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These bluebirds are busy raising kids

Living the Wild Life

A house full of kids always keeps parents very busy, especially if they are a hunting-and-gathering family with no supermarket let alone a convenience store nearby.

This week I ran into just that type of family – a family of Mountain bluebirds, west of Henrys Lake.

Poppa was sitting on a nearby fence post with a big caterpillar hanging out of his mouth as I pulled up. Just as I began taking pictures of him, a flying insect flew by him and I watched as his eyes followed it. I thought I heard him think as it flew past, “a bill full of soft food is better than chasing a crusty bug that is mostly wings and skinny legs.” A few seconds later, Mama came out of the entrance hole of the family home and nailed the spindly insect, returning to the nest as the nestlings begged for more food.

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The male bluebird hovers at the entrance hole trying to feed a caterpillar to the kids. | Bill Schiess, EastIdahoNews.com

Dad remained patiently on the post while the female went inside and then came out with a dirty diaper, flew across the road and deposited it on the top of a fence post. It was the first time for me to notice that most of the fence posts 100 feet away from the nest had multiple dirty diapers on them while the posts near the nest were clean. Each parent would wait on one of the clean posts while waiting for the other parent to exit the nest.

As I watched the nest for over an hour, the male appeared to be into “big bugs” as he brought a June bug, two grasshoppers and three caterpillars. Before delivering them to the kids, he would have to kill them by removing their heads. The grasshoppers were tough to dispatch as they fought with their legs by grabbing the bird’s feathers. Maybe the big bugs were to impress the kids, but I noticed that from time to time he would need to bring out the leftovers, like the wings and legs of his large offerings.

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The male attempts to clean off his bill after removing a fecal sac to a fence post. | Bill Schiess, EastIdahoNews.com

The female appeared to be satisfied with small offerings. Several times she captured flying insects, but mainly she delivered what appeared to be some sort of eggs, possibly large ant eggs. She would deliver three or four each delivery, organized in a row on most of the visits to the nest.

Mountain bluebirds are cavity nesters and is one of the species that the young produce their poop in fecal sacs. When a parent entered the nest box the young turn their backside to the adult which grabbed the waste and headed out to deposit it on a storage area. This usually happened after every second or third food delivery.

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The female bluebird takes a dirty diaper out of the nest to keep it clean and to protect the nest. | Bill Schiess, EastIdahoNews.com

Every time the female removed a poop bag, she held it carefully and placed it on a post while the male usually had it leaking before he dropped it. As a result, he would then land on a barbed wire and try to clean off the dripping guano.

Some species of birds, not these bluebirds, practice “coprophagia” which means that the adults will eat the poop bags. Scientists believe that the digestive system of young nestlings is not very developed, leaving energy and nutrients in the waste. They also believe that removing the droppings keeps the house clean and does not attract predators to the nest.

I was astounded at how busy these two parents were during the time I observed them. I learned a lot about them and enjoyed the show and hope to watch them until the nestlings fledge.

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The female waits patiently with four items of food while the male is feeding the youngsters. | Bill Schiess, EastIdahoNews.com
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