Do Eared Grebes fly?

Eared Grebes are small waterbirds that are known for their elaborate courtship displays. They are found across North America and Eurasia. One of the most frequently asked questions about Eared Grebes is whether they can fly or not. In this article, we will explore the flying abilities of Eared Grebes and understand why there is some ambiguity around this topic.

To quickly answer the question – Yes, Eared Grebes can fly. However, they only fly for relatively short distances and prefer swimming to flying. Their wings are small relative to their body size which makes them better adapted for swimming and diving rather than extensive flight. Now let’s understand this topic in more detail.

Physical attributes of Eared Grebes related to flight

Eared Grebes have physical features that indicate some flying ability but also set limitations on long flights. Here are some of the key attributes:

Small wingspan

Eared Grebes have a relatively small wingspan of around 53–63 cm or 21-25 inches. This is quite small compared to many other bird species. The wings are also placed posteriorly (towards the rear) on the body. The small span and positioning reduce aerodynamics and lift generation capacity for flight.

Lightweight body

These birds have a slim, lightweight body which reduces aerodynamic drag during flight. Their weight ranges from 220–400 g or 8-14 oz. The lightweight helps compensate somewhat for the small wingspan.

Large feet

Eared Grebes have large feet positioned far back on the body. While this helps propulsion in water, it increases drag during aerial flight. The feet are not streamlined and reduce aerodynamic efficiency in-air.

Pointed wings

Their wings are pointed which improves certain flight characteristics like speed and penetration. But the pointed shape also means that the wings cannot generate as much lift at slow speeds.

Musculature

The breast muscles that power flight are well developed. But they are smaller relative to aquatic bird species that are specialized for extensive flight such as geese. The muscle development indicates capacity for short bursts of flight.

So in summary, the physical attributes of small pointed wings with posterior placement, lightweight body, large hind-feet and medium developed flight muscles indicate adaptations for swimming as well as limited flight ability.

Flight behavior and patterns

The flight patterns of Eared Grebes also give insights into their aerial abilities:

Short flights mainly for migration

Eared Grebes fly only short distances at a time between water bodies. Their longest flights are during migration when they may fly nonstop 100-200 km.

Don’t perch or roost on trees

Unlike many other birds, they spend their resting time floating on water rather than perching or roosting. This shows their adaptation for water over aerial environments.

Shallow, fluttering wing beats

When in flight, they use shallow and rapid wing flaps in a fluttering motion rather than steady soaring or gliding. This rapid flapping is energy-intensive and can only be sustained briefly.

Flight speed around 72 km/h

Their estimated flight speed is only about 72 km/h or 45 mph. This is considered relatively slow compared to specialized flying birds like geese and ducks. The slower speed indicates limitations in sustaining speed and altitude.

Low flight altitudes

Eared Grebes are most often observed flying at less than 100 meters or 330 ft altitude. Some other aquatic species fly at much higher altitudes. This shows their preference for staying low, likely because higher altitudes are more challenging.

So in summary, the flight behaviors corroborate the physical adaptations – that Eared Grebes are capable flyers for short distances but are ecologically adapted for aquatic environments rather than extensive aerial flight.

Differences between Eared Grebe species

There are two subspecies of Eared Grebes that show slight differences in their flight abilities:

Eurasian Eared Grebe (Podiceps nigricollis nigricollis)

This subspecies is native to Europe and Asia. It migrates long distances of thousands of kilometers between breeding and wintering grounds. This indicates better flying capacity for marathon migrations.

American Eared Grebe (Podiceps nigricollis californicus)

This subspecies lives in western North America. It is non-migratory or migrates shorter distances around 500-1,000 km. The more limited movements suggest poorer flight capacity compared to the Eurasian subspecies.

The differences are believed to be mainly behavioral rather than physical. Both subspecies appear to have essentially similar body structures. The Eurasian race undertakes more arduous migrations likely because of severe winter conditions rather than greater flight skills. Overall, both subspecies have broadly similar aerial capabilities.

Comparison to other aquatic bird species

Comparing Eared Grebes to other waterbirds also clarifies their limited flight adaptations:

Loons

Loons are similar-sized diving waterbirds like Eared Grebes but show much stronger flight adaptations. They have longer, broader wings and more powerful flight muscles. Loons migrate extremely long distances of thousands of kilometers.

Cormorants

Double-crested Cormorants are fish-eating diving birds like grebes. But Cormorants often fly 20-30 km between feeding and breeding grounds daily. This is far beyond the regular flight distances of grebes.

Ducks

Dabbling ducks are also frequent fliers. Most ducks fly 50-100 km daily between feeding and roosting areas. Ducks can also sustain continuous flight at speeds over 100 km/h.

Geese

Geese are the ultimate flying waterbirds. They migrate thousands of kilometers between continents in nonstop marathon flights. Geese can fly continuously for 6-12 hours at speeds of 65-80 km/h.

Clearly, Eared Grebes have much more limited flight adaptations compared to other major waterbirds. This contrasts shows their ecological focus on swimming over flight.

Conclusions

To conclude, the evidence clearly shows that Eared Grebes are capable of flight but have adaptations that limit them to relatively short flights:

– Their small wings and large feet are beneficial for swimming but reduce aerial lift and efficiency.

– They use rapid, shallow flapping for brief flights rather than soaring or gliding.

– Their flight speeds and distances are very limited compared to specialized flying birds.

– They spend most of their time in water rather than air and do not use aerial perching.

– Their longest flights are during migration but these are still short compared to excellent fliers like geese.

So in essence, flight for Eared Grebes is a means of moving between bodies of water rather than a primary ecological adaptation. Their physical attributes and behaviors reflect adaptations for aquatic diving and swimming as their main survival strategy.

This table summarizes the comparatively slow flight speed and limited daily flight distances of Eared Grebes relative to other waterbirds