BIO113 Studying Mammals Unit 2: Studying Mammals: The Insect Hunters - OPEN University

Open University

S182_2
10 Hours

Level

Introductory

Course Home (Click Here)

Course Description

Sixty-five million years ago, animal and plant life were very different from nowadays, but there were rat-sized placental mammals living successfully on the ground. They were insect eaters, i.e. insectivores, feeding on the vast numbers of insects and other invertebrates living in soil, leaf litter and low-lying vegetation. Insectivore means ‘insect eater’, and in this unit we will explore the world of insect-eating mammals, classified together on the basis of a reasonably close evolutionary relationship.

This is the second in a series of units about studying mammals. To get the most from these units, you will need access to a copy of The Life of Mammals (2002) by David Attenborough, BBC Books (ISBN 0563534230), and The Life of Mammals (2002) on DVD, which contains the associated series of ten BBC TV programmes. OpenLearn unit S182_8 Studying mammals: life in the trees contains samples from the DVD set. You should begin each unit by watching the relevant TV programme on the DVD and reading the corresponding chapter in The Life of Mammals. You will be asked to rewatch specific sequences from the programme as you work through the unit.

Learning Outcomes

By the end of this unit you should be able to:

describe the lifestyle of a variety of insect eaters, from four orders;

give examples of adaptations linked to feeding in insect eaters;

explain the limited extent to which insectivores can be regarded as ‘primitive’;

characterise typical adult mammalian dentition and understand dental formulae;

recognise teleology and write down accounts of evolution that do not assume purpose or direction;

describe the relationship between surface area, volume, body mass and BMR;

identify strategies that insect eaters use to cope with cold and food shortage;

explain the events of bat and hedgehog hibernation and the evidence for the control of this process.

	Introduction Introduction Resource Sixty-five million years ago, animal and plant life were very different from nowadays, but there were rat-sized placental mammals living successfully on the ground. They were insect eaters, i.e. insectivores,...

	1 Meeting the insect eaters 1 Meeting the insect eaters Resource As you work through this unit you will come across boxes, like this one, which give you advice about the study skills that you will be developing as you progress through the unit. To avoid breaking up...

	2 How insect eaters obtain their food 2.1 Mammalian dentition Resource Insects are generally very small animals. Many kinds are hard work to collect and not very nutritious because a high proportion of their mass is a protective and indigestible outer layer, called cuticle.... 2.2 Feeding techniques Resource In Activity 1, below, you are asked to make notes from a TV sequence and then select some of the information from your notes and combine it with some from LoM into a single short piece of writing. Check...

	3 Adaptations linked to feeding in insect eaters 3.1 Introduction Resource How evolution proceeds is obviously of central importance when studying mammals. Of fundamental importance to the way evolution works is the notion of natural selection, and in S182_3 Studying mammals:... 3.2 Shrews Resource Drawing on the notes you made about shrews in Activity 1, describe in a couple of sentences the water shrew's strategy for searching for and catching insect larvae. 3.3 Moles Resource In this section, you will meet one of the ways in which scientists are very precise about the way that they use ordinary words. Spot the difference between ‘The golden mole evolved webbed hind feet so... 3.4 Anteaters Resource View ‘The Insect Hunters’ on the DVD from 22.40–26.54, which shows the giant anteater, and make notes on what you see. On the basis of your notes, what features of the giant anteater could be regarded... 3.5 Bats Resource There are two more activities in this section that give you more practice in writing. You will see that you are again given an approximate number of words to aim for in your answer. This number is a guide...

	4 Thinking about adaptation 4 Thinking about adaptation Resource Section 3 identified a range of adaptations in insect eaters, most linked with their mode of feeding. Particular structures are identified as having particular functions. But there are problems with the...

	5 Temperature regulation and the consequence of size 5.1 Introduction Resource If you have already worked through S182_1 Studying mammals: a winning design, you'll be aware (from Section 5) that animals break down their food for conversion into usable forms of energy; thus, breakdown... 5.2 Body size and metabolic rate Resource Figure 6 is a slightly more complex graph than those used in S182_1. In particular, the masses of the mammals that are plotted on the horizontal axis vary so much that a normal scale would squeeze together... 5.3 Body size and surface area Resource You will be using some more maths in this section. Remember that areas are measured in units such as m2, which is read as metres squared or, more usually, square metres. Volumes are measured in units such...

	6 Strategies for coping with cold and food shortage 6.1 Toughing it out Resource For small insectivorous mammals, the best solution to the problem of obtaining sufficient energy for their requirements, notably the maintenance of body temperature, is to feed continuously. But in temperate... 6.2 Opting out Resource This last section of the unit contains, I think, some of the most challenging science that you have met so far. Take it slowly, translating all the abbreviations in your head as you come to them (read...

	References and Acknowledgements Acknowledgements

Citation: administrator. (2010, January 30). BIO113 Studying Mammals Unit 2: Studying Mammals: The Insect Hunters - OPEN University. Retrieved July 31, 2010, from Free University Courses OCW Courses OpenCourseWare Freeversity Foundation Web site: http://www.freeversity.org/science-and-mathematics/biology/bio113-studying-mammals-unit-2-studying-mammals-the-insect-hunters-open-university.

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