The Common Goldeneye (Bucephala clangula) is a medium-sized diving duck that breeds across the northern parts of Eurasia and North America. In North America it is usually called just “Goldeneye”. As their name suggests, Common Goldeneyes are distinguished by their golden-yellow eyes. They exhibit sexual dimorphism, meaning that males and females have different plumage. Males have a greenish-black head with a circular white patch between the eye and bill, a dark back, and a white underside. Females have a chocolate brown head and a grayish brown body. Both sexes have grey wings with black wingtips.
Common Goldeneyes are medium-sized ducks, measuring 41–51 cm (16–20 in) in length with a 71–80 cm (28–31 in) wingspan. They weigh approximately 0.7–1.4 kg (1.5–3.1 lb). As we will explore throughout this article, male Common Goldeneyes tend to be larger than females. But first, let’s look at some quick facts about the Common Goldeneye’s size:
Quick Facts
| Length | 41-51 cm (16-20 in) |
| Wingspan | 71-80 cm (28-31 in) |
| Weight | 0.7-1.4 kg (1.5-3.1 lb) |
As a medium-sized duck, the Common Goldeneye is smaller than larger diving ducks like Canvasbacks but larger than small dabbling ducks like Green-winged Teal. Next, we’ll break down the size differences between male and female Common Goldeneyes.
Size Differences Between Males and Females
As mentioned earlier, Common Goldeneyes display sexual dimorphism in their size. On average, males tend to be larger than females:
Male Common Goldeneye
– Length: 46-51 cm (18-20 in)
– Wingspan: 76-80 cm (30-31 in)
– Weight: 1.0-1.4 kg (2.2-3.1 lb)
Female Common Goldeneye
– Length: 41-46 cm (16-18 in)
– Wingspan: 71-75 cm (28-29.5 in)
– Weight: 0.7-1.0 kg (1.5-2.2 lb)
| Measurement | Male | Female |
|---|---|---|
| Length | 46-51 cm (18-20 in) | 41-46 cm (16-18 in) |
| Wingspan | 76-80 cm (30-31 in) | 71-75 cm (28-29.5 in) |
| Weight | 1.0-1.4 kg (2.2-3.1 lb) | 0.7-1.0 kg (1.5-2.2 lb) |
As the table illustrates, male Common Goldeneyes average 5-10% longer and heavier than females. Their wingspans are also 5-7% greater. These size differences are common among duck species and allow males and females to utilize somewhat different feeding niches. Next, we’ll look at how the Common Goldeneye’s size compares to other diving ducks.
Comparison to Other Diving Ducks
The Common Goldeneye is considered a medium-sized diving duck. Here is how it compares in size to some other diving duck species:
Smaller than:
– Canvasback (Aythya valisineria) – Length: 48-58 cm (19-23 in)
– Redhead (Aythya americana) – Length: 44-57 cm (17-22 in)
– Greater Scaup (Aythya marila) – Length: 43-51 cm (17-20 in)
Larger than:
– Bufflehead (Bucephala albeola) – Length: 30-38 cm (12-15 in)
– Long-tailed Duck (Clangula hyemalis) – Length: 34-43 cm (13-17 in)
– Ruddy Duck (Oxyura jamaicensis) – Length: 34-43 cm (13-17 in)
| Species | Length |
|---|---|
| Canvasback | 48-58 cm (19-23 in) |
| Redhead | 44-57 cm (17-22 in) |
| Greater Scaup | 43-51 cm (17-20 in) |
| Common Goldeneye | 41-51 cm (16-20 in) |
| Bufflehead | 30-38 cm (12-15 in) |
| Long-tailed Duck | 34-43 cm (13-17 in) |
| Ruddy Duck | 34-43 cm (13-17 in) |
The Common Goldeneye is moderate in size compared to other diving ducks – larger than the smallest species but smaller than the largest. Its medium size allows it to be more agile underwater than very large ducks when pursuing prey. Next, we’ll look at how the Common Goldeneye’s size relates to its diving ability.
Size and Diving Ability
The Common Goldeneye’s medium size gives it some advantages for diving. Smaller ducks like Buffleheads can dive deeper but are limited in the size of prey they can consume. Larger ducks like Canvasbacks can take larger prey but are less agile swimmers.
Some key facts about the Common Goldeneye’s diving ability:
– Can dive to depths up to 60 feet (18 m) to forage
– Powerful wings allow them to dive explosively and pursue prey underwater
– Compact size makes them more maneuverable than larger diving ducks
Diving Advantages Due to Size
– Moderate body size requires less oxygen and allows longer dives than very large ducks
– Large enough to take wide variety of prey items unlike smaller diving ducks
– Compact wings provide thrust for submerged chases after prey
– Shorter legs produce less drag than long-legged diving ducks
The Common Goldeneye’s medium size gives it a good balance as an agile swimmer and diver. It cannot dive quite as deep as tiny stiff-tailed ducks, but its diving abilities rival much larger ducks. Next, we’ll discuss the Common Goldeneye’s size in flight.
