The snowy plover is a small shorebird that nests along the coasts of North America, parts of South America, and the Caribbean islands. They have unique nesting behaviors and habitat requirements that aim to protect their eggs and chicks from predators and high tides.
When is the snowy plover breeding season?
The snowy plover breeding season varies across their range, but generally occurs between March and September. In warmer southern regions like Florida and the Gulf Coast, breeding starts earlier from February to July. In cooler northern areas along the Pacific Coast, nesting is later from April to September.
Snowy plovers often nest during the spring and summer months when temperatures are warmer and food sources like insects and crustaceans are more abundant along shorelines. The timing ensures chicks can hatch during peak conditions to improve survival.
Where do snowy plovers nest?
Snowy plovers nest right on open sandy beaches and flats near water. They prefer wide open spaces with sparse vegetation and plenty of sand or small pebbles. Typical nesting habitat includes:
- Ocean beaches along the coast
- Beach strands along lakes, rivers, and alkali flats
- Sand or gravel bars
- Levees and dikes
- Coastal inlets and estuaries
Nests are shallow scrapes or depressions in the sand lined with small pebbles, shell fragments, plant debris, or other objects. The small depressions help camouflage the eggs and protect them from wind and rain. Snowy plovers avoid dense vegetation that can conceal predators.
How do snowy plovers build their nests?
Snowy plovers exhibit simple nest building behavior, relying more on camouflage to protect their nests. To build a nest scrape, the male will use his feet and wings to rake an area of sand and create a shallow depression. He may line the inside with bits of shell, pebbles, plant debris, or other objects.
Once the scrape is ready, the female will inspect it. She may add a few more lining materials or make some adjustments. When satisfied, she will lay her clutch of eggs in the nest. The eggs blend in remarkably with the surrounding sand or pebbles.
Some key facts about snowy plover nest building include:
- Nests are simple scrapes in open sand, usually 2 to 6 inches across
- They add pebbles, shells, debris for camouflage and insulation
- No substantial nest structure is built
- Nests rely on camouflage in open sandy areas away from vegetation
- Nest cups are often lined towards completion by the female
How many eggs do snowy plovers lay?
A typical snowy plover clutch size is 3 eggs, but can range from 2 to 6 eggs. Only the female lays the eggs, at a rate of about 1 egg every other day. The eggs are oval shaped with darker speckling to help camouflage them against the nest background.
Some key facts about snowy plover clutches:
- Clutch size ranges from 2 to 6 eggs
- Average clutch size is 3 eggs
- Eggs are laid approximately every other day
- Only the female lays the eggs
- Eggs are speckled and well-camouflaged
Larger clutches may improve chances at least some eggs will survive, but the parents may struggle to adequately incubate and care for all the hatchlings. Snowy plovers are vulnerable to nest predation which influences clutch size over time.
How do snowy plovers incubate their eggs?
Snowy plovers use an incubation strategy called uniparental incubation where one parent, usually the male, is left to incubate the nest while the female deserts the nest. The male parent sits on the nest and rotates the eggs frequently. Incubation lasts about 25-33 days until the precocial young hatch.
Some key facts about snowy plover incubation include:
- Primarily the male incubates while female deserts the nest
- Eggs are rotated and repositioned in the nest frequently
- Incubation lasts approximately 25-33 days
- Eggs hatch asynchronously over a period of days
- Young are precocial and mobile soon after hatching
Uniparental incubation behavior is believed to improve survival. If a parent is predated, the other may still be alive to re-nest. Frequent egg turning also may prevent embryo death and improve hatching success.
How do snowy plover chicks grow and fledge?
Snowy plover chicks are precocial, meaning they are mobile with eyes open soon after hatching. They leave the nest within hours and are brooded by parents away from the nest site. Chicks feed themselves by foraging on small invertebrates along the beach.
Growth is rapid and chicks usually fledge around 25-35 days after hatching. Parents do not feed the chicks directly. Their role is to protect, brood, and lead them to good foraging sites. Mortality in the first few weeks is high due to predators and exposure.
