Photo (above): Six orphaned opossums in care at the National wildlife Centre Field Hospital, where they are being overwintered until spring conditions allow for safe release. Photo credit: Denise Petrie, National Wildlife Centre Fundraising and Outreach Coordinator.
Winter inside a wildlife hospital feels different.
At the National Wildlife Centre Field Hospital in Caledon, the phones still ring, and the work never stops, but the rhythm changes. Fewer baby animals arrive and releases slow down. Winter is still busy, but it brings a quieter intensity, shaped by injury, close monitoring, and preparations.
During the colder months, wildlife cases are more often injury-based. Migrating birds that fall behind are more vulnerable, and frequently arrive with fractures sustained during their journey. Window strikes are also common as some bird species fly further, into unknown territories in search of food.
Mammals are generally well-adapted to our Canadian winters; however, animals that lose fur due to disease, such as mange, or are weakened by starvation can develop frostbite, particularly on extremities like tails and ears. As wildlife moves between foraging areas and hibernation sites, road injuries become more common. These cases require careful long-term monitoring, rather than quick intervention, making winter work less visible but no less complex.
Some wildlife remain in our care through the winter, not because they are weak, but because they lack time to prepare for the cold. Mid-November is typically the point after which release is no longer safe for certain species and orphaned animals. After this time, orphaned wildlife may not be able to successfully acclimatize to dropping temperatures, build shelter, or store food, making overwintering the safest option until spring. Currently, the National Wildlife Centre is caring for 56 wild patients of various species.
Winter is also a time when wildlife behaviour is often misunderstood. With fewer resources available, some nocturnal species expand their foraging range and shift activity times. Raccoons, for example, may be seen more frequently during daylight hours, prompting concern from residents who assume something is wrong. In many cases, these behaviours are normal responses to winter conditions rather than signs of illness or distress.
Inside the hospital, Rehabilitation Team Lead, Isabel Tremel says winter is “crazy, but in a different way.” While admissions may decrease, the veterinary team manages more frequent checks, surgeries, and intensive care. The rehabilitation team also uses this time to review protocols, repair and build enclosures, and prepare for the busy spring season, maintaining a steady, deliberate pace as clinical demands increase.
Winter work may not always be visible, but it plays a critical role in what comes next. The care, preparation, and patience invested during these months help ensure wildlife has the best possible chance when spring arrives. Long before release season begins, that work is already underway.
Dr. Tania Taieb conducting a routine follow-up exam on a Snowy owl after wing surgery. The owl is sedated to allow for a safe assessment. Photo Credit – Denise Petrie.
