This is concerning because penguin<\/a> colonies that relied more heavily on krill were doing worse than those foraging fish \u2013 and global warming is causing sea ice to decline, pushing penguins towards a more krill-based diet.\u00a0<\/p>\n The study came about because lead author\u00a0Casey Youngflesh<\/a>, assistant professor at Clemson University, wanted to understand the inner workings of the Antarctic ecosystem. \u201cThere are many processes that we just can’t observe directly,\u201d Youngflesh says.\u00a0<\/p>\n So, he turned to penguins. These seabirds are what\u2019s known as an indicator species. \u201cThey\u2019re a really great bellwether of change in that system because they’re integrating all of these different things that are going on in the environment,\u201d he says.\u00a0<\/p>\n For example, they nest on land and rely on different ocean resources \u2013 including shrimp-like krill and silverfish \u2013 for their food. That\u2019s why studying penguins helps experts understand what\u2019s going on in the wider system.\u00a0\u00a0<\/p>\n Nesting Ad\u00e9lie penguins, Paulet Island, Antarctica. Credit: Michael Polito, University of California Santa Cruz<\/p>\n Antarctic<\/a>\u00a0research is not easy. Getting to this remote, harsh continent is difficult and conducting science is expensive, not to mention logistically challenging. \u201cBut luckily we have satellites that we can actually see penguin colonies from,\u201d says Youngflesh.<\/p>\n Ad\u00e9lie penguins\u00a0\u2013 the species he was studying \u2013 nest in huge colonies. \u201cYou know, hundreds of thousands of pairs,\u201d he says. \u201cA lot of penguins in one concentrated area.\u201d<\/p>\n And with a lot of penguins comes a lot of penguin poop.\u00a0<\/p>\n That\u2019s what Youngflesh and colleagues were looking for in the satellite images. \u201cYou can see those guano deposits from satellites,\u201d he says. Against the bright snow, \u201cit pops out at you.\u201d<\/p>\n \u201cIt\u2019s exactly what it sounds like,\u201d says co-author Michael Polito, a professor of ocean sciences at the University of California, Santa Cruz, in a\u00a0statement<\/a>. \u201cWe spied on penguins from space by using satellite images to figure what they eat all around Antarctica to help\u00a0explain their diet and population response to recent climate change.\u201d<\/p>\n The idea of using faeces stains to find penguin colonies isn\u2019t new \u2013 NASA scientist\u00a0Mathew Schwaller<\/a>\u00a0came up with the idea many years ago \u2013 but Youngflesh and the team wanted to go a step further.\u00a0<\/p>\n What if they could colour-match the poo to discover what the penguins have been eating, they wondered.\u00a0<\/p>\n Penguins eat shrimp-like crustaceans called\u00a0krill, which have bright pink exoskeletons that turn the penguins\u2019 poop pink, as well as Antarctic\u00a0silverfish, which produce whiter guano. The scientists wanted to measure the proportion of each in the birds\u2019 diet based on the colour gradient of their excrement.\u00a0<\/p>\n \u201cWe didn’t just do this through Pantone colour cards, holding it up next to guano,\u201d Youngflesh says. \u201cThat\u2019s just not the way to do science.\u201d<\/p>\n \u201cStep one, go out on the penguin colony and scoop up little poop samples and put them in your bags with your plastic spoon,\u201d he says. He then brought the samples back to the ship, spread them out and measured the colour.\u00a0<\/p>\n Using a spectrometer \u2013 an instrument that measures light wavelengths \u2013 Youngflesh and the team quantified how much light was being reflected off the guano from each visible part of the electromagnetic spectrum (\u201cThat’s the rainbow,\u201d Youngflesh clarifies).<\/p>\n Once they\u2019d measured the colour, they could link up the shade of scat with how much fish or krill the penguins were eating. They did this in their North American lab using a chemical technique called stable isotope analysis, which tells them what the birds had been eating.\u00a0<\/p>\n Penguins aren\u2019t the only animals eating krill and silverfish.\u00a0Whales<\/a>,\u00a0seals<\/a>\u00a0and a whole bunch of other creatures also devour these key food items. \u201cYou have just these couple things that everything else is eating,\u201d he says.