| ORNIS | Greek word for "bird" that refers to a region's collective avifauna (5) |
| FAUNA | Carl Linnaeus's word, essentially invoking the name of an ancient rustic goddess of the countryside and nature's bounty, for a region's collective animal life, as opposed to its flora (5) |
| AVES | Pluralisation of the Latin word for "bird" that is the class of the aforementioned vertebrate, from Abbott's babbler to zebra finch (4) |
| BIOTA | From the Greek meaning "life", a region's collective flora and fauna (5) |
| ORNITHO | Greek word for "bird", used as a prefix in avian terms including those relating to augurship, auspices, fowl-lore and volucrine phobia (7) |
| QUOIN | A homophone of a word for a nummary bit, flan or piece, that refers to a corner/keystone, a salient angle of a building, a voussoir or a wedge (5) |
| STADE | ___ was a sprint of approximately 200 yards in the Ancient Olympics. Fill in the blank with a word that shares its root with an English term that refers to a sports arena. |
| SIGMA | Greek letter that refers to a lone wolf, in Gen-Z slang |
| WADER | Common high boot for bird that walks in water |
| OPCIT | Latin abbreviation that refers to a previously mentioned work, thus avoiding repetition of the full title |
| NOUNS | Words that refer to a person, place, or thing. (5) |
| RHYME | Word for bird |
| ASSAM | Multitude going back to a region famous for tea (5) |
| NUBIA | Excellent hairstyle returns to a region of Africa (5) |
| BIRDS | Vertebrates described in or forming an avifauna such as the Passeriformes that include, amongst others, the British songsters (5) |
| FLORA | A region's flowers, as opposed to fauna |
| AREAL | Relating to a region (5) |
| CLIME | A region's climactic conditions (5) |
| SYLVA | Written work on a region's trees (Var.) |
| ZONAL | Relating to a region |
