Table 3. Morphology and numbers of sensory pits in the North Island brown kiwi, Eurasian woodcock and bar-tailed godwit.

Species	Bill bone	Sensory pit shape	Sensory pit orientation	Sensory pit size: width at surface x depth (mm) (n pits, n individuals)	Number of sensory pits
					0-5 mm	5-10 mm	10 -15 mm
North Island brown kiwi	Premaxilla	Oval in cross-section, tapering with depth. Broad, ovoid perforations at the base communicate with underlying nerve channels.	Backward-facing proximal of the premaxillary symphysis, outwards-facing distal of the nares, forward-facing at bill-tips. Face downward and forward in sensory pad region.	0.35 ± 0.07 x 0.56 ± 0.18 (57,3)	113	15	5
	Dentary	As above.	Ventral, lateral and dorsal sensory pits outward-facing; forward-facing at bill tips.	0.36 ± 0.06 x 0.49 ± 0.14 (49,3)	91	27	No tissue
Eurasian woodcock	Premaxilla	Multi-sided in cross section giving the bill-tips a 'honey-combed' appearance. 'Flat bottomed' with broad perforations communicating with underlying nerve channels	Distal-most face forwards, all others face outwards.	0.35 ± 0.07 x 0.37 ± 0.10 (23,1)	159	132	86
	Dentary	As above.		0.32 ± 0.05 x 0.36 ± 0.05 (23,1)	134	116	131
Bar-tailed godwit	Premaxilla	Oval in cross-section, tapering with depth. Broad, ovoid perforations at the base communicate with underlying nerve channels.	All pits forward-facing.	0.24 ± 0.05 x 0.33 ± 0.10 (20,1)	110	43	0
	Dentary	As above.		0.23 ± 0.04 x 0.39 ± 0.15 (20,1)	49	41	No tissue

Number of pits were counted from micro CT scans of segments of the bill bones between 0-5 mm; 5-10 mm and 10-15 mm proximal of the tip of the premaxilla and dentary bones.