Manx BirdLife did not have the opportunity to comment on the article, 'Concern grows over greylag geese numbers' (Isle of Man Examiner, November 16 to 22, 2021) before this article went to press.
We apologise to Isle of Man Examiner if the newspaper’s staff tried but were unable to reach us for comment.
We should like to clarify the situation regarding feral Greylag Geese in the Isle of Man and also to correct the implication that the Point of Ayre gravel pits (now part of the embryonic Manx BirdLife Point of Ayre National Reserve) are the root cause of these concerns.
Greylag Goose in the Isle of Man
The status of Greylag Goose in the Isle of Man is confused. It is both a resident and winter visitor to the Island. The population most likely originates from a mix of domesticated birds gone feral, supplemented by immigrating feral flocks from overseas and a few genuinely wild birds from the Arctic and European Continent.
The Island’s resident breeding population almost certainly derives from domesticated birds that have ‘gone feral’. The source of these birds will have been farm ‘stock’ as well as private and public collections.
Domesticated Greylag Geese are adept at ‘going feral’. Their numbers quickly increase due to the ample supply of suitable breeding and feeding areas and the paucity of natural predators of the full-grown adult geese.
The habits of resident feral geese
In summer, resident feral geese disperse across the Island to breed in many different locations. Areas of grassland or rush are favoured especially where there are seasonal or permanent dubs or nearby rivers or ponds.
In late summer, family parties of resident feral geese collect in communal ‘nurseries’. These provide safety for young birds while they grow their first adult feathers and attain their full size and strength.
Families stay together in large flocks throughout the autumn and winter, feeding by day at favoured locations across the Island. Their choice of feeding site will depend on a combination of availability of food and security from disturbance. In winter, the hundreds of resident feral geese are bolstered by visiting geese from overseas.
At night, most of the flocks join together to roost communally at a few favoured locations. It is these flocks that can be seen in impressive skeins against the backdrop of sunset skies, making their way to roosting sites.
Winter wild geese
During the winter, resident feral geese are joined by a few genuinely wild geese from overseas.
It’s impossible to know how many wild Greylag Geese from the Arctic or European Continent join our resident feral flocks. Wild Greylags are difficult to distinguish from feral birds. But we can identify wild Pink-footed Geese from Iceland and White-fronted Geese from Greenland.
Occasionally, Russian White-fronted and Arctic or Scandinavian Barnacle Geese can be seen on the Island; and this October (2021), the first ever Tundra Bean Goose was discovered on the Island by Manx BirdLife staff.
Why do we have so many resident feral Greylag Geese?
The number of resident feral Greylag Geese is problematic. Damage is caused to agricultural fields and crops; and the presence of so many geese is causes problems for wildlife habitats and native species.
The way land is changed and used by people inadvertently provides ample breeding and feeding habitat for resident feral Greylag Geese. The geese thrive on pasture and arable fields.
Added to this, feral geese are more tolerant of human proximity and activity than are wild geese. As far as we know, no genuinely wild geese breed on the Isle of Man. Wild geese require huge open expanses of natural, highly undisturbed land for nesting. They are people averse. While feral Greylag Geese can seem wary, especially when breeding or with young, they are positively tame compared to genuinely wild geese.
Geese at the Point of Ayre
From among the hundreds of resident feral Greylag Geese in the Isle of Man, just four or five pairs nest at the Point of Ayre on islands in the quarry pits (now part of the Manx BirdLife Point of Ayre National Reserve). Nonetheless, they are a nuisance. They are highly dominant and territorial, ousting native breeding species.
Many conservation projects have struggled with feral geese. Subject to further discussions with the Department of Environment, Manx BirdLife might seek a licence to control these feral breeders on its nature reserve. Shooting has been tried by others in the past, but this proved to be an inefficient method of control and ultimately failed (as others have experienced elsewhere). Pricking unhatched eggs in the nest is perhaps the most effective and humane method of control, though this is challenging in practice.
Causes versus symptoms
The large late summer nursery, and the mass autumnal and winter evening roost, that gather on the former gravel pits at the Point of Ayre is not the root cause of the problem. It is merely a symptom.
Attempts to prevent the birds from roosting on the site will simply push them somewhere else. There are other suitable roosting sites; and while plentiful breeding and feeding areas remain across the Island, the geese will continue to proliferate.
Other feral geese species
It is worth commenting on two more species that are equally adept at ‘going feral’.
The Island hosts a modest but increasing population of some 25 resident feral pairs of Canada Geese. Unless these are brought under control soon, they too will soon prove problematic. Canada Geese are larger and heavier and just as aggressively territorial as Greylag Geese when nesting.
There are also eight Barnacle Geese at large. It is presumed that these originate from captivity, though recent research has shown that this species can occasionally establish new resident populations borne of wild birds that decide not to migrate back to their Icelandic, Scandinavian and Arctic breeding grounds. Nonetheless, a precautionary approach might be advisable as the chances of a wild origin for this nascent Island population seems remote.
Parallel problems with other alien species
The Isle of Man has its fair share of problems relating to alien species. Feral geese is just one example.
Red-necked Wallabies are non-indigenous Antipodean marsupial 'rodents'. Their feral population is causing damage to valuable Manx habitats. Their presence is holding back much-needed conservation work to restore ‘native’ biodiversity. The Wallabies are implicated in the demise of native biodiversity in the Curragh, including Hen Harriers. Had the Curragh continued to host its winter roost of harriers (as cited in the site’s RAMSAR designation), it would today be one of Europe’s greatest natural wonders attracting sightseers from far and wide.
Peafowl are another growing problem. These omnivorous Asian birds have voracious appetites. They compete for food with native species and will readily predate the eggs and young of animals that breed on or near the ground. If action is not taken soon, they might well become another ‘out of control’ problem.
Effective solutions are not easy once such problems are out of control. It is vital that newly arising problems are ‘nipped in the bud’.
Keeping it native
Manx BirdLife believes, first and foremost, that the Island should cherish and protect its native wildlife. That is, the wild species which are resident here or arrive naturally.
Where the interests of our characteristic and charismatic avifauna are put at risk by species brought here by people – and which would never have arrived here naturally – we must put our native species first.
There are, of course, both conservation and welfare considerations to be taken into account when discussing proposed control of animals. Effectively safeguarding our Biosphere is ‘to do the right thing’. Efficiently going about this is ‘to do the thing right’. Resources must be applied prudently. It is far more cost-effective to act sooner than later.
At the end of the day, we have a choice – to look after our natural heritage, or to allow the landscape to be filled with out of place exotics that destroy the Island’s character and its ecology.
Manx BirdLife would look forward to working constructively with interested parties in resolving the well-founded ‘concerns over greylag geese (sic) numbers’.
As a nature conservation body, we will always strive for a thriving natural biodiversity of Manx wildlife of which we can all be proud.
Manx BirdLife, 17th November 2021
 Greylag Geese were introduced to southwest Scotland and East Anglia in the 1930s to establish feral flocks, presumably as hunting quarry. In the 1960s and the 1970s the Wildfowlers' Association of Great Britain and Ireland translocated and released more than 1,300 birds that had been caught or taken as eggs from Scotland or reared on their reserves, with the object of re-establishing the species as a breeding bird in England. (Myrfyn Owen & D. G. Salmon. 1988. Feral Greylag Geese Anser anser in Britain. and Ireland, 1960–86, Bird Study, 35:1, 37-45, DOI: 10.1080/00063658809476978)