A Northwoods Almanac for March 2 – 15, 2012
When is Too Much of a Good Thing a Bad Thing?
It’s Sunday morning, and I’m looking at a swarm of goldfinches and common redpolls – perhaps 50 or 60 – which are energetically competing for access to one particular tube feeder and a platform feeder outside our home. And while I’m delighted, I’m also worried – has this high number of birds now exceeded some healthy threshold and our supplemental feeding now transformed from something we thought was “good” to something “bad”?
I’ve always ascribed to “moderation in all things,” but how does one define moderation? When does one cross the invisible line from moderation into excess? When does too much helping become harming?
This notion of a middle-way, a balanced life, suffuses nearly everything all of us do. How much is too much when we eat? When are we speaking too loud, or too long, or too forcefully? When are we paying too much attention to one thing and not enough to another? When does too much work make us a workaholic? When is one more pill an overdose?
On a social scale: When do visitors stay too long? How many fishing boats on a lake, or hikers on a trail, or people at a campground, make it too crowded? How many kids are too many in a classroom?
The examples are literally endless, but to bring the question back to feeding wildlife, how much feeding is “just right”? If one tube feeder is good for the birds, are 10 feeders? One hundred feeders? Likewise, if one can of corn attracts two deer, what about a five-gallon pail that attracts six deer? Why not a wheelbarrow then, or pick-up truck load?
When do we go from helping a wildlife species, or many species, to actually creating potential harm? Dr. Doolittle was an entertaining Walt Disney character, but turning large numbers of wild animals into semi-domesticated pets is not the middle way.
I don’t have any absolute answers to this question. Based on the best science and observation that we can bring to bear, there’s an art and a wisdom needed in finding the middle way. And the way is dynamic – it changes as seasons and behaviors change.
So what do we need to be considering? Well, there’s a long list. For one, too many animals feeding in one space creates a much higher risk of disease. Over the years, we’ve had salmonella poisoning occur at our feeders at least twice in the late winter/early spring, and whether that was because we were feeding too many birds, or we hadn’t cleaned our feeders sufficiently, or birds were arriving from elsewhere already with salmonella is something we’ll never know. But we do know that hordes of animals – birds or mammals – feeding from the same general plate greatly increases the risk of transmitting disease.
Two, crowding increases stress. However, how stress plays out is highly variable, and we only see what is in view of our feeders. All animals have breeding territories that vary in size according to how well their needs are met not only for food, but also for cover, for breeding/nesting/denning, for rearing of young, et al. So, when we bring many individuals together within a territorial pair’s domain, what are the consequences? What is the difference in winter when territories are less restrictive and animals are more social? How about spring migration?
All animals also have a home range, an area in which they may wander in search of food or other needs. When we change their normal travel and feeding behaviors by dint of providing a five-star restaurant in our yards, what are the consequences? The deer that no longer yard up in the winter or no longer travel their normal feeding paths throughout the year are now concentrated in one area. Habituation often becomes an issue – if animals become too familiar or comfortable with the presence of humans they may fail to exercise their natural instinctive behaviors, such as response to danger.
All animals also have adaptive behaviors that have been honed over thousands of generations to “fit” all the needs of their life histories throughout all the variations of the seasons. How are we altering essential behaviors if we feed too much? When does our home become the equivalent of a feedlot rather than merely a supplemental source of food? When are we creating a dependency, particularly for juveniles who need to learn how to fend for themselves?
We all get great enjoyment from watching wildlife, but along with the privilege of interacting with wild animals comes a responsibility to ensure their health is maintained.
I should add that we also have responsibility to our human neighbors. When we entice a herd of deer into our yard, the deer are also very likely to browse every tree, shrub, and wildflower in the general vicinity. When we entice 50 geese to our shoreline, their predilection for eating grass spills over onto other peoples’ properties, as does their waste, both in the water and in yards.
So, now that swarms of redpolls are arriving at people’s feeders – I’m getting phone calls from people saying they have hundreds of birds now at their feeders – is it the “right” thing to do to vastly increase our seed output to feed them all, or should we continue feeding modestly so that they don’t concentrate at our feeders for weeks thereby increasing the risk of disease?
I’m opening this up as a discussion, and I’d like to hear from you – please e-mail.
