NRC 261 1st Edition Lecture 11Outline of Last LectureI. Movement — Home Range A. Home Range B. Travel Paths C. Areas of Frequent UseII. Movement Patterns a. Range Residents b. Migrators c. Nomads III. Social Interactions — Land Use a. Territoriality IV. Social Interactions — Family Life Outline of Current LectureII. Species DistributionIII. Species InteractionIV. Competitiona. Responses to Competition b. Solutions to Competition V. Case Study — East African Jackals and Patagonian Foxes a. Morphology b. Behavioral Overalp c. Prey DiversityVI. Competition Case Study — Gray Foxa. Study Area b. Objectives c. Methods d. ResultsVII.Conclusions Current LectureSpecies InteractionHow is it that wolves, coyotes, and red foxes; cougars, lynx, and bobcats; black bears and grizzly bears, and wolverines can all co-exist in the Greater Yellowstone Ecosystem?Species distribution: if they interact they must have similar distribution and occur in the same placesAllopatric species: distributions do not overlap, there is no chance for them to interactSympatric species: distributions do overlap, chance for interactionExample – “ground squirrels” in Texas – Allopatric or Sympatric?SpeciesBlack-tailed prairie dogs- only occur in short-grass prairiesRock squirrels- live in rocky areas (definitely not prairies)Mexican ground squirrels- live in brushy, but also grassy areas (rocky areas that have brush, grassy areas that are short-grass prairies)*could say that on a much smaller area, that Black-tailed prairie dogs and rock squirrels are allopatric, because when you look at a landscape they don’t live in the same patch or landscape. They likely don’t live together. Mexican ground squirrels may be able to live in other areas, so they could be sympatric with bothof the other speciesCharacteristicsphysical appearancedistribution maps: parts of central texas and west texas wherethey overlap, you could say that there is a large swatch of Texas where theyappear to by sympatric (they occur in the same counties) if you’re talking state-wide*important to be thinking about are two individuals actually living in the same spot (with overlapping home ranges), but sometimes all you need to know is on a bigger scale (like if all three occur in the state of Texas)Species Interactions1) neutralism - (o) (o)- Bat species & mouse species — both live in same patch of forest - neither species care about the presence of the other, and they don’tinteract - they happen to be small mammals and occur in the same place 2) commensalism - (+) (o) -oxpeckers & rhinos- oxpeckers pick ticks off the rhino (rhino provides them with potentialfood source), but rhinos get nothing from the oxpeckers but they tolerate it - definition = it helps one/is positive to one but doesn’t do anything to theother 3) predation - (+) (-)- lion & wildebeest — what’s good for the lion in the interaction is NOT good for the wildebeestparasitism - (+) (-)- sea lamprey & lake trout — lamprey latch onto fish and suck juices out,which is harmful to the lake trout- one wins and one loses4) mutualism/symbiosis - (+) (+)- ants & acacia trees — acacia have thorns that can be hollow which provide home for ants (good for ants)- benefit for acacia tree is that when a predator comes to feed on theacacia tree, the ants come out of the thorns and starts biting the predator - one provides something for one, the other provides something foranother cooperation - (+) (+)- badgers & coyotes — when hunting ground squirrels - badgers dig holes, coyotes chase squirrels in, coyotes watch forsquirrels to come out of other holes and the idea is that they chase them back in towardsthe badger- 2 different species working together to get the same benefits5) competition - (-) (-)- spotted hyena & lion — each steal kills that the other makes (both large carnivores that kill their prey)- potential for bad things to happen to both of themCompetitionCompetitive exclusion principle - The probability that two or more competing species may coexist in the same area is inversely proportional to their niche overlap.- probably that they’re gonna exist depends on niche overlap - if they completely overlap, they’re not going to coexist - if they live in the same place but there’s very little that once species uses thatthe other one does too, then the likelihood that they’ll coexist is fairly high - no two species can have the exact same niche and live in the same place Responses to Competition — ways that animals make sure they have different nichesNumerical consequences --different reproduction and survival rates — some might not reproduce as well or not as many might survive- different density and distribution at different placesFunctional changes -- morphological: in order to get along, over time they had to change theirphysical parts - behavioral: can behave in a different way when they’re competing with aspecies vs. when they’re not competing Solutions to competition:Avoidance (morphological solution) –Character displacement - evolution of physical differences to allow exploitation of different resources- competition drives evolution, something that different that does really well will survive more and those characteristics will survive inthe population, and eventually the population will evolve to be different - ex: Galapagos Finches (Darwin) — very isolated on these islands - opportunity because of variety of resources an no competitionfrom other species caused them to evolve into several differentspecies - island with different mixes of species are shown in diagram: topisland has all 3 different species), the next island only has two,and the last two only have one each - measurement/differentiation was beak length and beak depth— some have larger thick bills (more depth) and some havelonger, smaller bills (more length) - the reason they’re able to survive is that there are nuts, insects,seeds, all of different sizes. Ones with big bill can utilize food thatothers can’t - use different food and all three have evolved to best utilizefood of different sizes - some medium sized birds with big-ish bill don’t have to worry aboutcompeting with the much larger one so they can evolve slightly larger bills (on the second island without any big billed birds but both medium and small billed birds) - on the