Horned Grebe

Summary

Known for its dramatic feathery “horns,” the horned grebe belongs to the grebe family Podicipedidae. Also known as the Slavonian grebe, the horned grebe maintains two distinct populations in North America and Eurasia. Like other grebes, they nest in freshwater marshes, lakes, and ponds and overwinter in marine estuaries or bays. Horned grebe populations have fallen dramatically over the last three decades, leading to calls for stronger regulations and conservation efforts to protect the remaining birds. 

5 Horned Grebe Amazing Facts

• A horned grebe has full control of the feathery “horns” on the sides of its head and can raise or lower them at will.  
• The chicks often ride on their parents’ backs, particularly when startled or sleeping. 
• Sleeping horned grebes tuck one foot up and use the other to navigate in the water. This causes them to lean to one side. 
• The oldest wild horned grebe on record was approximately 5 years and 11 months old.   
• Like other grebes, horned grebes often eat their own feathers to help filter out fish bones and other indigestible material. You can often see adults feeding feathers to their young. 

Where to Find Horned Grebes

You can find them throughout North America and Eurasia. The North American population breeds primarily in central and western Canada, as well as south-central Alaska and part of the northern United States from Washington to Minnesota, although a few birds also breed on the Magdalen Islands of Quebec. Some then migrate to their winter range along the western shores of the United States from Alaska to California. Meanwhile, others overwinter along the eastern shore from Nova Scotia to the Gulf of Mexico. 

The breeding range of the Eurasian population extends from southeastern Norway to western China. That said, a small number of horned grebes also breed in scattered parts of Iceland, Scotland, Greenland, and northwestern Norway. Eurasian horned grebes often overwinter along the coasts of Norway, the United Kingdom, and Scotland, as well as around the Mediterranean and the Caspian Sea. However, populations situated further east often opt to overwinter along the coasts of Japan, China, or Korea. 

They breed in temperate freshwater marshes, lakes, and ponds. They prefer areas with plenty of emergent vegetation, such as cattails, rushes, and sedges. These plants provide the grebes with suitable material to build and anchor their nests as well as cover them from predators. After the breeding season ends, they migrate to brackish or saltwater bays, estuaries, or inland lakes to feed and ride out the winter.  

Horned Grebe Scientific Name

They are a member of the grebe family Podicipedidae. Its genus name Podiceps comes from the Latin words podicis, meaning “rear-end,” and ped, meaning “foot.” Taken together, the name translates roughly as “feet at the buttocks.” Meanwhile, the species name auritus comes from Latin words auris, meaning “ears,” and the declension -itus, and translates to “having ears” or “having the form of an ear.” This name refers to the yellowish feathers on the side of its head, which go by the name horns. These horns also serve as the source of the horned grebe’s common name. Scientists separate North American and Eurasian horned grebes into separate subspecies. The Eurasian stock goes by the name P. a. auritus, and receives the nominative name. Meanwhile, the North American subspecies is named P. a. Cornutus.

In some regions, they also goes by the name Slavonian grebe. The name comes from a region in the eastern part of Croatia and likely serves as a reference to the geographic range of the subspecies. 

Horned Grebe Size, Appearance, and Behavior 

The horned grebe features two different coats depending on the time of year. During the breeding season, it sports striking red and black plumage and its characteristic yellowish “horns.” Outside of the breeding season, the plumage changes to white and black, and the horns disappear. The back and crown appear black regardless of the season, while the neck, chest, and cheeks vary between red and white. Generally speaking, Eurasian horned grebes appear slightly darker than North American horned grebes. Juveniles look similar to adults, except their back looks black-brown, and their white feathers appear duller. 

They possess a long neck and flat forehead. The eyes are bright red, and the beak is straight and ends in a white-tipped point. On average, horned grebes measure 12.2 to 14.9 inches long and weigh between 10.5 and 20.1 ounces. The wingspan can vary from 21.6 to 29.1 inches. 

Unlike some of their more quiet relatives, they are known for making a lot of noise. The chicks emit trilling peeping noises similar to those of domestic chicks. Meanwhile, the adults make numerous sounds during their elaborate breeding rituals and mating. Like all grebes, they spend most of their lives on the water and struggle to move around on land. They sleep with one leg tucked up while the other helps them to navigate through the water. This causes one side to appear higher than the other as they inevitably lean to one side. 

