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SPECIES INTERACTIONS. ANNOUNCEMENTS. Final Exam is in ONE WEEK: Tues. Dec 20 th 8 – 10 am Last name begins with letter A – L LH 5 Last name begins with letter M – N LH 7 We will be checking IDs Bring student ID, pencils & erasure No calculators or hats. ANNOUNCEMENTS.
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ANNOUNCEMENTS • Final Exam is in ONE WEEK: • Tues. Dec 20th • 8 – 10 am • Last name begins with letter A – L LH 5 • Last name begins with letter M – N LH 7 • We will be checking IDs • Bring student ID, pencils & erasure • No calculators or hats
ANNOUNCEMENTS • Review sessions for Final Exam: • Open to all students irrespective of section • Wed Dec 14th by Will & Carlos • Begins at 3pm in LH2 • Sunday Dec 18th by Will & Carlos • Begins at 7 pm in LH1 • Mon Dec 19th by Jennie • 11am – noon in BS 004 • 1 – 2 pm in BS 004
ANNOUNCEMENTS • Extended Office Hours • Monday Dec 19th • Noon – 4pm • Hints for Final Exam • Questions from previous exams will be modified • Look for overarching themes • As usual, apply what you know. Don’t memorize! • Material from last 2 lectures = 25 – 30% of Final Exam
ANNOUNCEMENTS • Exam 2 • Exam 3 • Distribution & Approximate Grade Cutoffs • Look for grades on Blackboard by tomorrow
SPECIES INTERACTIONS Populations Do Not Exist in Isolation! • Populations are tightly linked to other populations that share the same habitat
SPECIES INTERACTIONS Types of Interactions Between Species: • Neutral relationships (0 0) • Commensalisms (+ 0) • Mutualism (+ +) • Competition (- -) • Parasitism (+ -) • Predation (+ -)
SPECIES INTERACTIONS: COMMENSALISM Commensalism: • Relationship directly helps one species without having effect on other species • Ex: Birds uses trees as roost site • Birds benefit from tree • Trees get nothing, but are not harmed
SPECIES INTERACTIONS: MUTALISM Mutualism: • Beneficial interaction between two species • Co-exploitation (not altruism) • Obligatory Mutualism: • Species can’t grow/reproduce without the other
SPECIES INTERACTIONS: MUTALISM • Yucca Plant and Yucca Moth: • Plant only pollinated by yucca moth • Moth larva can only grow in yucca plant
SPECIES INTERACTIONS: MUTALISM Mutualism between fish
SPECIES INTERACTIONS: COMPETITION Interspecific Competition: • Competition across species • Occurs when niches overlap • Niche = a set of habitat requirements • Two species struggle for same resources • Negatively impacts both species • Two outcomes: • Coexistence • Competitive Exclusion
SPECIES INTERACTIONS: COMPETITION Intraspecific Competition: • Competition between members of the same species
SPECIES INTERACTIONS: COMPETITION Competitive Exclusion: • Occurs when niches overlap completely • Fierce competition for overlapping resources • One species drives another towards extinction
SPECIES INTERACTIONS: COMPETITION One Species Eats Seeds of One Size Range Number consumed Seed size
SPECIES INTERACTIONS: COMPETITION Complete Niche Overlap Species 1: Strong competitor Species 2: Weak competitor, Driven to extinction Number consumed Seed size
SPECIES INTERACTIONS: COMPETITION Coexistence: • Occurs if niches do not overlap completely • May lead to suppressed growth and/or reproduction • Species partition/share available resources • Use same resource in diff ways or at diff times
SPECIES INTERACTIONS: COMPETITION Partial Niche Overlap: competition for seeds of intermediate size Species 2 Species 1 Number consumed Realized Niche Seed size
SPECIES INTERACTIONS: COMPETITION Competition occurs when organisms compete for the same resources. These trees are competing for nitrogen and other nutrients.
SPECIES INTERACTIONS: COMPETITION Competition occurs when individuals occupy space and prevent access to resources by other individuals. The space preempted by these barnacles is unavailable to competitors.
