Loons are unique waterbirds that nest on freshwater lakes across North America. They build their nests right at the water’s edge, incubating their eggs for around 28 days before they hatch. This exposes the eggs to threats like flooding, predators, and disturbances from humans. As a result, loons have developed some interesting nesting behaviors to protect their eggs, including occasionally leaving the nest for hours or even days at a time. But do loons ever fully abandon their eggs? Let’s take a closer look at loon nesting habits to find out.
Do Both Parents Share Nesting Duties?
Yes, both male and female loons share nesting duties equally. They take turns incubating the eggs, switching off every 24 hours or so. This gives each parent time to leave the nest to feed and preen.
When one adult leaves the nest, the eggs are never left alone. The nest exchange is meticulous, with the returning adult loon arriving before the sitting adult leaves. This coordination ensures there is always an adult loon protecting the eggs from predators and the elements.
Some key facts about loon nesting duties:
- Loons form long-term pair bonds and return to nest at the same site each year.
- Nest is a mound of vegetation built at water’s edge.
- Female lays 1-3 olive/brown colored eggs over several days.
- Parents share incubation duties equally.
- Exchange incubating duties every 24+ hours.
So while loons regularly leave the nest, their eggs are never unattended thanks to the tag-team nesting strategy.
How Long Do Loons Leave the Nest?
When not incubating eggs, loons leave the nest for necessary activities like feeding, preening, bathing, and defending their territory. But they do not stay away for long periods.
Typically, the off-duty parent remains within 200-300 yards of the nest. This allows them to hear warning calls from their mate or investigate any disturbances quickly. Loons rarely leave eggs unattended for more than 2 hours at a time.
Loons may spend longer stretches off the nest later in incubation when eggs are less vulnerable. But during the first 2 weeks, adults are rarely gone from the nest for more than 60-90 minutes.
So while loons regularly leave the nest, absences are brief and strictly for necessities. The incubating adult will always return before the next exchange of duties.
Do Loons Ever Abandon Their Eggs?
Full abandonment of a loon nest is very rare. Loons are incredibly dedicated parents that will go to great lengths to incubate their eggs successfully.
However, there are some scenarios where loons may be forced to abandon a nesting attempt:
- Flooding: Since nests are built at water’s edge, flooding can inundate the nest and eggs. If flooding persists, loons may be forced to abandon a nest.
- Disturbances: Loons are wary of human activity near their nest. Disturbances like boating or shoreline development can cause temporary abandonment. Too much interference may lead to full abandonment.
- Lack of food: If fish populations crash or become unavailable, loons may abandon nests to find food elsewhere.
- Predators: Repeated predator attacks on adults or eggs may force loons to abandon the nesting site.
- Infertile eggs: Loons may abandon eggs that do not hatch after 30+ days of incubation.
However, loons exhibit tremendous nest fidelity. They prefer to reuse the same nest site for many years rather than abandon it altogether. Loons will only desert a nest as a very last resort after all other options are exhausted.
How Do Loons Protect Their Eggs When Leaving the Nest?
Loons have adaptations that help conceal eggs and deter predators while incubating adults are away from the nest:
- Nest location – Built right at water’s edge to deter land predators.
- Nest materials – Vegetation helps camouflage eggs.
- Egg color – Olive/brown eggs blend in with surroundings.
- Egg shape – Pointed oval shape helps eggs roll back into indented nest.
- Distraction displays – Loons may act injured to lure predators away from nest.
Loons also never strays too far and have their mate stand guard nearby when briefly leaving the nest. By taking turns incubating and remaining vigilant, loons keep their eggs safe from harm.
Do Loons Recognize Their Own Eggs?
Researchers believe loons have the ability to recognize their own eggs. When returning to the nest, loons identify their eggs possibly by sight, sound, or scent.
This recognition allows loons to:
- Separate their eggs from intruder eggs laid by territorial loons.
- Remove eggs that fail to hatch after the expected incubation period.
- Identify eggs that may have rolled away from the nest site.
- Locate eggs hiding under nesting material.
Anecdotal evidence also indicates that loons may reject eggs after a nest takeover or attempt to incubate other objects resembling eggs. All of this points to loons having a sense of egg ownership and identity.
How Do Loons Defend Their Eggs from Predators?
Loons rely on a variety of strategies to protect their eggs from different predators:
Against mammals like raccoons, foxes, or mink:
- Nest location offers protection, built completely surrounded by water.
- Vigilant attendance – rarely leave eggs unattended.
- Distraction displays like injury-feigning.
- Territory defense through yodeling calls.
- Physical attacks like diving, pecking, or holding intruder underwater.
Against birds like gulls, crows, ravens:
- Camouflaged nest and eggs avoid aerial detection.
