Kestrel Diet and Size: Feeding Habits, Predators, and Measurements

Kestrels are a fairly common sight in the UK especially alongside roads in rural areas. They hover high in the sky without moving their heads as they track their prey before swooping in for the kill.

Kestrels are relatively easy to recognise with their pointed wings held out as they hover. Males have a grey head and tail which has a prominent black stripe, they also have reddish-brown backs, creamy-white underparts which are speckled with black markings.

Females are a similar colour but lack the grey head and are more uniformly brown with dark bands on their tail.

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

The Dietary Habits Of The Kestrel

Kestrels are carnivorous birds of prey, and their diet varies depending on where they live, the time of year and the availability of prey. They have a black malar stripe which reduces glare from their eyes making it easier to spot their prey.

What Does A Kestrel Eat?

The Kestrels diet mainly consists of small mammals like; voles which are their primary food source, mice, and shrews. They also eat large insects like crickets, grasshoppers and beetles.

They will also eat small birds especially in areas where small mammals are hard to find. In some areas, they will also hunt for small lizards and frogs.

What To Feed A Baby Kestrel? 

Adult Kestrels bring food back to the nest and usually tear it up into smaller easier to eat pieces for their chicks. They feed the chicks on the same food that they eat only in smaller pieces.

At first, they might start the chicks off on some smaller, softer, easier to digest foods like insects or softer, internal mammal organs. As the chicks grow and develop, the parents will introduce larger, tougher pieces of food to their diet.

Until the chicks reach a stage where they can tear their own food into smaller pieces just like their parents do.

Breeding Habits Of Kestrels

During courtship, male Kestrels perform acrobatic flight displays which include hovering, soaring and diving; he will also give repeated calls to attract a mate. Once a mate is found, the male will present her with small mammals or insects.

This behaviour signifies that he will be a good provider for her and her brood. He will also lead the female to various nesting sites from which she will choose the one she prefers. These nests are not built by Kestrels, but are either abandoned corvid nests or crevices in cliffs or buildings.

Once the eggs are laid, the female takes on most of the incubation duties with the male taking over occasionally to allow her to feed and stretch.

Do Kestrels Mate For Life?

Although they don’t mate for life, Kestrels remain with one partner for the length of the breeding season. The following year, if they both survive, they will often pair up with new mates.

Having said that, if a pair successfully raises young and both individuals survive, they might return to the same nesting area and reunite the following year. This is more likely in areas where both mates are territorial and where nesting sites are limited. 

Kestrels tend to be loyal to their nesting territory rather than to each other.

The Size & Weight Of Kestrels

Kestrels are relatively small for birds of prey, they’re roughly the same size as the Magpie.

How Much Does A Kestrel Weigh?

The average weight of an adult Kestrel is anywhere between 156 to 252 grams, with males being slightly lighter than females.

This sexual dimorphism extends to colouration and markings as well. With females being less colourful than males having a uniform brown plumage with no grey head or tail.

How Big Is A Kestrel?

An adult Kestrel has a length of around 32 to 35 cm with a wingspan of around 71 to 80 cm. This makes the Kestrel slightly shorter in length than a Magpie but with a larger wingspan.

Are Kestrels Under Threat?

Kestrels are not considered to be under threat globally. In fact, the IUCN red list classifies the Kestrel as a species of least concern. This is because they have a wide range and a large, stable global population.

Having said that, Kestrels do face certain problems including; the loss of their habitat due to expansion of agricultural land and urbanisation of many greenbelt areas.

They are also susceptible to pesticides and rodenticides that can accumulate in their food which can cause health and reproductive issues.

Changes in weather patterns caused by climate change can affect the number of prey available or disrupt breeding seasons. 

What Eats A Kestrel?

Due to their speed and agility, Kestrels have few natural predators. However, they can become prey to larger birds of prey like; Peregrine Falcons, Goshawks and Eagle Owls. Foxes, weasels and martens will often target Kestrels if they’re on the ground.

Crows and Ravens will take eggs and chicks from nests and in some areas, snakes will also take eggs and chicks. 

Where Can I See Kestrels In The UK?

Kestrels are widely distributed across the UK and can be seen in a number of different habitats including; open countryside, grassland, farmland, heathland and urban areas.

Some of the best places to see Kestrels include;

• The South Downs (Sussex)
• The White Cliffs of Dover (Kent)
• The Yorkshire Dales
• Bempton Cliffs (Yorkshire)
• Dartmoor (Devon)
• Exmoor (Devon)
• The Peak District (Derbyshire & Staffordshire)
• The Pembrokeshire Coast (Wales)

Other sites that report Kestrels sightings include RSPB sites like Minsmere (Suffolk) and Rutland Water. They can also often be seen in urban environments hunting in parks, along main roads and around derelict buildings.

To spot a kestrel, look for their distinctive hovering behaviour as they scan the ground looking for prey. They tend to be most active during the early mornings and late afternoons.

SEE ALSO: Marsh Harrier Diet and Size: Feeding Habits, Predators, and Measurements

Frequently Asked Questions