- Shifts in the timing of lifecycle events, like reproduction or migration, are widely thought to be the most common response of wildlife to global warming.
- In recent years, pikas have been observed modifying their foraging habits in ways that may be behavioral adaptations to a changing climate.
- A long-term study in Kutai National Park on the island of Borneo in Indonesia has shown how extreme weather, brought by the intensifying El Niño Southern Oscillation (ENSO) cycle, is affecting the behavior, habitat requirements, feeding ecology and birth intervals of orangutans.
- Researchers have discovered that African penguins, may be falling into a sort of “ecological trap,” one that humans created through overfishing and climate change.
Recent studies of Twitter posts have shown that people can be quick to shrug off extreme weather as normal. However, researchers are also finding that some wildlife — maybe better attuned to changes in the natural world around them — are adapting successfully to climate change.
As the United Nations prepares to convene for the 2019 Climate Action Summit on September 23 in New York City, and for Climate Week (Sept. 22-29), Mongabay has gathered here some of our reporting, showcasing how three animals: the American Pika, orangutan and penguin are shifting their behaviors to face the challenges of a rapidly altering world.
The American Pika beats the heat
It may be a tiny tailless mammal, but the American pika could teach humans a thing or two about adapting to the impacts of global climate change.
Shifts in the timing of lifecycle events, like reproduction or migration, are widely thought to be the most common response of wildlife to global warming, and according to research in Frontiers in Ecology and the Environment, the scientific literature on the subject mostly bears that assertion out. Since behavioral responses were most noticeable in species with a lifespan of at least three years, the American Pika (Ochotona princeps) provides an apt example to explore.
Pikas don’t dig burrows and typically make their homes in alpine rockpiles at the base of cliffs, known as talus slopes, at high-elevations in western North America’s mountains. These relatives of rabbits and hares inhabit an expansive range as a species, but individuals don’t typically stray more than a kilometer from their stony habitats. And that has led to several distinct populations, which makes the pica an especially good species to study — population comparisons offer us a better understanding of localized responses to quick changing environmental conditions.
For example, one population of more malleable pikas turned out not to be home bodies, but instead appear willing to seek out new cooler places to live as temperatures rise. They give up their old, hotter rockpiles and seek out new favorable and cooler microclimates nearby. This move allows the animals to remain more active during the daytime when ambient temperatures at their original talus habitat — frequently subjected to full sun — had turned much higher.
Scientists think that pikas capable of adapting their behavior in this manner might have better chances of surviving as global warming advances.
Another important area of adaptation that’s been observed in American pikas is thermoregulation. In the more northern parts of the species’ range, freezing temperatures in winter are severe. In response, pikas moderate their body temperature to some degree through posture — squeezing into a fluffy ball, a pose with minimum surface area, to hold in heat during winter; or stretching out their body surface area to cool down in summer.
Orangutans adjust their birth cycles
A long-term study in Kutai National Park on the island of Borneo in Indonesia has shown how extreme weather, brought by the intensifying El Niño Southern Oscillation (ENSO) cycle, is affecting the behavior, habitat requirements, feeding ecology and birth intervals of orangutans.
Kutai’s protected habitat is one of the driest regions on the island and also the driest, least productive rainforest where orangutans can be found — in fact, it is the least wet of all current orangutan research sites. In this part of Borneo, the ENSO cycle is marked by periods of drought, interspersed with periods of normal rainfall and unusually heavy rains.
Researchers found that the ENSO cycle influences the lives of Kutai’s orangutans in a surprising way. Much like humans, orangutan females don’t ovulate when their bodies are malnourished, especially during an El Niño drought, so bear no young during such periods.
Interestingly, El Niños occur every six years on average, and Kutai orangutans possess an average inter-birth interval of 6.1 years — roughly in sync with the ENSO cycles. In comparison, orangutans in Sumatra reproduce every 8.75 years, and every 7.7 years in wetter central Borneo, meaning that orangutan mothers are still caring for their previous infant when the next El Niño comes along. This phenomenon is known as infant stacking and is rarely recorded in orangutans.
