There isn’t anything more hard-core birding geeky than running numbers on potential bird sightings for a big year or big day, even if the projections are limited to your backyard!
I’m trying to gauge how I’m doing so far on my big year. I’m a bit behind where I was hoping to be, as far as species totals go, but otherwise running numbers to see if I can make any projections based on my previous years birding in the county.
For the past three years, I’ve birded Hunterdon County pretty heavily but mostly birded my yard fairly casually. Here’s how my birding has compared to the sum total of all eBirding in the county:
Here’s how my January birding in the county has compared to the rest of the year’s birding:
Usually, the top local county birders hit the month of January pretty hard, scour the county pretty good, and try to see all of the species seen in the county–including overwintering lingerers that are much more easily seen later in the year. Hence the high percentage of all year birds seen in January.
If my 2015 Backyard Big Year birding were to follow that kind of trajectory, based on finding 47 birds in January, it looks like my total yard birds for the year would end up around 112 and 152, based on finding 31-42% of the ultimate total year birds in January.
There are reasons to believe that this trajectory won’t hold for the yard big year. Instead of scouring a wide area, with yard birding I’m much more restricted to waiting for birds to come to me. While there are daily and seasonal bird movements going on in January, there is a lot less movement than later in the spring or fall–so less chance of seeing many of the birds found in small numbers or scattered across the wider area.
Here’s how my casual yard birding has fared over the past few years:
Based on these totals, my 47 January birds may be only 26-30% of my total birds for the year, leading to a projected total for the year of 157 to 181 birds.
Are these realistic projections? Time will tell. Yard birding is in many ways different from county birding–it is much more challenging to find many species as flyovers or moving through a stationary point, than it is to go to where they are more easily found across a wider area. In addition, I am recording nocturnal flight calls–which might actually increase my ability to find some species. In 2012 I recorded Virginia Rail, Whimbrel, and Short-billed Dowitcher from my yard–birds which no other county birders were able to find on the ground during the year. So hopefully nocturnal recording will boost my totals even higher. How high? How many birds will only show up as nocturnal migrants? It will be exciting to find out!
Based on my projections, I should end up between 150 and 200 species for the year from my yard. Anybody care to predict on a final total? If yard birding were like other betting sports, how would we run betting on a backyard big year like this?
Only time, a lot of birding and recording review time, will tell what the final numbers will be. In the meantime, there’s a whole year of geeky bird number crunching to keep me busy in the down times…oh wait, there really aren’t many down times when you’re at least always sitting by a window or listening to the OldBird 21c mic in the yard!
