It’s Mark Catesby’s Birthday — or is it?

Mark Catesby, a little-known English naturalist, spent 12 years exploring Britain’s colonies in south-eastern North America in the early decades of the 18th century. The book that he published afterwards in London, The natural history of Carolina, Florida and the Bahama Islands (1729-1747), was the first fully illustrated work on the flora and fauna of any part of our continent. In two large folio volumes, he included 220 full-page, hand-colored illustrations of hundreds of species of trees, flowers, birds, fish, reptiles and amphibians, and mammals, most of them the first view Europeans had of North-American plants and animals.

Mark Catesby, The natural history of Carolina, Florida and the Bahama islands: containing the figures of
birds, beasts, fishes, serpents, insects, and plants , 1731-43 [1729-48], Plate 86 – The Great Booby.

His book was greatly celebrated through the 1700s and remains important in the natural sciences to this day. So he deserves to be remembered on his birthday, but when is it? It is recorded in the village church where he was baptized as March 24, 1682, but this needs to be translated to modern dates.

First of all, in England in Catesby’s time the civil or legal calendar-year changed in March — New Year’s Day was March 25, to be exact — so he was born on the last day of 1682, as they saw it. But if one counts the year as changing in January, as we do, the year of his birth is really 1683. (Because January was used as the start of the year for other purposes back then, you’ll sometimes see the year written as 1682/83, for example, for dates from January 1 to March 24.)

Plate 15 – Blue Jay.

And secondly, Britain was using the Julian calendar. Devised in ancient Rome under Julius Caesar, by the 16th century the Julian calendar was significantly out of synch with the astronomical seasons that the Church used for calculating various holy days, notably Easter which was keyed to the Spring equinox. The Julian calendar was replaced in the late 1500s by the Gregorian calendar (named for Pope Gregory XIII) throughout most of Europe, but Britain stuck with the Julian until 1752. In Catesby’s day there was a difference of 10 days between the two calendars, and thus England’s March 24 was April 3 elsewhere.

So, when should we celebrate Mark Catesby’s birth? Why not both dates!

HAPPY BIRTHDAY, MARK CATESBY — 328 YEARS AGO TODAY (and next week…) !!!

— Leslie Overstreet