Guanaco abundance and monitoring in Southern Patagonia: distance sampling reveals substantially greater numbers than previously reported

Zoological Studies

Table 2 Density and population size

Social unit	Relative abundance	Contacts	g ( w )	Groups/km ²	D (ind/km ² )	Lower limit	Upper limit	CV	N
	Low	11	0.15	0.0431	0.4413	0.1289	1.5101	69.04	26,173
	Medium	103	0.13	0.2249	2.3047	0.8001	6.6393	57.77	200,020
	High	64	0.10	0.3455	3.5409	1.2066	10.3910	58.95	270,700
Breeding group	Pooled	178	0.12	0.2179	2.2328	0.7839	6.3600	57.04	496,900
	Low	18	0.14	0.0347	0.3712	0.1792	0.7681	37.81	22,013
	Medium	129	0.15	0.1413	1.5128	0.9988	2.2914	21.29	131,290
	High	100	0.19	0.2656	2.8437	1.6483	4.9059	27.77	217,400
Non-breeding group	Pooled	247	0.17	0.1556	1.6658	1.1253	2.4657	20.02	370,710
	Low	29	0.06		0.0814	0.0434	0.1643	36.72	4,828
	Medium	159	0.05		0.2538	0.1495	0.4309	27.42	22,029
	High	111	0.12		0.4297	0.2375	0.7774	30.76	32,849
Solitary individuals	Pooled	299	0.08		0.2683	0.1595	0.4512	26.90	59,706
	Low	7	0.13	0.0396	0.0910	0.0201	0.4130	89.33	5,402
	Medium	86	0.14	0.2766	0.6364	0.1479	2.7370	85.15	55,236
	High	47	0.22	0.3665	0.8434	0.1964	3.6225	85.04	64,481
Undetermined	Pooled	140	0.17	0.2443	0.5622	0.1328	2.3801	83.91	125,120
	Low	63	0.14	0.1920	1.1228	0.6663	1.8920	26.89	66,590
	Medium	464	0.14	4.7028	4.7028	3.1082	7.1156	21.32	408,160
	High	315	0.17	1.3236	7.7419	4.9303	12.1570	23.16	591,870
All contacts	Pooled	842	0.15	0.8194	4.7928	3.2704	7.0240	19.65	1,066,600

Estimates of guanaco density (D) and population size (N) for each observable social unit and in three classes of expected relative abundance of guanacos in Santa Cruz Province, southern Patagonia, during the 2004 and 2005 breeding seasons. The number of intervals used to fit the most parsimonious detection function was 10 in all cases. g(w) is the value of the detection function at the truncation distance (600 m for solitary guanacos, 500 m for other social units). Upper and lower limits of 95% confidence intervals for density estimates are reported. CV coefficient of variation of density estimates.