Namaste, and welcome to this course on Wildlife Ecology. I am Dr Ankur Awadhiya. I am an officer

in the Indian forest service of the Madya Pradesh Cadre. So, this course is going

to have 12 modules, with 3 lectures in each module, and we begin with the first module,

that is the Introduction to the Course. And this module will be having 3 lectures,

first is introduction to the course, second is a historical overview of

ecology and third is ecology and evolution. So, let us begin this course with a story. Now,

this story concerns a girl who lives in a village. So, let us call this girl as Miss

X and she is living in a village. This village is a very beautiful village. It is surrounded

by some beautiful hills. It has a river that passes through it. It has some trees around,

some grasslands, some fields; and this girl is fond of looking at nature;

and she is very fond of looking at different kinds of birds that are found in this village.

So, there are some flying birds, there are some water birds, there are some ground bearing birds,

there are some parakeets that live on the trees and so on. But then

this village also has a lot of infestation of mosquitoes and mosquitoes result in malaria,

which is a major issue in this village. So, one day the government decides that let us take a

plane full of insecticides to this village and spray this village with the insecticides to kill

off the mosquitoes. A very fine idea, a number of people would say so, and mind you, the chemical

that is being sprayed here is an insecticide, it only kills insects, also the company claims.

So, the village is sprayed with insecticides, and lo and behold the girl finds that after a short

while all her beautiful birds that were there in the village die off. Now, (we) . this story

might appear hypothetical, but we are observing such instances in a number of places around the

world. We have seen situations in which the spray of DDT has resulted in the death of birds. Now, if

you spray DDT in a very low concentration, because to kill a mosquito you do not require a very huge

amount of DDT. So, you spray this insecticide in a very low concentration and still a number of

birds die and when their bodies are autopsied, it is found that they have a very huge concentration

of DDT that is found inside their bodies. Let us look at another story. Now,

this is a paper which says high levels of PCBs in breast milk of Inuit Women from Arctic Quebec. Now

PCBs are polychlorinated biphenyls. Now, these are chemicals that are added to a number of plastics,

and when Inuit women refers to women who have an eskimo lifestyle. So, Quebec is a place in Canada.

So, there are some eskimo women that are living in the arctic region of Canada,

and when their breast milk was analyzed, it was found that it had a very high concentration

of polychlorinated biphenyl. Now, the question arises that arctic is a very serene place. It is,

we do not go there and dump these chemicals in the arctic, and still, in the human population

there we observe that there is a very huge concentration of a number of chemicals;

a number of which are toxic to the newborn babies. So, some people have even argued

that the most toxic food that a human being can eat is the breast milk of an Eskimo woman

that is living in the arctic regions. Now, how do these chemicals reach there?

and is it important for us? Well, it is important because, if you have chemicals

in the breast milk, invariably they are going to reach another human body,

and in this case, the body of a human baby. And in certain instances, this may

even result in very tragic consequences. For instance, this was a case in which an infant

was killed because it was breast-fed by its mother and the mother of the baby was .was on some drugs,

she was taking drugs and the baby died. Because the baby was getting a very high concentration

of the drugs. Now questions such as these are arising everywhere; they are arising

anywhere and everywhere on this planet. And ecology deals with a number of these

questions. So, if you look at the word roots ecology comes from the

Greek words or Oikos and logos. Oikos means a household ; household where people live.

So, when we say ecology; Oikos is home and logos is study. Now we can see eco as a word root also

in things such as economics, in which eco , or oikos is home and nomy is to count. Now,

ecology is the study of home; it could be my home, it could be your home, it could be somebody else s

home or it could be the home of other animals, it could be the home of tiger, it could be the home

of elephant, it could be a marine home and so, on. Now, because of these word roots, we can have a

number of different kinds of ecologies. So, for instance when we are looking at the population of

humans, we can have a subject of human ecology, if you are looking at different population,

we can have population ecology. If we are looking at marine environment, we can have marine ecology;

because the marine environment is also a home to a number of animals; we can have forest ecology or

we can even have things like lacustrine ecology, which is a lake ecology. So, in all of these

what we are doing is we are studying the home of some organisms or some groups of organisms. So,

which is why it is called ecology. So, ecology is the study of life at home;

at the home of you, me or some other organism. So, if you went to define ecology; ecology can be

defined as the scientific study of interactions among organisms and their environment.

