1_Lecture 1 Intro to behavioural ecology.pdf

Introduction to Behavioural Ecology BIOL325 Behaviour & Reproductive Ecology  Please note Please come to all lectures and Tut’s There will be many spot tests Please take notes during lectures I will be uploading PDFs of slides Please read Prac manual carefully bef...

Introduction to Behavioural Ecology BIOL325 Behaviour & Reproductive Ecology  Please note Please come to all lectures and Tut’s There will be many spot tests Please take notes during lectures I will be uploading PDFs of slides Please read Prac manual carefully before coming to Prac’s If you study hard, you will pass!  What is Behavioural Ecology? Actions and reactions of whole organisms  What is Behavioural Ecology? Relationship between behaviour, ecology and evolution In other words, the evolutionary basis for animal behaviour Why has a particular behaviour evolved? E.g., Solitary vs group living, courting and mating, cooperation  Natural selection Natural selection is the process of how species adapt to their environments Adaptations are evolutionary changes How is animal behavior adapted to an animal's environment? Traits which provide a selective advantage (adaptive significance) are favored by natural selection  Outline We will be focusing on functional questions about behavior. Remember: The aim of behavioral ecology is to understand how an animal's behavior is adapted to the environment in which it lives Behavioural ecology focuses on how the behavior of animals affects their ability to survive and reproduce Why measure Behaviour? Adaptations to changing environments Evolution of behaviours Natural principles Direction of evolution  Founders Konrad Lorenz (1903-1989) Niko Tinbergen (1907-1988) Charles Darwin ‘The expression of emotions in man and animals’ (1872) Konrad Lorenz Innate behaviours Instinct Genetically determined behaviours Konrad Lorenz Imprinting 36 hours after hatching Filial imprinting Adaptive in wild Konrad Lorenz Mechanistic approach Physiology Development Ethology  Ethology (reminder) Ethology studies animal behaviour Focus on behaviour under natural conditions Views behaviour as an evolutionarily adaptive trait Niko Tinbergen Lorenz’s student Learning and decisions Whole animal Behavioural Ecology  Niko Tinbergen Tinbergen stressed the importance of instinctive and learned behaviour to survival Niko Tinbergen “aims to determine the ways in which behaviour contributes to fitness and how behaviour has changed through evolution” Beewolves How do they find their nests? Hover before leaving (Observation) Hypothesis: memorise landmarks?  Beewolves Formulated a Prediction Wasp would be confused by changing landmarks Tested his Prediction through experimentation: When he changed the area around the burrow – returning females were confused (circled repeatedly)  Beewolves 2nd Prediction Since landmarks were important moving them would confuse returning wasp Tinbergen's Four Questions Causation- How do physiological mechanisms control behaviour? Ontogeny (development)- How do these mechanisms develop? Adaptive Value (function)- Why is the behaviour used? Survival value Phylogeny (evolution)- What were changes that lead to modern behaviours? Four Questions rephrased Causation- How does it work? Ontogeny (development)- Does it change with development? Adaptive Value (function)- Why did this character evolve? Phylogeny (evolution)- How did this character evolve? Phylogenetic perspective Behavioural characteristics Ernst Mayr(1961) Proximate (How?) Ultimate (Why?)  Migration Proximate Changes in photoperiod, temperature, etc. Ultimate Naturally selected genotype Starve without food  Peacock Proximate Hormones or genetic growth factors Ultimate Sexual selection and attempts to gain mates Causes Proximate Mechanisms underlying behaviour Ultimate Evolutionary history and selection process which shapes function  Ethology Causation Proximate Ontogeny Behavioural Ecology Adaptive Value Ultimate Phylogeny  This does not mean that proximate and ultimate are mutually exclusive, and that proximate explanations are of no use when pursuing ultimate explanations, but it is important to know whether the answer to your scientific research question is proximate or ultimate Remember for your Prac’s One of the goals of this Practical course is to make a distinction between Causal (Proximate) and Functional (Ultimate) explanations of animal behaviour  What is Behavioural Ecology? Behavioural ecology is concerned with functional questions about behaviour, namely how a particular behavioural pattern contributes to an animal’s chances of survival and reproductive success Adaptation & Behavioural Ecology Foundations in Evolution and Natural selection Common features Variation in traits Heredity Differential reproduction Adaption & Behavioural Ecology If individuals do not have the same likelihood of survival, evolutionary change (adaptation) would be the inevitable outcome when these three conditions occur in a species.  Natural Selection Elimination of unfavourable traits that compromise reproduction Spread of beneficial traits (i.e. selection) is a natural consequence of individual differences in reproduction & fitness  Natural Selection Selection on individuals will favour alleles that build bodies that promote the survival of those alleles Animal behaviour studies seek to determine why alleles that underlie a particular adaptive trait or behaviour were copied more often than other alleles Group selection Group selection is proposed as an evolutionary mechanism in which natural selection acts at the group level rather than the gene level or individual level Group selection Alleles/behaviours become fixed in a population because of the benefits they bestow on groups Regardless of the effect on the fitness of individuals within that group Group selection The adaptive significance of any behaviour involving social interactions benefits multiple individuals in the group (e.g. alarm calls) Selection takes place on the basis of differences between groups Wynne Edwards Group selection Fatally flawed concept Self-serving vs Self- sacrificing behaviour Group selectionist population would be eliminated by natural selection! Evolutionary paradigm = Individual Selection Individual selection Don’t help ANY individuals unless YOU or YOUR genetic relatives benefit Conflict of interest between members of all social groupings- mates, parents and offspring Sociobiology ‘Sociobiology, the new synthesis’ The extension of population biology & evolutionary theory to social organisation Systematic study of the biological basis of all social behaviour (E.O. Wilson 1975) Sociobiology Link between population biology & behaviour Behaviours are partly inherited Human behaviour may be partially explained by genetics Extremely controversial (E.O. Wilson 1975)  Sociobiology Natural selection explains everything Genes play the ultimate role in behaviour (e.g. aggressiveness) & not social environment Culture explained by biology & genes Pseudoscience (E.O. Wilson 1975)  Behavioural Ecology Proximately about the ways organisms interact with conspecifics, other species and their environment, in the light of their evolutionary past Ultimately about the strategies individual organisms use to maximise their genetic representation in future generations  Readings Pp. 1-23 Davies, Krebs & West (2012) An Introduction to Behavioural Ecology 4th edition Pp. 4-23 Krebs & Davies (1993) An Introduction to Behavioural Ecology 3rd edition Pp. 4-51 Alcock (2005) Animal Behaviour 8th edition Pp. 2-112 Dugatkin (2004) Principles of Animal Behavior 2nd edition Pp. 1-53 Danchin et al. (2008) Behavioural Ecology 1st edition