A grassy meadow high in the Sierra Nevada Mountains of eastern California is known to support a variety of organisms. During the summers when grass is thick and lush, and wildflowers abound, butterflies take advantage of this abundant nectar source. Bears graze on the berries in shrubs at the edge of the meadow. Deer also forage at the edge of the meadow. In the early mornings, coyotes are known to prey on the squirrel and mouse populations that burrow into the meadow soil. A variety of birds prey on the butterflies and other flying insects, such as bees and wasps.

If the biomass of flowers that support the butterflies was known to contain 100,000 units of energy, and certain bird species were eating the butterflies that foraged on the flowers, what amount of energy, on average, could be expected to be transferred to the birds?
Group of answer choices

a)100

b1,000

c10

d10,000

e50,000

In a typical food chain as described in this question, flow of energy occurs from one organism to another when they feed/fed upon. As one organism feeds, energy gets transferred to it. However, only about 10% of the available energy in the lower trophic level gets transferred because majority of the energy (about 90%) is lost as heat during metabolic processes of the organism.

Hence, if a flower contains approximately 100,000 units of energy and is fed on by butterflies. 10% of 100, 000 = 10,000 units gets transferred to the butterflies.

Likewise, the butterflies gets fed on by certain bird species. 10% of the available 10,000 units of energy in the butterfly gets transferred to the birds.

= 10/100 × 10,000 = 1000 units of energy.