SPECIES INTERACTIONS: COMPETITION Competition occurs when an organism grows over another, blocking access to resources. This large fern has overgrown other individuals and is shading them.
SPECIES INTERACTIONS: COMPETITION Competition occurs when one species produces toxins that negatively affect another. Note how few plants are growing under these Salvia shrubs.
SPECIES INTERACTIONS: COMPETITION Competition occurs when mobile organisms protect feeding or breeding territory. These red-winged blackbirds are displaying to each other at a territorial boundary.
SPECIES INTERACTIONS: COMPETITION Competition occurs when organisms interfere with each other’s access to specific resources. Here, spotted hyenas and vultures fight over a kill.
SPECIES INTERACTIONS: PARASITISM Parasitism: • One organism drains nutrients from another, while living on or within it • Beneficial to parasite • Negative effect on host organism • Weaken host sterility, decreased fecundity • Genetic effects • Sometimes death
SPECIES INTERACTIONS: PARASITISM Deformed frog limbs due to parasitic infection by Trematodes Adult roundworms in the intestine of a pig
SPECIES INTERACTIONS: PARASITISM Blood fluke in the intestine of a human 833 µm
SPECIES INTERACTIONS: PARASITISM Social Parasites: • Manipulate social behavior of another species • Ex: Cuckoo Bird • Females lay eggs in another species nest • Cuckoo hatchlings are usually first to emerge • Ejects other eggs from nest • Demands food
SPECIES INTERACTIONS: PREDATION Predator – Prey Interactions: • Predator: • Animals that feed on other living • organisms • Do NOT take residence in or on • prey • Prey: • Targets of predators • Usually killed for food • Have wide array of mechanisms • to defend against predation
SPECIES INTERACTIONS: PREDATION Predators can regulate prey populations and/or reducethem below carrying capacity BABOON PREY POPULATION LEOPARD PREDATOR POPULATION
SPECIES INTERACTIONS: PREDATION Canadian lynx & Snowshoe Hare
SPECIES INTERACTIONS: PREDATION Co evolution of Predator and Prey Has Resulted in Incredible Adaptations: • Camouflage • Mimicry • Warning Coloration • Predator Responses
SPECIES INTERACTIONS: PREDATION Camouflage: • A method to escape detection • Prey blends in with surroundings • Morphological adaptations • Patterning • Coloration • Behavior
SPECIES INTERACTIONS: PREDATION PREY CAMOUFLAGE LEAST BITTERN LOOKS LIKE REEDS DESERT PLANT LOOKS LIKE ROCK CATERPILLAR LOOKS LIKE DROPPINGS
SPECIES INTERACTIONS: PREDATION PREY CAMOUFLAGE
SPECIES INTERACTIONS: PREDATION Mimicry: • Prey organism deceives predators • Copy form and/or behavior of another species • Must resemble dangerous or unpalatable species
SPECIES INTERACTIONS: PREDATION MIMICRY INEDIBLE BUTTERFLY (LEFT) IS A MODEL FOR ITS EDIBLE MIMIC (RIGHT) STINGING YELLOWJACKET (LEFT) IS MODEL FOR NONSTINGING and EDIBLE INSECTS (RIGHT)
SPECIES INTERACTIONS: PREDATION MIMICRY
SPECIES INTERACTIONS: PREDATION Warning Coloration: • Prey (usually toxic) sends warning signal to predators • Bright colors and/or conspicuous patterns • Prey makes little or no effort to conceal its presence • Predators associate distinctive pattern/coloring with foul taste or poison Poison Dart Frog
SPECIES INTERACTIONS: PREDATION Methods to Counter Prey Defense: • Predators: • Camouflage • Clever ways of avoiding repellants
SPECIES INTERACTIONS: PREDATION PREDATOR RESPONSE: GRASSHOPPER MICE PLUNGECHEMICAL- SPRAYING END OF BEETLE INTO THE GROUND BEFORE EATING IT PRAYING MANTIS (PREDATOR) CAMOFLAGUED IN PLANT