So, essentially if we have a forest and then we have some animals here in the forest. So,

let us say that we have an elephant in the forest. Now, this elephant would be deriving its nutrients

from these trees, or maybe from the grasses below. So, they also act as food; now and when

this animal is living in the forest there might also be some other animals in this forest. So,

let us have so here we have say another animal, let us say that this animal is a sambar; and this

sambar also eats this grass. So, we could have competition between both of these animals, so,

this animal, our elephant is interacting with the trees, it is interacting with the sambar,

it is interacting with the number of other organisms and it is also interacting and it

is also dependent on the environment that is here. So, for instance it would depend on the amount of

sunlight that is there, if it is very hot or if it is very cold, then probably this animal might

not be able to live in that area, probably this animal might have to migrate from this area. Or

for instance, if we have a river that is passing through this area and if this river dries out. So,

this animal is now not getting enough water so, it might have to move out. So, ecology is the study

of all of these. So, ecology is the scientific study of interactions among organisms and their

environment. So, in this in this system we have the organisms, we have the environment

and we are studying all of these interactions. Another definition could be that, the ecology

is the scientific study of interactions that determines the distribution and abundance of

organisms. So, what we are looking here is the distribution of animals or organisms

and the abundance of organism. Now to take another example;

suppose we have this mountain and in this mountain, at this level, we have an average

temperature of say around 20 degree Celsius and as we move up the temperature reduces.

So, in this region we have around 15, 10, 5, 0 and this area has an annual average temperature

of minus 5 degree celsius. Now, the organisms that are found in this zone, let us call it zone 1,

will be very different from the organisms that are found in zone 2 and extremely different from

the organisms that are found, in let us say this is 3, 4, 5, 6 so in zone 6...Now, if you look at

the definition again, Ecology is the scientific study of the interactions that determine the

distribution and abundance of organisms. Now, what we will be asking here in the

case of ecology is, what organisms are found in this zone, what organisms are found in this zone

and so on. And if they are different, why are they different. Is it because of the temperature? Is it

because of wind? Is it because of less amount of sunshine that this region gets? or Is it because

of less amount of moisture or differences in moisture that are there in different areas?. So,

what are these factors that are determining the distribution of these organisms. And secondly,

what are the factors that are determining the abundance of these organisms?

Now, when we say abundance, what we are referring to is that, if we take any of these parameters,

so, let us say temperature. And we look at the number of organisms per square kilometer;

number of organisms of species x per square kilometer. Now, what we will observe is that

there would be a set of temperature in which these organisms find it very easy

or very congenial to survive. So, for instance in the case of us human beings, if our if our

surrounding temperature is say around 25 degree Celsius, we will feel extremely comfortable. So,

this is the most comfortable zone. But then, if we increase this temperature so,

this was say 25 degree Celsius .Now let us increase it to say 40 degree Celsius. Now at

40 degree celsius, a number of us might not be able to feel very comfortable. So, there would

be some people who would find it comfortable, but there would be a very huge chunk of people

who would find it relatively uncomfortable. So, little less number of organisms would be found

in this region or let us increase the average temperature to say 60 degree celsius and probably

one or even zero of us human beings would be found in that region; in that temperature range.

Now, similarly if we reduce the temperature to say 10 degree celsius, you would find that less number

of people are able to do to find this temperature to be congenial. If you reduce it to even less to

say zero degree celsius probably very few of us would be able to live there. So, we can now draw a

curve that is something like this. Now, this curve is telling us the abundance of human beings that

would be found at different temperatures. So, there is this zone we are arbitrarily

defining dividing this curve into 3 regions. So, in this zone we will have less number of

animals; in this zone we will be having more number of animals; in this zone will be having

less number of animals; and in these zones will probably be having zero number of animals. Now,

similarly for every organism, so for elephant there would be a certain range of temperature

in which it will find congenial to survive. For the case of tigers, there would be a very

different range of temperatures. For polar bears it will be a very different zone. So, in the case

of polar bears we could even have a situation in which we have a maximum, somewhere here.

