A visit from the queen

Wasp

The temperature today was an incredibly balmy 8 degrees Celsius. This was a one-off, however, because a cold front is supposed to roll in tonight and tomorrow is forecasted to be -10 oC (I shouldn’t complain; today in the Canadian prairies it was -50. Before windchill). Still, the warm weather was nice. I wasn’t the only one to think so. This afternoon I found a wasp crawling, somewhat sluggishly, along the windowsill in the den.

In my very first post I talked about the appearance of ladybugs mid-winter. Wasps are very similar visitors. They crawl in to cracks in the walls of the house in the fall when looking for hibernation spots to spend the winter. Normally they would only come out when the warmer spring weather finally arrives, but warm spells can cause a few to come out prematurely. Those that chose to hibernate in your house will quite often go the “wrong” way, toward the warmer temperatures inside, and end up crawling along your floor or windowsill.

Wasps are like honeybees, in that most species spend the majority of their year living in colonies. There’s a queen who “rules” the colony, although her primary job is simply laying eggs. There are sterile worker wasps, who spend their time collecting food for the young grubs and the queen (and themselves), repairing and defending the nest. And there are fertile male wasps, whose only job is to mate with new queens.

Wasp

In the spring, a new queen, who mated with a male before going into hibernation in the fall and stored the sperm inside her, will pick a site for the nest and start a new colony. Depending on the species, she may start it alone, or with a few of her sisters who overwintered with her. She lays fertilized eggs, which develop into sterile female workers. She’ll care for the first couple of broods herself, but once there are enough workers to tend to the eggs and larvae properly, she concentrates on just laying more eggs. Once the sperm runs out, in mid- to late summer, the unfertilized eggs grow into fertile males and new fertile queens, who go out and mate, and start the cycle again. The wasps that turn up in your house in the middle of winter are all young mated females who have gone into hibernation till the spring. All the other groups – the original queen, the sterile workers and the males – died once the weather turned cold (if not before).

These mated females are stingless. The initial reaction upon seeing a wasp, particularly if you have kids or pets, is to worry about someone getting stung. However, the stinger in wasps and bees is a modified ovipositor (the body part used to lay eggs). Males don’t have an ovipositor to begin with, and mated females need theirs to lay their eggs come spring. Only the sterile worker females have the ability to sting. I suppose she could give you a good chomp with those powerful jaws (look at the size of them in that first photo!), but it’s unlikely to feel like more than a pinch. Paper wasps use their jaws to strip bits of wood from logs or dead trees, which they then mix with saliva to create the “paper” used in building their grey papery nests. If you spend a lot of time on your deck in the summer, you might catch one collecting wood from the deck or siding.

Wasp

Wasps are generally predatory, preying on other insects, although they can sometimes be seen feeding on the nectar of flowers. The particular composition of their diet depends on the species. They’re useful to have around your yard because they’ll take care of many other undesirable bugs in your garden or around your home. As long as you don’t actively disturb their nest, or pester an individual (intentionally or not), they’re generally fairly docile, willing to let you do your thing while they do theirs. If it’s a mild day when you come across a wasp in your house, let her crawl onto a piece of paper and then transport her outside, where she can find herself a new hibernation spot, and she’ll take care of your garden for you come spring.

Tunnels in the snow

Trails1

There was a period before Christmas where we had a lot of snow accumulation on the ground. Some rain over the holidays, followed up by this warm stretch, melted off most of it, and the receding snow can reveal some interesting things that take place under the snow layers, where we can’t see them. One that many homeowners are probably familiar with are these strange half-tunnels carved into grassy lawns. Only an inch or two wide, they can carve intricate networks or simple purposeful trails into the grass and soil which many people find unsightly and can often be difficult to fill in again.

Meadow Vole
Meadow Vole (Gillian Bowser, NPS Photo)

The culprit, at least here in the east, is the common and widespread Meadow Vole. It’s the only species of vole that occurs in eastern North America, but it’s also found as far west as Alaska. It doesn’t usually come into homes, so like most rodents, it’s rarely seen itself. However, it leaves ample evidence of its presence. The trails in the lawn are a network of pathways that the vole uses to travel between its burrow, where it sleeps and stores food, and the food itself.

In the winter the voles travel under the snow, rather than over it, for three reasons. The first is to avoid predation. It’s much easier for an owl or a fox looking for a meal to track a rodent running across the snow than it is to find something underneath the snow (although these predators are adept at doing that as well!). Also, given the excellent insulative properties of snow, it’s much warmer underneath it all than above it, where the little vole would be exposed to wind and cold. This makes it much easier for the vole to remain active during the winter.

Trails3

And thirdly, it provides much easier access to its food sources. In the winter, voles will eat seeds and grasses, which are usually found close to the ground, as well as roots and the bark of young saplings. If you have birdfeeders out you might chance to spot one munching on fallen seed when snow cover is low, but more likely the evidence of feeding you’re likely to come across is finding a sapling stripped of bark around its base. Munching by voles can be differentiated from that of rabbits (who will also chew the bark from saplings) in that rabbits won’t usually chew all the way to the ground, and the pattern of gnawing by voles isn’t uniform. I didn’t notice any such saplings around these particular trails. Once the snow melts, you can also often see little piles of grass clippings within the trails, where the vole has snipped the grass off at the base, pulled it down, snipped off some more, etc, until it can reach the seed heads.

Trails2

This long trail was crossing a narrow stretch of lawn between two naturalized patches (a group of sumacs to a couple of wild apple trees). I’m not sure if the voles are actively foraging for roots or seeds when making these trails, or if they’re directionally challenged (or perhaps just sleepy?), but it seemed like a very curvy trail for just going from one place to another. Perhaps it’s a mechanism to throw off predators listening to rodents running under the snow cover?

Surprisingly, there weren’t very many trails on the lawn, just these couple. In the winter, voles often nest communally in groups of anywhere from two to a number of generations . Female voles breed for the first time when about half grown, at about 25 days. They breed nearly continuously, mating again immediately after giving birth to a litter, and can have three to six litters (depending on latitude and food resources) of four to seven young in a year, which would quickly become quite a large group! Most individuals live less than a year, however. I suppose larger groups would be likely to make a broader network of trails, and a pair would probably just have a handful of well-used trails. A colony of voles can occupy a territory of up to 100 feet in diameter.

Voles aren’t uniformly appreciated by everyone, and particularly in urban settings, the damage to lawns can result in an unsightly mess. There are lots of vole-control solutions to be found by a quick Google search, but my recommendation is just to not have a lawn – plant a garden, it’s more useful to wildlife and prettier anyway! :)