Behavioural Ecology Presentation PDF

Behavioural Ecology: Presentation #1 Alex Mills 1 What am I teaching this year? NATS 1660 Biology of Sex (year-long course) ENVS 3420 Environmental Law (Fall) Three 4th year BIOL courses BIOL 4250...

Behavioural Ecology: Presentation #1 Alex Mills 1 What am I teaching this year? NATS 1660 Biology of Sex (year-long course) ENVS 3420 Environmental Law (Fall) Three 4th year BIOL courses BIOL 4250 Birds and the Environment (Fall) BIOL 4245 Conservation Biology (Winter) BIOL 4070 Behavioural Ecology (Winter) In the past numerous others: e.g. BIOL 1001 and BIOL 4001 (field course) 2 When people ask me “what is my area”? Sometimes: “Ornithologist” Other times: “Behavioural Ecologist” My publication record is mostly behavioural ornithology Especially migration behaviour And reproductive behaviour 3  Behavioural Ecology New course! When I began here, we had insufficient ecology offerings Population Ecology I created Community Ecology in 2021 (now taught by Gordon Fitch) And now this course, Behavioural Ecology in 2025 Behavioural Ecology The behavioural interactions among individuals at both the intraspecific level in natural populations and the interspecific level in natural communities. Ask questions about, e.g.: proximate and ultimate causes of behaviour, adaptive value of behaviours for survival and reproduction, Overarching theme: behavioural interactions against the metric of evolutionary fitness Course Structure Monday and Wednesday lectures 11:30 to 12:45 Lectures are not recorded No labs Mid-term #1 (15%) January 29 on first 6 lectures Mid-term #2 (20%) March 5th on lectures 7 to 13 Cumulative Final Exam (45%) in April exam period Behavioural Ecology “Conference” 15-minute AV presentations, in pairs (15%) 1-page summary of the presentation (5%) There is no course TA; I do all the grading 6  eClass 1. Course Outline, Schedule 2. Posted office hours with Zoom link: Thursdays from 11 to 11:50 am 3. Announcements, etc. 4. Lecture material: PowerPoint slides, Readings Don’t email me through eClass because I won’t get it! Use [email protected] 7 These folks I generally These folks attended only saw at the Mid-term classes and were the ones Some of these were not and Final Exam who visited during office prepared for the Mid- hours to ask questions These folks bombed term but recovered for the questions based on the Final Exam the posted Readings How to do well Come to all classes The PPT slides are not a complete set of notes! So, create your own notes Ask questions about things you don’t understand Either during class, or in office hours You must know “stuff”, and… You must be able to answer questions where you draw from lecture material Themes Constraints on behaviour Development of behaviour What mediates behaviour? Optimization and trade-offs Reproductive behaviour Behaviour related to feeding Etc. From descriptive natural history … to predictive natural history… to experimental behavioural ecology Descriptive: Eastern whip-poor-will. Many descriptions noted that they sing in (a) twilight and (b) moonlight, but not in (c) daylight, or (d) dark night.  Predictions: Overall: They are lunaphilic Specifically: 1. They move more in moonlight 2. They feed their nestlings more in moonlight 3. They synchronize their reproductive schedule with the lunar cycle 4. They synchronize their migration schedules with the lunar cycle Predictive: Eastern whip-poor-will. Do they forage more in moonlight? Needed technology: Mist nets and song lures Do they forage more in moonlight? Needed technology: Mist nets and song lures Radio tags Radio Tag Radio Tag 16 Moonlight correlated with more movement Do they feed their young more in moonlight? Nest monitoring Do they synchronize nesting with the lunar cycle? Historical nest records at the Royal Ontario Museum Do they synchronize migration with the lunar cycle? We had to defer answering this question for more than 35 years! Do they synchronize migration with the lunar cycle? Needed technology: Mist nets and song lures GPS tags GPS tag Do they synchronize migration with the lunar cycle? We had to defer answering this question for more than 35 years! 25  1. Pre-Darwin: top one is Dung Flies “riding” male, and the two are mating. That is basic descriptive natural history. 2. Darwin: Males compete for access to females. The larger size of the males is evidence of sexual selection. 