MODULE: INTRODUCTION TO WILDLIFE ECOLOGY

1. MODULE: INTRODUCTION TO WILDLIFE ECOLOGY COURSE: TECHNICIAN CERTIFICATE IN WILDLIFE TOURISM, 2013/14 MODULE LECTURERS: JUMA KEGAMBA 1

2. Ecology is the study of the interaction between living organisms and the environment in which they occur/live. • Or is the study of the interactions between living organisms and their abiotic and biotic environment. 2

3. History of ecology "Ecology" comes from the Greek words oikos, meaning "house," and logos, meaning "logic" or "knowledge." The term was coined by German zoologist (scientist who studied animals) Ernest Haeckel in 1869. 3

4. Division/Branches of Ecology:- It can be divided into two major subdivisions:- 1. Autecology: Is the study of ecological relationships between a single organism or a species and its environment. 4

5. Example. The Autecology’s of the superb starling meaning study the following about that species as • Appearance and distribution • Feeding habits • Roosting behavior • Reproduction • Starling and humans 5

6. 2. Synecology: Is the study of ecological relationships between several species or an entire community and its environment. • Example: Study of forest community (unity entity) 6

7. Scope of ecology Ecology is largely concerned with several level of organization and this is from organism, population, community and ecosystem. • species individuals which share a common gene pool and can potentially interbreed and bear fertile, viable offspring; 7

8. population means organism of the same specie living in the same area at the same time, • community means a number of species living together and interact with one another, • ecosystem are the biotic community and its abiotic environment functioning as a system. 8

9. Biomes are groupings of ecosystems with similar environment and vegetation structure (physiognomy) • Biosphere includes all living organisms on earth and part of the earth that extends from are few hundred meters beneath the surface to several kilometres into the atmosphere. 9

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11. Importance of understanding ecology • Understanding of ecosystem ecology enable a wildlife manager to decide on: -Infrastructure development, -Visitor use, -Harvesting season and extent It should be born in mind that population is the basic unit of management and that all management objectives (in protected area) are focused toward maintaining 11

12. Importance cont…… certain levels of populations that can be supported by the ecosystem. • To know why population density has gone up or down in a particular species, • To be able to interpret the movement of individual of a given population with respect to environment and seasonality 12

13. Population ecology. • Apopulation is a group of organisms of the same species that live in a particular area. • A population has group characteristics or biological attributes that differ from those of the individual characteristics and can be statistically measure. 13

14. Primary population parameters/ primary characteristics of the population • Density, • Natality (births i.e. production of offspring), • Mortality (deaths i.e. death of individuals), • Immigration (individuals entering in the population), • and Emigration (individuals moving out of the population). 14

15. Births and Immigration increase the size of the population; • Where as, Deaths and Emigration decrease the size. • The increase in the number of organisms in a population is referred to as population growth. • There are factors that can help populations grow and others factor can slow down and even prevent populations from growing. 15

16. Populations also possess the secondary characteristics such as; • Age distribution, • Sex composition, and • Spatial distribution of individuals. • Changes in these characteristics are what make population dynamic. • NOTE: The secondary population parameters cannot be applied to individuals • why population density changes, we are asking which one or more of these parameters has changed. 16

17. Biotic Components • The living organisms are the biotic components of an ecosystem. • In ecosystems, living things are classified after the way they get their food. • Autotrophy produce their own organic nutrients for themselves and other members of the community; called the producers. • Two kinds of autotrophy, 1.Chemoautotroph and 2. Photoautotroph's. 17

18. Chemautotrophs are bacteria that obtain energy by oxidizing inorganic compounds such as ammonia, nitrites, and sulfides , and they use this energy to synthesize carbohydrates. • Photoautotrophs are photosynthesizers such as algae and green plants that produce most of the organic nutrients / or food for themselves using sunlight energy. 18

19. Heterotrophs, asconsumers that are unable to produce, are constantly looking for source of food from elsewhere. • Herbivores like giraffe are animals that graze directly on plants or algae. • Carnivoresas wolf feed on other animals; birds that feed on insects are carnivores, and so are hawks that feed on birds. • Omnivoresare animals that feed both on plants and animals, as human. 19

20. Detritivores are organisms that rely on detritus, the decomposing particles of organic matter, for food. • Earthworms and some beetles, termites, and maggots are all terrestrial detritivores. • Non- photosynthetic bacteria and fungi, including mushrooms, are decomposers that carry out decomposition, the breakdown of dead organic matter, including animal waste. • Decomposers perform a very valuable service by releasing inorganic substances that are taken up by plants once more. 20

21. Abiotic Components • Abiotic components are such physical and chemical factors of an ecosystem as light, temperature, atmosphere gases (nitrogen, oxygen, carbon dioxide), water, wind, soil. • These specific abiotic factors represent the geological, geographical, hydrological and climatological features of a particular ecosystem. Separately: • Water, which is at the same time an essential element to life and a milieu 21

22. Air, which provides oxygen, nitrogen, and carbon dioxide to living species and allows the dissemination of pollen and spores • Soil, at the same time source of nutriment and physical support. The salinity, nitrogen and phosphorus content, ability to retain water, and density are all influential. • Temperature, which should not exceed certain extremes, even if tolerance to heat is significant for some species • Light, which provides energy to the ecosystem through photosynthesis 22

23. Populations Density, Distribution and Size • Population density is the number of individuals of a certain species per unit area or volume. E.g number of elephants per square kilometer, or number of trees per square kilometer. 23

24. Types of population density • Crude density: It refers to the number (or biomass) per unit total space. E.g. The number of Dik dik in ANAPA per unit total area of ANAPA, (Here you talk of the total area mindless if it is habitable or not to a particular species). 24

