CHICAGO \u2014 Shortly after her arrival last fall, Amelia Gray met Hudson, and the pair hit it off immediately. They touched their noses together in greeting and chuffed \u2014 a soft, breathy, snorting sound that signals affection or reassurance. Amelia Gray rolled on her back, gently pawing at her counterpart. Later that same day, they played in the pool together.<\/p>\n
<\/p>\n
Kristen Boyer and her 3-year-old son, George Boyer, watch as Amelia Gray, a 9-year-old polar bear, swims at Brookfield Zoo on Jan. 8, 2026.\u00a0<\/p>\n
Stacey Wescott\/Chicago Tribune<\/p>\n
The connection has fueled hopes at the Brookfield Zoo Chicago that the two polar bears will soon breed, offering scientists a glimpse into how mothers care for newborns inside their maternal dens \u2014 and, in the Arctic wilderness, where climate change already threatens their survival.<\/p>\n
The usual challenges to studying polar bears in their natural habitat \u2014 a harsh climate, a vast, isolated territory and the dangers the massive predators pose to humans \u2014 have been further complicated after President Donald Trump in October announced plans to open 1.6 million pristine acres of the Arctic National Wildlife Refuge coastal plain in northeastern Alaska to leasing for oil and gas drilling.<\/p>\n
The Trump administration\u2019s move has rekindled a sense of urgency among conservationists, eliciting legal challenges from activists and advocates, as well as prompting a coalition of institutions, including Brookfield Zoo, to accelerate research efforts, especially because so much about the species\u2019 reproduction remains unknown.<\/p>\n
\u201cThat\u2019s where zoos really have such a unique opportunity to really understand what takes place within that neonatal period with the cub,\u201d said Mike Adkesson, president and CEO of the suburban zoo, \u201cto understand what the bears need in terms of ideal terrain for the construction of that den, to understand breeding interactions and how a natural range space may be impacted by changes to wild landscapes.\u201d<\/p>\n
Climate change from fossil fuel extraction and burning has already significantly affected polar bears in the wild; their populations have rapidly declined as rising global temperatures melt polar caps and reduce the sea ice they need to hunt seals. Photos of bedraggled, emaciated polar bears floating on slabs of ice have become emblematic of the far-reaching impacts of climate change on wildlife. Since 2006, the species has been classified as vulnerable by the International Union for the Conservation of Nature.<\/p>\n
But experts worry that drilling in the species\u2019 natural habitat would accelerate their decline even more by further downsizing where they can roam and den, adding physiological stress on the mammals and altering their behavior. Currently, polar bears from the Arctic Ocean\u2019s Beaufort Sea den at high densities in the stretch of coastal plain that is being opened to drilling.<\/p>\n
\u201cThe frightening part is, they are a species that we\u2019re seeing such dramatic declines in,\u201d Adkesson said, \u201cand it\u2019s a species that we could conceivably lose from the face of the Earth in the next 100 years.\u201d<\/p>\n
Rita Stacey Vondra, who leads Brookfield Zoo\u2019s animal care and community engagement teams, added, \u201cAnd I\u2019ll throw in there: Extinction is forever, and we\u2019ll never get this species back if we don\u2019t do something.\u201d<\/p>\n
Spanning roughly 19 million acres in the northeastern corner of Alaska, the Arctic National Wildlife Refuge is one of the world\u2019s last intact ecosystems. Located on the traditional homelands of the I\u00f1upiat and Gwich\u2019in peoples, the refuge is critical habitat for many migratory birds, caribou and polar bears.<\/p>\n
The U.S. Geological Survey has estimated that its coastal plain contains between 4.3 billion and 11.8 billion barrels of recoverable oil. The low end of the estimate is less than the total crude oil production in 2024 in the United States, which was 4.6 billion barrels.<\/p>\n
Institutions from the newly formed Polar Bear Population Alliance hope their collaborative efforts \u2014 to understand the repercussions of habitat disturbances on wild populations from drilling before they occur \u2014 can be used to inform policy around timing and siting for drilling, Adkesson said. How would the polar bears\u2019 diets and their metabolism change in a smaller range? Would that, in turn, affect their reproductive success if they don\u2019t have enough fat reserves to nurse their cubs?<\/p>\n
The goal is to offer science-backed guidelines for rules and regulations, including time periods related to breeding and reproduction during which disturbances should be kept at a minimum, as well as areas where it is critical that drilling be avoided. Whether or not the government and fossil fuel companies would heed the advice is hard to predict.<\/p>\n
\u201cThat would be the hope,\u201d Adkesson said.<\/p>\n
Collecting samples from even just a few bears in wild, remote areas, however, can be a painstaking, yearslong process. Research with captive polar bears can fill in that gap, supplying additional samples, Adkesson said.<\/p>\n
At Brookfield Zoo, the polar bears \u2014 with some enticement \u2014 voluntarily take part in the research, offering their paws for blood draws and opening their massive jaws up for a mouth swab. They are trained multiple times a day to practice participating in their own care and medical evaluations. Specifically, researchers at the zoo are focused on the animal\u2019s welfare and reproduction, such as figuring out smart pairings for breeding, as well as understanding what den designs best support successful births.<\/p>\n
On a chilly January morning, senior animal care specialist Erin Hennessy stood in front of a grate door looking into Hudson\u2018s habitat. The male bear, having been summoned with a bell, approached at a lumbering pace.<\/p>\n
\u201cPaw,\u201d Hennessy said, putting her hand against the metal. Hudson raised a large, furry front paw to meet her hand, earning a tasty spoonful of smooth peanut butter that he happily licked across the grating.<\/p>\n