Horned Grebe Evolution and History

They are a waterbird in the family Podicipedidae. At some point during its history, the Eurasian stock split from the North American stock. This split explains the morphological differences between the two and also the reason why scientists separate them into distinct subspecies. Although horned grebes closely resemble ducks, their closest living relative is actually the flamingo. Meanwhile, it shares a number of common features with related species, including the black-necked grebe, red-necked grebe, and great crested grebe. Grebe fossil records go back millions of years to the Late Oligocene or Early Miocene, sometime 23 to 25 million years ago. While some evidence suggests that the first grebes emerged even earlier, at this time not enough evidence exists to support this theory. 

Horned Grebe Diet

This bird is an opportunistic carnivore whose diet varies according to the seasons. They excel both at diving under the water to catch prey and also at hunting for aquatic or airborne prey near the surface. During the summer, they prefer to eat aquatic and airborne arthropods. Meanwhile, they eat a larger quantity of small fish and crustaceans during the winter. Horned grebes often feed either alone or in small groups containing up to 5 birds. They typically swallow their prey whole, which can lead to digestive issues. To resolve this, horned grebes begin eating their own feathers at a young age. The feathers form a cushion between the stomach and intestines that filters out bones and other indigestible material. This aids in the eventual regurgitation of this material as pellets. 

Horned Grebe Predators and Threats

Predators primarily target juveniles due to their inability to defend themselves adequately. Their main predators include eagles, falcons, owls, and minks. Chicks must also watch out for predatory fish such as pike or bass. The biggest threat to horned grebes comes from human activities. Fishing nets, pesticides, and oil spills can all directly harm horned grebes. Additionally, the draining of wetlands and grasslands denies horned grebes with suitable nesting and feeding grounds. Moreover, using motorboats, explosions, or forestry equipment near nesting sites can cause horned grebes to abandon their nests. This leaves the eggs and chicks vulnerable to predators and decreases their chances of survival. 

Horned Grebe Reproduction, Young and Molting

During the summer, they collect in colonies of up to 40 birds either alone or in pairs. Mature horned grebes engage in elaborate mating ceremonies consisting of four parts, including the discovery, weed, head-shaking, and triumph ceremonies. First, they hold themselves upright and make advertising calls with their “horns” erect. Next, they dance around one another to determine if they are compatible mates. Once they’ve determined sex compatibility, next comes the weed ceremony, wherein females and males exchange “gifts” of weeds pulled from the water in unison. This process may happen multiple times until the ceremony wraps up with the bonded pair shaking their heads. 

Horned grebes mate on top of platform nests built of vegetation. Both parties contribute to building the nest and typically anchor it to nearby vegetation to secure it against waves or inclement weather. Females lay between 3 and 8 whitish-blue eggs. The males and females take turns sitting on the eggs, which take between 22 and 25 days to incubate. Until the eggs hatch, the parents will aggressively defend their nest from predators but can easily get scared off by human activity. 

Although they can swim and dive within a few days of birth, chicks prefer to stay close to their parents for several weeks. They often ride on their parents’ backs and may even stay fixed when their parents dive to hunt. At around 2 months old horned grebes learn to fly, and they sexually mature at around 2 years old. While horned grebes can likely live up to 10 years, most don’t live that long.

Horned Grebe Population

As of 2016, the numbers in North America measured between 200,000 and 500,000, while the population in Eurasia measured between 12,900 and 18,500. Over the past few decades, the total horned grebe population worldwide fell by nearly 30 percent. North America witnessed the greatest declines, as the declines there account for nearly 79% of the decline during the past three decades. Researchers primarily blame population declines on human activities such as deforestation, activity around breeding sites, and the introduction of species that compete for food with horned grebes. Horned grebes will abandon their nests if disturbed, which leaves the eggs and chicks vulnerable to predation. Habitat loss, such as draining wetlands and grasslands, puts even more pressure on horned grebes. Due to these threats and declines, the IUCN lists the horned grebe as a Vulnerable species. 

Related Animals

• Duck
• Flamingo
• Grebe

1. , Available here: http://datazone.birdlife.org/species/factsheet/horned-grebe-podiceps-auritus/text
2. , Available here: https://www.projectnoah.org/spottings/957276133