The red-necked grebe is a small to medium-sized waterbird found in North America and Eurasia. It is classified in the family Podicipedidae, along with other grebes. The red-necked grebe gets its name from the distinctive red coloration on its neck during the breeding season. Though small in stature, the red-necked grebe is an elegant waterbird with some intriguing features when it comes to size. In this article, we’ll explore the typical length, wingspan, and weight of red-necked grebes to get a sense of just how big these birds can grow. Read on to learn more about the dimensions of this fascinating species!
Average Length of Red-Necked Grebes
The red-necked grebe averages around 14-19 inches (35-48 cm) in length. This makes it a relatively small to medium-sized grebe species. Here’s how the red-necked grebe’s length compares to some other grebe species:
| Grebe Species | Average Length |
|---|---|
| Western grebe | 19-24 in (48-61 cm) |
| Clark’s grebe | 14-19 in (36-48 cm) |
| Red-necked grebe | 14-19 in (35-48 cm) |
| Eared grebe | 13-15 in (33-38 cm) |
| Little grebe | 10-13 in (25-33 cm) |
As you can see, the red-necked sits right in the middle, smaller than some of its larger relatives like the western grebe but larger than the little grebe. Overall, the red-necked grebe can be described as a small to medium-sized grebe in terms of length.
Average Wingspan
In addition to body length, wingspan is another useful measurement for determining the size of a bird. The red-necked grebe has a slim, tapering wingspan averaging around 23-29 inches (58-74 cm).
Here’s how the red-necked’s wingspan compares to other grebes:
| Grebe Species | Average Wingspan |
|---|---|
| Western grebe | 26-34 in (66-86 cm) |
| Clark’s grebe | 23-29 in (58-74 cm) |
| Red-necked grebe | 23-29 in (58-74 cm) |
| Eared grebe | 17-20 in (43-51 cm) |
| Little grebe | 13-17 in (33-43 cm) |
Again, the red-necked falls right in the middle, with a wingspan broader than the smallest grebes but more compact compared to the largest species. The wings allow the red-necked grebe to swim and dive efficiently in search of food.
Average Weight
When it comes to weight, the red-necked grebe is exceptionally light thanks to its compact, streamlined body and bone structure adapted for floating and diving. These grebes weigh just 12-20 ounces on average (340 to 567 grams).
Let’s see how the red-necked grebe’s lightweight build stacks up against other grebes:
| Grebe Species | Average Weight |
|---|---|
| Western grebe | 1.5-2.5 lb (0.7-1.1 kg) |
| Clark’s grebe | 12-20 oz (340-567 g) |
| Red-necked grebe | 12-20 oz (340-567 g) |
| Eared grebe | 5-9 oz (142-255 g) |
| Little grebe | 5-10 oz (142-283 g) |
The red-necked is among the lightest grebes, allowing it to float high on the water and accelerate quickly when diving in pursuit of fish. Its light frame contributes to its diminutive size overall.
Size Differences Between Males and Females
When it comes to size, there are some slight differences between male and female red-necked grebes. Males tend to average larger in overall length and weight compared to females.
Typical size differences:
| Measurement | Male | Female |
|---|---|---|
| Length | 17-19 in (43-48 cm) | 15-16 in (38-41 cm) |
| Wingspan | 25-29 in (63-74 cm) | 23-26 in (58-66 cm) |
| Weight | 16-20 oz (454-567 g) | 12-14 oz (340-397 g) |
The differences are relatively modest. But in most grebe species, the males are 5-15% larger than the females on average. The size dimorphism is likely related to subtle differences in the roles and energy demands of males and females when it comes to breeding and raising young.
Changes in Size During the Year
Red-necked grebes go through a complete molt of their feathers twice per year. Interesting, their body size can fluctuate over the course of the year linked to this molting process.
In the late summer and fall, after breeding, red-necked grebes molt into a dull winter plumage. During this time, their weight drops to its lowest point, down to about 10-15 oz (283-425 g). Having less body mass allows them to stay buoyant and limber in the colder water.
In spring, they undergo another molt into bright breeding plumage. At this time, their weight increases back up to 12-20 oz (340-567 g). The higher weight prepares them for the energy demands of breeding season.
So throughout the year, red-necked grebes can shed and regain up to 25% of their body mass depending on the season! Their size and weight flux helps optimize their survival and adaptability through molting cycles.
