Rudolf and his red nose is actually a marketing gimmick created in 1939 and almost certainly became the first and the only male reindeer in the bunch. How so?
Rudolph the Red-Nosed Reindeer first appeared in 1939 when Montgomery Ward department store in Chicago asked one of its copywriters, 34-year-old Robert L. May, to create a Christmas story the store could give away to shoppers as a promotional gimmick.
The retailer had been buying and giving away coloring books for Christmas every year; and it was decided that creating its own book would save money. In the first year of publication, 2.4 million copies of Rudolph’s story were distributed by Montgomery Ward.
May’s brother-in-law, songwriter Johnny Marks, decided to adapt the story of Rudolph into song. Marks’ musical version of Rudolph the Red-Nosed Reindeer was recorded by Gene Autry in 1949 and Rudolph's place in modern folklore was securely embedded.
So, why he all female theory prior to Rudolph's later fictional addition? Well, did you know that male reindeer shed their antlers in early December? Females retain their headgear all winter long. In pretty much every depiction of St. Nick making his Christmas Eve run, the team pulling his sleigh are sporting antlers, ergo, said reindeer are female.
To top this off, there’s an eminently practical reason for Santa to hitch his harnesses to an all-female team: Female reindeer have about a 45 percent greater fat-to-body-mass ratio than their male counterparts. This extra tissue serves as insulation that keeps them warm in frigid conditions as low as minus 45 degrees Fahrenheit (minus 43 degrees Celsius), and baby, it’s cold outside - especially in the upper atmosphere.