This third post in the Ask Chloe series gives us an overview of dolphin sexuality and the social dynamics of pod relationships. Answering these questions allowed me to learn about the intensely social nature of dolphins. In my opinion, this is one of the major ways in which a dolphin’s way of life differs from a human’s.
Thais RH: how many dolphins in a typical family unit? do siblings stay together once mom and dad die? whats the prevalence of family reunions?
Unsurprisingly, a typical family unit for dolphins looks different than a typical family unit for humans. A dolphin’s concept of “family” may even extend to the whole pod. Dolphin pods can be as small as a few dolphins or as large as hundreds of dolphins. Pods can be broken into three sub-groups: female and nursery groups, juvenile groups, and male groups (which are often pairs). So in terms of direct offspring, mothers do most of the early caregiving. Dolphin Dance Project is lucky to get to know some mother-baby pairs during the time they spend dancing with dolphins. This video shows a mother spotted dolphin, Notcho, looking after her baby Jalapeño who has not yet developed spots.
Older siblings often babysit younger siblings and other young pod mates while the moms hunt for food or rest. This functions as help for the mom and training for the older sibling to learn how to look after young ones of its own one day.
Depending on the activity, such as hunting or resting, the pod splits off into pairs or other groupings and comes back together collectively. This is called a fission-fusion society, which is just a term to describe shifting group compositions as animals sleep together and separate for hunting or socializing. So, these returns either to rest or hunt with the pod could be considered a daily family reunion.
Mari (10 yrs old from Illinois) : How,where, when and why do dolphins reproduce? Are dolphins born under water? And, if so, can they breathe when they’re born?
Dolphins can reproduce at any time of the year. However, it’s difficult to view a dolphin giving birth in the wild because the whole pod will protectively surround the mother as she gives birth. Dolphins are born tail-first underwater so that the last thing to come out is their blowhole. This way, they can’t accidentally breathe underwater while being born. After being born, babies instinctively swim or are pushed to the surface by fellow dolphins in the pod, enabling them to take their first breath. Dolphins are born with whiskers that fall off soon after birth (this is the only time a dolphin has hair in its life).Dolphins have one baby at a time, every 2-4 years or so. Dolphins can give birth to twins, but less than 1% of dolphins have twins.
Ben D (NYC filmmaker): Do Dolphins mate for life? At what age is a Dolphin an adult? How old is the oldest recorded living Dolphin?
Dolphins do not mate for life. Dolphin sexual life is very different from human sexual life. For dolphins, sex is not only reproductive or pleasurable, but is also used for social community bonding within the pod. Dolphins engage in caressing behaviors quite frequently, and can even use echolocation to buzz each other’s genitals from afar.
While male and female dolphins don’t mate for life, male dolphins develop life-long bonds with one fellow male dolphin, creating a best-friend pairing.
Female dolphins reach the age of reproduction around age 9, and male dolphins mature much later, around age 14. In spotted dolphins, the fused spot pattern (when they have so many spots that their bellies look black) appears in males and females around age 16, which could be considered the moment of adulthood for that species. The oldest dolphin in captivity was 61 year old Nellie, a trained bottlenose dolphin at Marineland Dolphin Adventure. There has not been a lot of field research that has been long enough to get a sense of the true life-expectancy of most wild dolphin species. Dolphins in captivity don’t usually live longer than 25 years, while wild dolphins can live between at least 40-60 years. Life expectancy also varies by species. The oldest wild spotted dolphins are probably in their 50’s.
For Further Thought…
These answers show us that dolphins have much deeper social connections than humans do. In our modern world, we humans spend a lot of time separated from our families. Imagine what it would be like to not only live with your family your whole life, but to also live, hunt, and play with several other friends for your entire lifetime. Imagine how your world would be different if the line between family and friends was blurred.
This scenario becomes even more dynamic when we consider how physical dolphin relationships are. Sex plays a vital role in the maintenance of a dolphin’s society. Dr. Kenneth Norris, marine mammal biologist, described sex as being a “social glue” for dolphin pods, strengthening their relationships and binding them as a community.
What do these realizations about this fundamental aspect of a dolphin’s life tell us? As rich and meaningful as human relationships are, we may not even be able to fathom how much more meaningful dolphin relationships are. Which means that when dolphins get separated from their pods due to being hunted and killed or captured to be put in a hotel, or other anthropogenic causes such as getting caught in fishing line, we may similarly not be able to fathom how deep of an emotional wound we are inflicting on these animals. And even further, we may not yet be capable of measuring how that emotional suffering affects a dolphin’s physical health.