Nests, Eggs & Chicks
Watch where you step,” warns Lauren Dinan, bird biologist with the Nebraska Game & Parks Commission. The birds’ nests, eggs, and chicks blend in so well they are nearly invisible on the sand and gravel where they have chosen to nest.
Terns and plovers come to Nebraska from April through August to build nests, lay eggs, hatch chicks and begin raising their young. The birds are threatened in Nebraska mainly due to habitat degradation, human disturbance, and predators, which means it’s even more important to protect their nests. So during these 10 to 12 weeks, people need to find a way to share the environment with the birds.
By understanding more about the birds’ nesting habits, we can avoid areas where they are present. Keith Carroll, the superintendent at Western Sand and Gravel, says, “I actually look forward to sharing the sand with the birds. It adds a layer of meaning to our work. They chose us, we didn’t choose them, and the sand piles have provided a lifeline for the birds.” Biologists monitor the birds to ensure their success.
Tern and plover nests, eggs, and chicks are well camouflaged, making them difficult to see.
By comparing the images above, note the differences between the tern (right) and plover (left) nests and eggs:
- Terns lay two to three eggs in a small cup-like depression. They are a little larger than a quarter and are pale to tan with dark spots. Coloration is highly variable. Terns’ eggs take about 21 days to hatch.
- Typically, piping plovers lay four eggs in a small, cup-like depression on the ground. They line their nest with small pebbles and place eggs with the narrow ends pointing toward the center of the nest to prevent them from rolling out. The plovers’ eggs are a pale buff color, usually with subtle black markings, and are uniform in size and coloration. They take about 28 days to hatch.
When breeding, the interior least tern is like a heating pad. Female birds lose a patch of feathers on their bellies. This is called a brood patch. The side feathers remain, but the feathers on the underside come out as the skin swells, acting as a hot water bottle for the eggs. And so when she settles down on the nest, the side feathers will drop down and make a little incubation chamber for her eggs. After the eggs hatch, the brood patch will eventually disappear, and the belly feathers will grow back.
If birds have an option, they will always take off into the wind and land into the wind, just like airplanes. Similarly, to protect their nests and keep them warm, they will always sit with their tail into the wind. This also keeps sand from blowing directly into their eyes.
Birds respond to environmental cues. During a day, the pattern of a bird’s movement indicates how the wind is changing. Can you use this information to predict the weather? Watch this time-lapse video to see how a plover shifts position throughout a single day (May 30, 2015).
Activity: Bird as a Wind Vane
Click here to download and print the Bird as Wind Vane Lesson.
Click on the bird icon to download and print the Bird as Wind Vane Activity.
Once the chicks hatch, it is interesting to note their differences. Compare the photos of tern and plover chicks above:
- Tern chicks (left) vary from grayish-brown to yellow to nearly reddish or sandy-brown with white undersides and tiny dark spots on head and back.
- The tern’s white egg tooth (left) helps the chick break out of its egg.
- The plover chick (right) is downy with white undersides, buff and grayish back and head with dark speckling, white collar around the back of the neck, pale orange legs, and black bill.
Watch the short video clips below to observe tern and plover chicks right after hatching.
The tern is semiprecocial, which means they have open eyes, down, and can move around right after they hatch. They typically leave the nest within two days of hatching but are flightless and depend on parents for food (small fish) and protection until they are about 21 days old.
The plover is precocial, which means they are relatively mature and mobile, with down and eyes open from time of hatching. Once they hatch, they can scamper along the sand with their long legs and feed on insects. Chicks can fly 28 days after hatching.