What does a warm, wet winter mean for the valley’s plants and animals?
“Animals are designed for average conditions,” said Carl Koch, assistant area wildlife biologist with the Department of Fish and Game in Juneau, “and this year is anything but average.”
Lots of rain and low snow favor many herbivores, but threaten those that rely on snow for protection and insulation.
Ungulates like mountain goats and moose will do well this year, Koch said. “Males have depleted a lot of energy in the rut,” Koch said, “so they start the winter season with low body weight.”
For them, snow covers food and restricts movement, so some starve when there’s too little forage. According to a recent 2011 article in the Journal of Wildlife Management, during average conditions, up to one-third of adult male mountain goats die by spring. In a year like this one, though, up to 90 percent could make it through the winter.
Moose can also be trapped in heavy snowpack, and tend to survive better in low snow years. “They’ll be more dispersed this year. They can go higher and find more food,”
Koch said Fish and Game traditionally counts moose in the fall, but this year there wasn’t enough snow to track them.
While this winter means lots of food and easy travel for ungulates, it’s a tough time for voles, hares and ptarmigan in Southeast Alaska. Nearly every Alaskan predator eats voles, mice-sized, fuzzy rodents. Voles aren’t very good at regulating their metabolisms, so they starve to death if they don’t eat every few hours. Voles move around a lot to find food, and prefer to travel under snow to avoid predators.
Snow also acts as a blanket to maintain a relatively warm ground temperature. As of mid-January, the ground still wasn’t frozen, but Pam Randles, who maintains a ground frost monitor near the Haines School. But cold without snow cover can change that quickly, she said.
Randles said that without snow cover that could change quickly. The ground froze down to 48 inches during a recent, snowless winter.
Very few voles would survive those conditions, putting extra pressure on foxes, hawks, owls and other predators to find food. For prey, they might turn to snowshoe hares and ptarmigan – which turn white every winter regardless of snow – making them easy to spot.
While most predators can use the bare ground to their advantage, wolverines may have to travel higher into the mountains to find den sites in deep snow. They, like wolves, rely on winter-killed animals for food, and may have to work harder for their meals this season.
Fish and Game sportfish biologist Richard Chapell said that wet and mild is generally good for salmon stocks. “What really hurts them is cold temperatures. It freezes and dries up winter rearing areas. But there’s plenty of water and it’s warm,” he said before temperatures dropped recently.
Fish in Sawmill Creek would do better to have more snow on Mount Ripinsky, which feeds the stream, Chapell said, but there’s still time to build that before spring. There’s heavy, wet snow on the mountain according to Paul Swift – about a foot and a half at 2,400 feet elevation.
There were several bear sightings in January, but this season isn’t much different than normal, in terms of activity, said Koch. “(Activity) is mostly about food for them and less about temperature,” he said. “We had more reports of bears last year by this time.”
Winter rains are mostly wasted on the local spruce-hemlock forest, said forester Roy Josephson. “A lot of the rain isn’t going into the ground. In the Kelsall, there’s a lot of water sitting on top of the ground.” In winter, spruce and hemlock are dormant and have “pretty much stopped growing” and roots aren’t taking up water, Josephson said. “Spring rains are important because that’s when trees are most actively growing.”
A stand of yellow cedar near the Lutak tank farm site, one of the most northern stands of the tree in Alaska, would tend to benefit from a warmer, wetter winter, Josephson said.