Reproduction Versus Immigration in North Carolina’s Piping Plovers
The beach: the sun, the sand, the water. It’s a wonderful place to be in the summer, whether you’re a shorebird or a human.
The beach: the sun, the sand, the water. It’s a wonderful place to be in the summer, whether you’re a shorebird or a human.
I have co-taught a workshop on R at every AOS meeting since Oklahoma in 2015. The exact content has changed based on participant feedback, but the goal has remained the same: to help those who have some R experience already gain new skills that we feel are valuable to most ecologists who are working with data in R as apart of their scientific work.
One of the daily joys of summer is waking to the sounds of bird song. Those early morning bursts of singing herald the start of our days, for birds and people alike. If we listen carefully, though, the dawn chorus also reveals something about the state of nature.
Many shorebirds migrate across continents and oceans, relying on key areas to rest, eat, and refuel. Habitat loss, climate change, and other factors are affecting these birds at their breeding, migration, and wintering grounds.
For bird aficionados, waking up on Guam can be a surreal experience. The soundscape is nearly devoid of birdsong other than the clucking of chickens and the occasional chirp of a Eurasian Tree Sparrow. Guam’s silent forests are the work of the brown treesnake, an invasive predator that was accidentally introduced to the island after World War II.
About 25 years ago, I started a research position at the Instituto de Ecología AC in Veracruz, Mexico. During my first explorations of the cloud forest there, I heard the marvelous sound that eventually became a key part of my work and that of my assistant Clementina González.
As many marshes along the Gulf Coast were drained in the late 1970s, Snow Geese that had used them as wintering areas began shifting to agricultural land instead. Leftover crops in farm fields provided them with a generous new winter and spring diet, and the population began growing at an unprecedented rate. While they have ample habitat in the south, the growing number of geese, coupled with their destructive foraging behaviors, has led to increasing and widespread habitat destruction in the Arctic coastal habitats where they breed.
Imagine having a conversation with someone next to a very busy intersection at rush hour. You can’t hear one another at a normal volume, so what do you do? You could talk louder, maybe wait for the noise to die down, or simply pick up your belongings and move to a quieter setting to converse.
Scientists have long thought that for two related populations of birds to evolve into separate species, they needed to be completely separated. This usually means the kind of total separation produced by isolation on islands or by features such ice sheets, mountain ranges, or rivers. However, the complex distributions and migratory nature of many birds mean that long-term total separation of bird populations, long the assumption in speciation research, is actually not necessary for speciation to occur.
Many species of migrant songbirds have a reproductive strategy called protandry, where males arrive at stopovers and breeding sites earlier than females. Ornithologists believe that males do this because it increases their mating opportunities and reduces competition among males for high-quality nest sites. Although it’s a common phenomenon, the question of how males arrive earlier is still unanswered for most species.