HORNBILLS FEEL
Researchers monitoring the breeding habits of three hornbill species
in the Pakke Tiger Reserve in Arunachal Pradesh have noted disrupted nesting this year, with fewer active nests and several failed
ones, because of extreme weather conditions.
ZAZU, the diminutive red-billed hornbill depicted in the movie The Lion King, is a familiar endearing character. Recently, its cousin, the southern yellow-billed hornbill in the Kalahari Desert, made world headlines. A study found that this small desert-dwelling African hornbill species has been impacted by climate change and is likely to be facing a collapse in breeding by 2027. The study found that from 2008 to 2019, the percentage of occupied nests declined from 52 per cent to 12 per cent, while the percentage of successful breeding attempts declined from 58 per cent to 17 per cent. The mean fledglings produced per nesting attempt used to be more than one but by 2019 had declined to fewer than one.
Poor breeding effort and performance were linked to external factors such as higher temperature, drought during the breeding season, late nesting, and shorter time spent by females in the nests after chick hatching.
The consequences of rising temperatures because of climate change on hornbill breeding are very clear for an African hornbill in an arid region. However, the Asian hornbills in tropical forests in Arunachal Pradesh seem also to be feeling the heat, and the story is messy and complicated for the larger-bodied hornbills in these wet forest habitats.
Hornbills are especially vulnerable to the effects of climate change because of their unique breeding habits. They nest in tree cavities