AP BIOLOGY

Detailed explanation-1: -Q#1: Red-crowned cranes breed in spring and early summer. Choose a proximate explanation: Breeding is most likely to be successful in spring and early summer. Increasing day length triggers the release of breeding hormones.

Detailed explanation-2: -Red-crowned cranes are very communal and live in flocks. Their family group is the largest social organization of cranes. Red-crowned crane pairs are generally monogamous. Nests are built on wet ground or in shallow water.

Detailed explanation-3: -These birds are known to be monogamous: They often find one partner and mate for life. This may be why they symbolize loyalty in Asian cultures. When a couple is together, they use their long windpipes to vocalize with a unison call, which strengthens their bond.

Detailed explanation-4: -The population of red-crowned cranes is split into a migratory continental population in Korea, China, Mongolia and Russia (with all birds wintering in Korea and China), and a resident Japanese population in Hokkaidō.