Joint state/signal probability matrix for 1 and 2 sites.

= (i, j): i sites are occupied & j sites are restricted = (i, j): i unrestricted sites have successful fledging & j sites are occupied next year.= $(i, j)$：$i$个位点（site）被占据且$j$个位点受限制 = $(i, j)$：$i$个未受限制的位点成功出巢，且次年有$j$个位点被占据。