The other situation is if mom has O type blood. The same thing can happen as with the (-) and (+) blood type difference, but it is not as severe. If mom has O+ or O- blood type, and the baby has A+, A-, B+, B-, AB-, or AB- blood type, an ABO incompatibility can develop.
Why do howler monkeys howl? Howler monkeys live in family groups in the rain forests of South America. They howl so that other monkey groups do not stray into their territories. The sound also helps group members stay in contact with each other. Monkeys are communal animals that live in exclusive groups.
The mantled howler's appearance is similar to other howler monkeys of the genus Alouatta except for coloration. The mantled howler is primarily black except for a fringe of yellow or golden brown guard hairs on the flanks of the body earning the common name mantled howler monkey.t is one of the monkey species most often seen and heard in the wild in Central America. It takes its mantled name from the long guard hairs on its sides. The mantled howler is one of the largest Central American monkeys, and males can weigh up to 9.8 kg (22 lb).