Covering Climate Now

As climate crisis deepens, wildlife adapts, maybe with lessons for us

Scientists think that pikas capable of adapting their behaviour to rising temperatures might have better chances of surviving as global warming advances.
Scientists think that pikas capable of adapting their behaviour to rising temperatures might have better chances of surviving as global warming advances.PHOTO: TASHI R GHALE

NEW YORK - 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 Monday (Sept 23) in New York City, and for Climate Week (Sept 22-29), Mongabay, a non-profit conservation and environmental science news platform, has gathered some of our reporting, showcasing how three animals - the American pika, orang utan and penguin - are shifting their behaviors to face the challenges of a rapidly altering world.

AMERICAN PIKA BEATS THE HEAT

It may be a tiny tail-less 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 life cycle 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 behavioural 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 kilometre from their stony habitats. And that has led to several distinct populations, which makes the pika an especially good species to study - population comparisons offer us a better understanding of localised responses to quick changing environmental conditions.

For example, one population of more malleable pikas turned out not to be home bodies, but instead appeared willing to seek out new, cooler places to live as temperatures rose. They gave up their old, hotter rockpiles and sought out new favourable and cooler microclimates nearby. This move allowed 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 behaviour in this manner might have better chances of surviving as global warming advances.

Another important area of adaptation that has been observed in American pikas is thermo-regulation. 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.

ORANG UTANS ADJUST THEIR BIRTH CYCLES


Researchers found that the orang utans in Kutai National Park possess an average inter-birth interval of 6.1 years - roughly in sync with weather cycles. PHOTO: AFP

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 Nino Southern Oscillation (Enso) cycle, is affecting the behaviour, habitat requirements, feeding ecology and birth intervals of orang utans.

 

Kutai's protected habitat is one of the driest regions on the island and also the driest, least-productive rainforest where orang utans can be found - in fact, it is the least wet of all current orang utan 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 orang utans in a surprising way. Much like humans, orang utan females don't ovulate when their bodies are malnourished, especially during an El Nino drought, so bear no young during such periods.

El Ninos occur every six years on average, and Kutai orang utans possess an average inter-birth interval of 6.1 years - roughly in sync with the Enso cycles. In comparison, orang utans in Sumatra reproduce every 8.75 years, and every 7.7 years in wetter central Borneo. This means that Kutai orang utan mothers are still caring for their previous infant when the next El Nino comes along. This phenomenon is known as infant stacking and is rarely recorded in orang utans.

Because the Kutai orang utans live in the most challenging and variable conditions of any of their species, these findings could help conservationists understand how orang utans 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


Penguin numbers in South Africa's Western Cape have plummeted by around 80 per cent in recent decades. PHOTO: ST FILE

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 55km to the south of Halley Bay. While the estimated number of adult penguin pairs at Dawson-Lambton 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 International Union for Conservation of Nature (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 per cent in recent decades. Biologists chalked this decline up to the disappearance of their favourite 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 favourite 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' behaviour 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 could take ongoing trial and error to find the right survival response - with some individuals making viable choices, and others not.

This story originally appeared in Mongabay.com. It is republished here as part of The Straits Times' partnership with Covering Climate Now, a global collaboration of more than 250 news outlets to strengthen coverage of the climate story.