I based those figures off of my own visit (which includes a bts into the rodent section) plus my knowledge of the collection beyond the species I physically saw. It's the same way I worked out the Bronx figures. As we've all noted many times, ZTL is extremely outdated so using it will give you exaggerated figures.
For the sake of reliability however, I counted 134 species of bird in Plzen, over twice the number of species you counted - surely that is not down to ZTL inaccuracy?
I was curious about this discrepancy, so I did a ZTL count as well. My count yielded a very similar 136 species. Here is the list for reference:
African grey-headed gull
Maccoa duck
Eastern purple heron
Atlas Horned lark*
Eurasian Oystercatcher
White wagtail (Nominate subspecies)
Blue-winged goose
Blue-headed wood-dove (Maiden dove) (Blue-headed dove)*
Blue-naped mousebird (Blue-naped coly)
Common Linnet (Eurasian Linnet) (Nominate subspecies)
Chestnut-bellied sandgrouse (No Subspecific status)
Sudan golden sparrow
Senegal turaco (Buffon`s turaco)
Moussier's redstart (Coroneted redstart)*
Madagascar pond-heron (Malagasy pond-heron)
African three-banded plover
Slender-billed gull*
Spotless starling*
Eurasian siskin
Eurasian teal (Eurasian green-winged teal)
Eurasian Song thrush (Throstle)
Eurasian great cormorant
European Turtle dove
Eurasian quail (European quail)
Common chaffinch
Western black redstart (European black redstart)
European starling (Common starling)
European stone curlew
European kestrel (Eurasian kestrel)
European white stork
Common sandpiper
Common redstart
Grey wagtail
Fulvous whistling-duck (Fulvous tree duck)
Yellow-billed duck (African Yellow-billed duck) (No Subspecific status)
Common rock pigeon (Western rock pigeon)
European serin
African comb duck (Old World comb duck) (Grey-sided comb duck)
Eurasian golden plover (European golden plover)
Grey heron
Ring-necked dove (Cape turtle dove)
Hadada ibis (No Subspecific status)
Collared Kingfisher (White-collared Kingfisher) (Black-masked Kingfisher) (No Subspecific status)
Hamerkop (Hammerhead)
Harlequin quail
House bunting*
Rufous scrub-robin (Rufous-tailed Bush-robin) (Rufous-tailed Scrub-robin)*
Wood lark*
Stock dove (Stock pigeon)
Ruff
Namaqua dove (Long-tailed dove)
Eastern crested guineafowl (Kenya crested guineafowl)
Hawfinch (Grosbeak) (Nominate subspecies)
Kilimanjaro White-eye
Garganey
Red-crested pochard
Egyptian plover
Common cuckoo (Eurasian cuckoo) (European cuckoo)
Western cattle egret (Buff-backed heron)
Greater short-toed lark*
Black-headed gull (Common black-headed gull)
Lanner falcon (No Subspecific status)
Northern shoveler
Maghreb magpie*
Green-backed heron (No Subspecific status)
Marbled teal (Marbled duck)
Grey-headed social-weaver (Nominate subspecies)*
Mistle thrush
European greenfinch*
African openbill (African open-billed stork)
Eurasian Blackcap (Nominate subspecies)
Ferruginous duck (White-eyed pochard) (Ferruginous pochard)
Black-crowned night heron (Nominate subspecies)
Yellow-crowned bishop
Red-backed shrike
Egyptian goose
Yellow-billed stork
African chaffinch*
Upper Guinea bulbul*
Eastern grey-crowned crane (East African crowned crane)
Eurasian wigeon
African sacred ibis (Sacred ibis)
Eurasian golden oriole (European golden oriole)
Oriole warbler (Oriole babbler)*
Purple glossy-starling
Barn swallow
Tufted duck (Tufted pochard)
Common woodpigeon (Wood pigeon)
Greater flamingo
Great white pelican (Eastern white pelican) (Rosy pelican)
Ruddy shelduck
Pink-backed pelican
Collared pratincole
Red-footed falcon
African spoonbill
Red-breasted goose
Red-throated bee-eater*
Common redshank
Red-billed teal (Red-billed duck) (Red-billed pintail)
Black-cheeked lovebird
Pied avocet (Eurasian avocet)
Saker falcon (No Subspecific status)
Common ringed plover
Northern Carmine bee-eater (Blue-throated carmine bee-eater) (Nubian Bee-eater)
Greater spotted eagle*
Pied crow
Emerald starling (Iris glossy-starling)
Blacksmith lapwing (Blacksmith plover)
Gadwall (Gadwall duck)
White-crowned robin-chat
Black crake
Black-necked stilt
Little egret (Nominate subspecies) (Common Little egret)
Senegal Laughing dove*
Glossy ibis
Northern pintail
Pin-tailed sandgrouse (Subspecies caudacutus)*
Golden eagle (no subspecific status)
Black-winged stilt
Common ostrich (No Subspecific status)
South African black duck
Miombo blue-eared starling*
Common pochard (European pochard)
Coal tit (Nominate subspecies)*
Common moorhen (Eurasian moorhen) (Nominate subspecies)
Dusky turtle-dove (Pink-breasted turtle-dove)
Spotted crake
Corncrake
Northern bald ibis (Waldrapp)
Western water rail (Water rail)*
Common waxbill (St. Helena waxbill) (no subspecies-status)
Western eurasian griffon vulture
Egyptian vulture
White-faced whistling-duck (White- faced tree duck)
Trumpeter finch
Common Little bittern (Little bittern)