- Hunker down over eggs when other birds approach.
- Distraction displays on the water to draw birds away.
- Aggressively chase away flying intruders.
Thanks to their attentive behavior and fierce protection, loons are often able to successfully defend their nests against various types of egg predators.
Conclusion
In summary, loons have complex nesting behaviors centered around keeping their eggs safe from harm. While loons regularly leave the nest unattended for brief periods, full abandonment of eggs is very rare. Loons have physical and behavioral adaptations to conceal, recognize, and defend their eggs from predators when briefly away from the nest. Their dedication as parents ensures loon eggs have the best chance of survival against the many threats found in the freshwater environments where they nest. So even though loons periodically leave their nest for essential activities, they always ensure their fragile eggs remain protected.
| Loon Egg Facts | Description |
|---|---|
| Clutch Size | 1-3 eggs |
| Egg Color | Olive or brown |
| Incubation Period | 24-28 days |
| Nest Exchange Frequency | Every 24+ hours |
| Maximum Leave Duration | 2 hours (early incubation) |
Why Do Loons Nest So Close to the Water?
Loons build their nests right next to the water for several key reasons:
- Avoids detection – Nests blend into marshy surroundings.
- Deters land predators – Nest isolated on water.
- Close to foraging areas – Easy access to food.
- Chick safety – Easy to shelter chicks in water.
- Escape option – Can dive/swim away from danger.
Despite the risks like flooding and wave damage, a waterside nest offers loons the best protection overall thanks to their superb swimming and diving abilities.
Nest Placement Considerations
Loons do make some careful considerations when choosing an exact nest site:
- Sheltered areas like bays or channels to avoid wind/waves.
- Emergent vegetation for nest building material.
- Adjacent deep water for escape/underwater threats.
- Good sight lines to spot approaching predators.
- Areas of past successful breeding.
By picking sites with the right balance of protection and accessibility, loons ensure their waterside nests provide safety plus quick water access.
How Do Loons Care for Their Chicks After Hatching?
Loons provide intensive parental care for their precocial chicks after hatching:
- Warmth – Chicks sheltered under parents’ feathers until feathers develop.
- Protection – Ferried around on parents’ backs away from danger.
- Food – Parents catch small fish and allow chicks to feed from their throats.
- Swimming Lessons – Chicks taught to swim and dive by parents.
- Territory Education – Parents show chicks territorial boundaries.
This close care continues for at least 10-12 weeks until chicks fledge and can survive independently. The parents’ aquatic abilities and attentive chick-rearing ensure loons successfully transition their vulnerable chicks into juvenile loons.
Key Stages of Loon Chick Development
Loon chicks go through several key growth stages under their parents’ care:
| Stage | Age | Abilities |
|---|---|---|
| Hatchling | 0-2 weeks | Rides on parent’s back for warmth/safety. |
| Downy Chick | 2-5 weeks | Able to swim short distances alone. |
| Fledgling | 6-12 weeks | Capable of diving/sustained flight. |
Thanks to attentive parenting, loon chicks grow quickly from vulnerable hatchlings to increasingly independent fledglings ready to survive on their own.
How Do Loons Find Food When Rearing Chicks?
Loons rely on their speed, stamina, and adaptability as swimmers to catch enough fish to sustain themselves and feed rapidly growing chicks:
- Chase down schools of small fish like minnows, suckers, or alewife near the surface.
- Dive and pursue larger prey underwater up to 60 feet deep.
- Adjust tactics based on availability – can fish both day and night.
- Expand foraging territory up to a square mile around nest site.
- Regurgitate small food items directly to chicks.
Loon parents take turns fishing while the other tends to the chicks. They may also temporarily leave the breeding territory if local food sources become scarce. By hunting cooperatively and widely, loon parents ensure themselves and their chicks get the nourishment needed.
Fishing Adaptations
Loons have special adaptations that aid their fishing success:
- Pointed bill spears and grips slippery fish.
- Streamlined body built for diving.
- Solid bones for underwater pressure.
- Webbed feet propel strong kicks.
- Sharp eyesight to spot prey.
- Special blood vessel countercurrent exchange keeps warm underwater.
This aquatic design allows loons tocatch enough fish to raise their chicks – a key duty of loon parents.
Conclusion
In raising their chicks, loon parents demonstrate a remarkable level of skill, dedication, and coordination. They work as a team to incubate eggs, fend off predators, and transport fragile chicks on their backs. Loon parents serve as fishing tutors and swimming instructors, teaching chicks how to survive independently. This attentive parental care lasting over 10 weeks gives loon chicks the best chance at fledging successfully. So while loons face their own survival challenges living on lakes and large ponds, their adaptations and family commitment ensure their species lives on by carefully nurturing each new generation.
