Posted on: July 8, 2014
Author: Ian Davies
Fuzzy adorable shorebird chicks – does it really get any better? About 3-4 days ago many of our nests began to hatch, so now each day on the tundra is occasionally punctuated by a small troop of chicks with accompanying parents. As we spend the summer up here watching shorebirds go through the nesting process, the amount of hardship that these impressive little birds face never fails to amaze. I wish I could tell their side of the story, but I can only give you the view of a shorebird researcher.
When we arrived here at the beginning of June, the world was made of snow and ice. Summer seemed impossibly far away, and yet the birds that brought us here had already been present for a week or more. Feeding at the margins of ice puddles, they eked out an existence on the insects that are hardy enough to tolerate the same conditions. This year the earliest egg laid in a nest we found was a Pectoral Sandpiper that laid the first of its four eggs on May 31 – truly impressive! Over the next week as the 80% snow cover rapidly recedes, the shorebirds jostle with other members of their species to compete for territories and mates. For some species, such as the Semipalmated Sandpiper and Dunlin, males return to the same territories year after year, and will often pair up with the female if she returns as well. This site fidelity really makes our lives easier, enabling us to use previous nest locations of marked birds to narrow our search for their nests this year.
After the battling for territories and mates has finished, it is time to actually nest. Each species has its own specific habitat preferences, and once you get familiar with the birds, you can often look at an area and know where you will have the best chance of finding a nest of any given species. Semipalmated Sandpipers like drier habitats, often on the dry rims of tundra puddles or near the edges of ponds. They often line their nest with a certain type of white lichen that makes for some great home décor. Pectoral Sandpipers and Dunlin are more varied in their habitat choices, but usually opt for a bit marshier and damper locations, closer to water and sometimes on little rises in the middle of a mostly wet area. Phalaropes, both Red and Red-necked, are the water specialists. Almost invariably within a half-meter of a wet ditch or pond, their nests often have grasses pulled over them in a dome, rendering the eggs and incubating bird nearly invisible from above. Each bird chooses their nest location and gets down to business.
All the nests will top out at four eggs, the most efficient number for conserving heat and fitting nicely under an incubating bird. The eggs are generally laid one per day, and once the fourth egg is laid, the incubation process begins. For about 20-26 days, depending on the species, the eggs will be kept warm underneath the parent bird. Semipalmated Sandpiper and Dunlin pair members both take turns with incubation duty, as opposed to Pectoral Sandpipers and the phalaropes, where the burden falls on one bird. Female Pectoral Sandpipers care for the nest and any resulting offspring, and the reverse is true in phalaropes, where the males are the sole parental presence. Leaving only for brief feeding breaks or to avoid a predator, the incubating birds will spent their 3+ weeks on nest duty before hopefully having a brood of young to tend to.
With 2-3 days left before the chicks leave their shelled abodes, they face the first hurdle of their lives – exiting the egg. Using a hardened protrusion on the tip of their beaks called an “egg tooth”, each chick must break its way out into the world. From the outside this appears as a spiderweb of cracks visible on the surface of the egg, which we look for in our nest checks as a sign of chicks soon to come. Initial haphazard cracks eventually converge into a star pattern that radiates out from a central point, known as a “star pip” for its star-like appearance. The next step is when a flake of the shell is actually popped out into the nest, leaving a tiny hole, or “pip”, in the egg. This hole will eventually widen and be at the location of the passageway out of the egg. After the chick finally chisels its way out and flops damply into the nest cup, the parent carries away the now purposeless egg and incubates the new chick and remaining eggs. This process is repeated until all chicks are fluffy and happy, and eggshells are absent. After several hours in the nest cup, the squadron of parents and young leaves the nest, never to return.
The chicks will stick close to the parents for a few days, learning how to feed and exist in the tundra environment, but after a couple weeks they are on their own. With still over a week until they are able to fly, these half-grown chicks are left to fend for themselves as the parents make their way to migration staging areas, beginning the long migration south. These “teenage” chicks often form little roaming groups with other young of their same species, wandering around the tundra with their compatriots for a few days before eventually parting ways as they head south in the wake of the adults.
Most people don’t glimpse the annual cycle of shorebird life until this stage – when our beaches are speckled with migrant birds. In the local Manomet area there are several important migration stopover sites that can be excellent places to encounter large numbers of shorebirds taking advantage of the natural resources. Plymouth Beach in Plymouth (MA) and the South Beach/Monomoy NWR complex in Chatham (MA) can both harbor thousands of shorebirds at any given time, and perhaps some of the same individuals that we see up here during the summer! Next time you’re on the beach, keep an eye out for any shorebirds that might be stopping by – perhaps with a newfound appreciation of where they’ve come from and what they’ve done!