1. Seed-crushers Note the short, wide, and deep bill (“conical”); hooks absent or tiny; rictal bristles typically absent; upper mandible can be curved or straight. Alaudidae (Larks; 7+ species) Thraupidae (Tanagers; 75+ species) Cardinalidae (Cardinals; 40+ species) Passeridae (Old World Sparrows; 40 species) Note relative bill size varies dramatically, depending on relative seed size Fringillidae (Finches; 140+ species) Emberizidae (Sparrows; 100+ species)

2. Seed-crushers Note the short, wide, and deep bill; hooks absent or tiny; rictal bristles typically absent. Ploceidae (Weavers; 20+ species) Calcariidae (Longspurs; 6 species) Viduidae (Whydahs; 20 species) Note that although many families show this bill type, they are all closely related except Alaudidae, and all are in Passeriformes. Estrildidae (Waxbills; 120+ species) Icteridae (blackbirds; 4 species) At least 11 families, 550+ species

3. Carnivores Note the short, wide, and deep bills like seed-crushers, but strongly hooked for killing and tearing; upper mandible curved and typically much deeper than lower mandible. This bill is for tearing pieces out of prey too large to swallow whole. The killing is done with the feet. Strigiformes Falconiformes Accipitriformes Strigidae (Owls; 180 species) Tytonidae (Barn Owls; 15 species) Falconidae (Falcons; 65 species) Pandionidae (Osprey; 1 species) Accipitridae (Hawks; 230+ species) With the exception of some of the big eagles, bills size in carnivores relative to body size is SMALL. 3 unrelated orders, ca. 500 species

4. Large insect/small vertebrate eaters Note the relatively large bill in all dimensions, pronounced hook for holding and tearing, and (often) large rictal bristles. Bucconidae (Puffbirds – ca. 35 spp.) Alcedinidae (Kingfishers – 1 species) Coraciidae (Rollers; 12 spp.) Brachypteraciidae (Ground- rollers; 5 spp.) Piciformes Coraciiformes

5. Large insect/small vertebrate eaters Note the relatively large bill in all dimensions, pronounced hook for holding and tearing, and (often) large rictal bristles. Thamnophilidae (Antbirds; ca. 50 species) Cotingidae (Cotingas – 1 or 2 genera) Furnariidae (Ovenbirds – 1 species) Grallariidae (Antpittas; ca. 60 species) Tyrannidae (Tyrant-Flycatchers -1 genus) Passeriformes

6. Large insect/small vertebrate eaters Note the relatively large bill in all dimensions, pronounced hook for holding and tearing, and (often) large rictal bristles. Passeriformes Laniidae (Shrikes; ca. 30 species) Corvidae (Crows and Jays; ca. 100 species) Malaconotidae (Bush-shrikes; ca. 30 species) Cracticidae (Butcher-birds; 6 species)

7. Large insect/small vertebrate eaters Note the relatively large bill in all dimensions, pronounced hook for holding and tearing, and (often) large rictal bristles Passeriformes Laniidae (Shrikes; ca. 30 species) Cracticidae (Butcher-birds; 6 species) Malaconotidae (Bush-shrikes; ca. 30 species) Vangidae(Vangas; 2-3 species) Nicatoridae (Nicators; 3 species) Note: there is a continuum of variation between this bill type and the insectivore bill, with entire families such as Vireos and Old World Orioles not falling cleanly in either category This bill is for grabbing and killing prey that is relatively large relative to the bird’s size. The large rictal bristles are primarily for protecting the eyes from struggling prey At least 3 orders, 16 families, 350+ species Pityriasidae: Bornean Bristlehead, 1 species

8. Gleaning insectivores Note the relatively long, thin bill; many have slight hooks and small rictal bristles. This bill is for gleaning relatively small prey. Thamnophilidae (Antbirds; 100+ species) Furnariidae (Ovenbirds; 100+ species) Pittidae (Pittas; 25+ species) Rhinocryptidae (Tapaculos; 50+ species) Acanthisittidae (New Zealand Wren; 4 species) Oldest lineage in Passeriformes Atrichornithidae (Scrub-birds; 2 species)

9. Gleaning Insectivores Note the relatively long, thin bill; many have slight hooks and small rictal bristles. Zosteropidae (White- eyes; ca. 100 spp.) Turdidae (Thrushes; ca. 100 spp.) Old World Warbler families; ca. 400 spp.) Pycnonotidae (Bulbuls; ca. 120 spp.) Maluridae (Fairy- wrens; ca. 30 spp.) Timaliidae (Babblers; ca. 250 spp.) … and many additional smaller families

10. Gleaning Insectivores Note the relatively long, thin bill; many have slight hooks and small rictal bristles. Thraupidae (Tanagers; ca. 50 spp.) Parulidae (Wood- warblers; ca. 100 spp.) Motacillidae (Pipits and Wagtails; ca. 65 spp.) Prunellidae (Accentors; 13 spp.) Fringillidae (some species of Hawaiian honeycreepers) Icteridae (some species of blackbirds and orioles)

11. Salliers Tyrannidae (tyrant- flycatchers; ca. 350 species) Conopophagidae (Gnateaters; 8 species) Dicruridae (Drongos; 22 species) Rhipiduridae (Fantails; 45 species Eurylaimidae (Broadbills; ca. 8 species) Caprimulgidae (Nightjars; ca. 75 species From side profile, like gleaning insectivores or, for some big species, large insect/small vertebrate-eaters. From above, base of bill much wider, giving it a triangular shape. Rictal bristles often prominent.

12. Salliers Muscicapidae (Old World Flycatchers; ca. 200 species) Monarchidae (Monarchs; ca. 75 species) Platysteiridae (Wattle-eyes; ca. 25 species) From side profile, like gleaning insectivores or, for some big species, large insect/small vertebrate- eaters. From above, base of bill much wider, giving it a triangular shape. Rictal bristles often prominent. At least 10 families; ca. 800 species Machaerirhynchidae: Boatbill, 1 species

13. Check out the wide bill and mouth, and the rictal bristles on this Eastern Whip-poor-will in this amazing photograph by Brian Zwiebel. Also, check out the placement of the rictal bristles and how they would help shield the eyes from kicking insect legs.

14. Screeners Caprimulgidae (nighthawk genera: 10 species ) Hirundinidae (swallows: 80 species ) Apodidae (swifts: 90 species ) Note the very short bills. They are extremely wide, but this is often difficult to see. Wings are extremely long for the body size. 3 Orders, 3 Families; 280 species I suspect the distended throat means that this individual has harvested hundreds of tiny flying insects