. situational factors of personality are charging according to the social situations. Every person face may situations in his life which enables him/her to change his/her behavior. For example, a teacher may be rigid and strict with students but may not with his/her family. An officer may behave with the subordinates differently as compare to his/her friends. Personality is not the result of only one factor but every factor is responsible to give complete share in its formation. A person behave and his/her personality exists when interacts with environment, culture, society, parents, friends and to those who come in contact by chance.

44.1 The Scope of Ecology

By the end of this section, you will be able to do the following:

  • Define ecology and the four basic levels of ecological research
  • Describe examples of the ways in which ecology requires the integration of different scientific disciplines
  • Distinguish between abiotic and biotic components of the environment
  • Recognize the relationship between abiotic and biotic components of the environment

Ecology is the study of the interactions of living organisms with their environment. One core goal of ecology is to understand the distribution and abundance of living things in the physical environment. Attainment of this goal requires the integration of scientific disciplines inside and outside of biology, such as mathematics, statistics, biochemistry, molecular biology, physiology, evolution, biodiversity, geology, and climatology.

Link to Learning

Climate change can alter where organisms live, which can sometimes directly affect human health. Watch the PBS video “Feeling the Effects of Climate Change” in which researchers discover a pathogenic organism living far outside of its normal range.

Levels of Ecological Study

When a discipline such as biology is studied, it is often helpful to subdivide it into smaller, related areas. For instance, cell biologists interested in cell signaling need to understand the chemistry of the signal molecules (which are usually proteins) as well as the result of cell signaling. Ecologists interested in the factors that influence the survival of an endangered species might use mathematical models to predict how current conservation efforts affect endangered organisms.

To produce a sound set of management options, a conservation biologist needs to collect accurate data, including current population size, factors affecting reproduction (like physiology and behavior), habitat requirements (such as plants and soils), and potential human influences on the endangered population and its habitat (which might be derived through studies in sociology and urban ecology). Within the discipline of ecology, researchers work at four general levels, which sometimes overlap. These levels are organism, population, community, and ecosystem (Figure 44.2).

Organismal Ecology

Researchers studying ecology at the organismal level are interested in the adaptations that enable individuals to live in specific habitats. These adaptations can be morphological, physiological, and behavioral. For instance, the Karner blue butterfly (Lycaeides melissa samuelis) (Figure 44.3) is considered a specialist because the females only oviposit (that is, lay eggs) on wild lupine (Lupinus perennis). This specific requirement and adaptation means that the Karner blue butterfly is completely dependent on the presence of wild lupine plants for its survival.

After hatching, the (first instar) caterpillars emerge and spend four to six weeks feeding solely on wild lupine (Figure 44.4). The caterpillars pupate as a chrysalis to undergo the final stage of metamorphosis and emerge as butterflies after about four weeks. The adult butterflies feed on the nectar of flowers of wild lupine and other plant species, such as milkweeds. Generally there are two broods of the Karner blue each year.

A researcher interested in studying Karner blue butterflies at the organismal level might, in addition to asking questions about egg laying requirements, ask questions about the butterflies’ preferred thoracic flight temperature (a physiological question), or the behavior of the caterpillars when they are at different larval stages (a behavioral question).

Population Ecology

A population is a group of interbreeding organisms that are members of the same species living in the same area at the same time. (Organisms that are all members of the same species are called conspecifics .) A population is identified, in part, by where it lives, and its area of population may have natural or artificial boundaries. Natural boundaries might be rivers, mountains, or deserts, while artificial boundaries may be mowed grass, manmade structures, or roads. The study of population ecology focuses on the number of individuals in an area and how and why population size changes over time.

For example, population ecologists are particularly interested in counting the Karner blue butterfly because it is classified as a federally endangered species. However, the distribution and density of this species is highly influenced by the distribution and abundance of wild lupine, and the biophysical environment around it. Researchers might ask questions about the factors leading to the decline of wild lupine and how these affect Karner blue butterflies. For example, ecologists know that wild lupine thrives in open areas where trees and shrubs are largely absent. In natural settings, intermittent wildfires regularly remove trees and shrubs, helping to maintain the open areas that wild lupine requires. Mathematical models can be used to understand how wildfire suppression by humans has led to the decline of this important plant for the Karner blue butterfly.

