The courtship rituals of the pair of Great Hornbill (Buceros bicronis) (above left) and Rhinoceros Hornbill (Buceros rhinoceros) (above right) at Eng Neo during 2006-7 intrigued many Singaporean birders and provided subjects for many bird photographers. Besides being of two different species, both the birds are female.
Apparently, mating between these two species is nothing new. In southern Thailand two hybrid offspring were found, a result of a cross between a male Rhinoceros and a females Great Hornbill. The hybrid juveniles were captured in 2004 and 2008. One of the suspected parents, the female Great, was also captured, but not the male Rhinoceros. Blood samples were taken, after which the birds were released.
Genetic analyses showed that the Great is the maternal parent of both hybrid juveniles. As the male Rhinoceros was not captured, it could not be established conclusively that he is the paternal parent. However, as hornbills generally mate for life, the authors assume that this particular Rhinoceros Hornbill would probably be the father.
Hybridisation between different species of the same genus is not uncommon among birds and hornbill is no exception. The probable causes of interspecific hybridisation are stress due to habitat fragmentation and low population density.
Images by YC.
Siriphatr Chamutpong, Wutthipong Charoennitkul, Pilai Poonswad & Mathurose Ponglikitmongkol: A hybrid between Great Hornbill (Buceros bicornis) and Rhinoceros Hornbill (Buceros rhinoceros) in the wild of southern Thailand: The impact from habitat fragmentation. Paper presented at the 5th Intn. Hornbill Conference, Singapore, March 2009.