Question

snails are eaten by birds. snails with plain yellow or cream shells are generally found in dry grass, while snails with stripes are often found in woodland. suggest why?​

Answer 1

So that they can camouflage to the surroundings

Answer 2

Camouflage

Thermoregulation

Explanation:

Cepaea nemoralis (opposite) is a land snail, and the background color of its shell may be either yellow or some darker shade of brown or pink.

• On top of the background color are a number, usually between zero and five, of dark bands.
• The snails are therefore highly variable in their external appearance; an individual snail may have any combination of background color and banding pattern.
• One possibility is that it does not matter, and Mayr remarked in 1942 that

"There is no reason to believe that the presence or absence of a band on a snail shell would be a noticeable selective advantage or disadvantage."

The analysis of adaptation may be difficult, but not impossible.

• So many selective factors have been shown to influence the pattern and coloration of Cepaea shells that 35 years after Mayrís remark, the polymorphism was called "a problem with too many solutions".
• A series of ecological geneticists, particularly Cain and Sheppard, has studied the question over many years.
• The first suggestive observation was that the proportions of the different shell types vary from place to place.