Community Ecology

A biological community consists of the different species within an area, typically a three-dimensional space, and the interactions within and among these species. Community ecologists are interested in the processes driving these interactions and their consequences. Questions about conspecific interactions often focus on competition among members of the same species for a limited resource. Ecologists also study interactions between various species members of different species are called heterospecifics . Examples of heterospecific interactions include predation, parasitism, herbivory, competition, and pollination. These interactions can have regulating effects on population sizes and can impact ecological and evolutionary processes affecting diversity.

For example, Karner blue butterfly larvae form mutualistic relationships with ants (especially Formica spp). Mutualism is a form of long-term relationship that has coevolved between two species and from which each species benefits. For mutualism to exist between individual organisms, each species must receive some benefit from the other as a consequence of the relationship. Researchers have shown that there is an increase in survival when ants protect Karner blue butterfly larvae (caterpillars) from predaceous insects and spiders, an act known as “tending.” This might be because the larvae spend less time in each life stage when tended by ants, which provides an advantage for the larvae. Meanwhile, to attract the ants, the Karner blue butterfly larvae secrete ant-like pheromones and a carbohydrate-rich substance that is an important energy source for the ants. Both the Karner blue larvae and the ants benefit from their interaction, although the species of attendant ants may be partially opportunistic and vary over the range of the butterfly.

Ecosystem Ecology

Ecosystem ecology is an extension of organismal, population, and community ecology. The ecosystem is composed of all the biotic components (living things) in an area along with the abiotic components (nonliving things) of that area. Some of the abiotic components include air, water, and soil. Ecosystem biologists ask questions about how nutrients and energy are stored and how they move among organisms and through the surrounding atmosphere, soil, and water.

The Karner blue butterflies and the wild lupine live in an oak-pine barren habitat. This habitat is characterized by natural disturbance and nutrient-poor soils that are low in nitrogen. The availability of nutrients is an important factor in the distribution of the plants that live in this habitat. Researchers interested in ecosystem ecology could ask questions about the importance of limited resources and the movement of resources, such as nutrients, though the biotic and abiotic portions of the ecosystem.

Career Connection


A career in ecology contributes to many facets of human society. Understanding ecological issues can help society meet the basic human needs of food, shelter, and health care. Ecologists can conduct their research in the laboratory and outside in natural environments (Figure 44.5). These natural environments can be as close to home as the stream running through your campus or as far away as the hydrothermal vents at the bottom of the Pacific Ocean. Ecologists manage natural resources such as white-tailed deer populations (Odocoileus virginianus) for hunting or aspen (Populus spp.) timber stands for paper production. Ecologists also work as educators who teach children and adults at various institutions including universities, high schools, museums, and nature centers. Ecologists may also work in advisory positions assisting local, state, and federal policymakers to develop laws that are ecologically sound, or they may develop those policies and legislation themselves. To become an ecologist requires at least an undergraduate degree, usually in a natural science. The undergraduate degree is often followed by specialized training or an advanced degree, depending on the area of ecology selected. Ecologists should also have a broad background in the physical sciences, as well as a solid foundation in mathematics and statistics.

Link to Learning

Visit this site to see Stephen Wing, a marine ecologist from the University of Otago, discuss the role of an ecologist and the types of issues ecologists explore.

Top 3 Factors Affecting Individual Behaviour

All the human beings have certain characteristics which are genetic in nature and are inherited. These are the qualities which the human beings are born with. These are the characteristics which cannot be changed at the most, these can be refined to some extent. If the managers know about the inherited qualities and limitations of the persons, they can use their organisational behaviour techniques more effectively.

All these characteristics are explained in detail as follows:

1. Physical Characteristics:

Some of these characteristics are related to height, skin, complexion, vision, shape and size of nose, weight etc. All these have an impact on the performance of the individuals. It is sometimes said that the eyes betray the character of a person. Similarly certain ideas about the behaviour can be formed on the basis of whether the person is fat, tall or slim.

Tall and slim people are expected to dress well and behave in a sophisticated manner and fat people are supposed to be of a jolly nature. Whether there is a correlation between body structure and behaviour or not has not been scientifically proven. Even if there is a correlation between these two, it is very difficult to understand which the independent variable is and which is dependent variable.

Age is considered to be an inherited characteristic because it is determined by the date of birth. The relationship between age and job performance is an issue of increasing performance. Psychologically, younger people are expected to be more energetic, innovative, adventurous, ambitious and risk taking. Whereas old people are supposed to be conservative, set in their own ways and less adaptable. Though it is incorrect to generalize all old people as unadoptable, physiologically, performance depends on age.

