Swans’ Months 4 To 6
Swans at this age have reached a pivotal stage in their lives. In fact, if they’ve made it this far, they’re probably biologically strong enough to make it to into adulthood, only accidental death is likely to prevent that.
But to make it into adulthood, two major events need to occur in their life; they need to fly and then leave the relative security of the family unit.
In this section, we will be discussing how they need to develop to enable these two things to happen.
Males And Females Separate
As they progress into months four to six, the cygnets get an increasingly sharp appetite. They are usually keener to get to a food source than their parents. Indeed, in the situation where the whole family is fed food by hand (as they are at Abbotsbury Swannery), the parents will give way to their young so ensure they are able to get their fill, even before they satiate their own hunger. The reason for the youngsters’ ferocious appetite is their rapid gain in weight.
At the very start of their lives, male and female cygnets start off at around the same weight, about 220g. Casual observations will hardly be able to see any disenable difference, but at two to three weeks, the males will start to outpace the females in terms of their weight gain. By the time it comes to being able to fly, the males could weigh as much as 25 to 30% more than their female siblings. They will be visibly larger, too, and potentially more aggressive when it comes to getting to a food source and general characteristic behaviour.
To give you an idea of the growth rates of Mute Swans, after around five months, the average swan will be about thirty four times its birth weight, which translates to approximately 7.5kg.
By the time they reach adulthood (more than a year later after their birth) the average Mute Swan will weigh in the region of 11kg, but the adult female swan is likely to weigh anywhere between 10 to 28% less than her male counterpart.
As the swans continue to grow up, they start making more sounds than they did in the run up to this time. In addition to the normal calls and hisses, they start to make snorting noises. They’re almost the kind of sounds you may hear coming from little piglets! They seem to come out with these snorts when moving around, particularly when getting near to another food supply. As anyone who has hand fed cygnets of this age will testify, these rather unexpected sounds are very evident as they pull or pluck the wheat grain, etc... out of the outstretched hand. However, when a swan reaches the stage where it can be called an adult, these snorting sounds are all but absent.
Boldness Has Its Dangers
In the last section (Swans’ First 3 Months) I mentioned how the young brothers and sisters will probably experience confrontations/battles with rival swans looking to challenge for their mum and dad’s territory. And initially, the cygnets would not play a major part in the standoff; more likely positioning themselves behind one of their parents for protection.
However, as the weeks pass by, the cygnets have grown-up appreciably and now they are getting bolder. Now their part in the confrontations/battles can be a little more active.
The kind of behaviour I have seen is that they will increasingly position themselves behind their defending/attacking parent, and not to the rear of the other adult, whose job is to protect the cygnets, rather their intention is to actively pursue/attack the intruder. The youngsters appear to be putting on a ‘united front’ right behind their defending/attacking parent – a kind of show of family strength.
But their boldness is rather misplaced. They are still a very long way from having the strength and endurance of the adults and when physically challenged by one of the intruding swans (usually the other cob), they beat a very hasty retreat!
On one occasion, I have seen a cygnet of just 106 days of age, directly challenge (from a distance of about 5 metres) a fully grown cob swan from another family group, whilst his own mum and dad were a few metres behind him. The challenge was in the form of a head back, sideways stare, raised wings and feathers, but when the other cob made a beeline for him, he beat a hasty retreat for the vicinity of his family group!
Young Mute Swans of this age ‘experimenting’ with potential battles (referring to the scenario above), are engaging in a very risky strategy. At this age, they are still a potential target for an aggressive cob wanting to clear the area of any other swan that’s not part of his young family and they will attack, with the intention of killing, youngsters from another family. But the bigger the cygnet, the better the chance of it being able to evade its attacker.
Where the intruding cob is actually in physical contact with another family’s offspring and it trying to kill it, I have seen the parents of the victim come to their cygnet’s rescue by attacking the assailant. The cygnet normally escapes in situations like this because the attacker then turns his attention to the defending parent.
