Goodbye Zazu: Climate Change Will Roast Desert Birds Into Extinction In Just Five Years

Science Goodbye Zazu: Climate Change Will Roast Desert Birds Into Extinction In Just Five Years GrrlScientist Senior Contributor Opinions expressed by Forbes Contributors are their own. Evolutionary & behavioural ecologist, ornithologist & science writer May 23, 2022, 01:11pm EDT | Share to Facebook Share to Twitter Share to Linkedin According to a recently published study, if extreme temperatures continue, the southern yellow-billed hornbill will become extinct in the hottest parts of its range by 2027 © Copyright by GrrlScientist | @GrrlScientist | hosted by Forbes A Southern Yellow-billed Hornbill in the Kalahari Desert, Botswana. (Credit: Mathias Maisberger / CC … [+] BY 2.0) Mathias Maisberger via a Creative Commons license As climate change worsens, it is driving ever more extreme temperatures and longer, more frequent droughts. These factors are pushing more bird species beyond their ability to cope due to a myriad of effects or simply by being roasted alive (read more about these horrors here , here , here , here , here and here ). One impending local extinction is that of the southern yellow-billed hornbill, Tockus leucomelas . Southern yellow-billed hornbills are desert specialists The southern yellow-billed hornbill is a medium-sized black-and-white speckled bird with a long black tail and a large, thick, downward curving yellow bill. These iconic birds are common and widespread residents throughout much of southern Africa, mainly occurring in scrub and dry woodland in the Kalahari Desert. They feed on insects, spiders, and scorpions as well as seeds that they find on the ground. A socially monogamous species, they are well-known for their unusual breeding and nesting habits where the female cements closed the entrance to her nest with mud and remains imprisoned there for 50 days. She leaves a narrow opening so her mate can pass food to her as she broods her eggs and, later, her growing chicks. Because this nesting strategy is such an effective deterrent to predators, breeding success in these birds mostly depends upon food availability and, of course, rain. Part of the Kuruman River Reserve in South Africa’s Kalahari Desert field site where the southern … [+] yellow-billed hornbill (Tockus erythrorhynchus) lives. (Credit: Nicholas Pattinson / University of Cape Town, FitzPatrick Institute of African Ornithology) Nicholas Pattinson / University of Cape Town, FitzPatrick Institute of African Ornithology MORE FOR YOU New Research Finds A Connection Between Domestic Violence And These Two Personality Disorders This Scientist Helps Andean Forests And Ecuador’s Women In STEM Exceptional Fossil Preservation Suggests That Discovering Dinosaur DNA May Not Be Impossible In appearance, the southern yellow-billed hornbill looks a lot like its sister species, the red-billed hornbill, Tockus erythrorhynchus — a species that was a major character in Disney’s 1994 animated feature-length film, The Lion King . Zazu, as this dynamic avian character was named, was the royal advisor to Simba and and his pride of lions, and was charged with preserving order in the kingdom. Unfortunately, Zazu’s advice was rarely taken seriously. What are the effects of climate change over decadal time scales? “There is rapidly growing evidence for the negative effects of high temperatures on the behaviour, physiology, breeding and survival of various bird, mammal, and reptile species around the world”, said conservation ecologist Nicholas Pattinson, who is a graduate student at the University of Cape Town ’s FitzPatrick Institute of African Ornithology . Mr Pattinson noted that heat-related mass die-offs that occur over just a few days are increasingly being recorded, and these pose a deeply worrying threat to population persistence and to ecosystem function. But what is happening to desert-dwelling birds over time frames that are longer than a few days? “[T]he motivation for this study was to investigate if rapid climate warming was having a demonstrable effect on the breeding success of an arid-zone bird over a longer time scale, and whether sub-lethal ‘hidden’ effects of high temperatures and drought could be affecting population-level breeding outputs”, Mr Pattinson told me in email. Thus, Mr Pattinson and his collaborators investigated the impact of climate change on hornbill breeding success over a 10 year period. The southern yellow-billed hornbill is an ideal species for these studies because it breeds during the hottest time of the year in the Kalahari Desert, and some of the links between temperature and its behavior and physiology are already fairly well understood. For example, we know that, although hornbills never drink water, they are triggered to breed by rainfall. Hornbill