3. ~1975: Males delay dismounting. This is evidence of sexual conflict, as males are guarding females to prevent them from mating with others.  4. 1980s: Copulation time is predictable. Dung Flies “riding” Copulation time is optimized for sperm transfer, and it varies with body size. 5. 21st century: sexual conflict leads to rapid evolution of seminal proteins at the molecular level. The larger size of the males is evidence of sexual selection. 6. Optimization models can be generalized.  The Behavioural Ecology lexicon Adaptation: a phenotypic character (physical or behavioural) that confers (inclusive) fitness benefits, resulting from natural selection Phenotype Behaviour (Inclusive) Fitness Natural selection Alligator Snapping Turtle phenotype includes (a) modified tongue, and (b) associated behaviour so that both work as an effective lure Behaviour Behaviour is the internally coordinated responses (actions or inactions) of whole living organisms (individuals or groups) to internal or external stimuli  Inclusive Fitness Fitness: a measure of an individual’s genetic contributions to subsequent generations Easy metric: “# of surviving offspring” The sum of Direct Fitness and Indirect Fitness Direct fitness: via personal reproduction Indirect fitness: via non- descendant kin (e.g. “your” genes passed on by a relative) Alloparenting Alloparenting: any form of parental care provided by an individual towards young that are not its own direct offspring (Note: Sometimes alloparents are unrelated, so they aren’t gaining indirect fitness) Golden Lion Marmosets engage in alloparenting  Selection Selection: The evolutionary effects of differences among individuals in their ability to transmit their genes to the next generation Sub-category 1. Natural selection: process that occurs when individuals differ in traits and the differences are correlated with differences in reproductive success Sub-category 2. Artificial selection: humans are the selective agent Sub-category 3. Indirect selection: the role of selection connected to indirect fitness Sub-category 1. Natural selection e.g. Parental care, in this case in African Savanna Elephants  Sub-category 4: Sexual selection Sexual Selection: A subset of natural selection that occurs when the selective agents are (a) conspecifics in the context of (b) mating. Sub-sub-category 1. Intersexual selection: where the agents of selection are conspecifics of the opposite sex (usually females)  Sub-category 4: Sexual selection Sexual Selection: A subset of natural selection that occurs when the selective agents are (a) conspecifics in the context of (b) mating. Sub-sub-category 1. Intersexual selection: where the agents of selection are conspecifics of the opposite sex (usually females) Sub-sub-category 2. Intrasexual selection: where the agents of selection are conspecifics of the same sex (commonly focused on males) We may encounter other “selections” Frequency-dependent selection Group selection Runaway selection Etc.  Don’t miss this message: what is best for the male, is not always what is best for the female. They need each Darwinian Puzzle other to achieve fitness, but aren’t' always aligned. A trait that appears to reduce fitness Whistling Moths: why do female mate with males that produce ultrasonic mimetic signals similar to those produced by predatory bats? Dangerous proposition for female moths? Female responses to bats in general: (a) freeze if farther away, or (b) take evasive action if nearby. Males emit frequencies of low intensity, producing (a). Sexual Conflict When the two sexes have conflicting optimal fitness strategies concerning reproduction Often leading to an evolutionary arms race between males and females Evolutionary Arms Race is a feature of competitive Co-evolution Evolutionary arms race: Where coevolution occurs in competitive or self-interested relationships But then, what is coevolution? Coevolution: Reciprocal evolutionary change occurring between two interacting gene pools A White-tipped Sicklebill (hummingbird) and its major nectar food source, Gallito. Evolutionary Arms Race Common Garter Snakes eat them with an Rough-skinned Newts are (imperfect) ability to tolerate the toxin. astonishingly toxic: why? Back to Behaviour: what is ethology? Rather bland definition: “Study of behaviour” More meaningful definition: Study of proximate mechanisms and the adaptive value of behaviour  Proximate causes Immediate, underlying causes based on the operation of internal