Southern yellow-billed hornbills live in the dry savannas of southern Africa. These two were photographed in South Africa"s Kruger National Park, one of the largest nature preserves on the continent. While hornbills tend to live and hunt alone, they do mate for life, maintaining a monogamous relationship year after year. And with a lifespan of 20 years in captivity, it"s entirely possible that there are some yellow-billed hornbill grandparents out there. Why do we mention that? Because we"re celebrating National Grandparents Day in the US today!