Dark-eyed Junco
There is a small and common bird that is often described as “bland” that visits your yard each winter, and perhaps you don’t even know it. It is charcoal gray in color with a white belly. The males are darker than the females. They have a small pink bill, which is really the only splash of color on this bird. They have a pair of white outer tail feathers that stand out strikingly against the dark tail, but are only seen when the bird is in flight. So, what is this common and unnoticed bird? It is the Dark-eyed Junco (Junco hyemalis). The Dark-eyed Junco is a type of New World sparrow. This means it is not related to the sparrows found in Europe, Asia, or Africa. They are unique to the Americas. In summer, it is found in the northern reaches of Canada, well into the Arctic, and in several of the northern tier states, where conifer forests can be found. Its genus name, “Junco” is from the Latin word for rush or reed and refers to the grass-like plants. The species name “hyemalis” is also Latin and means winter. So together its scientific name means “a winter bird that lives in reeds”. Well, they got part of it right. They are a winter bird, but it’s not usually seen in reeds or cattails. In summer, they live in conifer forests, and in winter, they are found in open areas. The Dark-eyed Junco shows up in most backyards in late fall or early winter. They are found in each and every state in the nation during winter and even parts of northern Mexico. To say they are widespread and in everyone’s backyards would be an understatement. They are highly migratory, with the females moving further south than the males. The males tend to stay in the northern states, which gives them a head start when returning in the spring to the breeding grounds. Every study shows that the males who return to the breeding grounds first obtain the best territories. These birds can look highly variable depending upon where you live. There are around 15 subspecies of the Dark-eyed Junco, and this is the very thing that drives a lot of people crazy, me included. So, let’s just say that no matter what your Junco looks like, it is still a Dark-eyed Junco. For the past 50 or more years, it was believed that small songbirds like the Dark-eyed Junco had no or very limited ability to smell anything. It was thought that the olfactory system in these birds was underdeveloped to the point of being non-functional. However, recent studies done with Dark-eyed Juncos show just the opposite. They do have the ability to smell and even identify individual family members by their unique odor. Now the most recent studies show that the Dark-eyed Junco have cryptochrome molecules located in the retinas if their eyes. These molecules create light-activated chemical reactions that are sensitive to the Earth’s Magnetic field. In other words, the birds can see the magnetic poles, allowing the birds to determine which way is north or south. To add to this amazing superpower, the Juncos have a strong sense of smell that helps the birds use the odor of the land to help them determine their exact location. It is thought that the birds can smell the landscape as they move about during migration. Experiments are showing the birds can smell the chemicals in the soil, lakes, streams, and other habitats. These two amazing senses help the birds to navigate across unfamiliar territory when migrating. Combining these senses helps determine how far they need to fly during migration and when and if they have reached their final destination. As you can see, we are just starting to understand the superpowers that many birds possess. The next time you look out your window and see one of these Juncos, think about how these birds eyed and smelled their way to visit your backyard. Until next time… Stan Tekiela is an author, naturalist, and wildlife photographer who travels extensively to study and photograph wildlife. He can be followed on Instagram and Facebook. He can be contacted via his website at naturesmart.com.
Hummingbird Migration
Bird migration is still one of nature’s most interesting and yet mysterious events. On the surface, migration seems rather simple and straight-forward, but if you stop and take a detailed look, you will see every shade of complexity possible. There are over 11,000 species of birds, and about 40 percent partake in some form of migration. Migrations range from simple elevational changes for species that live in the mountains, to short, distant movements to avoid unfavorable weather, to long, distant trips to warm climates to escape winter, to the granddaddy of them all, migration from one end of the earth to the other. Right away, you can see there is more to migration than perhaps you thought. In the 1800’s we didn’t understand much about migration. We thought it was impossible for a tiny bird to navigate over great distances and endure huge physical demands, so we said it was impossible and we “made up facts” such as hummingbirds had to migrate on the backs of geese, in order for them to escape winter. We also said that some birds dove down to the bottom of ponds and overwintered in the mud for the winter. The thoughts of these kinds of theories now seem preposterous and outlandish. Yet at the time, it was accepted as fact because someone didn’t understand, so they made up something that could explain the unexplainable. In the 1900s, we started to develop new ways to study birds. Some of the earliest attempts to track migration involved catching a bird and tying a brightly colored ribbon on their wing in hopes of being able to find this bird again during winter. This wasn’t very efficient, and you had to have an idea where they stayed for the winter already to make this work. When transistors were invented in the 1940s, it was the breakthrough that made small electronics possible, and by the end of the 1900s, small tracking devices were used to track the migration of free-flying birds. This was the beginning of our better understanding of bird migration, but just the tip of the migration iceberg. In just the past few decades, so much new and almost unbelievable information about bird migration has completely turned our understanding of migration upside down. Today, there are many ways to track migrating birds. One of these migration tracking tools is a website called Bird Cast from Cornell Lab. All you need to do is put in your county and state, and each day during the migration season, you can see how many birds passed over your county on the previous night. There is a ton of information available to anyone who is curious about what is going on with migration. In addition to the tally of the birds migrating through your county, there is also information about what time they migrated, the timing of each nightly flight, along with flight direction and altitude. They also have a list of the expected species that are migrating. For example, as I write this, 97,400 birds passed over my county last night, and at one given moment last night, 36,400 birds were in flight, traveling SSW at 14 mph, at an altitude of 600 feet, all at one time. In order to gather all this data, Bird Cast uses data from the national network of weather surveillance radars (NEXRAD). Sophisticated algorithms and machine learning models are applied to the radar data to separate weather, such as precipitation, from biological signals (the birds). It then analyzes the strength of the radar signals to estimate the number of birds that are flying. Just like the weather, they are able to give migration forecasts to predict the nocturnal bird migration for the next few nights. We sure have come a long way in the understanding of bird migration, unlocking some of the most mysterious natural events of nature. However, no doubt there is so much more we don’t understand about bird migration, and we will understand more in the years to come. Until next time… Stan Tekiela is an author, naturalist, and wildlife photographer who travels extensively to study and photograph wildlife. He can be followed on Instagram and Facebook. He can be contacted via his website at naturesmart.com.