Key facts about snowy plover chick development:
- Chicks hatch with open eyes and downy cryptic plumage
- Leave nest within a few hours after hatching
- Feed themselves by foraging along the shoreline
- Parents brood and protect mobile chicks
- Fledge around 25-35 days after hatching
- Mortality is highest in the first 2 weeks
How many broods do snowy plovers have in a season?
Snowy plovers are multibrooded and often raise 2-3 broods per breeding season. Their short 25-35 day fledging period allows time for multiple nesting attempts in a single season. It’s an important adaptation to high rates of nest failure and chick mortality.
Some key facts about snowy plover breeding in a season:
- Frequently raise 2-3 broods per season
- Short 25-35 day fledging period enables multiple broods
- Early season broods allow more renesting attempts
- Max recorded in one season is 6 broods
- Multibrooded strategy compensates for high failure rates
Raising multiple broods maximizes reproductive success. However, as the breeding season progresses, reproductive success declines. Later nests are less likely to succeed than earlier attempts.
What behaviors help snowy plovers survive?
Snowy plovers exhibit a variety of behavioral adaptations that aim to maximize egg and chick survival in their open, precarious beach habitat. These include:
- Camouflage – Eggs and chicks are speckled and blend in with their surroundings to avoid detection.
- Nest site selection – Open areas away from vegetation allow detection of predators.
- Nest scrapes – Shallow depressions help shelter eggs from sun, wind, rain, and cold.
- Uniparental incubation – If one parent dies the other may still successfully incubate eggs.
- Egg turning – Frequent turning by parents prevents embryo death.
- Precocial young – Mobile chicks can escape threats and self-feed soon after hatching.
- Brood mobility – Parents brood and move chicks frequently to new sites.
- Renesting – Will readily re-lay eggs to replace lost clutches, sometimes up to 6 broods.
- Flock defense – May mob predators in a group to drive them away from nests or chicks.
These adaptations compensate for the dangerous open beach habitat. However, snowy plover populations still face high egg and chick mortality from predation, trampling, weather, and human disturbance.
What are the main threats and challenges to snowy plover nesting success?
Snowy plovers face many threats during the breeding season that negatively impact nest and chick survival. Major challenges include:
- Predators – Animals like foxes, coyotes, raccoons, gulls, and crows readily eat eggs and chicks.
- Habitat loss – Human development reduces available undisturbed nesting habitat.
- Human disturbance – Beach recreation, vehicles, pollution, and fishing impact birds.
- Weather – Storms, high tides, heat and cold stress can kill chicks and flood nests.
- Trampling – Eggs are crushed by people, pets, vehicles, or livestock.
- Climate change – Sea level rise and increased storms impact nesting areas.
These compounding threats have led to population declines and recovery efforts. Many snowy plover breeding sites now have strict protections and monitoring programs to help the species recover.
How can we help protect snowy plover nesting?
There are various conservation actions people can take to help support snowy plover recovery during the breeding season. Some public involvement ideas include:
- Respect beach closures and nesting areas.
- Keep dogs and vehicles off beaches where plovers nest.
- Clean up trash that can entangle chicks.
- Use less plastic and reduce pollution.
- Join a plover docent or stewardship program.
- Educate others about giving nesting birds space.
- Support parks and wildlife agencies.
- Reduce your carbon footprint to slow climate change.
Following rules, getting involved in local conservation, and inspiring others to be mindful of shorebirds will improve snowy plover nesting success over time. Our actions can ensure future generations get to experience these special birds on our beaches.
Conclusion
In summary, snowy plovers have unique nesting behaviors and requirements well-adapted to their open beach habitat. Their precocial young, camouflage, and renesting abilities all aim to maximize reproductive success despite the many threats they face. While populations are still reduced, increased conservation focus in recent decades offers hope. We can all help snowy plovers thrive into the future by respecting protected areas and promoting stewardship opportunities that support their fragile beach nesting habitat.