Because the Kutai great apes live in the most challenging and variable conditions of any orangutans, these findings could help conservationists understand how orangutans are currently adapting to difficult climatic conditions — a potentially invaluable insight as the human-caused climate crisis escalates in future.
Penguin survival depends on following food and breeding cues
The emperor penguin (Aptenodytes forsteri) is the largest of all living penguin species and the only one that breeds during the Antarctic winter. A recent study gives a sneak peek into how the penguins might respond to disappearing stable sea ice conditions brought by climate change — for good or ill.
Female emperor penguins lay their single eggs early in the Antarctic winter, around May, then take turns with their partners incubating the eggs and subsequently raising the chicks through the extremely cold winter months. That’s to ensure chicks are ready to leave their nesting ground by the summer months of January or February.
Emperor penguins are the only known bird to never breed on dry land, preferring to hatch and rear chicks on frozen sea. But in 2016, following abnormally stormy weather, the sea ice of the emperor penguin colony at Halley Bay on the Weddell Sea broke up in October, long before the chicks had fledged and were ready to go out to sea. In 2017 and 2018, too, the ice broke up early, leading to the likely death of all the chicks at Antarctica’s second-largest colony of emperor penguins.
But it’s not all gloom. Between 2016 and 2018, satellite images picked up a massive increase in the numbers of emperor penguins at the nearby Dawson-Lambton Glacier colony, located 55 kilometers (34 miles) to the south of Halley Bay. While the estimated number of adult penguin pairs at Dawson-Lambton had steadily decreased from 3,690 in 2010, to 1,280 in 2015, those numbers jumped up to 5,315 pairs in 2016; 11,117 in 2017; and 14,612 pairs in 2018 — a surprise to scientists.
“It appears that many of the birds from Halley Bay have relocated to Dawson-Lambton, with the rest remaining at Halley Bay, but not breeding successfully,” the authors explained.
So it seems that some penguins are using migration successfully as a fundamental climate change strategy. But alter surroundings too much or too quickly, and suddenly such adaptations might point organisms in the wrong direction. For example, across the ocean from Antarctica, on the southern tip of Africa, researchers have discovered that African penguins (Spheniscus demersus), an Endangered species according to the IUCN, may be falling into a sort of “ecological trap,” one that humans created through overfishing and climate change.
Penguin numbers in South Africa’s Western Cape have plummeted by around 80 percent in recent decades. Biologists chalked this decline up to the disappearance of their favorite prey species, anchovies and sardines, from the Western Cape, the penguins’ preferred feeding ground to the west of their nesting sites. Overfishing and water chemistry changes — knock-on climate change effects — pushed breeding shoals of these fish eastward or wiped them out entirely.
In the past, penguins in search of their favorite foods adapted by picking up on cues, such as the chemicals that plankton release and water temperature, to tell them where to find food. But now, when they follow cues to formerly reliable feeding spots, they’re more likely to find jellyfish and low-calorie gobies, rather than energy-dense sardines and anchovies. Without the right cues, they go hungry.
Researchers used satellite monitoring to follow the movements of young penguins as they left their breeding grounds in Namibia and South Africa and headed into the open ocean to feed. The data revealed that the fledgling penguins’ behavior wasn’t flexible enough to accommodate the change to their environment, and instead led them to a subpar food source.
Again, there could be a lesson here for humanity: escalating climate change is complex, and it may take ongoing trial and error to find the right survival response — with some individuals making viable choices, and others not.
Read more at:
- Large emperor penguin colony suffers ‘catastrophic’ breeding failure
- Ecological trap ensnares endangered African penguins
Banner image caption: Emperor penguin colony. Image by IIP Photo Archive via Flickr
This story is part of Covering Climate Now, a global collaboration of more than 300 news outlets worldwide to strengthen coverage of the climate story.