Annual index results for British Columbia

Note: the range of the vertical axis has been scaled to highlight pattern in the annual indices. If estimates are imprecise, the graph may not include the upper credible limits.

View definitions of the annual index table columns.

Annual indices for Bobolink in British Columbia

Year	Annual index	Lower limit	Upper limit
1970	0.137	0.0466	0.253
1971	0.155	0.0604	0.285
1972	0.138	0.0542	0.244
1973	0.136	0.0584	0.22
1974	0.176	0.0877	0.281
1975	0.159	0.0859	0.244
1976	0.127	0.0708	0.193
1977	0.145	0.0736	0.224
1978	0.144	0.0888	0.218
1979	0.17	0.0946	0.248
1980	0.186	0.117	0.266
1981	0.211	0.13	0.299
1982	0.212	0.134	0.3
1983	0.218	0.138	0.308
1984	0.255	0.164	0.363
1985	0.236	0.153	0.331
1986	0.241	0.153	0.343
1987	0.23	0.149	0.328
1988	0.217	0.133	0.312
1989	0.18	0.11	0.258
1990	0.192	0.117	0.274
1991	0.167	0.0964	0.244
1992	0.165	0.0928	0.236
1993	0.178	0.106	0.251
1994	0.182	0.116	0.265
1995	0.179	0.107	0.256
1996	0.182	0.121	0.275
1997	0.19	0.119	0.272
1998	0.188	0.115	0.274
1999	0.187	0.116	0.268
2000	0.18	0.103	0.263
2001	0.165	0.0933	0.249
2002	0.179	0.116	0.271
2003	0.167	0.1	0.254
2004	0.145	0.0815	0.217
2005	0.15	0.0918	0.225
2006	0.13	0.0759	0.189
2007	0.11	0.0654	0.164
2008	0.0928	0.054	0.138
2009	0.0916	0.0533	0.137
2010	0.0852	0.0525	0.13
2011	0.0654	0.0333	0.0983
2012	0.0644	0.0311	0.102
2013	0.0505	0.0232	0.082
2014	0.044	0.0189	0.0729
2015	0.0366	0.015	0.0614
2016	0.0339	0.011	0.0574
2017	0.0287	0.00972	0.0528
2018	0.0248	0.00715	0.0475
2019	0.0224	0.00543	0.0433
2020	0.0204	0.00442	0.0411
2021	0.0179	0.00394	0.0381

Geographic area included in the Long-term trend for the Bobolink

      Coloured = Regions (analytical strata) included in trend estimate. The colour of the region reflects the approximate population trend in the region. The categories of trends based on the %/year values are indicated in the legend on the right, and the specific values can be found by searching on the analytical stratum trends for the same time-period and species.

      White = Regions not included in trend estimate

Bird Conservation Regions (BCR) with data included in Long-term trend estimates for British Columbia

• British Columbia (Great Basin (BCR 9), Northern Rockies (BCR 10))

This web site may be cited as: Smith, A.C., Hudson, M-A.R. Aponte, V.I., English, W.B., and Francis, C.M. 2023. North American Breeding Bird Survey - Canadian Trends Website, Data-version 2021. Environment and Climate Change Canada, Gatineau, Quebec, K1A 0H3

Any use of these BBS results for Canada should acknowledge the hundreds of skilled volunteers in Canada who have participated in the BBS over the years and those who have served as provincial or territorial coordinators for the BBS.

1. Smith, A. C., & Edwards, B. P. M. (2020). North American Breeding Bird Survey status and trend estimates to inform a wide range of conservation needs, using a flexible Bayesian hierarchical generalized additive model. The Condor, duaa065. https://doi.org/10.1093/ornithapp/duaa065