44 species in Slavonia and the Pannonian plain, each shown at the point of its year it has reached today.
Every species table is written for the Dalmatian coast. The other regions replay the same table a fixed number of days later — 10 for Kvarner, 14 for Slavonia, 24 for Velebit, 32 for Tukhlia — because altitude and latitude delay spring roughly that much. It stays a coarse instrument: a species that runs five days late and one that runs a month late both get the regional average. A few species — the adder, the viviparous lizard, red deer, the black stork — never reach the coast at all, so their baseline is back-calculated from the region they do live in.
The shift is fitted to spring, and it runs the back half of the year the wrong way: in a colder region hibernation and departure come earlier than on the coast, not later. One number per region cannot say that, so where the error passed about a month the region states its own dates instead, used as written with no shift on top. No species needs one here — this close to the baseline the shift is honest enough.
Breeding windows are compiled from published Croatian and wider Mediterranean field literature and atlases, rounded to the nearest useful fortnight. They are typical years, not this year: a warm February pulls half this page forward and the page will not know.
Nothing here is observed. This is a calendar, not a sighting — it says what is usually happening, not what is happening in your particular valley. Second broods, failed clutches and late replacements all fall outside a table that gives each species one phase at a time.
Most of these species are protected. Nests, dens and roosts are protected too, including empty ones. Watching from a distance is always legal; approaching a nest in the weeks this page marks as "on eggs" or "raising young" is the one thing most likely to make the attempt fail.