Meteorological winter began Dec. 1; it is close to halfway through. We've gained 21 minutes of daylight as of Friday since the solstice Dec. 21.

So it's time to hear the first whistled "what-cheer, cheer, cheer" songs of the northern cardinals, which is a sure sign of spring as they sing in response to the lengthening days. Yes, one season slides slowly into the next. On Jan. 8 in 2015, and again in 2016, we heard their first welcome spring music in the Waconia-Victoria area.

The male northern cardinal, a bit smaller than an American robin, is a predominantly red bird with a crest. Females are yellowish-brown with tinges of red and are recognizable by their crests. Plus, they have the same black mask and thick red bill. The singing by the male cardinals becomes more frequent by the middle of February, and from then until nesting both the males and females can often be heard whistling. This is closely connected with establishing breeding territories. These birds are nonterritorial during the winter, and in the southeast one-fourth of Minnesota they can be seen in flocks of 20 to 30 birds at some feeding stations.

Northern cardinals are permanent residents in the central and southern regions of Minnesota. The species has extended its range significantly during the last 130 years. The cardinal was only a visitant in the late 1800s.

Jim Gilbert's Nature Notes are heard on WCCO Radio at 7:15 a.m. Sundays. He taught and worked as a naturalist for 50 years.