No need to remind you that all birds lay eggs to reproduce. To successfully hatch and then tend them until they fledge generally requires a well-built and usually a specific kind of nest. Each species has a unique nest and an experienced birder or ornithologist can find an empty nest in fall, and without seeing the builder, identify what species built it.

What I find most amazing, and hopefully you will too, is that nest building is innate, referring to a trait an offspring has at birth without being taught.Think about it, a young robin hatched from an egg placed in a nest already constructed by a parent did not have the ability to watch mom or dad make hundreds of trips carrying specific nesting materials and placing them "just right" to complete a robin nest. If a young robin watched the nest building and this was a learned behavior, something wrong could occur.Let's refer to the three little pigs. Pigs one and two were apparently a bit lazy and built insufficient domiciles. Pig number three was the good learner and built a home like mom taught him. A species like robins could not continue to replenish its numbers if two out of three nests would fail because of being "poor learners."For a second example, my late father was an excellent sheet metal mechanic. I worked with him for five or six years throughout my teens. Try as I might, I could never construct a plenum or custom make a 45-degree sheet metal angle like he could. Luckily, for birds, they are born with the ability to build a carbon copy of their nest. In short, the robin nest in your backyard is almost an exact replica of a backyard robin nest in Ames, Iowa.Think of the tireless energy a bird has in building that "custom built" nest. A cliff swallow builds its nest under a cliff face or, more commonly today, under barn or building eaves.It needs to find a mud source, then beak full at a time, make 800 to 1,200 trips over a two-week period carefully packing the mud droplets and adobe style, let it slowly dry and come into shape.Next it needs to carry fine grasses, etc. into the opening to line the nest. All this is done so the pair can raise four or five young, hoping that a few of those offspring will survive to return to the same area next April to build their nest to perpetuate the species.Birds also choose specific locations to build their nests. The song sparrowmost commonly places her nest 2 to 3 feet high in a dense shrub or conifer. Meanwhile, a rose-breasted grosbeak, a Carbon County forest bird,generally chooses a forked limb 20 or more feet up a deciduous tree.Most birds choose specific nesting materials as well. A chipping sparrow uses horse hair to line its nest, but if not available, will substitute human or other animal hair. Not too surprising, a barn swallow lines its nest with chicken feathers. I unfortunately have many more examples, but due to my column size limit, will add these in another article.Test your knowledge: Chimney swifts "glue" their nests to the inside of brick chimneys (about 15 feet inside) and are most common in towns like Weissport, Lansford or Slatington. Why are they not as common in more rural newer developments such as Lake Hauto, Penn Forest or Franklin townships?Answer to last week's nature question: Birds dust bathe to help clean and soak up excess oil, not to camouflage them.Contact Barry Reed at

breed71@gmail.com.