\u201cThat\u2019s currently his favorite,\u201d said Brianna Pohl, lead animal care specialist. \u201cThey need a reason to want to participate.\u201d<\/p>\n
<\/p>\n
Amelia Gray, a 9-year-old polar bear, foreground, and Hudson, a 19 year-old polar bear, walk along the rocks at Brookfield Zoo, on Jan. 8, 2026, in Brookfield. There are three polar bears at the zoo.\u00a0<\/p>\n
Stacey Wescott\/Chicago Tribune\/TNS<\/p>\n
Since 1948, the zoo has cared for generations of polar bears, with many born on-site like Hudson, 19 years ago. Besides him, the zoo\u2019s polar bear population currently includes his potential mate, 9-year-old Amelia Gray, the female newcomer from the Oregon Zoo in Portland, and Hope, a 10-year-old female who made her local debut in 2021. The latter mated with Hudson last year, but despite spending October through December in a cozy den, no embryo implanted.<\/p>\n
\u201cShe did sleep an awful lot, but unfortunately, she did not have any cubs born this year,\u201d Vondra said. It prompted the search for another adult female to create a breeding group and let Hudson choose his mate.<\/p>\n
Scientists at the zoo have also been studying polar bears that were at Brookfield years ago but have since left. In a recently published study, researchers carefully examined seven video recordings spanning almost four hours of mother Arki and her male cub, Kinapak, during the first month after he was born in December 2000, to understand denning behavior. Arki had mated with Aussie, who at one point was the oldest male polar bear in an accredited North American zoo, until he was euthanized at 32 in 2017. Two European zoos also provided more recent video footage used in the study.<\/p>\n
\u201cIn the wild, this is the one time in a polar bear\u2019s life that you can\u2019t study and document their behavior,\u201d said Lance Miller, one of the study authors and Brookfield Zoo\u2019s vice president of animal welfare science. \u201cThis is impossible. And so the ability to have these amazing dens with the cameras right there, and be able to document and evaluate it \u2014 it\u2019s pretty phenomenal.\u201d<\/p>\n
During the first three months of their lives, a critical period for development, polar bear cubs are entirely dependent on their mothers for thermal regulation and nursing, which happens inside the den. A frame grab from video footage out of Zoo Hannover in Germany shows a tiny newborn cub nuzzled against its mother\u2019s neck as they slept.<\/p>\n
\u201cIt\u2019s just amazing to think about these 1,000-pound animals in the harshest climate you can imagine,\u201d Adkesson said, \u201cgiving birth to a baby that, I always joke, is like the size of two sticks of butter \u2014\u201d<\/p>\n
\u201cI call it a Twinkie,\u201d Vondra chimed in.<\/p>\n
\u201c\u2014 that it survives, that they have such intent maternal care that they\u2019re able to nurse this helpless little life,\u201d Adkesson said.<\/p>\n
Scientists don\u2019t know how climate change could shift denning locations and habitats, if at all, though declining sea ice may have adverse effects on females reaching traditionally preferred areas for the species. And, as winters shorten, female polar bears could be coming out of their dens earlier during their cubs\u2019 development period, possibly affecting the offspring\u2019s potential for survival, Miller said.<\/p>\n
It\u2019s important to understand how climate change affects polar bears, he added, to understand how it affects an entire ecosystem. As top predators in the food web, their removal would have \u201cdetrimental, ripple effects\u201d on the biodiversity and health of their environments, Vondra said. And threats to polar bears, such as human encroachment and loss of sea ice, also threaten other species along the way.<\/p>\n
\u201cBy the time you\u2019re impacting that top tier, you\u2019ve also had huge impacts and disturbances on everything else that falls into that ecosystem,\u201d Adkesson said.<\/p>\n
\u201cAnd we don\u2019t want to get to the point where there\u2019s no hope,\u201d Vondra added. \u201cSo, hope is now.\u201d<\/p>\n
The average person in Chicago won\u2019t ever get to see a polar bear in their natural habitat, Adkesson said.<\/p>\n
\u201cSo we, as an organization, play such a key role in making that connection,\u201d he added, \u201cand helping people to see and appreciate and understand an animal that\u2019s thousands of miles away and the conservation threats that are facing it.\u201d<\/p>\n
Joanne Moore, a zoo member and animal lover who houses old dogs, cats and horses in her DeKalb County farmhouse, visits every week and walks around the grounds for hours as a form of therapy.<\/p>\n
Even though she has seen the polar bears plenty of times before, that cold January morning Moore witnessed something new. From a distance, she watched in awe as animal care staffers trained Hudson.<\/p>\n
\u201cThis is very special, to see this,\u201d she said. \u201cYou don\u2019t often have the opportunity.\u201d<\/p>\n
Inside the other enclosure, Amelia Gray swam loops in the water, her fur rippling in gentle and mesmerizing movements. A mother and her young child approached the glass as the massive bear treaded water on the other side. The little boy put his hand up and offered a quiet \u201cHi.\u201d<\/p>\n
Miller recalled a study he did at Brookfield Zoo in 2019 to evaluate the emotional experience of visitors during a polar bear training. There were three groups: one that saw the session in person, another that saw it on video and a third that listened only to an audio recording from the training.<\/p>\n
\u201cWhat we found is that being able to see a polar bear up close and in person \u2026 you have that positive emotional experience, you actually retain information better,\u201d Miller said. \u201cYou have more empathy toward wild polar bears, and you\u2019re also more excited about getting involved in conservation.\u201d<\/p>\n
Adkesson said those connections are at the core of the zoo\u2019s mission: \u201cTo help (people) appreciate the majesty of nature, to help them appreciate these incredible species that we share this world with.\u201d<\/p>\n
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