With its long, downward-curving yellow beak and exotic appearance, the southern hornbill is in some ways one of the most intriguing birds in the animal kingdom. The species is a cousin of the red-billed hornbill that attracted the attention of bird lovers because it was the inspiration for Zazu from the Lion King. But now the southern yellow-billed hornbill needs the same attention, as the impressive bird is at risk of disappearing from the face of the Earth as a result of climate change.
Researchers from the University of Cape Town studied the reproductive health of the hornbill in an important period from 2008 to 2019. Thanks to the exhaustive analysis of its reproductive behavior, they realized that factors that had not been considered before have seriously affected the reproductive success of birds.
The heat has decreased reproduction
The yellow-billed hornbill lives in a region of the planet where temperatures are truly extreme. The Kalahari Desert is home to the exotic bird, however, like other biomes around the world, it is also suffering the consequences of the climate crisis and the high temperatures it has brought with it.
Researchers have discovered that the reproductive behavior of different species has been affected by heat and the hornbill is no exception. “There is increasing evidence of the negative effects of high temperatures on the behavior, physiology, reproduction and survival of several species of birds, mammals and reptiles around the world,” says Dr. Nicholas Pattinson, lead author. Of the investigation.
It also explains that heat-related mass mortality rates over the period of a few days are becoming more abundant. This undoubtedly represents a threat to the persistence of the population and its function within the ecosystem.
An earlier extinction than previously believed
To get a clearer picture of the true consequences for the yellow-billed hornbill, researchers studied the reproductive success of pairs in wooden nest boxes located in the Kuruman River Reserve. They then compared their findings to climate trends in the region and found that as maximum air temperatures increased, reproduction collapsed.
When comparing the first three mating seasons (2008-2011) with the last three (2016-2019), they found that the average percentage of occupied nest boxes plummeted from 52% to 12%. Not only that, but nest success, which involves raising and fledging at least one chick, also decreased from 58% to 17%.
Researchers have said that official documents stipulate that the climate crisis will peak in 2050, however, the actual figures predict much earlier consequences. It is estimated that southern yellow-billed hornbills could be extirpated from warmer parts of the desert as early as 2027.
“The effects of the climate crisis are current and can manifest not only in our lifetime, but even in a single decade,” says Dr. Pattinson, referring to an urgency to recognize that the effects of the climate crisis are already being experienced in the present and nature is the most affected.
References: Pattinson, N. Collapse of Breeding Success in Desert-Dwelling Hornbills Evident Within a Single Decade. Frontiers in Ecology and Evolution. 2022, DOI