User:Bio Neuro Student/Trumpeter swan

Courtship and Mate choice Behaviours
In late April, breeding pairs meet to begin the 11 to 35 day process of constructing a nest. Before this grueling process can come to be, much like many other species of birds, these creatures undergo several courtship rituals. Trumpeter Swans have a strong tendency to avoid interactions with conspecifics, therefore it is implied that at first contact of a potential mating pair there is some unwillingness in the male and female to make this connection. In order to overcome the initial encounter there are two common displays that can occur. At first, the male tends to pursue the female in a non aggressive way. When the female allows the approach the male will touch the breast of its body to the flank of the female which then causes both individuals the touch the beasts of their bodies together. At this point the feathers on the neck of the make is stood up and the bills of the mating pair are pointed down indicating pacification. Another act of courtship occurs when a male swims in the direction of a possible mate and continuously turns its head from side to side to get the attention or perhaps impress the female. Other common behavioural displays presented by the pair include spreading and raising their wings, the rapid or almost quivering motion of the wings, particular head motions that include bobbing, and finally the most known (and what the name of this animal originates) is the trumpeting that occurs. Acoustic communication among Trumpeter Swans is incredibly common among all ages of the species. From the young cygnets to the adult swans, their calls are incredibly distinct and have a wide variety of functions in the survival of the animal. The classic Trumpet call can be heard from long distances and is the most common communication mechanism heard among these birds. This type of call resembles a horn because the frequency can vary greatly. This call generally occurs when an animal is alarmed or feels threatened, the call acts as a warning or even a way in deterring incoming predators due to the abrupt volume of the noise being evoked .More specifically referring to mating, the call that is most common among mating pairs is called the duet. This call happens when a pair has come together near breeding season. The duetting process can begin as separate trumpeting solos and can evolve into an almost simultaneous duet that is very similar in frequency and very difficult to tell the individual calls apart. This performance of the pair is commonly associated with the particular movements mentioned above (head bobbing and wing movements) associated with the courtship. Also, the duet can aid in coordination of a duel attack on a predator that is too close to the nest of a mated pair. In terms of mate choice, the Trumpeter swan continuously returns to the mate from previous breeding terms, often the breeding pair will even return to their previous breeding grounds if previous offspring were successful in that area.

Nesting and Incubation Behaviour
The fabrication of a nest is an incredibly precise process that takes place over a series of 11 to 35 days and typically breeding pairs will begin construction in late April. The time of year the nest-building process begins can slightly vary due to weather conditions in the previous year, if the environment was more cold and wet the females may not be heathy enough to being mating right away and as a result the nesting behaviour might be slightly delayed. It is common to find nests of trumpeter swans surrounded by water or close to water. This is advantageous to the parents because it can reduce the risk of predation, it can provide optimal foraging sources such as aquatic vegetation as well as ensuring there is nearby water for when the cygnets are hatched. The long duration of the nest building process is predominantly due to the nest being so large (1.2 to 3.6m in diameter) and fabricated mainly from submerged vegetation as well as grasses and grass-like plants. The nest is mostly constructed by the male while the female of the breeding pair is focused on feeding and preparing for the arrival of the cygnets. It has been observed that adult Trumpeter swans do not directly bring the building materials directly to the nest building site. The males use a specific action that includes facing away from the nest and throwing organic materials over their shoulder moving closer and closer to the nesting area. Eventually when they arrive at the nesting site the two individuals of the mating pair are involved in the construction, but, as mentioned above the male spends the majority of its time doing the construction. During nest construction, female Trumpeter swans feed significantly more frequently than males in order to fuel up for laying the eggs. This is greatly supported by the male counterpart of the species because ultimately if the female is keeping itself healthy it will in the end ensure healthy offspring which improves the fitness of the mating pair. Typically a female Trumpeter swan will lay four to six eggs and will incubate them for 32 to 37 days until they hatch. After the eggs are laid it is the female that spends the majority of the time incubating, it has been observed that around every 20 minutes the female will stand up from incubating and reach down beneath itself to roll over the eggs with its bill before re assuming the incubation position. It can be inferred that this behaviour is used to ensure the eggs are kept an appropriate temperature on all sides, this is very important because exposure to the elements leads to high mortality rates in cygnets. The female only leaves the incubation process for brief recesses that last around 20 minutes. Before the female leaves for the recess it will cover the eggs with plant material and it has been observed that if the females does not cover the eggs the male will do so in the absence of the female. This time away from the nest is primarily used for feeding, but the female has also been observed using this time for bathing and preening. The only other time the female leaves the nest is when it must help the male chase away predators from their nesting territory. It is highly uncommon for both members of a mating pair to be absent from the nest at the same time, there is generally always a male or a female present guarding the eggs. The behavior of the male during and after the laying of the eggs can be best described as on alert. This is due to males being increasingly territorial and aggressive, particularly when a predator or conspecifics approach the nesting area. Generally when females leave the nest during their brief recesses the males will stand and guard the eggs, although in some cases the males would even sit on the eggs in the absence of a female swan.

Parental Behaviour
In the Trumpeter Swan there is a very clear division of labor between male and female parts of a breeding pair. This division is referring to clear roles that each parent knows to accomplish in the process leading up to, during, and after the mating process.

Males
After the meeting of the pair prior to mating or nest building the male will often initiate courting calls which results in the duet mentioned above. Before and throughout the laying period the male can be found dealing with construction of the nest and collection of resources. As the eggs are being incubated by the female the male does not feed or sleep as often particularly when the female left the nest. These trends also were associated with more aggressive behaviors from the male especially towards predators and other members of the species. When it comes to parental behaviour, the male has already completed the majority of its role. With this in mind, the male does continue to be territorial and protective of the newly developing cygnets as well as allowing the female to replenish its nutrient reserves. This makes migration to wintering grounds possible and allows for more years of breeding. Keeping the female of the mating pair healthy is important for Trumpeter swans because this species tends to only have one mate in its lifetime. A healthy female also improves the likelihood of having more successful clutches are well as better nesting experiences. When cygnets are young it is common to see the male accompanying them in feeding recesses outside the nest. This can fall under the category of the main male role in parenting being the protection of the offspring.

Females
The increased care and attention of the male to the young allowed for the female to feed more frequently and exert more energy toward protection and overall health to the developing cygnets. During the pre-laying/laying period the males are significantly more active than the females of the the breeding pair. This is advantageous in because it aids in the fitness of the species by improving reproductive success by allowing the female, as mentioned above, to feed more frequently and overall replenish the energy stored in order to aid in incubation and other crucial activities. When hatching occurs the females tend to not leave the nest, the only time a female may leave would be to chase away a nearby predator. After hatching the cygnets are brooded for the first one to two days by the female, cygnets are also brooded when needed (when it is cold or at night) for the first few weeks of their lives. Young offspring have a very close relationship with their parents in the first part of their lives spending the majority of their first few weeks with the female in the nest or in the water. Offspring tend to spend their first full winter with their parents and then they no longer need them.