Moments after the sun slips behind the horizon and only a few golden embers remain at the edge of the far western sky, I know it is time to listen for my resident cardinal. Like clockwork, this brilliant red male returns to roost every evening at exactly 10 minutes past sunset.
I can hear his nervous notes as he approaches from somewhere in the neighborhood. The calls grow louder as he flies closer to the rhododendron beneath my living room window. He settles there for the night after a few adjustments to a finer and safer perch. His calls stop when he has found his perfect place; it is a thin but stable rhododendron limb close to the house with a good vantage point.
One might wonder why he would choose to roost so close to the house. After all, a wild bird ought to find security farther away from such a busy place as my front door-yard. Though I have flushed the bird on many occasions while returning home late at night, the rhododendron has its advantages.
For starters, the rhododendron keeps its leaves and therefore helps to deflect heavy snow. The roost is also facing southwest, meaning the house acts as a wind break from the cold north side. It is also a few degrees warmer close to a house, as heat inevitably must escape from the interior of my home. Finally, few predators such as hawks and owls are likely to venture so close to a human dwelling.
Different species have different roosting preferences though. Some roost in large flocks, some in pairs, others choose to roost alone part of the year and in flocks at other times.
These differences represent strategies that help each species in their survival. Birds that roost in a huddle are obviously benefiting from each other's body heat, but a pair that roosts together may have other reasons for spending the night together. Pairs often roost together prior to nesting as a way of bonding in anticipation for the rigors of jointly caring for their young. In some cases, a female will roost closely with her mate to keep the male from wandering or having relations with another female.
There are numerous strategies to communal roosts. Large flocks that come together at dusk may have a better chance at spotting approaching predators with a collective set of many eyes; however, these birds may be "sharing" information about where food is available, too. In this way, younger, less experienced birds may follow the older individuals to food sources as foraging begins at daybreak.
For my cardinal, foraging begins while the sky is a wash of pre-dawn gray. The day begins as it ended, with the cardinal's call notes, and when the last star flickers and fades into the increasing light, he ventures to the feeder and then far beyond into the neighborhood. One cardinal survives into another day.
Robert Tougias is a Colchester birding author. He is available for slide presentations and can be reached at firstname.lastname@example.org.