The process of identifying a deer – and finding out who its parents are – begins within a few hours or days of birth, when we catch the calf and mark it with tags, and, for females, a collar. These markings allow us to identify the individual throughout its life, along with any natural variation and markings (such as ear rips) they pick up along the way.
What’s in a name?
Every deer in the Kilmory study area also has a name. A new born calf, of either sex, is named after its mother and its year of birth. For example, the calf born to a female called Sequoia in 1996 began its life as Sequoia96. In our database, this individual also gets a code - in this case, SEQ96. If a female calf survives to three years old (the youngest age at which females can breed) she is given her own name. This is usually a name related in some way to her mother’s. Sequoia96 survived to breeding age, and was re-named Yosemite in May 1999. Yosemite went on to give birth to Yogi in 2001. In fact, Sequoia had four other female offspring who themselves went on to breed successfully, named Cedar (born 1995), Apache (born 1999), Sioux (born 2001) and Navajo (born 2005). You can read more about the success of this family in the Hall of Fame.
The initial naming process for males is similar, but those born in the study area retain their mother’s name and year throughout life. So the male calf born to Yosemite in 2005 was called Yosemite05 throughout his life. Males who migrate into the study for the rut from other areas of Rum are given their own names and are identified by their appearance, including their antler morphology. For example, Sioux’s father was an immigrant male who rutted in the Kilmory study area. He was named MobyDick and could be identified by a healed natural slit at the back of his right ear.
From individuals to matrilines…
Recognition of female deer and their offspring has allowed us to build up detailed information on matrilines. The photo above is of Yogi and her daughter, Booboo. Details of her matriline, including Booboo, are shown on the right, going back to a female born in 1961 called Blue Tag Left. Each ofthe matrilines of females currently resident in Kilmory can be traced back to one of the 57 females present in the study area when individual-based research began in the late 1960s. Matrilines can now be traced back up to ten generations, with extremely detailed information on the lives of every individual.
And from matrilines to pedigrees...
Calving is also when we collect information to help us identify the calf’s parents. Calves spend the first few months of life in close proximity to their mothers, so identifying mothers can be done through observation. Identifying a calf’s father is less straightforward as females are held in the harems of numerous males during each rut. It is hard to determine reliably when and with which male a female has conceived through observation alone. Instead, we use samples collected from the deer to generate DNA profiles of calves, their known mothers and rutting males, and then use genetic paternity analysis to identify the most likely fathers. We are able to reliably assign over 90% of sampled calves to a father. This has allowed us to build up a detailed pedigree for the Kilmory deer population, going back numerous generations through both male and female lines. The pedigree to the right illustrates part of the pedigree for a hind called Yogi. You can see how genetic analysis has revealed extraordinary things about her mother’s (Yosemite) mating patterns- including mating with Athena91 and Tanya94 in multiple years, and mating with her half-uncle, Sycamore00!