Feeding BehaviorReading:What are some ecological factors that could cause animals to forage in non-optimal ways?Give a specific example.What is frequency-dependent selection? Give an example of how it applies to feeding behavior in Perisodus (the right- versus left-jawed cichlids).Occurs when the fitness of one phenotype is a function of its frequency relative to the other phenotypeRight jawed fish attack to the left, left jawed fish attack to the right-trait passed downPopulation is 50:50 so no fish has the element of surprise on their sideGive an example of a conditional feeding strategy. An inherited mechanism that gives the individual the ability to alter its behavior adaptively in light of the conditions it confronts-subordinates allowing best feeding spots to dominate animals.What is the information center hypothesis? Does it apply to all birds?Nesting colonies serve as information centers for flocks-does not apply to all.Describe some competing adaptive hypotheses for why orb-weaving spiders decorate their webs with UV-reflecting material. What would be a nonadaptive alternative?The ornamentation attracts prey and also helps to hide the spider.-experimentation proved that decorated webs caught less preyWhich component of the bee waggle dance indicates the distance to a resource? The direction?Duration of waggle indicates distance and direction of waggle (if outside) indicates direction in relation to the sun. What other cues may bees use besides the waggle dance to find flowers? What evidence shows that they rely mainly on the waggle dance?What is a possible sequence of the evolution of the waggle dance? Is there any phylogenetic evidence to support this sequence?What are several adaptive hypotheses about the effects of the waggle dance on a honeybeecolony's ability to collect food? How were these tested?Lecture:What are some of the aspects of carnivory versus herbivory that would drive the evolutionof these two different feeding styles?Herbivory:Costs: food relatively low-energy: must eat a lot, plant defesnses: toxins, spines and hard to digestBenefits: food abundant and renewableCarnivroyCosts: food well defended, mobile, and relatively scarceBenefits: food high in energy and nutrients and usually few toxins. Name 2 nonbehavioral adaptations for herbivory.Physiological: digestive enzymes or ruminationBehavioral: eating only most nutritious parts: fruits, nuts.What are some adaptations that minimize the costs of carnivory for large predators?These include structural adaptations (claws, frames built to run) and behavioral adaptations:Predators of large dangerous herbivores may: - hunt in packs - wait for wounded animals to bleed to death - focus on the weakest prey - eat large quantities when they can - be somewhat flexible in eating different prey typesdepending on availabilityStrategy- trapping/luring/mimicryWhat is behavioral camouflage- how does it work?The jumping spider Portia preys on web-building spiders.Its movements on the web might alert a potential prey item to its approach, but Portia only moves when the web is shaking anyway due to wind, etc.Draw a graph showing how a search image versus a lack of search image would affect the success of a predator over time.A search image is an experience- based template for prey items-blue jay given experience with #1 were better at picking out #1- blue jay given experience with #2 were better at picking out #2- blue jay given experience with both were not very good at pickingout eitherWhy has filter feeding evolved in such a diversity of animals?In marine vertebrates, filter feeding has evolved multiple times and involves:- the presence of rich resources (like krill)- large body size (low heat loss, can cover large distances in search of ephemeral krill)How can the fossil record tell us about the evolution of feeding styles? Give an example.teeth or other feeding structures are found in the fossil record.Herbivory vs carnivory in snails Many mollusks, including herbivorous snails, use a toothed radula to scrape algae.In predatory Conus snails, harpoons that they use to kill fish and reel them inWhy are ethologists so interested in the idea of optimal foraging? Is there any evidence that animals actually do try to optimize their energetic intake versus outlay? Is there evidence that this could increase fitness?-Food intake is a good proxy for FITNESS: animals that maximize energy intake are likely to be fitter (but this needs to be tested)-if enough large worms are available, redshanks will ignoresmaller ones, even if they make up the largest proportion of worms.-If the food of the orb-weaving spider Larinioides is supplemented, they will produce more eggs: 80% of egg sacs were made by < 37% of spiders-The numbers of young produced by water pipits varies with the biomass of food they provide.In terms of the costs versus benefits, why do crows prefer large whelks?crows eat large whelks to maximize their Caloric intake- smaller whelks are not worth opening.Observe: crows open whelks by dropping them from a height. Large whelks must be raised fairly high to break them, small and medium whelks much be raised even higher. Small and medium whelks result in a net loss of energy, given the fact that they are hard to break open and contain less.Do birds in experiments prefer common prey items that are small or large prey items that are