So, polar bears would probably prefer to live somewhere say around 1 or 2 degrees average

temperature or maybe even lesser. Now, when we look at ecology, what we are asking is the

interactions that are determining the distribution and abundance of organisms. So, distribution what

are the areas in which these organisms are able to live and abundance what is their number. Now,

these are physical factors, but we could also have a number of biological factors. So,

for instance in a forest in which you have ample number of prey animals.

So, if you have a forest in which you have a substantial population of chital or sambar,

you would find tigers that are living in that area. But if you have another forest in which we

have very less number of chitals and sambars, then probably tigers will not survive in that area;

because they are not getting enough food. So, you can even have a number of biological factors

or for instance,if you have a forest in which you have a very huge density of tigers, then

probably leopards will not be able to live in that area, because they cannot compete with tigers. So,

leopards would be found in an area where you do not have a very substantial number of tigers. So,

you can have physical factors that determine distribution and abundance

or you can have biological factors that determine the distribution and abundance.

Now, let us recount some of the physical factors. Now physical could be things like temperature or

say rainfall, or humidity, or wind speed, or the depth of soil that is found in that area

or the amount of sunshine that the area gets, or in the case of marine environments we could even

have things like the amount of salinity, that is there in a particular segment of water or things

such as the amount of sediment load that is there in the water or in the case of rivers we could

even have things such as the speed of water. So, for instance in the case of a river,

the central region that has greater speeds would be used by certain organisms and the

surrounding regions that have lesser speeds would be utilized by some other organisms. So,

these are all different physical factors that would determine the distribution and abundance

of different organisms and ecology would ask the question, what are these interactions that

are driving the abundance and distribution of these animals. Now, let us look at some

biological factors or the biotic factors. Now, biotic factors could include things such

as food. So, this food could include things like the amount of grass or vegetation that

you have or the amount of prey that you have in this area. It would also be another biotic

factor that would determine distribution and abundance would be the presence or absence

of predators in the area. So, if an area is having a very huge population of tigers,

then probably chital and sambar would not prefer to live in that area, because they will get eaten

if they live there or you can have things such as parasites or you can have things like diseases.

So, a number of these factors play a role in determining the abundance and distribution of

the annuals and ecology is the scientific study of all these different factors and their interactions

that are determining the distribution and abundance of organisms. So, what do we actually

study in ecology. So, this was the theoretical basis, but what do we actually look at in ecology.

Well, we look at habitats. Habitat is the home of an animal; the natural home, or the abode of the

animal. So, for instance this is the Indian wild ass and this lives in these sorts of habitats. So,

we have this Indian wild ass sanctuary in Gujarat and as you can see this is a very

plain topography area it hardly has any vegetation in most of the areas, there are some hills that

have slight amount of vegetation, then this is a very dry area, it has a lot of saline soil.

So, ecology would go out and study what are the kinds of habitats that are there in different

areas and how are these different habitats determining whether this organism is able to

survive in that area or not. So, for instance we find Indian wild ass only there, we do not find

it in, say, West Bengal, because the habitats that are provided or that are available in West

Bengal are very different from the habitats that are available in Gujarat. And similarly,

we have the royal bengal tiger that is found in West Bengal, but it is not found in Gujarat. So,

ecology would go out and ask the question what are the different kinds of habitats

that the organisms get in different areas. Then it would go out and ask what is the amount

of biodiversity that we have, so, for instance in the previous image, we saw that we have this

Indian wild ass and there are hardly any other animals that are seen here and also the kinds of

grasses that we have all the kinds of vegetation that we have here is very different from say

something that we will find in Bharathpur. Now, Bharathpur is a bird sanctuary and in

this area we will find a number of birds we will find and this area is regularly inundated with

water. So, in this area we will be having a number of water birds will be having ground

dwelling birds will be having a number of birds that live on these trees, even the

vegetation in this area will be very different, because this area has ample amount of water.

