One in four recorded species was seen just once

On 15 August 2026 the MykoRadar database held 1,377 species with at least one observation, and the total number of observations assigned to a species was 42,911. The ten most frequently recorded species account for 7,763 of them, or 18.1 per cent. The top twenty-five account for 31.7 per cent and the top fifty for 45.5 per cent. At the other end of the distribution, 329 species — 23.9 per cent of the whole list — have exactly one observation.

This shape is called a long tail, and in biodiversity data it is the rule rather than the exception. Two independent phenomena produce it. Some species really are rare. Others are simply rarely reported, because they form inconspicuous fruiting bodies, need a microscope to identify, or grow in places nobody walks through with a camera.

Separating those two causes is impossible from the record count alone, and that is the most important caveat attached to this statistic. The tinder fungus leads the table not because it is the most abundant fungus in Polish forests, but because it grows at eye level, is perennial and can be recognised without a key. A count of observations measures nature and observer attention at the same time.

For the service this has practical consequences. Trends can be computed reliably only for species in the upper part of the distribution — for the tail, every map and every chart describes a single event rather than a range. That is why species pages with one observation show it as a point rather than as a distribution, and why seasonal analyses require a minimum number of records.

Two ends of the same inequality

The 29 August snapshot includes 1,395 species with at least one observation. Exactly one record is linked to 336 of them, or 24.09%. At the other end, the ten most frequently recorded species hold 7,958 of 44,007 species-linked observations (18.08%), the top 25 hold 13,909 (31.61%), and the top 50 hold 19,936 (45.30%).

This distribution combines biological commonness with detectability, season, observer interest and ease of identification. A singleton does not prove extreme rarity, and a high rank is not a direct population count. The chart describes documentation structure and helps reveal where targeted effort is needed.