Black-Necked Grebe Diet and Size: Feeding Habits, Predators, and Measurements

Black-Necked Grebes breed in vegetated areas of freshwater lakes and other large bodies of water across Europe, Asia, Africa, North America and South America. Once the breeding season is over, they migrate to salt water lakes to moult.

Their migratory journeys can be as far as 3,700 miles (6,000 km) and they can spend as long as 7 to 9 months flightless. These birds are skilled divers and can dive around 2.5 metres deep underwater in search of food.

In this article we’ll take a closer look at the feeding habits, breeding habits as well as the size and weight of these fascinating birds and much more besides. Keep reading to find out more.

The Dietary Habits Of The Black-Necked Grebe

The dietary habits of Black-necked Grebes vary depending on the season and the habitat they occupy, but they primarily feed on aquatic plants and animals.

What Does A Black-Necked Grebe Eat?

The bulk of the diet of Black-Necked Grebes consists of aquatic invertebrates, including; insects like water beetles, flies, and larvae and small crustaceans like shrimps. 

They also eat small fish, snails and other molluscs and aquatic plants.

What To Feed A Baby Black-Necked Grebe? 

Black-Necked Grebe chicks are fed by their parents, particularly in the early stages after hatching. The parents catch soft bodied prey like insect larvae which is easy for the chicks to digest especially in the first few days after the chicks hatch.

As the chicks grow the parents will feed them small crustaceans like brine shrimp and small fish as well as other small prey once they are older and able to digest more complex foods.

Parents continue to feed their chicks until they are strong enough to forage on their own.

Breeding Habits Of Black-Necked Grebes

The breeding season for Black-Necked Grebes typically begins in late spring (around May to June), though the timing may vary slightly depending on the region. They are highly social birds, often nesting in colonies near or on freshwater lakes and marshes. These colonies can vary in size, and they often prefer areas with dense vegetation, such as reed beds, where they can build floating nests.

Black-necked Grebes have complex and highly synchronised courtship displays that help to strengthen the pair bond. During the early stages of courtship, both the male and female will perform synchronised movements. This includes rising up in the water, turning their heads together, and mirroring each other’s movements.

One of the most distinctive displays is the “weed dance,” where both birds dive and resurface with pieces of aquatic vegetation in their bills. They swim toward each other, present the vegetation, and rise out of the water in a synchronised display.

Another key behaviour involves the pair swimming rapidly side by side across the water’s surface, which reinforces their bond.

Do Black-Necked Grebes Mate For Life?

Black-necked Grebes do not typically mate for life. Instead, they form seasonal pair bonds during each breeding season. Once the breeding season is over, Black-necked Grebes usually separate from their partners. 

When the next breeding season arrives, they often find new mates, although in some cases, a pair may reunite if they return to the same breeding colony. Generally, they do not maintain long-term monogamous relationships beyond a single breeding season.

The Size & Weight Of Black-Necked Grebes

Black-Necked Grebes have no differences in size between males and females. This is also true of their breeding colours and markings making it difficult to differentiate between the sexes.

How Much Does A Black-Necked Grebe Weigh?

The average weight of an adult Black-Necked Grebe can be anywhere between 250 to 350 grams. These birds can double in weight after they have migrated and had their moult.

At which point they cannot fly for some time.

How Big Is A Black-Necked Grebe?

The average length of a Black-Necked Grebe is anywhere between 28 to 34 cm with a wingspan of between 56 to 60 cm. 

They are very similar in size to Moorhens and are relatively small for Grebes.

Are Black-Necked Grebes Under Threat?

Black-necked Grebes are not currently considered globally threatened. Their conservation status is listed as Least Concern by the International Union for Conservation of Nature (IUCN). In the UK they are Amber listed on the UK Birds of Conservation Concern which means they have decreased in numbers significantly or are rare breeders.

Like many species, the Black-Necked Grebe faces localised threats that could impact their numbers in certain areas. From habitat loss, pollution, disturbance from human activities as well as climate change.

What Eats A Black-Necked Grebe?

Black-necked Grebes are vulnerable to a number of predators, especially during the nesting season when their eggs and chicks are at risk. Birds like Herring Gulls and Herons are known to prey on eggs and chicks while Hawks and Falcons prey on adult birds.

Mammals like foxes, mink, raccoons and rats are common predators of eggs and chicks and in some habitats large fish and turtles prey on young chicks.

While adult Black-Necked Grebes are strong swimmers and can dive to escape predators, their eggs and young are much more vulnerable, especially in open nesting areas with little cover.

Where Can I See Black-Necked Grebes In The UK?

In the UK, Black-Necked Grebes can be seen in several locations, particularly during the breeding season and migration periods. While they are relatively rare breeders in the UK, there are certain places where they can often be spotted. 

In spring and summer look in places like;

• Woolston Eyes Nature Reserve (Cheshire)
• Fairburn Ings (Yorkshire)
• St. Aidan’s RSPB Reserve (Yorkshire)
• The Norfolk Broads (Norfolk)

In autumn and winter Black-necked Grebes move to larger, more sheltered bodies of water and coastal areas, where they can be seen in small numbers at places like;

• Langstone Harbour (hampshire)
• Poole Harbour (Dorset)
• Staines Reservoirs (London)
• Loch Ryan (Scotland)

Although they’re not  as widespread in the UK as many other Grebe species, enthusiastic bird watchers can often spot Black-Necked Grebes at the above sites.

SEE ALSO: Ptarmigan Life Cycle: Nest Building To Fledging (and everything in between)

Frequently Asked Questions