mechanisms possessed by an individual Changing photoperiod alters hormone levels. Ultimate causes An autumn cold snap Individuals that migrate or a strong north wind. south in the autumn survive better. A decline in food availability. Individuals that migrate north in the spring reproduce more Sandhill Cranes successfully. migrating. Invoke fitness or evolutionary history Sociobiology The use of evolutionary theory (particularly through the lens of adaptation) for the study of social behaviour Bonobos Evolutionary Psychology The adaptive value of psychological mechanisms Mostly applied to humans “adaptive” → sculpted by natural selection A key component of sociobiology Heavily criticized in methodology but at least this is true: “Some behaviors of modern humans reflect their evolutionary history. That is palpably uncontroversial, since many of our behaviours are clearly a product of evolution, including eating, avoiding dangers, and the pursuit of sex” [Jerry Coyne] Altruism Helpful behaviour that raises the receiver’s direct fitness but lowers the donor’s direct fitness A Darwinian puzzle… donor Eusociality Eu means “true” Groups that contain specialized nonreproductive castes that work for the reproductive members of the society Another Darwinian puzzle Termite castes Transactional Theory Social units form as a result of individuals’ ability to negotiate for reproductive opportunities with one another Proportion of Paper Wasp reproduction monopolized by the dominant female Dominance Hierarchy Social ranking within a group where some individuals give way to others, often conceding resources or mate opportunities without conflict Dominant individuals are often labelled “alpha”, with beta, gamma, etc. following Meerkats: Dominant male (DM), Subordinate male (SM), Outside male (OM), Dominant female (DF), Subordinate female (SF) Communication The cooperative transfer of information from a signaler to a receiver If it’s cooperative, it’s “honestly” conveying information, even if the information is unfriendly The more aggressive White- backed Vulture telling the Rüppell's Vulture to wait for its turn to eat Communication Another expression: An action on the part of one animal that alters the behaviour of another (E.O. Wilson) Focuses on relation between signaler and receiver The more aggressive White- backed Vulture telling the Rüppell's Vulture to wait for its turn to eat Honest signals Signals that convey accurate information about the signaler’s real intention (e.g. aggression) or real value (e.g. mating) (a): the roar of male red deer signals body size and hence fighting ability; the calls of male toads signal their body size to potential mates; the carotenoid-pigmented plumage of male house finches signals their health to females; and male rhinoceros beetles use enlarged horns to fight for access to mates. Illegitimate Receivers & Signallers Illegitimate Receiver: an individual listening to the signals of others that gains information it uses to reduce the fitness of the signaller Male frog mating calls include whines & chucks Songs with chucks are favoured by females Fringe-lipped Bat Fringe-lipped Bats are illegitimate receivers that cue on primarily on the chuck call Tungara Frog So, males tend to avoid the chuck call unless they are in large groups (Dilution Effect) Dilution Effect Safety in numbers that comes from reduced likelihood of being consumed by a predator or other consumer  Illegitimate Receivers & Signallers Illegitimate Signaller: use deceptive signals to reduce the receiver's fitness while increasing their own Photinus females use light signals to attract male conspecifics for mating Photuris females mimic those Photinus light signals (aggressive mimicry) to attract male Photinus, which they then capture and eat Photinus firefly Photuris firefly  Sensory Exploitation In signal evolution, a signaler taps into a pre-existing sensitivity or bias in the perceptual world of the receiver, gaining an advantage in transmitting a message to that receiver The Grote’s Tiger Moth (signaler) makes sounds in the frequency range of Big Brown Bat (receiver) Big Brown Bat Grote’s Tiger Moth sonar calls that jam the effectiveness of the bat sonar, gaining an advantage Display A stereotyped action used as a communication signal A typical agonistic behavior display between two large terminal phase male California Sheepheads at the border of their territories. Instinct Instinct: a behaviour pattern that reliably develops in most individuals, promoting a response to a releaser stimulus the first time the action is performed (It’s innate, meaning the predictable outcome occurs regardless of the external environment) Releaser stimuli and fixed action patterns Releaser stimulus: A stimulus originating in one individual that has social information for a responding second individual Three-spined Sticklebacks Fixed action pattern: an innate, highly (male left, female right) stereotyped response that is triggered by a well-defined, simple stimulus When activated, the response is preformed in its entirety Releaser stimuli and fixed action patterns Releaser stimulus: egg-swollen, iridescent female (during mating season) triggers a fixed action pattern in male Fixed action pattern: Male swims Three-spined Sticklebacks toward her in a zig-zag pattern (male left, female right) = Releaser stimulus: Male swims toward her in a zig-zag pattern Fixed action pattern: Female swims toward male with head held high Releaser stimuli and fixed action patterns He dashes towards his nest She enters the nest He prods at the base of her tail Three-spined Sticklebacks She releases her eggs and leaves the nest. (male left, female right) He enters and fertilizes the eggs He then chases her away Imprinting A form of learning where individuals exposed to key stimuli early in life form an association with the object Learning: a durable and usually adaptive change in an individual’s behaviour that emerges from specific experience(s) Konrad Lorenz, with precocial goslings that have, instead, imprinted on him. A female Mallard with precocial young that have imprinted on her in their first day following hatching Operant conditioning A kind of learning based on trial and error, in which an action (or operant) becomes more frequently performed if rewarded “A type of associative learning where an animal's behaviour is reinforced with a reward” Red-breasted Black-capped Nuthatch Chickadee Strategies: Conditional Strategy A set of rules that enables the individual to use different tactics under different environmental conditions, meaning it has an inherited, flexible behavioural capacity Bluegill Sunfish males have different reproductive behaviours (and associated bodies) depending on their age and associated condition Strategies: Evolutionarily Stable Strategy A set of rules of behaviour that, when adopted by a certain proportion of the population, cannot be replaced by any alternative strategy Can be “pure” → one strategy Can be “mixed” → two or more alternatives Gemsbock: Do I fight every time, regardless? Or do I sometimes fight, depending upon circumstances?  Game Theory Analysis of the payoffs to individuals associated with one behavioural tactic where they are dependent on what the other group members are doing  Optimality Theory An evolutionary theory based on the assumption that the attributes of an organism are optimal in the sense of fitness benefits exceeding fitness costs as much as possible This is the “Cost-benefit Approach” Economic Defendability A special case of optimality theory where the cost is defense of a territory or mate(s) or food resources  Phylogeny An evolutionary genealogy of the relationships among a number of species or clusters of species that can be used to develop, or reflect, hypotheses on the evolutionary history of a given trait – including behavioural traits! Horned Lizard  Phylogenetic inertia AKA Phylogenetic constraint Limitations on current or future evolutionary pathways result from previous adaptations “new” species never start from scratch; they build upon an existing gene pool Tetrapod Recurrent Laryngeal Nerve (RLN). Embryonic origin: it loops around the aortic arch. Big detour for later phenotypes with longer necks.  Phylogenetic inertia Behavioural example. Migration of the Northern Wheatear. Isabelline Wheatear Pied Wheatear Northern Wheatear  Comparative Method A procedure for testing evolutionary hypotheses based on disciplined comparisons among species of known evolutionary relationships Kudu are examples of ungulates African Painted Dogs are examples of carnivores Phenotypic Plasticity The changing of an organism’s phenotype in response to environmental conditions This can be physical or behavioural or both Deeper, red tails. Pond with predators Swim less. Eastern Gray Treefrog tadpoles Shallower, dull tails. Pond without predators Swim more.