Ruddy ducks are small diving ducks that are found in North America. They get their name from the reddish-brown coloring of the males during breeding plumage. Ruddy ducks are a relatively small species of duck, but just how small do they get? Here is an overview of ruddy duck sizes.
Typical Size Ranges for Ruddy Ducks
In general, ruddy ducks are considered a small to medium-sized duck species. Here are some typical size ranges:
- Length: 14-19 inches (35-48 cm)
- Wingspan: 20-24 inches (51-61 cm)
- Weight: 1-1.5 pounds (0.5-0.7 kg)
To put this in perspective, ruddy ducks are about half the size of a mallard duck. Their compact size makes them highly maneuverable during flight and diving.
Male vs. Female Size
There are some size differences between male and female ruddy ducks. The males tend to be slightly larger than the females:
- Male Length: 15-19 inches
- Female Length: 14-17 inches
The males also tend to weigh a bit more than females, with males averaging about 1.1 pounds and females averaging about 0.9 pounds.
The size dimorphism between the sexes is related to the males’ elaborate breeding plumage and courtship displays. The males’ bright colors and aggresive displays during breeding season are energy-intensive, so the slightly larger size provides more energy reserves.
Size Differences Between Subspecies
There are three recognized subspecies of ruddy ducks that show some minor variations in size:
- Nominate Oxyura jamaicensis jamaicensis – The largest subspecies, found in most of North America.
- O. j. andina – A smaller Andean subspecies that inhabits South America.
- O. j. ferruginea – The smallest subspecies found in northern South America.
The nominate subspecies has an average length of 17 inches and weight of 1.1 pounds. The Andean ruddy duck subspecies averages about 15 inches long and 0.9 pounds in weight. The ferrugineous ruddy duck averages 14-15 inches long and 0.7-0.8 pounds in weight.
Changes in Size During the Year
Ruddy duck sizes fluctuate somewhat depending on the time of year:
- Larger in autumn and winter due to fat stores.
- Smaller in spring after fat stores have been depleted.
Ruddy ducks build up fat reserves in the fall to provide energy for winter. Their weight may increase by over 50% compared to spring. This extra fat is crucial for surviving cold temperatures and is later metabolized during spring migration and breeding.
Juvenile Size
Newly hatched ruddy duck chicks start out quite small, but grow rapidly. Here is how their size progresses:
- Length at hatching: 2.2-2.6 in (5.5-6.5 cm)
- Length at 1 week old: 3.9-4.3 in (10-11 cm)
- Length at 3 weeks old: 6.3-7.1 in (16-18 cm)
- Length at 7 weeks old: 12.6-13.8 in (32-35 cm) – Adult size reached
Ruddy duck chicks reach their full adult size when they are around 7 weeks old. Their rapid growth allows them to become adept at diving and foraging not long after hatching.
Factors Affecting Ruddy Duck Size
Several factors can contribute to variability in ruddy duck sizes:
- Sex – As mentioned, males average slightly larger than females.
- Age – Younger birds are typically a bit smaller.
- Subspecies – The three subspecies have minor size differences.
- Nutrition – Better food availability leads to larger size.
- Season – Fat reserves increase weight in autumn/winter.
The combination of these factors explains why some ruddy ducks may be at the smaller or larger ends of the typical size ranges. However, their compact size remains relatively constant compared to other duck species.
Size Relative to Other Duck Species
Ruddy ducks are on the smaller end of the duck size spectrum. Here’s how they compare to some other common duck species:
Species | Length (inches) | Wingspan (inches) | Weight (pounds) |
---|---|---|---|
Ruddy Duck | 14-19 | 20-24 | 1-1.5 |
Mallard | 20-26 | 32-39 | 2-3.5 |
Northern Pintail | 26-32 | 34-38 | 1.5-2.5 |
Canvasback | 19-24 | 30-37 | 2-3.5 |
As you can see, ruddy ducks are quite petite compared to the mid-sized mallard and larger pintail and canvasback. Their tiny build allows them to dive and take flight rapidly.
Advantages of Small Size for Ruddy Ducks
Being relatively small in size provides some advantages for ruddy ducks:
- Enables quick take offs and fast, erratic flight maneuvers.
- Allows for easy diving and swimming underwater.
- Requires less food/energy to survive.
- Provides higher surface area ratio for retaining heat.
- Makes it easier to find sufficient habitat.
Their small stature suits their lifestyle perfectly. Ruddy ducks live in small marshy ponds where the ability to quickly dive, swim, and fly provides excellent mobility. Their energetic courtship displays also take advantage of their agile flight capabilities.
Conclusion
In summary, ruddy ducks are a small-sized duck species. Typical size ranges are 14-19 inches long with a 20-24 inch wingspan, and they weigh 1-1.5 pounds. Males are slightly larger than females on average. Their compact size provides advantages for their diving and foraging lifestyle in marshy ponds and wetlands. Ruddy ducks are less than half the size of larger duck species like mallards. Their diminutive build allows them to thrive in their favored wetland habitat as they duck and dive with speed and agility.