Chickadee Tree ID and Caterpillar Choices
We humans aren’t the only ones that can learn to identify trees. According to researchers at UC Irvine and Wesleyan University, birds learn to identify trees, too. In this particular study, the researchers showed that chickadees and other birds can learn to zero in on the species of tree as much as on the characteristics of their insect prey.
For the insects – caterpillars in this case – the study results also demonstrate that dining on the trees that are most nutritious for them, such as the black cherry, can increase their chances by 90 percent of being devoured by a discerning bird. Researchers discovered that the healthiest tree species harbor the greatest number of caterpillars, thereby offering the easiest targets for birds, and the birds learn this.
From the caterpillar’s standpoint, they’re between a rock and a hard place. The research illustrated a stark choice for them between gaining strength through a good diet utilizing the healthiest trees (but thus being more vulnerable to predators), or remaining weaker and hungrier but much safer by utilizing poorer quality trees.
One of the researchers summarized the study this way: "If a caterpillar could feed on nutritious, high-quality tree species and be left alone, this would be the best of all worlds. Instead, it's faced with a trade-off. Overall, it appears that it's better to feed on poor-quality tree species . . . than to be on a nutritious plant with many others."
It’s March! Loons will soon be tracking their way north, hop-skipping-jumping their way here as the weather dictates. But where are they now? Most likely in the Gulf of Mexico below the Florida panhandle. Kay Rhyner sent me on e-mail on 2/26 that read: “We visited Marco Island, Florida last week. We were at my brother's home along one of the canals. One morning a loon was out there diving and fishing. I, needless to say, was very excited and wondered if it was "our" loon from Yawkey Lake in Hazelhurst. Then he came up with a very large fish and seemed to be kind of struggling with it and then a pelican dove in and snatched the fish right out of the loon's beak.”
Kay was wondering about the loons from Yawkey Lake, and, of course, there is no way to know where they are right now. But a few of you do have a way! Loons on Trout, Star, Island, and Escanaba Lake were all outfitted with satellite transmitters last summer, and can be followed in their migration on the USGS Common Loon Migration Study site at: www.umesc.usgs.gov/terrestrial/migratory_birds/loons/migrations.html
I had several people contact me saying they had seen a small bear in the last few weeks, and were wondering what could be the explanation. My speculation is that they saw a yearling bear (last year's cub). This year's cubs would be very small yet, and probably still nursing. The young are typically born in late January and early February, and don't even open their eyes for 25 days, so a new cub "should" be out of the question (never say never, though). At one year of age, a yearling will weigh from 40-75 pounds, so perhaps they saw one at the very lowest end of that weight scale. Females breed every two years, so the yearlings stay in the den with the mother, though they may have nearby individual dens.
As to why a bear would be running around in February, something had to have disturbed the den. On occasion, loggers drop trees inadvertently on dens, or just the commotion of logging scares them out. One way or another, the yearlings will be hungry, and I suspect they may spend a lot of time near bird and deer feeders.
For planet watching in March, at dusk look for brilliant Venus in the west, and Jupiter, only slightly less brilliant, in the southwest. Before dawn, Mars will be low in the northwest, and Saturn will rise high in the south by 3 a.m.
Our average high temperature reaches 32°F on March 6. The full moon shines bright on March 7. Called the “Crust on the Snow Moon” by the Ojibwe, the name denotes very tough walking conditions for deer, which will constantly break through the crust, but fabulous conditions for lightweight creatures like snowshoe hares that can now stay on top of the crust.
We hit 11.5 hours of sunlight on 3/8, well on our way to the Vernal equinox on 3/20.
On 3/15, look for Venus just 3 degrees above Jupiter.
American Marten Grant to Mercer School
Congratulations to Zach Wilson and the North Lakeland Discovery Center! Coached by Zach, students in Mercer are participating in Wisconsin’s American marten management plan by helping researchers trap and track the animals. The students have helped place radio collars on 12 martens near Mercer and regularly perform radio-telemetry work to log the animals' movements. The Mercer project is among 12 finalists in a Samsung project selected from more than 1,500 applicants. Judges will select four grand-prize winners, and online voters will select a fifth. All winners will receive equipment for their school. To view the Mercer school marten video and support their contest entry, visit https://pages.samsung.com/us/sft/video/index.jsp. Voting ends at midnight March 12.