Lacreek NWR is a place of constant change. Changing seasons bring dramatic variations of temperatures, precipitation, day length, and plant growth. As the seasons change, so do the species and abundance of wildlife present on the Refuge. Spring (March-May) rushes in as the ice and snow melts and the days begin to lengthen. Northern pintails are the sentinals of spring here. When the first drake pintails arrive in late February, spring is around the corner. In some years, winter gives way readily and by March the temperatures are mild and many early season plants begin to green up. Other years, winter hangs on well into April. It is certain, however, that spring will bring many migratory birds to the Refuge that stop to feed and rest before moving on. Some will stay to nest and raise young. Resident species respond to the changes as well. Large concentrations of white-tailed deer, ring-necked pheasants, and sharp-tailed grouse begin to disperse from the Refuge to surrounding private lands. Some hibernating species, such as thirteen-lined ground squirrels awake from their slumber.
By early June, spring has faded into summer (June-August). Spring migration is complete, and the species that remain are busy raising young. Plants actively grow through the summer months, producing the vegetation, seeds, and tubers that will feed the wildlife that visit the Refuge until the next year. Summer begins to fade into fall (September-October) during the month of September. Some years, the heat of summer remains till the end of September and some years the cooler fall temperatures arrive in early to mid-September. The fall migrants begin to move ahead of the winter that is to come. The first trumpeter swans arrive in September when their cygnets (young of the year) learn to fly. The first snow of the season signals the arrival of winter (November-February). Many of the migratory bird species have moved on. Some species, such as mallards, Canada geese, bald eagles, and rough legged hawks arrive to spend the long winter with us.