The Killdeer, a common plover found throughout the Americas, is known for its distinctive double black breast bands and loud, two-syllable call. Unlike many shorebirds, the Killdeer thrives in various open habitats far from water, including fields, pastures, and gravel rooftops. Their nesting strategy is unique: they do not build an elaborate structure, choosing instead to lay their eggs directly on the ground. This ground-nesting behavior makes their egg-laying cycle and protection methods compelling to observe.
Laying Season Timing and Frequency
The timing of the Killdeer’s nesting season is heavily influenced by geography, generally beginning in early spring across their range. In the southernmost United States, nesting can commence as early as March, while central Canadian populations may not begin laying eggs until June. The entire egg-laying period can stretch from mid-March to as late as August, though populations in the Caribbean and Mexico occasionally nest year-round.
Killdeer are frequently multi-brooded, meaning they may attempt to raise more than one family in a single season. While northern pairs often produce a single clutch, birds in the southern US commonly raise two successful broods. They may lay up to three clutches if earlier sets fail due to predation or environmental factors. This ability to quickly replace a lost clutch maximizes their reproductive success within the available breeding window.
Characteristics of the Nest and Eggs
The Killdeer nest is remarkably simple, consisting of a shallow depression known as a “scrape” created in the soil or gravel. Parents select open areas with sparse vegetation, allowing them a clear view of approaching threats. After laying begins, the parents may add small debris, such as pebbles or shell fragments, to the scrape for camouflage.
A typical clutch size is four eggs, though pairs may lay between two and six. The eggs are distinctly colored, featuring a buff or pale tan base heavily marked with dark brown and black speckles. This coloration provides excellent camouflage, helping them blend seamlessly with the surrounding gravel and debris.
The eggs also possess a unique pyriform, or pear-like, shape. This geometry causes them to roll in a tight circle if disturbed, keeping the clutch contained within the shallow scrape. Eggs are laid at intervals of 24 to 48 hours, with the female often delaying incubation until the last egg is laid.
Incubation Duration
Following the completion of the clutch, incubation typically lasts between 24 and 28 days. Both the male and female share this responsibility, alternating shifts to ensure the eggs are constantly attended, with the male often incubating throughout the night. The adults also regulate the temperature of the eggs, shading them during heat or warming them during cold snaps.
Upon hatching, the young are precocial, meaning they are covered in downy feathers and can move around almost immediately. The chicks leave the nest scrape shortly after their down dries and begin foraging with their parents.
Protecting the Clutch
Killdeer employ several behavioral strategies to protect their vulnerable, open-air nests from predators. The most famous is the “broken wing display,” a distraction tactic used when a threat approaches the eggs or young. The adult bird moves a short distance away from the nest and drags a wing as if it is severely injured.
This conspicuous show is intended to lure the predator away from the actual nesting site by presenting the adult as an easy meal. Once the threat is far enough away, the adult bird will abruptly “recover” and take flight, leaving the predator far from the hidden clutch.
The parents also use other methods, such as loud alarm calls and a “false brooding” technique where an adult pretends to sit on a nest away from the real eggs. The intensity of these defensive responses increases once the eggs are laid and peaks after the chicks have hatched, demonstrating a clear focus on the survival of their offspring.