Northern Cardinals decreased until 1979, then increased until 2005 and have been stable since the (blue on map = increase, red = decrease). The increases have been at the northern and western edges of their range, and since 2005, they've been decreasing in the south.
#NABBS #BiologicalMonitoring #Birds #PopulationTrends #NorthernCardinal #NOCA

Pine Warblers increased across their range from 1966 - 2000 (blue regions on maps). Since then they've been fluctuating but overall relatively stable. That survey-wide stability is a composite of decreases in the south (red coloured regions in south) and ongoing increases in the north (blue coloured regions).
#NABBS #BiologicalMonitoring #Birds #PopulationTrends #PineWarbler

Here's another species that provides an interesting contrast:
American Kestrel, apparently cyclical pattern in time that is largely consistent across the species' range.
#AmericanKestrel
#NABBS
#CitizenScience
#BiologicalMonitoring #mcmcStan #birds