Maximum Size
The sizes described so far are average for the species. But in some cases, individual red-necked grebes may exceed the normal ranges. What are the maximum lengths and weights documented for this species?
Some key recorded measurements include:
| Measurement | Maximum Recorded |
|---|---|
| Length | 21 in (53 cm) |
| Wingspan | 31 in (79 cm) |
| Weight | 27 oz (765 g) |
So while averages sit around 14-19 in long and 12-20 oz heavy, in exceptional cases red-necked grebes may reach up to 21 in long and weigh over 25 oz! That’s still relatively petite compared to many other waterbird species. But it shows the potential range of sizes within this species.
Size at Hatching and Maturity
Like most bird species, red-necked grebes are smallest at hatching and reach mature adult sizes over a period of rapid growth.
Red-necked grebe chicks hatch from eggs that are about 1.5-2 inches (3.8-5 cm) long. The chicks themselves are tiny and vulnerable at first. Hatchlings weigh just 0.2-0.5 oz (5-14 g) and measure 1-2 inches (2.5-5 cm) in length. But they grow remarkably fast.
Within 3 weeks, the chicks are already 5 times their original size. They’ll reach about two-thirds of adult size by 6-8 weeks old.
Red-necked grebes are sexually mature and reach full adult size after their first year. So most breeding grebes are in their definitive adult plumage by age 1 or 2.
The rapid growth allows these grebes to take to water and learn to forage at a young age. Their bodies must grow to match the demands of an aquatic, diving lifestyle.
Factors That Influence Size
Several factors can contribute to the range of sizes seen among individual red-necked grebes:
– **Age:** Younger grebes are smaller. Adults reach maximal size after the first year.
– **Sex:** As mentioned, males average slightly larger than females.
– **Geography:** Grebes from different parts of the range may vary subtly in size. Northern populations tend to be larger.
– **Season:** Size and weight fluctuate across molting cycles.
– **Food availability:** Grebes may be smaller in areas or years with limited food.
– **Health:** Disease or injury can inhibit growth and condition.
– **Genetics:** Some natural variation in size is based on inherited genes.
So while averages give a general idea of size, many variables result in a range of dimensions among individuals of this species. The most important factors influencing red-necked grebe sizes are age, sex, geography, and seasonal molting cycles.
How Size Helps Survival
The red-necked grebe’s small-to-medium size is integral to its survival strategy and way of life. Here are some key benefits:
– **Flotation:** Compact size and light bones help grebes float high on water. This aids swimming and diving.
– **Flight:** Modest wingspan provides maneuverability for migration and evading aerial predators.
– **Thermoregulation:** Higher surface area to volume ratio helps dissipate heat and maintain temperature.
– **Agility:** Diminutive size increases agility to catch small fish and crustaceans.
– **Access to food:** Smaller size allows grebes to access shallow water refuges and find sheltered nesting locations along margins of lakes and marshes.
– **Energetics:** Lower energy demands compared to large waterbirds.
So in many regards, the red-necked grebe’s petite stature is optimal for its ecological niche and habits. Being smaller confers advantages in hydrodynamics, thermoregulation, energy efficiency, and accessing food resources.
Comparison to Other Bird Species
How does the red-necked grebe measure up against more familiar bird species? Here are some size comparisons:
– Slightly larger than a mourning dove
– Similar in size to an American robin
– Significantly smaller than a typical backyard mallard duck
– Dwarfed by trumpeter swans and other large waterfowl
The red-necked occupies a niche as a mid-sized diving bird. It’s compact and hydrodynamic compared to bulkier ducks and geese. But it’s no match size-wise for mighty swans and other giants of lakes and ponds. Next to familiar land birds, it approximates the size of a plump robin, small hawk, or petite chicken.
Conclusion
In summary, the red-necked grebe is a small-to-medium sized diving water bird, averaging about 14-19 inches (35-48 cm) in length, 23-29 inches (58-74 cm) in wingspan, and 12-20 ounces (340-567 g) in weight. Males tend to be slightly larger than females. They undergo seasonal fluctuations in size linked to molting. While compact, the red-necked grebe’s diminutive stature suits its ecological niche, allowing superb buoyancy, flight agility, and energetics. When comparing relative sizes, they are modestly larger than mourning doves but much smaller than swans. The red-necked’s streamlined profile and lightweight build allow it to thrive as a highly mobile diving bird across northern lakes and marshes.