Size and Flight Ability
The Common Goldeneye has moderately large wings relative to its body size. This gives it reasonably good flight capabilities despite its compact shape.
Some key facts about the Common Goldeneye’s flight ability:
– Powerful, rapid wingbeats interspersed with short glides
– Maneuverable in flight and capable of tight turns
– Medium to fast flight speeds recorded of 40-60 mph (64-97 km/h)
Flight Advantages Due to Size
– Compact body reduces drag in flight
– Medium wings provide good balance of power and agility
– Able to take off rapidly from water’s surface due to medium size and wing area
– Short, thick neck reduces head profile drag in flight
The Common Goldeneye’s medium wings and body give it strong flight capabilities. It is able to migrate long distances each year across North America. Next, we’ll look at how the male Common Goldeneye’s size relates to courtship displays.
Size and Courtship Displays
During courtship, male Common Goldeneyes perform various displays for females, including head-throwing and head-pumping. Their size plays a role in these displays in some interesting ways:
Head-Throwing Display
– Males snap head and neck backwards until head touches back
– Shows off white circular patch contrasting against dark head
– Compact size allows male to throw head back farther
Head-Pumping Display
– Males pump head up and down rapidly without moving body
– Performed both swimming and standing on the water
– Short, thick neck allows for greater head motion
| Display | Size Advantage |
|---|---|
| Head-Throwing | Compact size allows farther head throw |
| Head-Pumping | Short, thick neck allows greater head motion |
The male Common Goldeneye’s stocky shape and short neck allow for exaggerated motions during courtship displays. These help catch the female’s attention. Next, we’ll discuss the meaning of the species name “clangula”.
The Meaning of “Clangula”
The Common Goldeneye’s scientific name is Bucephala clangula. The genus name Bucephala comes from the Greek words boukephalos meaning “bullheaded”. This refers to the bulbous shape of the head.
The species name clangula is derived from the Latin word clangere meaning “to resound” or “to clang”. This likely refers to the male’s striking courtship call.
Some key facts about the Common Goldeneye’s call:
– Males give a high-pitched ringing or clanging call
– Call is rendered as “kling-kling-kling”
– Used to attract females during courtship season
– Call carries well over water
The onomatopoeic Latin name clangula captures the metallic, ringing quality of the male Common Goldeneye’s call. The name provides an auditory description identifying the species.
Other Common Goldeneye Vocalizations
While clangula refers specifically to the male’s courtship call, Common Goldeneyes produce other vocalizations as well:
– Females give a coarse croaking call
– Both sexes produce low quacks
So in summary, the species name clangula references a distinctive sound produced by the male Common Goldeneye. Next, we’ll look at some reasons why the Common Goldeneye is often simply called “Goldeneye” in North America.
Why Often Called Just “Goldeneye” in North America
Though its full scientific name is Bucephala clangula, in North America the Common Goldeneye is frequently referred to simply as the “Goldeneye”. There are a few reasons for this shortened name:
Only Goldeneye Species in Most of Range
– The only goldeneye species found across most of North America
– Barrow’s Goldeneye limited to western North America
– No need to distinguish “common” vs. other goldeneyes
Simple, Descriptive Name
– Highlights distinctive yellow eye coloration
– Calls attention to most noticeable feature
– Easy to say and remember
Parallels Other Duck Names
– Following convention of other ducks like Bufflehead, Ruddy Duck
– Many ducks referred to simply by key descriptor
– Avoids overly scientific or lengthy names
| Species | Simple Descriptive Name |
|---|---|
| Bucephala clangula | Goldeneye |
| Bucephala albeola | Bufflehead |
| Oxyura jamaicensis | Ruddy Duck |
So in summary, using the simple descriptor “Goldeneye” follows conventions for other North American duck names. It highlights the most recognizable feature of this common duck species.
Conclusion
In conclusion, the Common Goldeneye is a medium-sized diving duck distinguished by its golden-yellow eyes. Males average larger than females in length, wingspan, and weight. The Common Goldeneye’s compact size provides advantages in diving, flight, and courtship displays. Its scientific species name clangula refers to the male’s ringing courtship call. And in North America it is frequently called simply the “Goldeneye” due to lack of other goldeneye species over most of its range and for simplicity. Understanding details about the Common Goldeneye’s size helps appreciate how its physical traits relate to its behaviors and ecology.