So, the kinds of trees that will live here will be very different from what we are finding there in

Gujarat. So, the next question that ecology would try to study is the level of biodiversity that we

have; what are the different kinds of species that are found in each area , what is their

abundance and distribution. So, for instance if we look at this area, do we have, say 1000

birds of this species and say only 10 birds of some other species or do we have equal number of

birds of all of these different species. So, that is also another topic that is studied in ecology.

Next we look at population interactions. Now, population is a group of animals that

are living together and they belong to the same species. So, for instance in this image

we can see a troop of macaques so, we have these macaques. And if you look at these two animals,

this animal is grooming this second animal. So, what are the kinds of population interactions;

how do they behave together why do they behave in this manner? So, for instance, what is the profit

or loss or the gain or loss that is being provided to this animal by grooming this animal; because

in the first instance it might seem that this is an act of altruism; this animal is only grooming

this animal and not getting anything in return. Now, such a system might not work in practice. So,

in any case this animal should give something back to this animal that was grooming it. So,

how do these interactions work in these populations how is this animal able to

give back to the first animal, are the kinds of things that we will study in ecology.

Next we look at community interactions. Now community is a group of organisms that belong

to different species and they are living together. So, for instance in this image,

this is from Kaziranga, we can see we have a buffalo, we have some scavengers in the

form of vultures and then we have a number of different trees here, different species.

Now, community interaction means what are the kinds of interactions that are being held between

say this buffalo and the scavengers or between the between the buffalo and the trees and so on. So,

for instance in a number of trees we have a phenomena that is known as zoophily.

Now in zoophily. zoo is animal and philly is love. Now zoophily is a situation in which you say have

a tree and this tree bears fruits and then these fruits are eaten up by a bird and when this bird

eats up this fruit it gets nutrients, but at the same time the seeds also get inside the bird.

So, now the seeds of the tree are inside this bird and then this bird moves to say some other

location. So, let us say there is an electricity line and this bird, then goes there and then this

bird defecates these seeds out here and when it defecates you have all these seeds that have

fallen onto the ground and then after a while after the next rains, we will have some small

plants of this tree that grow up in this area. So, in this case this tree is using the bird

as a vehicle to transport its feeds. So, zoo is animal, so it is using this animal which is

the bird to transport its seeds. So, again in this case we can see that there is a one to one

interaction or a give and take relationship between both of these organisms. The tree

is giving food to the bird and the bird is giving a transport mechanism to the tree.

So, here we have organisms that belong to two different species and they are interacting in

a way that is mutually beneficial to both of these. Now, similarly in this situation

if we have the buffalo, is it helping the trees? or is it harming the trees? or some

other vegetation. Similarly if you look at these vultures are they helping the system?

or they are or are they harming the system? and how are they doing that. So, these are the kinds

of interactions that we observe in a community and this is also a topic of study in ecology.

Now, ecology also looks at the impacts or the effects of different changes that are

happening on our earth. So, for instance this is an image again from Gujarat and

here we can observe a number of goats and as you can observe, here we have these sand dunes

and we also have a very scanty vegetation. Now, if you have vegetation somewhere so,

the roots of the plants are able to bind the soil or are able to bind the sand in this region. Now,

if you have goats and if you have a large number of goats that are growing there and eating away

these plants what will happen in a short while is that these after these plants get removed the

sand will be able to move freely. Because it is now unbound and so,

you will have a situation in which the amount of erosion would increase in the system,

or for instance earlier this area was having some vegetation and so, we had a situation in

which this area is a semi arid area. But once you have removed all of these plants and you do

not have any further seeds that remain in this area, this area will become completely barren,

it will become a complete desert. So, things such as these, things

such as desertification that have been brought about by some human activities are also topics

that we study in ecology. So, effects of changes, so, these are some topics that we

study in ecology, but how do we study these. So, there are three approaches to ecology. The

first is called the theoretical approach. Now in the theoretical approach we use

equations and models in an Ab-initio manner to understand what is going on in the system.