25. Specific or ecological density: Refers to the number (or biomass) per unit of habitat space (i.e. available area or volume that can be habitable /colonized by the population. E.g. number of lesser flamingo per area of Lake Natron • Population size is the number of individuals in a population. Population size fluctuates in time. 25

26. Factors affecting population growth and density • a. Natality. Natality rate is the rate at which new individuals are added to a particular population by reproduction (birth of young ones or hatching of eggs or germination of seeds/spores). Greatest factor influencing population increase. 26

27. Aspects of reproduction • Fertility: This is a physiological notion that indicates that an organism is capable of breeding. • Fecundity: This is an ecological concept that is based on the numbers of offspring produced during a period of time. 27

28. Factors influencing natality rate • Birth rate or natality rates do always vary with the variation in environmental conditions both biotic and abiotic conditions. 28

29. 1. Body condition of Individuals • Age of the puberty, • The frequency of birth during the life of the individual, • The number of gametes shed at each ovulation or ejaculation and embryos retained to parturition. 29

30. 2. Age structure • The litter sizes of young or very old parent are significantly lower than that of moderate aged parents at the time of fertilization. • The population with many old and young reproductive parents has lower natality rates, and therefore low population density. 30

31. 3. Mating systems and dominance hierarchy • Sex ratio in population - typically assumed to be 1:1, but not always the case. • Proportion of reproductive females in the population depends on length of heat period. 31

32. 4. Environmental factors • Various environmental factors influence birth rates as a result of their influence to the physiology, behaviour etc. of individual organisms. • These include temperature and light, (photoperiodism). • The two may have direct or indirect effect on birth rate of individuals in the population. 32

33. b. Mortality • Mortality refers to death of individuals in the population. • Mortality is exactly opposite of natality. • Factors affecting mortality rate Predation/herbivory: • One organism (predator or herbivore) eats another organism (prey species). 33

34. Diseases and parasites: • Most organisms at most of the time are subjected to various kinds of infectious diseases and serves as hosts for numerous parasites. 34

35. Weather: • Such parameter may have indirect effect on mortality through its influence on food supply, parasites, predators, or other factors. • But also, it may have direct effects such as heavy rains can cause mass drowning of individuals. • Unusual cold or hot can reduce or increase temperatures to a point where some species can no longer maintain their body temperature. 35

36. Accidents: • Fires, drowning, highway collision etc can increase mass mortality. • Where humans introduce many modifications on the wildlife habitat (e.g. fences, roads buildings, power lines or other art facts), they increase hazards to wildlife. • In most cases young (inexperienced member of a population) are most frequently affected by accidents. 36

37. C. Age distribution (Age composition) The relative abundance of the organisms of various age groups in the population is called age distribution of population. • With regard to age distribution, there are three kinds of populations. 37

38. Rapidly growing population is a population, which has high birth rate and low death rate, so there are more number of young individuals in the population. • ii) Stationary population is a population, which has equal birth and death rates, so population shows zero population growth. 38

39. Declining population is a population, which has higher death rate than birth rate, so the population has more numbers of older individuals. 39

40. d. Immigration Immigration is the permanent entry of new individuals of same species into a population from outside. It increases the size of local population. • e) Emigration Emigration is the permanent movement/departure of individuals of same species out of the local population due to several reasons such as lack of food, scarcity of space (over crowding), etc. 40

41. f) Carrying capacity • The maximum number of individuals of a population, which can be provided with necessary resources for healthy living, is called carrying capacity of the habitat. • Population density of an area is largely determined by available resources like food, water, light and space. 41

42. g) Natural calamities • A drastic change in the environment destabilizes or even exterminates a population. • Natural calamities such as earthquake, volcanic eruptions etc. cause drastic changes in the environment leading to the destruction of the resources. 42

43. Population distribution Is the pattern of dispersal of organisms within that area. • Why are organisms of a particular species present in some places and absent in others? • No one species of organism occurs uniformly all over the world 43

44. Geographical - random, regular and aggregate • Uniform/ regular distributions are found in populations in which the distance between neighboring individuals is maximized. The need to maximize the space between individuals generally arises from competition for a resource such as 44

45. moisture or nutrients , or as a result of direct social interactions between individuals within the population, such as territoriality. •  Example allelopathy effect in plants leads to uniform distribution. 2. Random distribution, occurs when the members of a given species are found in homogeneous environments 45

46. in which the position of each individual is independent of the other individuals: they neither attract nor repel one another. Random distribution is rare in nature as biotic factors, such as the interactions with neighboring individuals, and abiotic factors, such as climate or soil conditions, generally cause organisms to be either clustered or spread apart. 46

47. Random distribution usually occurs in habitats where environmental conditions and resources are consistent. This pattern of dispersion is characterized by the lack of any strong social interactions between species. For example ; •  Seed dispersal by wind e.g spathodea companulata 47

48. 3. Clumped/ aggregate distribution is the most common type, the distance between neighboring individuals is minimized. Why clumped distribution? • patchy resources. Animals need certain resources to survive, and when these resources become rare during certain parts of the year animals tend to “clump” together around these crucial resources. 48

49. social factors such as selfish herds and family groups. prey organisms form clumped distributions in areas where they can hide and detect predators easily. • Mechanism to trap a prey (communal hunting )- predators such as African wild dogs, Lycaon pictus, • Inability of offspring to independently move from their group. 49

50. 2. Ecological distribution • The difference in numbers of species can be correlated in part with the number of different types of habitat. Types of environment normally inhabited by a species make up its ecological range. • The most obvious major divisions of the environments are salt (marine) water, fresh water and land. Some organisms are adapted to live in marine water only, while others in fresh water. 50