Experiences like these are all a very normal part to a young Mute Swan’s life and play an integral role in shaping how successful it will be later on, when it may have a family of its own.
On The Flight Path
As the weeks drift by, the ‘babies’ are really growing up. They will periodically drift further and further from their parents and the first flight will be coming soon. As mentioned in the previous section (see Swans’ First 3 Months) the signs of impending independence are prolonged shakedowns to strengthen the chest muscles and the growing of proper flight feathers on the wings.
Looking at the swans, if they are covered with brown feathers (and not lots of fluffy down) to the same extent as their parents (although, the parents will be white and not brown), the offspring are almost ready for lift off. Once the cygnets have quite a few white feathers interspersed with the brown ones and all the feathers on the underside of the wings are white, the youngster is ready to go for it.
The normal time scale that young swans take their first flight is anywhere between 120 to 150 days after hatching, although I have seen birds taking flight as early as 118 days and as late 159 days. In reality, I have probably seen younger and older swans than these taking their first flight, but since the hatching day wasn’t accurately known, it will be especially unreliable to put a number to their first flight day.
The normal routine you see when the youngsters are about to practise flying is as follows: They will form a loosely packed group on a stretch of water where they can take a good run-up. The birds will face into the wind, crane their necks and perform a few head nods. Then, just before they take the run-up and take off, they will coordinate their actions, so they all take off at the same time, by making calls to each other.
The run-up can be anything from 5 to 25 metres before they finally have liftoff. The airborne part of the motion will come to end after 30 to 200m, when they land on the water by pulling their head and wings up, skiing across the surface, coming to a holt. A vigorous shakedown completes the spectacle.
In the early days of flying, they will only do this once or twice a day, but as they get stronger and stronger, the flight times will get correspondingly longer, too.
The Key Signs That Change Is Afoot
Once the swans can fly, and fly well, there is very little need for the youngsters to be cared for their parents. And the parents know this.
What you will see at this stage is that the parents will start to intentionally distance themselves from their offspring. They will do this by swimming away from them and not beckoning them to follow, or, if the cygnets keep staying close to them, the pen and cob will start pecking them and will approach the young ones in a threat posture, with raised feathers and wings – rather like they deal with intruders into their territory.
What visual clue triggers this behaviour is probably related to the development of the young birds’ feathers. In the section, What Is A Swan?, it was discussed why swans are white - the white colour of the feathers acts a constant warning to other birds that a Mute Swan is present and maybe it’s wise to stay away, particularly, if that stretch of water forms part of its territory.
Swans don’t like other white birds in their territory (other than a mate) because that white bird could be another Mute Swan and, another Mute Swan is a potential threat.
Therefore, as the offspring’s brown feathers fall off and are replaced with adult white feathers, it triggers a natural response from the parents to chase them off because they could be perceived to be a threat and use up the pairs’ precious, territorial resources.
At first, these ‘chasing off’ motions will be quite gentle and unsustained, but as time passes, the parents will become gradually more aggressive in their actions and the offspring must get the message soon; their time with parents has come to an end and they need to fly off. The reasons for the parents chasing off their offspring that they cared so much for over the past six months or so, is that spring is fast approaching and they need space and resources to start the breeding cycle all over again.
When the young swans actually leave their parents can be anywhere from 5 to 10 months, depending on the growth rate of the offspring (slower growing youngsters will leave later than faster ones) and the physical resources of the territory.
Sometimes, the cygnets leave as a whole group, at other times in singles or smaller groups. If a swan stubbornly refuses to leave its parents, the cob has been known to kill it, although I have not witnessed this.
Normally though, a young swan will have left its parents when its feathers are still primarily brown. The whiter the swan gets, the more aggressive the cob and pen will be in chasing off the youngster. Eventually, it starts to look too much like an adult swan (i.e. a threat to the parents and territory), the attacks get too much for the offspring to take and it finally departs for pastures new..... its new independent life would have just started.
The next section will discuss what happens now.