Performance declines with advancement of age because older people have less stamina, memory etc. Younger people are likely to change jobs to avail better job opportunities, but as one grows old, the chances of his quitting job are less. There is a relationship between age and absenteeism also. Older people tend to absent more from their jobs due to unavoidable reasons e.g. poor health.

Whereas younger people absent themselves from job due to avoidable reasons e.g. going for a vacation. In the organisations which are subject to dramatic changes due to latest innovations, the older people get less job satisfaction as they start feeling obsolete as compared to their younger colleagues. Though there is no clear cut demarcation between young age and old age but according to Lehman the peak of creative ability is among people between the ages 30 and 40.

Being a male or female is genetic in nature and it is considered to be an inherited feature. Whether women perform as well as in jobs as men do, is an issue which has initiated lot of debates, misconceptions and opinions. The traditional view was that man is tougher than woman or women are highly emotional than men. But these are some stereotyped baseless assumptions. Research has proved that there are few if any, important differences between man and woman that will affect their job performance.

Specially, in some are like problem solving ability, analytical skill, competitive drive, motivation, leadership, sociability and learning ability, there are no consistent male-female differences. Initially, some roles were considered to be exclusive domain of women e.g. nurses, airhostesses etc. but now with the passage of time, we have males in these professions also. Similarly, some jobs which were considered to be exclusive domain of men e.g. pilots, defence jobs, etc. have started accommodating women also, though with some conditions.

Gender has its impact on absenteeism. The tendency to abstain from work is more in females than in men, because historically, our society has placed home and family responsibilities on the females. When a child is ill, or the house is being white washed or some unexpected guests turn up, it is the female who has to take leave.

The turnover is also more in female employees, though the evidence is mixed in this case. Some studies have found that females have high turnover rates, while the others do not find any difference. The reasons for high turnover can be that sometimes the females have to quit their jobs or change into part time jobs to look after the children and their homes.

Sometimes they have to quit their jobs if their husbands get transferred to some other place and the females’ job is non-transferable. Although this trend is changing with the passage of time, but majority of the Indian families still follow these norms.

Though there are no scientific studies to prove it and we cannot generalize it, but religion and religion based cultures play an important role in determining some aspects of individual behaviour, especially those aspects which concern morals, ethics and a code of conduct. The religion and culture also determine attitudes towards work and towards financial incentives.

People who are highly religious are supposed to have high moral values e.g. they are honest, they do not tell lies or talk ill of others, they are supposed to be contended. But there is another side of the picture also. Though there are no evidences but it has been observed that sometimes people who are highly dishonest and immoral are more religious as compared to the others.

There are not enough studies to draw any conclusion as to whether there is any relationship between marital status and job performance. Research has consistently indicated that as marriage imposes increased responsibilities, to have a steady job becomes more valuable and important. Married employees have fewer absences, less turnover and more job satisfaction as compared to unmarried workers. But no research has so far identified the causes for this.

Moreover, there are a few other questions which need answers e.g.:

(i) What will be the effect of divorce or death of the life partner on the performance of an employee?

(ii) What about couples who live together without getting married. So far there are no answers to these questions.

The next biographical characteristic is tenure or experience. The impact of seniority on job performance is an issue which is subject to a lot of misconceptions and speculations. Work experience is considered to be a good indicator of employee productivity. Research indicates that there is a positive relationship between seniority and job performance. Moreover studies also indicate a negative relationship between seniority and absenteeism.

Employee turnover is also considered to be negatively related to seniority. But in considering this relationship, past experience i.e. experience of the employee on the previous job is also to be considered. Research indicates that experience and satisfaction are positively related. Here we have to distinguish between chronological age and seniority of the employee. Seniority experience is a better indicator of job satisfaction than the chronological age of the person.

Generally, it is considered that intelligence is an inherited quality. Some people are born intelligent or in other words intelligent parents produce intelligent children. But practical experience has shown that sometimes very intelligent parents have less intelligent children and sometimes average parents have very intelligent children.

Moreover intelligence can be enhanced with efforts, hard work, proper environment and motivation. Anyway, whether it is an inherited trait or acquired trait this factor affects the behaviour of the people. Intelligent people are generally not adamant and stubborn, rather they are considered to be stable and predictable.

Ability refers to the capacity or capability of an individual to perform the various tasks in a job. Ability is the criterion used to determine what a person can do.

Ability of an individual can be of two types:

(i) Intellectual Ability:

If the individual is expected to perform mental activities, he must have a particular level of intellectual ability. Some important dimensions used to ascertain intellectual ability are number aptitude, comprehension, perceptual speed and test of reasoning. For some important jobs or assignment, a person has to clear some admission test.