population collapse is imminent Mr Pattinson and his collaborators studied a population of southern yellow-billed hornbills at the Kuruman River Reserve in South Africa’s Kalahari Desert between 2008 and 2019. They examined the long-term trends (2008-2019) in breeding success as well as the success of individual breeding attempts. They also analyzed climate trends (1960-2000) for the region. The team then used these data to clarify the links between climate change and the breeding success of hornbills by modelling the relationships between rainfall and temperature, female entry into a nest cavity and the number of days that the female spent incarcerated in her nest after her chicks hatched. Two southern yellow-billed hornbill (Tockus erythrorhynchus) nestlings inside a wood nest box. … [+] These birds are ready to fledge. (Credit: Nicholas Pattinson / University of Cape Town, FitzPatrick Institute of African Ornithology) Nicholas Pattinson / University of Cape Town, FitzPatrick Institute of African Ornithology What they found was deeply disturbing. When Mr Pattinson and his collaborators compared the 2008-2011 breeding seasons to the 2016-2019 breeding seasons, they found that occupied nest boxes declined from 52% to 12%, that the chances of successfully raising and fledging at least one chick declined from 58% to 17%, and the average number of chicks produced per breeding attempt decreased from 1.1 to 0.4. Further, Mr Pattinson and his collaborators did not record any successful breeding attempts when ambient air temperatures reached or exceeded 35.7°C (96.26°F). “During the monitoring period, sub-lethal effects of high temperatures (including compromised foraging, provisioning, and body mass maintenance) reduced the chance of hornbills breeding successfully or even breeding at all”, Mr Pattinson explained in email. Mr Pattinson and his collaborators also found that overall breeding output collapsed even in non-drought years. This is because many desert-dwelling birds are constrained to breed in response to rainfall, and this makes it difficult for them to shift breeding outside of the hottest periods of the year when it corresponds to the rainy season, as it does for hornbills. But the birds in this study exclusively nested wood boxes, which tend to be warmer than natural tree cavities. Was this a problem? No, Mr Pattinson explained, because a significant portion of the negative effects of high temperatures on breeding success and the probability of skipped breeding are experienced outside of the nest through the effects of extreme temperatures on the foraging success of adult birds. “Moreover, the air temperatures at our study site are generally lower than at the hottest margins of the Southern Yellow-billed Hornbill range”, Mr Pattinson added. “As a result, we suggest that these findings are still biologically meaningful and representative of the effects of high temperatures on hornbills at the hottest parts of their range.” Rapid temperature increases are killing birds before they can adapt The rapid pace of climate change-driven temperature increases are occurring faster than the birds can adapt. Current warming predictions at the study site indicate that the hornbill’s threshold for successful breeding will be exceeded during the entire breeding season by 2027. Thus, southern yellow-billed hornbills could be locally extinct in the hottest parts of their range as soon as 2027. This loss would result because no young birds will survive to join the ageing breeding population and because of massive changes to the entire ecosystem that we all — birds and humans alike — depend upon. “Much of the public perception of the effects of the climate crisis is related to scenarios calculated for 2050 and beyond. Yet the effects of the climate crisis are current and can manifest not just within our lifetime, but even over a single decade.” Source: Nicholas B. Pattinson, Tanja M. F. N. van de Ven, J. Finnie, Lisa J. Nupen, Andrew E. McKechnie and Susan J. Cunningham (2022). Collapse of Breeding Success in Desert-Dwelling Hornbills Evident Within a Single Decade, Frontiers in Ecology and Evolution: Behavioral and Evolutionary Ecology 10:842264 | doi: 10.3389/fevo.2022.842264 26a8b4067816acd2da72f558fddc8dcfd5bed0cef52b4ee7357f679776e6c25d NOTE: This piece is © Copyright by GrrlScientist . Unless otherwise stated, all material by GrrlScientist and hosted by Forbes is © copyright GrrlScientist and is intended only to appear on Forbes. No individual or entity is permitted to copy, publish, commercially use or to claim authorship of any information contained on this website without the express written permission of GrrlScientist. Follow me on Twitter or LinkedIn . Check out my website . GrrlScientist Editorial Standards Print Reprints & Permissions