I once had designs on seeing my name on the list of eBird’s Top 100 All-time World Birders, based on species count. That is almost certainly not going to happen now. The rate at which the species count needed for membership in this exclusive club is rather high, even with the pandemic. I’d likely need to get 1,000 lifers in the next year. Fat chance.
Starting in March of 2020, I tracked the species count of the 100th top eBirder over the course of the year. Basically I would query the Top 100 list every few days and record the results. I now have a year’s worth of data, shown in the plot below, with the species count for the 100th spot plotted versus date.

Something happened in late May of 2020 where a sizeable jump occured. I’m not certain, but I think this was due to several birders with hefty counts joining eBird and porting their lists in. I don’t see why there would be a sudden uptick at that point, especially given that many COVID-related restrictions were set in place in March and April. I was expecting it to trend down.
But other than that jump, the trend is fairly linear. Perhaps another little jump in October?Neglecting the May bump, a linear regression gives a slope of 0.64 species/day. At this rate, a year will result in a change of 234 species. Extrapolating, by March of 2022, you’ll need about 5,400 species to make it on this page. I’m guessing it will be even higher than that, as the pandemic restrictions ease, although it cannot stay linear forever – it will asymptote out eventually. But when? Check back in a year…
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