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Biology-Related Homework Help Environmental and Conservation Biology Topic started by: NAZ on Apr 3, 2011



Title: ecological principle
Post by: NAZ on Apr 3, 2011
Explain which of the following ecological principles could be active in each particular situation. More than one may apply.

Ecological principles:

predation     realized niche     fundamental niche
competitive exclusion   resource partitioning   character displacement
disturbance   keystone species   competition
top-down vs. Bottom-up controls   


a. A small clan of hyenas killed an antelope. While they were feeding on the carcass, two female lions approached, growled at the hyenas, and chased them away from the carcass.


b. Known as the “Hawaiian woodpecker,” the `akiapola`au (aki-a-pul-a-ow) is found only in montane mesic old-growth koa/`ohi` forests, and only on the Big Island (Hawaii). It has a distinctive beak that is like a multiple-use tool. The short straight lower mandible is used to peck holes in the wood and the long curved upper mandible is used to probe for insects and larvae. Males have larger beaks than females and feed on the trunks of trees. Females feed higher on branches and twigs. ‘Akiapola`au are thought to have the lowest reproduction rate for a small bird—only one chick per year, which is cared for by the parents for 6 months or more. The decline in their numbers appears to correspond with the introduction of rats, cats and logging on the island.




Title: Re: ecological principle
Post by: bio_man on Apr 3, 2011
(a) This is an example of interference competition. One species is actively keeping another away from a resource. In exploitative competition, all species have equal access to the resource; however, some are better able to “capture” the resource.