Quick Answer
No, brown pelicans do not typically nest in trees. Brown pelicans build their nests on the ground, on islands and beaches.
Do Brown Pelicans Build Nests in Trees?
Brown pelicans (Pelecanus occidentalis) are large seabirds that are found in coastal areas of North America and South America. They are known for their large throat pouches that they use to scoop up fish while hunting.
Brown pelicans make nests on the ground, typically on islands with very little or no mammalian predators. They do not build nests in trees like some other bird species do. Here are some key facts about brown pelican nesting habits:
Nesting Locations
– Brown pelicans nest in colonies on islands and beaches that provide protection from land predators. Islands off the Atlantic and Gulf Coasts are prime nesting spots.
– Favorite nesting islands tend to be sandy with very little vegetation. The barren terrain helps provide visibility to spot potential threats.
– Beaches and dredge spoil islands are also used for nesting. The birds prefer sites with some shelter from vegetation like mangroves or shrubs.
– The nests are shallow depressions in the sand or soil that may be lined with feathers, shells or vegetation for comfort.
Nesting Habits
– Brown pelicans do not carry nesting material to their nest sites. Instead, they make simple nests by scraping depressions out of the sand or soil using their beaks and feet.
– The nests are usually within 2-4 feet of each other, often so close that the nests touch. They nest in dense colonies that can include thousands of pairs.
– Both the male and female participate in building the nest. The process takes around 2-4 days.
– The nests are very sparse and exposed. Their island habitats help protect them from land-based predators.
Tree Nesting
– While brown pelicans occasionally use mangroves for nesting, they do not build actual nests in trees. The mangrove branches may provide shelter, but the nests themselves are still on the ground.
– Similarly, they may seek marginal shelter in low shrubs, but their nests remain on the substrate rather than up in the bushes and trees.
– The lack of true tree nesting appears hardwired in this species. The exposed island habitats where brown pelicans evolved simply had no trees suitable for nesting.
Brown Pelican Nesting Materials
Brown pelicans do not line their nests with soft materials the way some birds do. Here are some facts about what brown pelicans use in their nests:
Nest Contents
– The nest is simply a shallow depression in the sand, soil or gravel that may be lined with feathers, shells or debris that happens to be nearby.
– Nest lining materials can include seaweed, bones, sticks, shells, rocks or any nearby items. However, nests frequently lack any lining at all.
– While other birds actively collect soft materials like grass, moss or feathers, brown pelicans do not purposefully bring nest materials. Items in the nest are happenstance.
– The eggs and chicks rest directly on the bare ground, whether it be sand, soil, gravel, or any substrate at the nest site.
No Imported Materials
– Brown pelicans have not been observed to actively collect or import materials to line their nests from afar.
– The lack of imported nest lining means fewer calories expended on nest building. Lining is unnecessary in their warmer coastal habitats.
– Their minimalist nests are likely an evolutionary adaptation to their preferred treeless, low vegetation habitats. Nest materials would have been scarce.
– Exposed island nest sites with little plant matter select for simple nests requiring less work to construct and maintain.
Nesting On The Ground
– Ground nesting is safer in their island habitats lacking mainland predators. Elevated nests are unnecessary.
– Sparse nests allow eggs and chicks to rest on the bare ground, facilitating direct transfer of warmth.
– Nesting right on the ground also provides stability in coastal habitats prone to high winds. Elevated nests could blow away.
– Overall, the lack of imported soft materials reflects the brown pelican’s minimalist, no-frills approach to nest building.
When Do Brown Pelicans Nest?
Brown pelicans nest in the spring and summer months. Here is an overview of brown pelican nesting season timing:
Location | Nesting Season |
---|---|
Atlantic Coast U.S. | February to August |
Gulf Coast U.S. | March to July |
California | December to August |
Mexico | October to June |
Galapagos Islands | Year-round |
Key Details
– Nesting season corresponds with peak fish availability in the region.
– Brown pelicans may have multiple broods in a season, often re-nesting after a failed first attempt.
– El Nino events can negatively impact food supply, leading to delayed breeding or nest abandonment.
– Habitat disturbances often coincide with nesting season, a vulnerable time, highlighting the need for protection.
– Adults arrive early to establish nest sites, up to 2 months before eggs are laid.
– Young fledge 70-80 days after hatching, leaving the nests by early fall in most regions.
Regional Variations
– On the cold water California coast, nesting is delayed until spring upwelling brings nutrient rich waters.
– In the stable Galapagos climate, nesting occurs year-round, peaking between February and June.
– Southern Gulf Coast colonies nest earlier, typical from February to May, taking advantage of early fish availability.
– Farther north, Chesapeake Bay nesting spans May to August, tracking food supplies in colder waters.
