You’ve gone to peek at a nest. For a moment, all the little feathered heads regard you with large, dark eyes—and then in a flurry and a tumble they are out of the nest, running every which way along the ground, and their parents are scolding you and swooping among their babies in apparent panic. Oh no! Will the babies be okay?
This is possibly the question I am asked most frequently. Sometimes the inquirer has managed to catch a few of the babies and replace them in the nest, only for the babies to promptly hop back out. Other times the babies have swiftly vanished, and the inquirer—often someone who has watched the nest over the course of weeks, growing attached to their fluffy neighbors—is left, quite suddenly, with silence and absence and a gnawing guilt.
Photo by jayhem on flickr, used via a Creative Commons license.
Sea urchins do more than you might expect from a spiky ball. They seek out holes to hide in, travel in search of food, cover themselves in costumes of seaweed and rocks, and flee their slower predators. (Even the speediest urchin can’t flee a sea otter, but it has a chance against a sea star.)
All of this is a bit astonishing for an animal that has no eyes. How do they spot their hidey-holes? How do they see the sea stars in time to run away?
Science requires careful planning, foresight, and scrupulous attention to detail. Everything must be controlled so that the variables of interest can be examined. One mistake could bring everything down. Only with years of training can someone hope to add to our body of knowledge.
But if you take all of that too seriously, you’ll spend all of your time planning and theorizing rather than looking—and the most important part of science happens when people just start looking.
Peder V. Thellesen is a dairy farmer in Denmark. He has no formal scientific training. Evidently he loves starlings: he started banding them and observing their nests in 1971 and continued to do so every year, in nestboxes on his own farm and on his neighbors’ farms.
It’s easy to see how you might fall for that gorgeous plumage. Photo by Phil McIver, reproduced from flickr under a Creative Commons license.
Photo by Patrick Emerson*
The full moon is pregnant with foreboding interpretations, from the legendary werewolves who are supposed to transform under its malevolently shining face to a recent article about November’s upcoming full “supermoon” that faux-reassures, “despite all the rumors… there is no evidence linking supermoons to natural disasters.”
If you look at a full moon and shiver, you aren’t alone—but you are a bit of a mystery. In humanity’s past, the full moon should have been the safest time of the month, since our nocturnal predators tend to attack most on dark nights. The new moon should be spooky, as your hindbrain—unaware that you no longer live on the African savannah (unless you do!)—looks out for predators slinking in the shadows. This is presumably why the fear of darkness is such a common and instinctual one. But the full moon is bright: it should be comforting.
In the spring of 2015, a male House Wren and his mate built their nest inside a nestbox near a honeysuckle. His mate laid her eggs and dutifully incubated them. Then, one morning— cheep! cheep! High-pitched calls and gaping red mouths cried hungry, daddy! and the male wren was off in a paternal tizzy, collecting bugs and delivering them to his new offspring.
It was, maybe, odd that his new offspring weren’t in the nest that he had built. It was, maybe, odd that other, larger birds were also feeding his babies. It might even have been called odd that his mate was still sitting in their nest, atop whole and silent eggs. But— cheep! No time for that! The chicks were hungry!
What this male House Wren was doing, no doubt to the profound irritation of his mate, was feeding the offspring of a pair of Northern Cardinals who had nested in the honeysuckle near his nestbox.
Male Golden-winged Warbler. Photo by Mark Peck*
This story begins when Streby et al. (2015) decided to track Golden-winged Warblers during their annual migration. We know that lots of birds migrate, but for most of them, we know surprisingly few details about that migration. Often we know generally where they go (to a specificity of, say, “somewhere in South America”) but not exactly where; rarely do we know what paths they take to get between wintering and breeding grounds. This kind of information is especially important for birds of conservation concern, since to protect a migratory population, you need to protect its wintering grounds and migration route as well as its breeding grounds.
The researchers relied on technology to tell them where the warblers went when they migrated. There are several different ways to track animal movements; in this case, researchers used light-level geolocators, which record the amount of light hitting the geolocator. Collected over time, these light intensity measurements allow researchers to calculate where the geolocator was, based on things such as day length. This location information isn’t as accurate as the data you would get from a GPS logger, but the light-level geolocators have a big advantage over GPS loggers: they can be much smaller, so you can put them on tiny birds like Golden-winged Warblers. A Golden-winged Warbler attached to a heavy, clunky GPS logger would not be migrating anywhere.
There is a thing that happens a lot in biology, especially in animal behavior: one set of researchers finds an interesting relationship, like, say, “Birds prefer to eat bugs off of cows with lots of spots, and don’t like to eat bugs off of cows with no spots.” (This is a made-up example.)
Blackbirds flying near a cow, Pt Reyes, CA.
Then, some other researchers do a study and say, “Hey, our birds prefer to eat bugs off of cows with no spots! That’s the opposite!”
Then still different researchers do another study and say, “Our birds don’t care at all about the number of spots, they just care whether the spots make a shape like a smiley face. You guys must all have made a mistake. The Smiley Face Rule is the new Lek Paradox! #nobelplease”
To put it less ridiculously: scientists get different results sometimes, and it can be hard to figure out why. Did someone make a mistake? Who is right? Today’s featured paper takes an example of this confusing scientific disagreement and elegantly makes sense of everything, with the help of this handsome little bird:
Common Yellowthroat (male).
Photo by Dan Pancamo*