So, for instance to give an example you have say a predator and you have a prey population. Now,

if the number of prey increases then we will observe that the number of predators would

also increase, because they are getting more amount of food and because they are getting

more amount of food they will be able to devote more resources to reproduction.

So, an increase in the prey population would increase the predator population,

but then if you have more number of predators, because of this increase; that would provide a

negative feedback. So, a negative feedback to the prey population because now; because you have more

number of predators, so, these predators would be preying upon the prey population and would

reduce their numbers. So, this would reduce it down. Now if this number reduces, if the number

of prey animals reduces that would again go back and reduce the population of the predators and

when that number reduces that would again give a feedback that would increase the prey population.

So, to put it in other words, if you have more prey that would give you more predators. Now,

if you have more predators that will result in which a number of prey animals are eaten

up which would result in less prey. Now, if you have less prey, so you will have less amount of

food that is available to the predators. So, that would result in less number of predators,

because less number of prey population is able to support a lesser number of predator population.

Now, if you have less number of predators the prey would be able to increase. So,

then we would be having more number of preys. Now this is something that we can understand

intuitively. Now, if you go to the theoretical approach. So, theoretical approach would begin

with such a framework and would then go on and define different equations and different

models through which we can understand the system. So, for instance if you have prey population that

is represented by small p and predator population that is represented by capital P . So, the our

theoretical approach would ask that, if you have this prey population, it would be a function

of the predator population and the existing prey population and what would be the equation through

which we can model this system and we will have an example so this system is governed by what

we call as the Zotka-Volterra equations and we will have a greater look at this system in

more detail in one of the later lectures. Now, the second approach to ecology is a

laboratory approach. So, laboratory approach uses the scientific method of formulating

hypotheses and testing them through experiments. So, to give an example; suppose we have this area

and so, suppose this is a pond. And in this pond we are having very less amount of algae. Now the

question that we could ask here is, what are the factors that are limiting the algae population

in this pond. So, again we are looking at the abundance and distribution of an organism, in

this case, this organism is algae. And now we are asking the question, what are the limiting factors

in this pond because of which the population is less. So, what we can do in this case is that

we can divide this pond into different regions so, we can set up curtains. And once we have

set up these curtains we have these different regions 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15.

Now, once we have set up these curtains water cannot move from one of these areas to another

area so, all of these zones have now become different from each other. Now, what we can

do is that, say we have a hypothesis that we have a less population of algae here, because there is

less amount of nitrogen that is available to the plants. So, in that case what we will do is that,

in this area we will add nitrogen maybe there is another hypothesis that this could be because of

less amount of phosphorous that we have in this area. So, in another area we will add phosphorus;

in another area we will add potassium and so on. So, we can formulate n number of hypotheses and

then we can perform this experiment, we can alter all of these different factors, maybe you could

even have a factor of temperature. So, probably temperature is very less and so, your plants are

not able to grow here. So, probably in this area we will put up a heater and we will heat up this

water or probably temperature is too high. So, in another area we could reduce the

temperature or in the case of these nutrients, you could have a sector in which we reduce nitrogen,

we reduce phosphorus, we reduce potassium. In some other areas we add iron, in some other

areas we reduce iron. So, we can perform n number of experiments and in all of these experiments, we

will keep certain areas as controls. So, control is a sector in which we are not doing anything.

So, this is how our system was without doing any of the interventions. So, in this approach what

we will do is we will formulate hypotheses that, we can have these n number of reasons,

because of which we are having less number of or less population of algae in these waters. We

could have a deficiency of certain nutrients, we could have an excess of some nutrients that

are becoming toxic to these plants or maybe we could have less temperature, higher temperature,

less amount of sunshine, more amount of sunshine; we can formulate a number of hypotheses. And then

we can perform experiments to check all of these. So, we can alter all of these different variables

and then we can check them with the controls. So, probably it turns out that in this experiment;

see there was an area in which magnesium was added, magnesium was reduced or say chloride

was added or chloride was reduced and so on. So, probably it turns out that in all of these

different areas nothing changes, but in the area with magnesium, we can see more number

of plants that are that have come up. So, once this happens, we will be able to tell

that we have a less population of algae in this pond, because of a deficiency of magnesium. So,

this would be a laboratory approach. So, we are using the scientific method of formulating

hypotheses. So, the first step is to formulate hypothesis; what are the things that could be

playing a role in having a reduced population and then we can test them out using experiments. So,

we looked at the theoretical approach and the laboratory approach. The third approach

is the field approach. So, field approach is through observations in the field. Now a

very good example of the field approach is what we refer to as the Langur Chital association.

