DOLPHIN BIOLOGY

Bottlenose Dolphin
Is the most familiar of all the dolphin species and probably
the most popular and the most common in British waters.

Description
Upper body is gray, underneath is a cream color, the body is large and stocky dolphin length 2.5 meters to 3 meters but up here in Scotland of the West coast and North east coast  grow up to 4 meters, due to the sea water being cooler. There dorsal fin is a sickle shaped fin, they are named bottlenose because of there beak shape this name originates from the shape of a bottle of Gin.

Behavior And Theories
Highly active and powerful swimmers inquisitive and curious animals will bow ride with boats will also display acrobatics, breaching, lobtails, leap splashing, body surfacing, there’s a number of reason why they may do this.

1. Playful and social bonding

2. A form of learning for calf’s juveniles for haunting and feeding,

3. They will use some of these acrobatics while chasing and rounding up there prey.

Dolphins live in herds despite to which we are lead to believe that they live in pods or schools, any numbers from five to seven dolphins upwards is called a herd.

At times when approached if there’s calf/s in the herd the male of the group will come in to check the situation, and if unsure of you or think you’re a threat to the group the male warn you off by slapping his fluke/tail aggressively at you. They will also take this action if you harass them for long periods of time or approach the herd too closely, other reasons for fluke/ tail slapping is a form of communication or sometimes to stunt their prey.

Smaller groups of herd’s maybe families or like extended family groups, mainly groups of females and calf’s, it is know that some calf’s when they reach adulthood may often stay with their mother up to ten years old of age before seeking their own way in life, males may join in these groups for short period of time, but also know to live in bachelor herds.

It has been know for some male to separate from herds for long periods of time and eventually seeking out human contact as in boats, canoeists, swimmers  and usually stay in the area for years, for example a dolphin called a Fungi in Dingle, Co, Derry.

Unfortunately Bottlenose dolphin do have an aggressive side to there nature, but in de fence of them what animal does not, like man their have emotions and feelings, like anger, sadness especially hunger, and aggression which is the main part of survival and their emotions.

There is an aggression that is not fully understood by marine biologist or scientists; they kill porpoise which is a cetacean but no relation to dolphins unlike killer whale which is a cousin to the dolphin.

There is a theory as to why the bottlenose is aggressive towards porpoise for instants the porpoise 1.3/1.5 meters adult average size 3ft in length is the same size as a dolphin calf, it is know that adult male dolphins will kill calf/s of another male dolphin to fertilize the adult female of the dead calf for his sexual gratification.
But the theory is that the adult male dolphin will kill the calf from striking with his nose or beak underneath of the calf’s body the stomach, this will be repeated again and again until death occurs to the dolphin calf.

Reproductive Biology
Female bottlenose dolphins usually give birth around spring and summer between March and September gestation period is 12 months, when calf is given by the mother other females in the herd will assist if necessary.
For example if mother is exhausted due to giving birth, they will help calf to the surface for its first breath, and will also help the mother if to weak.
Usually the mother is unable or cannot breed for up to 2/3 years, the calf is suckled for 18 to 20 months young male reach maturity between 8 to 15 years and females and 5to 13 years old, the life span of a bottlenose is usually up to 25years but some female can live up to 50 years kept in captivity their life span is shorted.

Diet
Dolphins diet consist of mackerel, herring, salmon, sea trout most shoals of fish depending were they bread and live it’s a case of what’s on the menu, it is believed the they also eat small jellyfish as I believe jellyfish are a form of plankton.

Threats
Dolphins as are other cetaceans are vulnerable to mainly due to man, such as pollutants oil spillage, chemical industrial waste, and human sewage waste, sound pollution from large number of pleasure craft, fishing nets and vessel collisions.

Other Facts