Walking with wildfowl

Why the words ‘black swan’ and ‘mating season’ give York grads weak knees

There’s a 99.9% chance that York grads will scramble up the nearest tree if they hear the words ‘black swan’ or ‘mating season’. For our own peace of mind, we asked Environmental Science student Ian Kilburn to delve deeper into the array of wildfowl quacking and squawking around our university’s two lakes.


We’ll get these out of the way first. There are four species of ducks on the campus lakes: the common mallard, the tufted duckpochards and the ruddy shelduck.

The first three are very common on the lakes, but there are only a few of the ruddy shelducks which were given as a gift to the university.

A ruddy shelduck (Image: Adrian Pingstone)
A ruddy shelduck (Image: Adrian Pingstone)


The university is home to the snow goose, the Canada goose and the barnacle goose. The snow goose changes its plumage coloration from grey to white due to the colder climate of winter. 

The barnacle goose is the most common on the campus and is also grey. The Canada goose however is more distinctive as it has a grey or brown body with black head. It’s also the noisiest of all the geese species on campus.

Barnacle goose (Image: Linnea Samila)
Barnacle goose (Image: Linnea Samila)

As many alumni will be aware, these birds are well known to be aggressive when provoked.


Distinctive black birds with white bills and relatively long spindly legs. 

Black Swans

The campus is home to two black swans which are a common sight on Heslington West.

Black swan (Image:  fir0002)
Black swan (Image: fir0002)


These are less frequent than the ducks on the campus lakes, but just as noticeable due to their coloration and sharp pointed beaks.

Horned grebe (Image: Connor Mah)
Horned grebe (Image: Connor Mah)

Grey Herons

These larger predatory birds are often seen standing in the water catching fish with their long spear-like beaks.

Grey heron (Image: Gidzy)
Grey heron (Image: Gidzy)

Garden Birds


The common crow is an everyday seen large black bird. It has a distinctive call and can be found in any part of the country as it is very adaptable to various environments.


Again, another bird that is seen every day, it is also very versatile and thrives in the countryside and urban centers alike.

Great Tits

These are the largest of the Tit family, and is the most common in the UK. They are common to most gardens and woodland areas, and forage on the ground as well as in the canopies of trees.

A pair of Great tits (Image: Shirley Clarke)
A pair of Great Tits (Image: Shirley Clarke)


Despite common misconception, these small birds are not black at all, but in fact have a dark green and purple sheen to their plumage.

Sand Martins

These are closely related to swallows, and are the smallest species of their family. They nest in the sand banks of rivers.

Sand martin (Image: Ken Billington)
Sand martin (Image: Ken Billington) 

The introduction of these birds was one of the reasons for creating the sand banks on the side of the lake at the Heslington East campus.

Yellow Hammer

The males of the species with a bright yellow head and chest these birds are very striking to the eye, and easy to pick out. But they’re also in trouble, now red listed due to dramatic population decreases.

A male yellow hammer (Image: Alan Vernon)
A male yellow hammer (Image: Alan Vernon)

Mistle thrush

This is a large and powerful thrush, which has brown plumage, with a white chest with black spots on it. It’s often seen just above the ground as it flies, seeming as if it is bounding across the ground.

Mistle thrush (Image: Gerard Blokhuis)
Mistle thrush (Image: Gerard Blokhuis)


The University is home to two species of Finches, the goldfinch and the bullfinch. The goldfinch is recognizable because of its bright yellow plumage, while the bullfinch is grey and black with a reddish/orange/pinkish breast.

European goldfinch (Image: Dibyendu Ash)
European goldfinch (Image: Dibyendu Ash)

Tree Sparrow

These are a smaller version of the more well-known house sparrow, but they are more common in woodland areas than the urban areas that their relatives thrive in.

Tree sparrow (Image: Shyamal)
Tree sparrow (Image: Shyamal)


The redwing is a common winter bird, and is the smallest thrush native to the UK. Even though it is seen as native, these birds do not breed in this country, and only a few pairs will breed in the UK.

Redwing (Image: Andreas Trepte)
Redwing (Image: Andreas Trepte)

Barn Owls

One of the most beautiful birds throughout the UK. It is normally the apex predator of its surrounding area, and is silent when in flight.

Barn owl: (Image:Tony Hisgett)
Barn owl: (Image: Tony Hisgett)

The numbers of the barn owl population have decreased ever since the 20th century. This is believed to be due to increased usage of pesticides, which would then be passed up the food chain, causing detrimental health issues.