Now, this association between these two species was figured out in Kanha. So,

what people observed was that, if you have a big tree and in this tree you have some Langur

population that is a troop of langurs that are there on the trees; you will also find a number

of Chitals that would come below this tree. So, what are the factors that are resulting

in this particular distribution of animals that wherever you get langurs on trees you

find chitals coming there. So, what people did was they just sat and they observed what

are these langurs doing to the Chitals. So, they observed that if you are a langur and you are on

top of a tree you have a very good vantage location to observe the surroundings. So,

if you have a tiger that comes up here and if you have these tall grasslands, so, you have these

grasses that are there. So, a chital will not be able to observe the tiger, but a langur will be

able to observe the tiger and whenever this animal observes that either it starts giving out calls;

alarm calls. So, that other Langurs are also alarmed that there is a predator nearby.

Now, when this happens and you have a chital that is also nearby. So, chital also hears the

alarm. So, even though the Chital was not able to see a tiger, because it was there on the ground,

it was not perching high up on the tree, if it is close to the langurs, it can make use of

that information. So, that is one benefit that is provided by the langurs to the Chitals. Secondly,

whenever the langurs are eating the leaves of the tree, they tend to be a bit destructive feeders.

So, what they will do is, they will pluck up a leaf then eat up its petiole and they will throw

the rest of the leaves down. Now especially in seasons, where you have scanty vegetation or you

have less number of green grass that is available. So, say in the summer season you will have this

area that has all the dry grasses, now dry grasses are mostly unpalatable, because they have a very

high amount of silica content. If Chital is going to eat up dry grass it is going to injure

its mouth. So, it requires green vegetation. Now, when it comes to the bottom of this tree,

Langurs that will be plucking a leaf eating its petiole and throwing the rest of the part down.

So, Chital will automatically get access to this food resource. So, this Chital,

it is unable to climb up a tree and it is unable to get those leaves by itself, but by coming in

close contact with the langurs by just coming where the Langurs are eating and it can eat now

all the leaves that are falling from the trees. So, this is a kind of observation that can only

be made in the field. Now, similarly why does Langurs tolerate Chitals when it is there;

because a langur is getting a viewpoint from here, it is not getting a viewpoint from here. Chitals

also have a very good sense of smell, so, probably if you have a tiger here and a Langur was not able

to see this tiger and the wind was blowing in this direction. So, Chital was able to get a sense. So,

when Chital gets a sense of this predator nearby it will also give out an alarm call,

it would run away and that would alert the Langurs. So, essentially this kind of

an association in which you have two different organisms that are interacting with each other

or a community interaction can also be studied using the field approach. In the field approach,

we use observations in the field. So, these are three approaches to

ecology and in the rest of the course we will make use of all of these three different approaches

to understand why an organism is somewhere, why an organism is not from somewhere else

and what we can do to help these organisms or to conserve these organisms. So, these are the three

approaches to ecology the theoretical approach, the laboratory approach and the field approach.

So, in this course we will be having so, let us now have a look at the outline of the course. So,

we will be having 12 modules in this course the first module is introduction. Introduction to

the course, a historical overview of ecology which will tell us who did what to make the

field of ecology ,what are the contributions of different people different scientists who

made ecology the field that exists today. Next we will have a look at ecology and

evolution. Does ecology drive evolution and if yes, how does it do that, the second module

will be about ecological structure. So, in structure we will have a look at the levels

of organization. So, when we say a population of animals or a community of different organisms,

what is an ecosystem and things like that. So, we look at different levels of organization and

how this organization helps the system to survive. Next we will have a look at species abundance and

distribution or biodiversity and we will look at it in greater detail in the third lecture.