Physical abilities include a person’s stamina, manual dexterity, leg strength and the like. If the performance of a particular job requires some specific physical abilities, it is the duty of the management to identify the employees having those abilities. This is accomplished by either careful selection of people or by a combination of selection and training.

B. Learned Characteristics:

Learning is defined as, “a relatively permanent change in behaviour resulting from interactions with the environment.” A person is born with biographical characteristics which are difficult to change or modify. Therefore, the managers lay much stress on studying, learning and predicting the learned characteristics.

Some of these learned characteristics are as follows:

By personality we don’t mean the physical appearance of a person. Psychologists are not concerned with a smart person, with a smiling face and a charming personality. They consider personality as a dynamic concept describing the growth and development of a person’s whole psychological system. Rather than looking at parts of the person, personality looks at some aggregate whole that is greater than the sum of the parts.

Personality generally refers to personal traits such as dominance, aggressiveness, persistence and other qualities reflected through a person’s behaviour. Some personality traits like physical built and intelligence are biological in nature but most traits like patience, open mindedness, extrovertness etc. can be learned.

An individual’s personality determines the types of activities that he or she is suited for. According to Tedeschi and Lindskold, people who are open minded seem to work out better in bargaining agreements than people who are narrow minded. Similarly people who are extroverts and outgoing are more likely to be successful as managers than those who are introverts.

Perception is the viewpoint by which one interprets a situation. In other words, “perception is the process by which information enters our minds and is interpreted in order to give some sensible meaning to the world around us. Psychology says that different people see and sense the same thing in different ways. For example, if a new manager perceives an employee to be a job shirker, he will give him less important jobs, even though that employee is a very able person. Sometimes, we tend to lose good relatives and friends because we change our perceptions about them.

Attitude is just like perception but with a frame of reference. It is a tendency to act in a certain way, either favourably or unfavourably concerning objects, people or events. For example, if I say I am satisfied with my job, I am expressing my attitude towards work. An attitude may be defined as the way a person feels about something, a person, a place, a thing, a situation or an idea. It expresses an individual’s positive or negative feeling about some object. An attitude may be unconsciously held. Most of our attitudes are such about which we are not aware QNE most common of this is prejudice.

A person’s attitude towards a given situation can be ascertained by measuring and understanding his feelings, thoughts and behaviours. When we directly ask questions from the individuals, we can measure his feelings and thoughts. Behaviour can be measured either by observing the actions of the individual or simply by asking him questions about how he would behave in a particular situation.

In general, if a person has positive attitude about his work it will be reflected by very good work performance, less absenteeism, less turnover, obedience towards rule or authority etc. If a person has got negative attitude towards his work, he will act in exactly the opposite way. The negative attitude can be changed by simple persuasion or by training and coaching.

According to Milton Rokeach, “Values are global beliefs that guide actions and judgements across a variety of situations. Values represent basic convictions that a specific mode of conduct is personally or socially preferable to an opposite mode of conduct.” Values carry an individual’s ideas as to what is right, good or desirable. All of us have a hierarchy of values that form our value system. This system is identified by the relative importance we assign to some values like freedom, self respect, honesty, obedience, equality and so on.

Values are so closely embedded in the people that these can be observed from their behaviour. Individual values are influenced by the parents, teachers, friends and other external forces. A person’s values also develop as a product of learning and experience in the cultural setting in which he lives. Values vary from person to person because every person learns in a different way and have different types of experience.

Values are very important in the study of organisational behaviour because these help in understanding the attitudes and motivation of individuals as well as influencing their perceptions. Values determine what is right and what is wrong, where right or wrong is interpreted in terms of perceived values of the decision maker. Values sometimes overpower even objectivity and rationality. The value system can significantly influence the manager’s outlook and behaviour.

II. Environmental Factors:

The external environment is known to have a considerable impact on a person’s behaviour.

A brief description of the external factors follows:

1. Economic Factors.

The behaviour of an individual is affected to a large extent by the economic environment.

A few economic factors which directly or indirectly affect the individual behaviour are as explained below:

The employment opportunities which are available to the individuals go a long way in influencing the individual behaviour. If the job opportunities are less, the individual will have to stick to a particular organisation even though he does not have job satisfaction. He may or may not ‘ be loyal to the management but he will remain in the organisation for monetary benefits only. On the other hand if the job opportunities are more, the employees’ turnover will be more. They will continue changing their jobs till they find the ideal job, which gives them maximum satisfaction, monetary as well as psychological.

