Swans’ Life In The Field Groups
Swans that live in the United Kingdom don’t migrate in the true sense of the word. However, many of them do have to move from one area to another during the course of the year because the food in one area becomes depleted or during their annual moult, they need a place where they are unlikely to experience any threats where escape through flight is necessary (since when moulting, flying is not possible).
One of the locations where Mute Swans tend to migrate to during late autumn and winter is in open, grassy, fields. You’ve probably seen them for yourself – groups of swans feeding in a field, adjacent to a waterway, like a river or lake. And the reason why they’re there? Food.
As the weather cools down in the autumn, the natural food like water weeds, etc... die back and, if they’ve got no other food source, they’ll fly off looking for a field of grass to feed on during the cold months.
In this section, we will discuss why some fields are chosen over others and what the swans do in these fields through the winter months.
Only The Young Ones
As mentioned in the section, Swans After Leaving Parents, it’s a place where only the young birds tend to gather – immature swans that have just left their parents and adult birds less than four or five years old. Older swans would have found a partner and flown off to find a permanent territory. There will be exceptions, of course, but this is what normally happens in the majority of cases.
When it comes to seeing what fields are chosen for the swans to gather in, it’s very noticeable that some particular fields are chosen year in, year out. Why is this?
The first thing to bear in mind is that when swans move from one place to another, they normally follow a water course – that could be coastline, a chain of lakes or, in most cases, a river valley. So, any field in the vicinity of these features is on the radar.
The next variable in the equation is that the field they select needs to have access to water. This doesn’t have to be a river or lake, etc... a flooded field will do. The reason for that is because they like to swim regularly and normally use the body of water to sleep on at night.
Although, you may see large numbers of swans in a field during the day, the birds normally gather in the water at night because they will be safer from the attentions of marauding foxes and such like. In addition to that, they also need to drink quite a lot of water.
The quality of the pasture is a very important factor, too. Many farmers spread fertiliser on their fields during the course of the year to artificially enrich the grass yield – often because they’re intending to produce hay later on, or, to increase the quality of the food for their cattle, etc... The swans will become aware that some fields will have richer pasture than others, so those will be selected.
Being free from disturbance and interruptions is another thing that will appeal to the swans, too. Being harassed by dogs, foxes, farm machinery, etc... will have a negative impact on them, but it will not drive them off permanently, if a certain area conforms to all the other features that the birds like.
A bird flying through the air will not need to ‘assess’ a given field to see if it meets all of its requirements – it only has to do one thing; to see if there’s already a cohort of other Mute Swans in residence. If there is, all of the other previous factors are likely to have been met. It’s the short cut to finding a good home.
This is one reason why swans are social foragers. The birds are indirectly sharing information on the locations of good food source, etc...
Why Do Swans Gather In Flocks?
The first reason is given above; the existence of a group of swans already feeding in an area immediately reduces the amount of time and energy needed for a bird to individually make an assessment as to particular field’s suitability.
Flocks of swans are particularly beneficial to immature birds. Young swans don’t have their repertoire of favoured feeding spots, so by heading for a group of birds, they are harnessing the years of accumulated knowledge by their elder brothers and sisters.
This information sharing model of behaviour not only applies to field selection, but also, preferred locations within a given field. When you next see a group of swans in a large field, it is unlikely that they will be spread uniformly across it. They tend to gather in groups within the field.
What happens is that one or two birds will find a particularly good area for access to food, water, etc.... and once the other swans see that, they will gravitate towards that spot, too.
As is common for many animals that gather in groups, there’s safety in numbers. Swans don’t have too many natural enemies in the United Kingdom, but there are foxes. Foxes will kill even adult swans – it not a common addition to their diet, but they are a threat, nonetheless.
If a fox was to approach a lone swan, the odds of making a kill are greater than if it approached a member of a herd of swans. A single swan has just one set of eyes and ears to make a predator detection, but a swan amongst a group is safer because the fox has got to avoid not just one pair of eyes and ears, there’s numerous other birds on the look-out, too. And, as soon as any threat is detected, the birds will telegraph alarm throughout the flock in the form of hisses, moving rapidly away from the threat and generally causing a commotion.
Birds present in flocks of swans can experience problems, though. Some individuals can be more aggressive than others and when one of these lands amongst a herd, there will be an increase in the number of confrontations and fights, which will cause problems for immature birds that have yet to learn some of the more challenging aspects of being a swan.
A Swan’s Social Needs
Apart from the essentials necessary to a swan’s life, they also forage in groups to bring them into contact with other swans for social reasons - young swans need to find a mate and to do that, they have a developed a courtship routine.
Here’s a typical courtship routine:
The two birds will approach each other and as they get nearer, each will raise their wings, the feather will be fluffed up, both on their wings and neck. At a first glance, it’s not like unlike a hostile approach, except, their heads will be to one side and not pulled back between their wings like it would be if the approach was aggressive.
Each bird will look at each other by moving their head side to side - remember their forward vision is not as good as their side-ways acuity.
They will get to within about a foot of each other, often closer – so close, in fact, that their breasts may actually touch.
The swans will then raise their necks up, approaching vertical, and then lower then again, making sideways glances to each other. All the time whilst they do this, each bird will simultaneously emit a snorting/rumbling sound.
When they lower their necks, they pull their heads in and sideways, and if their chests/breasts are touching, this formation can produce that classic heart shape outline that we see depicted so often in illustrations.
They will do a few more sideways looks at each other. Sometimes even repeating the raising and lowering of the necks and making that rumbling sound.
