Stay-at-home Cardinals

In an earlier posting I described how our local pair of cardinals succeeded in fostering three broods this summer—an uncommon occurrence. To succeed in raising three broods is a good sign that mom and pop are healthy. I watched the fledglings from the first two broods disperse shortly after they left the nest. Their parents were about to start a follow-up brood and didn’t have time to coddle the previous batch, who by then knew how to fly and maybe even fend for themselves. It’s a tough world in the avian kingdom—babies don’t get pampered at all and thus the mortality rate for them is quite high, in those first few critical weeks after fledging. They fly off to locate new territory, but are very vulnerable to predators or starvation, until they learn some critical skills.

This third and final batch of offspring from our resident cardinal parents has hung around much longer than their older siblings. It’s a month or more since they fledged and they’re still loitering at the feeder. They are also beginning to molt and change into their winter colors. All cardinal young are drab colored—much like mom. As the fall ensues, they begin to replace some feathers through the molting process, and begin to acquire their adult plumage, which will not be completed until the next spring, following a couple more molts.

Two of the last three juveniles appear to be males, as their plumage is gradually getting a brighter red. I’m guessing that the third sibling is female, as she’s staying pretty drab colored, like mom. I’ve never seen the youngsters hang around this long, so I’m closely watching them, to see what will happen next.

Dispersal of the young is something that must occur for all species. Why? First, the parents may have claimed the only productive territory in the immediate vicinity, so the kids must leave in order to find their own habitat. Second, all animal species have adapted behaviors that discourage inbreeding, to keep the species healthy and robust. The way that happens is either the parents abandon the kids (if the parents do not have a home territory to defend) or the juveniles disperse. That way, family members are far less likely to breed with each other. In fact, for most songbirds, the young females tend to fly off farther than their brothers, which helps to reduce possible sister-brother inbreeding. The techniques Mother Nature has evolved are amazing!

It’s been very difficult for ornithologists to follow the dispersal habits of songbirds, because they leave the immediate area for parts unknown. How far must one try to track them? Recent technology has developed an ultra-light radio transmitter that is beginning to reveal how young songbirds disperse, so some of the mysteries will soon be solved.

So I will keep watching my cardinal family. A key question: Why has the last batch of kids stayed home thus far? I think I see dad trying to shoo them off at times, but I’m not sure that’s what’s really happening; maybe he’s just in a bad mood. Will the kids hang around all winter? The feeder sure seems to be a magnet for them. Are they still here because they’ve tried to find their own territory, but have been rebuffed by their older siblings or other unrelated cardinals?

If they stay, they might decide to help mom and dad raise more broods next summer. By doing so, youngsters can either help family genes move into the future (the main objective of any species) and/or learn nesting skills that will help them to be more successful parents the following year. I guess I’ll have to keep a close eye on this cardinal family—they’ve obviously got more to teach me.