Freely available satellite radar imaging is being used for the first time to help track colonies of endangered emperor penguins in Antarctica throughout the winter months.

Typically satellite images need sunlight to be useful, and Antarctica is dark in the winter. This has meant that colonies have been hidden at a critical time in the emperor penguin breeding cycle, when eggs are laid, chicks hatch and adults take part in those iconic huddles.

Almost 70 colonies of emperor penguins, many of which have never been visited by humans, occupy the sea ice that is fastened to the coastline surrounding Antarctica.

Now using synthetic aperture radar (SAR), an instrument operating on satellites that sends microwave pulses down to Earth, and measures how those pulses return, our research team has been able to track what the penguins do during these months.

Unlike other forms of satellite imagery, SAR is not reliant on sunlight, or affected by cloud, and therefore provides radar imagery of Antarctica through the dark polar winter.

SAR’s signal is sensitive to the properties of what it interacts with, and has been used for years in the poles to research things like the properties of sea ice and melt on glaciers.

When looking at SAR images from the free European Space Agency satellite, Sentinel-1, showing the location of an emperor penguin colony during winter, my team started to notice a bright white splodge of pixels moving around against a backdrop of dark, smooth sea ice.

Features like icebergs or rough sea ice can look bright in SAR imagery, but it didn’t make sense for those to be moving around at that time of year, when the sea ice was fixed and stable. Could it be the emperor penguin colony?

We soon found the same thing at the locations of other colonies – clusters of bright moving pixels on stable ice. We were then able to obtain optical images from September when the sunlight first starts returning, and compare them with the SAR, and confirmed it was indeed the colonies we were observing.

Tracking through the whole year

This finding opened up an exciting opportunity to track colonies throughout the whole breeding cycle, by combining SAR images in winter with optical images in spring/summer, and all using freely available data that has been routinely collected for years.

We went back through eight years, from 2017 to 2024, and followed three of the largest colonies year-round. We were able to follow their movement, sometimes even daily from early in the winter until chicks grow their first feathers in December and January.

We observed that colonies were typically less mobile in the winter, before spreading out and moving greater distances in the spring and summer. Interestingly, we found that the Atka Bay colony moved up from the sea ice onto the glacier ice that flows from the continent in seven of the eight years in the early spring. The colony did this despite the sea ice – the typically preferred habitat for the species – being stable. We need more research to understand why this is.

Satellite remote sensing has been a crucial tool for observing the emperor penguins in the summer months since 2009. It was discovered then that colonies could be found in satellite images because of the dark guano stains they leave on the snow and ice. Overall, these observations have revolutionised our understanding of the species and have led to the discovery of many more colonies.

After a period of stability, Antarctic sea ice has declined markedly since 2016 and likely entered a new state, characterised by lower extent and increased instability. Earlier this year, emperor penguins were added to the International Union for Conservation of Nature’s red list and classified as endangered, predominantly due to projected declines in sea ice.

This makes better understanding and monitoring of emperor penguins more important than ever. The ability to observe colonies throughout the breeding cycle using freely available, routinely collected satellite data creates opportunities to better understand their response to changing environmental conditions.

Grant Macdonald receives funding through a Natural Environmental Research Council project. He is a member of the Green Party of England and Wales.

For captive animals, engaging in natural behaviour is a pillar of the animal welfare framework. But when it comes to sex, one important behaviour has been largely ignored, and sometimes even punished: masturbation.

Solo sex is surprisingly common across the animal kingdom. It is well documented in primates. Tortoises are surprisingly vocal during their solo lovemaking endeavours, if not very graceful. Camels masturbate by rubbing their penises in the sand and porcupines make inventive use of all sorts of objects.

Our new study could change how other scientists view masturbation in birds and improve their welfare.

Masturbation also seems to be common in birds. A quick internet search brings up an abundance of video clips on social media and dedicated posts on bird-keeping forums, largely from worried or bemused hobbyist bird keepers.

It has often been treated as an abnormal problem behaviour in captive birds (particularly parrots). Folklore husbandry has assumed it is the undesirable outcome of stress, bad health or poor environment. Bird keepers often therefore discourage masturbation via punishment or veterinary interventions such as diet or care changes and, sometimes, even drugs and surgery. Despite the welfare implications, masturbation in birds had been largely unexplored by the scientific community.

We set out to change that, by investigating the distribution and evolutionary history of masturbation in birds for the first time. We studied 120 species of bird across 22 major groups, gathering data from the scattered scientific literature, online reports and community forums, and surveys of bird experts.

Our study found that masturbation is widespread across birds with a strong evolutionary history, meaning that it’s an ancient trait probably similar in closely related species. Although we found more records of masturbation in male birds, it occurs in both sexes and across all age groups.

Solo sex also seems to be linked to species that mate with multiple partners, supporting the idea that it might help to increase reproductive success when there is a high degree of competition over fertilisation. For instance, in males it may flush out old sperm to leave newer (better condition) sperm for mating. In females it may increase sexual arousal to help with sneak mating with males other than their partner.

Wild behaviour

Crucially, we discovered that masturbation is actually less common in captivity than the wild, and more common in birds reared by their own parents than by humans. What this tells us is that masturbation in birds is neither an unnatural behaviour, nor a consequence of captivity. Given this finding, it is important that birds are not prevented from masturbation. Of course, as with any behaviour, there may be extreme cases where chronic masturbation could indicate underlying health or husbandry issues.

Avian self-pleasure is usually a rather inelegant affair, in which a bird rubs their cloaca (a shared orifice for both excretion and reproduction) against an object, like a branch, twig or toy. This is often accompanied by a lot of flapping and self-satisfied vocalisation.

One potential reason for the lack of scientific studies exploring avian masturbation may be because the cloaca is thought to have fewer nerve clusters, and therefore lower sensitivity, than our own genitals.

Clearly however, birds are getting some satisfaction from masturbation, so perhaps there is more to a bird’s sensations during sex than has previously been recognised. Further exploration of this could have important implications for both welfare and captive breeding programmes. While sexual pleasure may not be exactly the same experience as for mammals, it is wildly premature to dismiss the idea that birds also feel pleasure.

The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.