Owl Pellets Predator/Prey Food Webs Macaroni Lab Competition Predator/Prey Fig Newtons Symbiosis/mutualism Niches Studying Species Interactions Organisms interact with biotic & abiotic factors Organisms shape their environment & the environment shapes organisms!

What happens when 2 niches overlap? how species interact Environmental Science 302

Problem: 2 niches overlap 1.Migrate 2.Change feeding habits 3.Adapt behavior 4.Suffer a sharp population decline 5.Become extinct in that area What type of species overcome this more easily?  Generalists  or Specialists? WHAT IS YOUR SOLUTION?

Phrased another way: I want something that you want… Will we compete? Will I eat you? Will we work together some how? In nature, there are 3 basic types of interactions… Competition Predation Symbiosis

InteractionInteractingExamples Competition Predation Mutualism Parasitism Commensalism

I. Competition INTERFERENCE Species A limits Species B’s access Aka: establishing a territory EXPLOITATION A & B have equal access but differ in how fast or efficiently they exploit it Ex: invasive species

Is there a solution to competition? RESOURCE PARTITIONING  dividing up scarce resources 2 species use the same thing – In different ways – At different times – In different places big preysmall prey

What does this graph say?

II. Predation Predator feeds directly on all or part of a living organism (the prey). – The prey does not have to die – Predation is not only about carnivores! Can be GOOD for prey population because…  drives natural selection! – Sick, weak, & aged die, leaving resources for the healthy

Capturing Prey Herbivores got it easy! – Special digestive adaptations EX: Carnivores must hunt! – Predator needs MOBILITY, SENSES, and ABILITY TO HANDLE prey EX?

Prey Escape & Defense RUN!!! Physical Defenses – Structure – Crypsis – Warning Coloration Chemical Defenses

Deception –L–Looks –B–Behavior Behavioral –S–Scare tactics Loss & Regeneration

Some cool cases of prey adaptations

Synchlora larvae Wavy-lined Emerald Caterpillar

Utetheisa ornatrix Recently, while experimenting with a gaudily colored moth, Utetheisa ornatrix, a group of us found that scales can be impregnated with toxins. As a larva, Utetheisa feeds on leguminous plants of the genus Crotalaria, which has long been known to contain poisonous alkaloids. The larva is unaffected by these poisons, which it stores in its body and retains through metamorphosis into the adult stage. Some of the alkaloid in the adult is built into the scales, so the moth is unpalatable to spiders. Utetheisa therefore does not need to flutter free when it lands in a spider web; instead, it lies still and relies on the spider to cut it loose. The strategy never fails: the moment the moth lands in the web, the spider darts toward it, briefly inspects it, then uses its fangs to sever each strand that imprisons the moth, setting the moth free.

HOW DO YOU CATCH YOUR FOOD?

Do you know what type of relationship your Fig Newton was involved in? Mutualism

Life Cycle of the Fig Wasp

YUMMY! Thank an insect for your food! The FDA allows 13 insect heads per 100 grams

III. Symbiosis “Living together” in a long-lasting relationship 3 typesParasitismMutualismCommensalism

Parasitism 1 species (PARASITE) gets nourishment by living on, in, or near another species (HOST) over an extended period of time – Endoparasites – Ectoparasites Rarely Lethal! Why would you kill a good thing?

Mutualism Both species benefit in various ways – Having pollen dispersed for reproduction – Being supplied with food – Receiving protection Not as much cooperation as exploitation

Commensalism One species benefits, the other is neither helped nor harmed Clownfish & Sea Anemone – Protection – Feed on anemone’s leftovers

Detailed fig life cycle The process starts when a pregnant female wasp enters a fig through a secret hole (hidden by scales) at the top of the fig. In the process, the wasp transfers pollen from the male flowers of the fig from which she emerged to the “female” flowers of the new fig she entered. The wasp also deposits her eggs in a type of “female” flower that will not set fruit. The fruits of figs are actually nutlets formed within the fruiting structure, called a fig. The tiny fruits impart the crunch to figs and Fig Newtons. The deposited pollen not only enables the fruits to grow, but also becomes a food source for the young wasps. The adult female wasp does not leave the fig; she dies there. When the larvae mature into wasps, the wingless males hatch and impregnate the females still developing in the flowers; the males of many species then also die inside the fig. The young, pregnant females, however, emerge from the flowers and exit the fig— usually before it ripens and falls to the ground—and move on to a new flowering fig, where the entire process begins again.