Log In

Reset Password

It’s in your nature: Some questions answered

The past few years I have been asked questions, mostly about birds, and now since I’ve been submitting my columns, I get quite a few more. I thought I would share a few.

“Why do the blackbirds keep flying over my pool and keep putting their droppings there?” That is one question I have been asked.

Altricial birds, those who have young that are entirely dependent on the parent bird for the first few weeks of their life, have natural bodily functions just like all other animals.

Birds, especially those that nest in cavities or nest boxes (bird houses), need to keep the nest clean. Nearly every time a nestling eats a bug it defecates, and with both parents making hundreds of trips to them each day, imagine all the “droppings” in the nest or nest cavity.

Parent birds have adapted to this by carrying away the nestling’s fecal sac on each trip from the nest. The fecal sac is important for keeping the nest rather clean and to help keep it from smelling and attracting predators. The fecal sac is an important adaptation for passerine birds.

If you take your dog for a walk, a plastic bag accompanies you to enable you to clean up the mess. The fecal sac is like a tiny disposable bird diaper. It is a super thin mucous sac that contains the feces so that it can be quickly and easily removed from the nest.

Back to the reader’s question: For some still-not-explained reason, grackles and other birds such as tree swallows like to drop the fecal sacs in water. If your backyard pool is the closest body of water, it gets the aerial gift.

Another question I’ve been asked: “Why is the house wren in my yard building multiple nests?” Male house wrens arrive back to the Times News region before the females and get to work quickly. The male wren wants to impress a potential mate and quickly builds partial nests in your wren houses, a clothes pin bag on the wash line, or a coffee can in your shed. After she arrives and accepts one of the nest sites he still may stuff the other options full to discourage any other males from trying to claim his “area.” He seems to be a tireless builder.

Another question: “Do bluebirds migrate from our region in autumn?” Surprisingly, Eastern bluebirds, which feed mostly on insects spring through fall, are able to switch their dietary habits. Since bluebirds can eat small fruits, they may remain in the Times News region even through our colder months. They also have adapted by finding cavities (or your bluebird boxes) which they enter as darkness falls. But here may be the surprise. Many bluebirds cram into this cavity to conserve energy and share the body heat. I was curious one January evening a few years ago at my home in East Penn Township. I bundled up, grabbed my binoculars, and counted the bluebirds as they roosted in one of my nest boxes. Six bluebirds entered the box and spent the night protected from the biting January winds.

Unfortunately, they don’t always survive. This past February, I checked my one bluebird trail at Troxell’s Dairy farm to clean the boxes and remove the old nests. I was saddened when I opened one and found three desiccated male bluebird carcasses. How they died is open to conjecture.

Learn more, get out there.

Test Your Outdoor Knowledge: House wrens have___ brood(s) each year. A. one, B. two, C. three.

May 22 Trivia Answer: Ground temperature signals the emergence of Brood X cicadas, precisely 64 degrees F.

Contact Barry Reed at breed71@gmail.com.

This brown thrasher nest was only about 3 feet off the ground in this concolor fir tree. If the nestling's fecal sacs weren't removed the smell would certainly attract predators. BARRY REED/SPECIAL TO THE TIMES NEWS
Above: Cliff swallows, with their nearly enclosed nests, certainly need to remove the fecal sacs for the nest to be successful.
If you have bluebirds utilizing one of your nest boxes, spend a few minutes watching the birds bringing grub into the box, but note when they exit, they carry away a fecal sac.
Left: By lifting the side clean-out of a bluebird box, I discovered hundreds of small twigs a male house wren used to keep other wrens from moving into his territory.