After that they will separate and go back to doing whatever they were doing before.
This whole process can last for anytime between ten seconds to around a minute, but around twenty five seconds is typical.
There are many variations on this Mute Swan courtship ritual, but the basic procedure is roughly the same. Sometimes, one bird will stay sitting/laying on the ground, whilst the other stands, or, both birds will raise their necks and the ritual will simply be each other turning their heads towards each other.
What I have noticed is that adult swans within the group are more likely to press chests to each other when they raise and lower their necks than the first year birds.
During the course of a day, some individuals will have several courtships with other members of the flock, whilst others, tend to stay away from densely populated parts of the herd and do their own thing.
An Interesting Discovery
As we now know, swans start off single and in their need to find a mate, they go through a courtship routine – outlined above. But I have seen something very interesting when it comes to swans social behaviour and their courtship.
Having spent many, many hours observing swans in the field setting, I have observed how Mute Swans occasionally gather in cluster groups (groups within the flocks), to ‘meet’ each other.
This is what happens: Individuals can be contentedly feeding on the grass and going about their normal ‘swan business’, and then suddenly, something triggers a number of them to get up and gather in a group of around ten to twenty individuals and have a mass social interaction. Pairs of birds will perform the usual raised wings, head raising and lowering courtship routine, along with the snorts and rumbling sounds. But this time, with other birds are in very close proximity to them.
Of course, swans do this all the time in a field setting (where they can be very close to other birds when going through a courtship routine), but it seems in these cases they have intentionally moved to a position where they can be very close to the other swans going through the courtship routine with another swan. Rather than other swans being close to them because their courtship was performed when there were other individuals in close proximity on an incidental basis.
Why they should choose to gather in these transient clusters is not clear. Maybe when the swans get together, they can make a visual assessment of a number of individuals in a very short space of time, expediting a possible pairing up process.
But what I have noticed is that a given bird will only choose to have a courtship with one other individual in the group; they don’t move from one partner to another, like women and men on a speed dating event!
So, although, the mini gathering could have the benefit of assessing a number of birds simultaneously, probably just on a visual basis, the courtship trial is limited to one other bird, before the cluster separates out again and all the birds carry on doing their own thing. It’s very interesting and something I will be looking at again in the future.
A Typical Day
A fairly normal day in the life of a field swan will start off with coming out from the water and clambering onto the land. Moving towards a favoured area of the field, they will have a bit of a preen and feed.
After that, they will have another preen, longer this time, and then settle down onto the grass and then preen some more. Several hours could have passed by this point.
Commonly, the swan will then rest its head in the space between its wings and have a sleep. One eye will often be kept open slightly, to have some vague awareness of what’s happening around it.
After the rest, it will often have a feed and move a short distance to another spot, to repeat the same process. But in doing so, it may have a courtship ritual with another swan and/or blunder into the territorial space of an aggressive male. In which case, there could an altercation if the other bird is of similar status, or more likely, it will make a swift escape. Swans in the field setting appear to have a status ladder, or pecking order – kind of social hierarchy. This will determine who gives way to whom. Conflicts occur when two swans of the same status meet and they need to sort out who is senior to the other.
At some time, the bird is going to need a drink. If there is a pool of water nearby in the field, it will move over to get a drink. It’s here, where other swans will gather to do the same thing, where there’s an increase in the probability of having another courtship routine, or having a hostile reception from an aggressive individual.
If there isn’t a convenient drinking pool available, it will make for the nearby body of water, either by flying or on foot.
Swans have a need to visit the water (river or lake) at sometime during the day anyway, whether there’s a drinking pool in the field, or not. They like to have paddle around and have another preen, which will probably involve a proper bathe along with the preen.
When it comes to entering and leaving the water, normally at least one of those activities will involve flying. They need to keep their chest muscles in good condition and regular flight will help in that respect. Sometimes that flight will be short one merely taking the most efficient route from water t the field, or vice versa. At other times, the flight may be an extended one involving a circuit of the nearby fields and even beyond that. Inevitably, some will fly off so far that they will actually take up temporary residence at another location.
Eventually, the swan will land on the grass again and repeat its earlier activities.
As the day draws to a close, all the swans will move into the body of water and get prepared to spend the night there. Preparations include having yet another preen (possibly a bathe, too), maybe a little feed on any remaining plants and finally, a sleep. When resting, they tend to stay quite close together, like they do in the field.
The above description applies to a single bird, but when the swans have paired up, each bird will go through the same procedure as the single, except that they will not undergo the courtship routine with another swan.
What normally happens with established pairs of birds is that they stay fairly close to each other during the day, but they do get separated for a short while, when they come back to each other, they will go through a courtship ritual with each other. This is their way of maintaining the pair bond between the two, especially when they’ve been separated for a while.
Mating And Nesting, Without Breeding
In these field groups, the swans that have forged a link with another individual, may actually go beyond the routine courtship ritual and mate, as well. Even though, the pair have not established an exclusive breeding territory, they may still mate and, even, produce a nest. Places where they mate include on the large body of water nearby, or, if there it’s sufficiently big and deep enough, a pool/ditch, will do.
In these cases, even though a nest is made, no eggs are laid because the parents are still not old enough. Mute Swans need to be at least two years old to start breeding.
The nest that pair made will simply be abandoned.
As the winter draws to a close, the swans will start to desert their winter fields and either look for a breeding territory (if paired up with another), or, go to a large open body of water to take advantage of the newly grown plants and have their annual moult.
What Happens Next?