The major consideration of every employee who is working in the organisation is his wages. Though job satisfaction is very important, but what a person will get in money terms, is the major factor affecting the decision of a worker to stay in a particular organisation or shift to another one which will pay more wages.

(c) General Economic Environment:

Some employees who are working in Government offices or public sector undertakings are not affected by economic cycles. Whatever the economic position of the organisation, they will receive their salaries. Whereas, the employees, who work in the organisations, which are severely affected by economic cycles are subjected to layoffs and retrenchment. For these employees job security and a stable income is the most important factor whereas the former employees will be motivated by some other factors.

(d) Technological Development:

Though technology is not an economic factor, but we include it in the economic factors because of the impact it has on the individual job opportunities. The technological development has made the job more intellectual and upgraded. Some workers will be dislocated unless they are well equipped to work on new machines. This makes it the duty of management to retrain the employees. For those, who pickup and acquaint themselves with new technology, the jobs will be rewarding and challenging.

2. Socio-cultural Factors:

The social environment of an individual includes his relationship with family members, friends, colleagues, supervisors and subordinates. The behaviour of other people not with the individual, but in general, is also a part of his social environment. Similarly, every individual has a cultural background, which shapes his values and beliefs. Work ethics achievement need, effort-reward expectations and values are important cultural factors having impact on the individual behaviour.

3. Political Factors

Political environment of the country will affect the individual behaviour not directly, but through several other factors. In a politically stable country there will be a steady level of employment (both in quantity and quality) and high level of capital investment. Whereas companies are reluctant to invest large sums of money in a politically instable country.

The political ideology of a country affects the individual behaviour through the relative freedom available to its citizens. A country can have a controlled society or less controlled society. The relative freedom available to the individuals can affect their career choice, job design and performance.

4. Legal Environment.

Rules and laws are formalized and written standards of behaviour. Both rules and laws are strictly enforced by the legal system. Laws relate to all the members of the society e.g. Murder is a crime which is illegal and punishable by law and applies to all the people within the system. Observing the laws voluntarily allows for predictability of individual behaviour.

III. Organisational Factors:

Individual behaviour is influenced by a wide variety of organisational systems and resources.

These organisational factors are as explained below:

1. Physical Facilities:

The physical environment at a work place is the arrangement of people and things so that is has a positive influence on people. Some of the factors which influence individual behaviour are noise level, heat, light, ventilation, cleanliness, nature of job, office furnishing, number of people working at a given place etc.

2. Organisation Structure and Design:

These are concerned with the way in which different departments in the organisation are set up. What is the reporting system? How are the lines of communication established among different levels in the organisation. The behaviour and performance of the individual is influenced by where that person fits into the organisational hierarchy.

3. Leadership:

The system of leadership is established by the management to provide direction, assistance, advice and coaching to individuals. The human behaviour is influenced to a large extent by the behaviour of the superiors or leaders. Behaviour of the leaders is more important than their qualities.

4. Reward System:

The behaviour and performance of the individuals is also influenced by the reward system established by the organisation to compensate their employees.

Ecological Conditions

Conditions within or adjacent to an environment also affect its carrying capacity. For example, if the environment is located close to a human population, this may affect its carrying capacity. Pollution may also affect an environment's carrying capacity. A natural disaster, such as a hurricane or a flood, also affects the ability of an environment to sustain animal or plant populations. The inability of the land to sustain either crops or plants because of erosion, desertification, or degradation also affects its carrying capacity.


6. Compare the actual size to the estimated size. Did you overestimate or underestimate?

Trial Number Number Captured Number Recaptured with mark
New Total:

7. Continue the experiment by filling out the data table.
Recalculate your estimate using the formula. (Show below)

a. Is the second estimate closer than the first one? ______

b. To get the most accurate results, you would generally do [ more / less ] trials . (circle)

8. Given the following data, what would be the estimated size of a butterfly population in Wilson Park.

A biologist originally marked 40 butterflies in Wilson Park. Over a month-long period ­ butterfly traps caught 200 butterflies. Of those 200, 80 were found to have tags. Based on this information, what is the estimated population size of the butterflies in Wilson Park? SHOW WORK.

9. He later does another capture exercise at the community garden near the high school. In this area, he captured and marked 40 butterflies. The traps in this location found 100 butterflies where 50 of them had tags. What is the population size of the butterflies at the school? SHOW WORK.

10. The department of natural resources regularly collects data on population numbers in states. Discuss reasons why population numbers would be important and how this data could be used to manage wildlife populations in the state.

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