Ecology #2: Competition

Competitive Release: 1 of 2 competing species disappears ==> remaining competitor uses shared, limiting resources more fully vs. in first species’ presence Example: Both Evasterias and Pisaster eat barnacles and muscles ==> Evasterias’ population increases b/c more food available without Pisaster competition

Exploitation Competition: Limiting resources (territory/prey/food) used by 1 individual decreases amount available for other individuals (indirect interaction) Example: Both Evasterias and Pisaster eat barnacles and muscles ==> Evasterias’ population did not increase b/c less food available for them with Pisaster competition

Interference Competition: 1 organism/species physically restricts/depletes (aggressive displays or fighting) another organism/species’ access to resources Anti-Example: Pisaster did NOT physically prevent Evasterias from feeding ==> Evasterias’ access to food was NOT interfered by Pisaster