How Many Eggs Do Brown Pelicans Lay?
Brown pelicans typically lay 2-3 eggs per clutch. Here are some details on brown pelican egg laying:
Clutch Size | 2-3 eggs |
---|---|
Egg Color | Chalky white |
Egg Size | 63-76 mm long 42-46 mm wide |
Incubation Period | 29-32 days |
Broods per Year | 1-2 broods |
Key Details
– The parents share incubation duties, taking turns sitting on the eggs.
– Both parents feed the chicks after hatching through regurgitation.
– The semi-altricial chicks are born with eyes closed and stay in the nest 2-3 months.
– Re-nesting may occur if the first nest fails, as brown pelicans breed opportunistically based on food availability.
– Egg laying is synchronized within colonies for predator protection. Groups nest within a few days.
Clutch Size Variability
– Average clutch size ranges from 2-3 across populations. Regionally, averages may be 2.2 or 2.8.
– The tropics see smaller clutches, possibly due to year-round food availability requiring fewer young.
– Larger clutches occur where seasonal food spikes enable temporarily higher provisioning.
– Individual pairs may lay 1-4 eggs depending on the parents’ condition and environmental factors like food supply.
What is the Brown Pelican Nesting Process?
Brown pelicans follow a typical nesting pattern from courtship through fledging:
Courtship and Pairing
– Courtship occurs at the breeding colony 2-3 months before nesting season.
– Males select a nest site then court females through calls, gestures, and moving sticks.
– Once paired, couples reinforce bonds through synchronous behaviors like bowing/preening.
Nest Preparation
– Both males and females build the nest by digging a shallow depression in the ground.
– Nest preparation takes 2-4 days of scraping out the bowl-shaped indentation.
– Existing debris like shells may be incorporated into nest sides but no lining is actively collected.
Egg Laying
– Females lay eggs over 1-2 days, usually 2-3 eggs per clutch.
– Eggs are chalky white and elongate, about 3 inches long.
– Laying is synchronized, with most females in a colony initiating clutches within a few days.
Incubation
– Both sexes incubate, trading duties every 1-4 days. Shifts last around 20 hours.
– Incubation takes 29-32 days until eggs begin hatching.
– If eggs are lost, re-nesting may occur, especially early in the season.
Chick Rearing
– Chicks are semi-altricial, born helpless with closed eyes.
– Parents protect chicks and provide food by regurgitating fish.
– Chicks fledge at 10-11 weeks, fly at 11-12 weeks, and leave nest at 11-13 weeks.
Fledging
– Young congregate in pods and are fed by parents another 3-4 weeks after fledging.
– Juveniles disperse from the colonies within about 13-16 weeks after hatching.
Brown Pelican Nesting Behaviors
Brown pelicans engage in various learned and instinctual behaviors around nesting activities:
Synchronously Nesting
– Brown pelicans in a colony synchronize their nesting cycles. Most start clutches within days.
– Synchronous nesting may help facilitate group anti-predator responses. Thousands may act together.
– Simultaneous nesting also concentrates demanding chick-rearing during peak food availability.
Habitual Nest Sites
– Brown pelicans exhibit high nest site fidelity. Pairs return to the same colony and often nest site annually.
– Returning to habitual sites may improve breeding success in a familiar locale.
– Traditional nesting islands become important cultural heritage sites for regional populations.
Nest Attendance
– Parents take turns incubating and guarding the nest, trading duties every 1-4 days.
– Males attend the nest more often earlier in the season, while females invest more later.
– After hatching, one parent stays to protect while the other collects food for the chicks.
Nest Defense
– Brown pelicans are highly defensive of their nests, aggressively driving away potential predators.
– A distraction display, involving broken wing imitation, lures predators from the nest.
– Defensive responses are stronger as eggs near hatching, followed by reduced aggression towards predators.
Re-nesting Attempts
– Brown pelicans frequently re-nest if eggs are lost or fail to hatch, especially early in breeding season.
– They may lay up to 4 clutches if environmental conditions remain favorable.
– Later in the season, they tend to abandon nests rather than initiate new clutches.
Conclusion
In summary, brown pelicans are ground-nesting seabirds that nest in large colonies on coastal islands and beaches. They do not build nests elevated up in trees. Brown pelican nests consist of shallow scrapes in the sand, gravel, or dirt that may incorporate some incidental debris but no imported materials. Nesting occurs in the spring and summer months depending on the region and local food availability. Parents share incubation duties and aggressively defend their nests. Brown pelicans demonstrate a number of specialized nesting behaviors from synchronized breeding to re-nesting when needed. Their unique nesting habits help brown pelicans thrive as coastal seabirds in their island and beach habitats across the Americas.