\u00a0\u00a0<\/p>\n Seeing how their make-up in penguins\u2019 diet changes can give the experts an inkling about what\u2019s happening in the wider Antarctic food web. \u201cThese penguins are just eating what is available to them,\u201d he explains. \u201cWhen you have more ice, those penguins are eating more fish. Less ice during that year, penguins are eating more krill.\u201d<\/p>\n Changes in the sea ice \u2013 which is declining \u2013 impact the abundance of these food sources. As the ice melts, there will be fewer silverfish and the Ad\u00e9lie penguins rely more heavily on krill.\u00a0<\/p>\n This is a problem. \u201cPenguin populations that are eating more krill are more likely to be in decline,\u201d says Youngflesh. The silverfish are higher quality food because they are more calorie dense. \u201cStudies have shown that chicks that are fed fish are generally in better body condition. They have higher survival,\u201d he adds. \u201cSo, it seems likely that these penguins would prefer to be eating fish, but those fish are really no longer available in some regions or in some years, they’ve got to switch to krill.\u201d<\/p>\n There\u2019s also increasing competition for krill between all the Antarctic animals trying to eat them as well as from commercial krill fisheries. \u201cThis study does not paint a positive picture for long-term Ad\u00e9lie penguin population trends into the future with continued sea ice declines,\u201d says Youngflesh.\u00a0<\/p>\n Ad\u00e9lie penguins walking from beach to colony, Danger Islands, Antarctica. Credit: Michael Polito, University of California Santa Cruz<\/p>\n There are things everyone can do day-to-day to help, Youngflesh adds: reducing carbon emissions through actions including flying less, driving less and eating less read meat, and avoiding products that contain krill (such as supplements).\u00a0<\/p>\n Meanwhile, scientists are working through the huge swathes of data available from satellites, which have been capturing images from space for decades. \u201cWe need to find out how can we actually make use of this information, even if it wasn’t originally intended and designed to do the things that we’re interested in,\u201d such as study penguin diets, he says.\u00a0<\/p>\n To understand this complex ecosystem, \u201csometimes we need tens of thousands of data points,\u201d Youngflesh adds. \u201cAnd things like satellite-based sensors [camera traps, audio recorders and participatory science projects], they’re really providing an opportunity for us to do this.\u201d<\/p>\n Top image credit: Thomas Sayre-McCord\/WHOI\/MIT<\/p>\n More wildlife stories from around the world<\/p>\n","protected":false},"excerpt":{"rendered":"Researchers in Antarctica have used 30 years of satellite data \u2013 combined with hand-scooped poop samples \u2013 to…\n","protected":false},"author":2,"featured_media":807697,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[26],"tags":[49,48,66,323],"class_list":["post-807696","post","type-post","status-publish","format-standard","has-post-thumbnail","category-wildlife","tag-ca","tag-canada","tag-science","tag-wildlife"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/807696","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/comments?post=807696"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/807696\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media\/807697"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media?parent=807696"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/categories?post=807696"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/tags?post=807696"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"Ad\u00e9lie](\"https:\/\/www.newsbeep.com\/ca\/wp-content\/uploads\/2026\/07\/Adelie-penguin-feeding-two-small-chicks-Danger-Islands-Antarctica-scaled.jpeg\")
Ad\u00e9lie penguin feeding two small chicks, Danger Islands, Antarctica. Credit: Michael Polito, University of California Santa Cruz<\/p>\n![\"Landsat](\"https:\/\/www.newsbeep.com\/ca\/wp-content\/uploads\/2026\/07\/Landsat-satellite-image-of-a-collection-of-Adelie-penguin-colonies-off-the-Antarctic-Peninsula-scale.webp\")
Landsat satellite image of a collection of Ad\u00e9lie penguin colonies off the Antarctic Peninsula (Danger Islands), taken on 22 January 2023. The pink patches are penguin guano, where Ad\u00e9lie penguins are nesting. Credit: NASA<\/p>\n![\"Casey](\"https:\/\/www.newsbeep.com\/ca\/wp-content\/uploads\/2026\/07\/Casey-Youngflesh-spreading-penguin-guano-out-in-preparation-for-analysis.jpeg\")
Casey Youngflesh spreading penguin guano out in preparation for analysis. Credit: Casey Youngflesh<\/p>\n