1. This "have among" sounds awkward to me. Don't they usually say "have something among"?
2. This "spotting" is translated as "of small mark", but I think it is "easy to spot or notice", what do you think?
ex) ...They are male village weaverbirds, advertising their nest-building accomplishments to a nearby flock of females. The males do have something to boast about, as weavers are considered to be the most proficient nest builders in the bird world.
Once a female has chosen a nest, she lays eggs of nearly identical appearance throughout her lifetime, but the eggs of the population as a whole have among the widest variety of colors and spotting patterns of any bird.
For most people who live with the village weaver, however, appreciating its nest-building and egg artistry can be difficult...