(Portland, OR)  --  The baby rhino at the Oregon Zoo has ventured out for the first time.  Temperatures were warm enough over the weekend to allow the mom, Jozi, and her two-month-old 225-pound male baby to briefly walk outside of their den.  It'll be later in the year, when temperatures are warmer, that they'll spend more time outside.  The zoo staff says the baby is gaining weight and doing fine.  Jozi continues to be a good mom.  The baby's birth is important for the critically endangered black rhinoceros species.