A photograph holds an animal still; a population study follows change across years. Reading the two together means asking what was measured, where the animals lived, and which years were compared. A finding about one population may not describe the whole species. A projection is different from an observed loss, and a proposed listing is different from a final decision. The studies and management documents below offer a wider view of the gallery's subjects, with their limits kept beside their findings. For each animal, start with the study's location and time span. Those details explain whether a result concerns one region, the species' whole range, or a future climate scenario.
Grizzlies of the Greater Yellowstone
The bear in Feels So Good leads into a question about which bears should be considered together. In its January 15, 2025 finding, the U.S. Fish and Wildlife Service concluded that a petition to establish and delist a separate Greater Yellowstone distinct population segment was not warranted. The petitioned bears did not, on their own, represent a valid segment.
Geography helped frame that finding. Greater Yellowstone's estimated occupied range in 2022 extended beyond the 2017 western boundary. The document also reported 190 verified grizzly observations outside the estimated occupied range of lower-48 populations since 2017. That figure concerns observations across those populations, not a Yellowstone bear count.
A proposal published the same day would define a contiguous U.S. grizzly population including all of Washington and portions of Idaho, Montana and Wyoming. It would retain threatened status. The Service affirmed that the population remained likely to become endangered in the foreseeable future. This is the proposal's assessment and intended boundary, rather than a final rule.
Polar Bear Mothers of Western Hudson Bay
Mother's Protective Arms leads into a study of pregnancy before cubs appear beside their mothers. A 2025 study in Conservation Physiology assessed pregnancy through progesterone levels in blood collected from bears on shore in late summer and early autumn in Western Hudson Bay, Canada.
The researchers analysed 541 samples from 441 individuals in 1991-2021 and compared them with earlier data from 1982-90. The share of solitary females that were pregnant fell from 85% to 73% between those periods. Among four-year-old females, it fell from 82% to 55%. Annual pregnancy rates varied widely, from 46% to 100%.
Heavier females had higher pregnancy rates. The lightest pregnant female known to have produced cubs weighed 196 kilograms in autumn. That is a recorded observation, not a weight that guarantees cub production. Pregnancy rates should also be distinguished from cub survival: this study's pregnancy measure cannot by itself say how many cubs will live through later seasons.
Emperor Penguins, Counted from Space
The family in Emperor Penguin Family can be considered alongside two different satellite studies. A 2024 study covering the species' entire range combined remote sensing, validation surveys and statistical modelling. It estimated an 81% probability of fewer adults in 2018 than in 2009, with a median decrease of 9.6%.
The estimate carried substantial uncertainty: its 95% credible interval ran from a 26.4% decrease to a 9.4% increase. The researchers also saw an apparent uptick toward the end of the series. Both details belong beside the overall decline estimate. An interval that includes both a decrease and an increase makes the uncertainty visible. The probability of decline helps convey that uncertainty instead of turning an estimate into a certainty.
A 2026 study of seven Ross Sea colonies examined springtime attendance between 2005 and 2024. It found a 90% probability of lower attendance, with a mean change of minus 23% and a 95% interval from minus 46% to plus 20%. The steep 2020-2024 decline amounted to approximately 23,000 birds, about 32% of the regional population.
Cape Crozier and Cape Colbeck grew over the full period while several other colonies declined. Sea-ice anomalies and El Niño phases explained the most variation statistically. Regional attendance and a range-wide adult estimate answer related questions, but their different periods and measures should remain clear.
The Pika and a Warming Mountain
Between a Rock introduces a small animal whose genetic variation can be studied across a large range. A 2025 Molecular Ecology study collected genome-wide data from 363 American pikas across western North America. Adaptive genetic variation was most strongly associated with average warmest-month temperature, followed by precipitation during the coldest quarter.
The researchers projected genomic offset under multiple climate-change scenarios. This describes a potential mismatch between genetic variation and future climate conditions. Results differed across locations and were related to adaptive variation, elevation and latitude.
Northern Rocky Mountain sites showed the highest projected offset despite high adaptive variation. Having considerable variation therefore did not place those sites at the low end of the study's projected vulnerability. The result calls for attention to individual regions: it is a projection under climate scenarios, rather than a census of disappearing pikas or a prediction that every mountain will experience the same change.
Yellowstone's Winter Bison
The snow-covered animal in Snow Happens belongs in a seasonal picture of movement and changing group size. The National Park Service's bison account gives a 2025 Yellowstone estimate of nearly 5,300 animals in two primary breeding herds, northern and central. Recent years have ranged from 3,500 to nearly 6,000.
Winter groups average about 20 bison, compared with about 200 in summer. During the July and August breeding season, groups can reach about 1,000. A small winter group should therefore be understood in its seasonal setting rather than treated as a picture of the park's total herd.
As accumulating snow and dense snowpack develop, bison move from summer ranges to lower elevations. They migrate up to 70 miles between seasonal ranges. The park lists hydrothermal areas and the Madison River as winter viewing locations. Large shoulder and neck muscles let bison swing their heads from side to side to clear foraging patches — the practical work behind the snow on a grazing animal's face.