<span>It may be difficult for ecologists to determine the size of a bird population if that population migrates to different locations throughout the year. During migration, some birds may split off from the group and not return, others may die, and still others may join. Therefore, the bird population will be in constant flux. It is hard to know, when the birds return to their prior location, if the population consists of the same group of birds (in addition to deaths and births) or whether it has grown or shrank through other means. However, to estimate the size, an ecologist can track a migratory flock through several years, counting each year to get a general sense of the population size. Additionally, given one measurement, an ecologist could consider the average lifespan and birth rates of the population to extrapolate the size of the population in subsequent years.</span>
Answer:
D all of the above
Explanation:
a - provide protective covering on the land to prevent soil erosion
b - provide shade, protect from wind and help moderate the temperature
c - animals can't make their own food, so they depend on plants for supply of food
Therefore, the answer is D all of the above.
Mark as brainliest :)
Step- by - step - explaination
<span>The correct answer is that its primary function is to connect, support and anchor various parts of the body. It can either connect bones, or it can connect muscles. It also ensures that they don't move in an unexpected manner and that your bones don't randomly fall out of sockets. It's very useful and you couldn't move without it.</span>
