Table 1.

Abundance estimates in ten populations of Hydromantes ambrosii, obtained with different approaches.

Cave	N max	N-mixture models		Removal sampling
		Abundance	95% CI	Capture rate	Abundance	95% CI
Pignone left entrance	27	33.8	29/39	0.5	24	*
Pignone right entrance	38	50.1	45/56	0.702	53	51/63
Pignone main cave	38	53.3	48/59	0.636	59	57/70
Pignone – False snake’s hole	5	11.0	7/16	†	†
Pignone – Ambrosi’s sinkhole	3	8.7	5/13	†	†
Fornace	30	43.3	38/49	0.38	76	*
Fornace left entrance	15	23.8	19/29	0.6	20	19/33
Pignone abandoned mine	52	57.8	54/63	0.386	114	92/240
Spelerpes	6	13.1	9/18	0.426	13	*
Alta di Castè	123	144.5	138/152	0.382	244	219/300

N max: max number of individuals detected in one single survey session.

^†The method was unable to estimate population size.

^*Estimation of 95% CI was not available.