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.
Populations Do Not Exist in Isolation!
Types of Interactions Between Species:
Mutualism between fish
One Species Eats Seeds of One Size Range
Complete Niche Overlap
Species 1: Strong competitor
Species 2: Weak competitor,
Driven to extinction
Partial Niche Overlap: competition for seeds of intermediate size
Competition occurs when organisms compete for the same resources.
These trees are competing for nitrogen and other nutrients.
Competition occurs when individuals occupy space and prevent access to resources by other individuals. The space preempted by these barnacles is unavailable to competitors.
Competition occurs when an organism grows over another, blocking access to resources. This large fern has overgrown other individuals and is shading them.
Competition occurs when one species produces toxins that negatively affect another. Note how few plants are growing under these Salvia shrubs.
Competition occurs when mobile organisms protect feeding or breeding territory. These red-winged blackbirds are displaying to each other at a territorial boundary.
Competition occurs when organisms interfere with each other’s access to specific resources. Here, spotted hyenas and vultures fight over a kill.
Deformed frog limbs due to
parasitic infection by Trematodes
Adult roundworms in the
intestine of a pig
in the intestine
of a human
Predator – Prey Interactions:
Predators can regulate prey populations and/or reducethem below carrying capacity
BABOON PREY POPULATION
LEOPARD PREDATOR POPULATION
Canadian lynx & Snowshoe Hare
Co evolution of Predator and Prey Has Resulted in
DESERT PLANT LOOKS LIKE ROCK
CATERPILLAR LOOKS LIKE DROPPINGS
(LEFT) IS A MODEL FOR ITS EDIBLE MIMIC (RIGHT)
STINGING YELLOWJACKET (LEFT) IS MODEL FOR NONSTINGING and EDIBLE INSECTS (RIGHT)
Poison Dart Frog
Methods to Counter Prey Defense:
SPRAYING END OF BEETLE INTO THE GROUND BEFORE EATING IT
PRAYING MANTIS (PREDATOR)
CAMOFLAGUED IN PLANT