The third module is ecological interactions. So, we will have a look at positive interactions and

negative interactions and the study of behaviors and behavioral ecology. The fourth module is

ecological energetics. So, in this module we will have a look at food chains, food webs and tropic

levels and we will also understand how and why are the birds dying because of the insecticides,

we will have a look at primary production. So, primary production is how plants make food

out of sunlight and we will also have nutrient cycles, say carbon cycle, nitrogen cycle and so

on. The fifth module is population ecology. Now population is a group of animals that belong to

the same species. So, say a group of chital or a group of sambar; that is a population.

Now, if we want to study a population, we will have to define a number of population

parameters. So, what is the number of organisms that are there, what is their sex ratio,

how many off-springs are born to each mother and so on. We will also have a

look at different demographic techniques to get an idea of these population parameters.

Next we will have a look at population growth and regulation. So, for instance say we wanted to

conserve tigers, how does this tiger population grow? why is it not that we put tigers into a

forest and this population shoots up? what are the factors that regulate its growth? and what are the

factors that may even lead to its decline? are things that we will understand in this lecture.

Next population studies and their application, so, this is more of an applied topic.

The sixth module is about community ecology, community nature and parameters, community changes

and ecological succession. So, succession is a process in which the ecology changes

or the ecosystem changes from one state to another state. So, for instance if you have, say a piece

of barren rock. So, on this rock after a while we might observe that some algae grow up and when you

have some algae on these rocks, so, after a while they would start degrading this rock converting it

into soil. Once you have the soil there then you might have some other organisms that come in, say

you have grasses that come into this rock, rocky region; once you have these grasses they will

degrade the rocks even further and make way to, say small plants followed by some trees. So, this

is the process of ecological succession. So, in the process of ecological succession every species

makes way for the next species till you reach a climax. So, we will have a look at ecological

succession and also community organization. Now the seventh module is about distribution

and abundance. So, we have biogeography, that is the analysis of geographic distributions.

Next we have Why things where they are , what are the factors that regulate this distribution and

abundance and we will have a look at some push and pull factors in greater detail.

The eighth module is management of threatened species. So, what are the

different kinds of threats that we have to different species? So, there are a number

of species that we are trying to conserve, we have tigers, we have elephants and so on.

So, what are the threats that are being faced by these species and what can we do to reduce the

impacts of these threats. So, we divide it into in-situ conservation and ex-situ conservation.

The 9th module is topics in human ecology. So, we will have an introductory session

followed by human population growth and food requirements and sustainable development.

The 10th module is ecology of change. So, we will have impacts of climate change,

impacts of plastics, especially on biodiversity and impacts of oil spills.

The 11th module is applied ecology. Here, we have the optimum yield problem,

biological control, ecotoxicology and pollution management and restoration ecology. Finally,

we will devote a week to revision of all the topics that we have covered so far.

In this course, we will have continuous assessment. The assessment will be in the

form of assignments and in the form of a final exam. Assignments will comprise multiple choice

questions which will be based on the weeks topics, and the final exam will be having three kinds of

questions. We will be having final exam in two different slots; a morning slot and evening slot

and we will be having three different kinds of questions. We will have recall questions;

recall questions are those questions in which you have to give an answer based on

recall from the lectures. Then we will have some questions that will come from the assignments,

maybe slightly modified, but more or less based on the assignment and third will be open type

questions that will test your wider understanding of the whole topic. And the final exam will also

comprise multiple choice questions. Now, the final exam will be computer based and

will not require you to write any of the answers. So, in this lecture we had a look at what ecology

is; what are the different kinds of topics that we study in ecology; what is habitat, what are

the kinds of interactions that we have, what is a population what is the community and so on. We

also had a look at three different approaches to ecology, we have theoretical approach,

we have a laboratory based approach and we have the field approach and we make use of all of these

approaches as we move forward in this lecture. So, thank you for your attention. Jai Hind [FL]