I have a friend who teaches fourth grade. Each year she takes her class to visit a Great Blue Heron colony. I have joined her for this outing the past few years. After my first trip I realized that the children would get much more out of it if they could look at the herons with binoculars.
I received two pair in response to a FREECYCLE wanted post.
In my thrift store excursions I have been watching for more binoculars. Most of the ones I find are broken and/or too expensive. However over the years I have collected 10 pair. My most recent find was this pair; 
The binoculars themselves are in good shape. I can’t say the same for the strap. So I set out to make another one of my thrifty fixes.
In my sewing supplies I had this lanyard
That and a needle and thread gave me a new neck strap,
Which I put to use Tuesday.
What are they looking at?
As I told the children:
Great Blue Herons (GBH) live throughout North America. But here in the Puget Sound area we have the non-migratory Pacific subspecies consisting of about 1500 pair.
GBH are seasonally monogamous. Each February the herons return to their nesting colonies, claim and rebuild a nest. When existing nests are claimed new nests are built (usually by birds that are nesting for the first time). The males collect sticks 
and the females construct the nests.
By mid-March they lay 3-7 eggs that are about 2 ½ “ long. Male and female share incubating duties for the next 28 days. When the eggs hatch one parent keeps the chicks warm while the other forages for food for the family. They regurgitate predigested fish for the newborns. By 1 month of age the chicks can be left alone, they have enough feathers to keep them warm and it takes both parents to satisfy their growing appetites. When the chicks are older they are fed whole fish.
Adult herons also eat frogs and small mammals.
At two months of age the chicks start “branching”, climbing out of the nests and exercising their wings. From this activity they learn about wind current, navigation, and landing techniques. When they have learned their lessons its time to leave home. The young birds are tended by their parents for about two weeks after they leave the nest, then they are on their own.
In two years they will be fully mature and raise a family of their own.
afrugalspinster 
Interesting on the herons. It never occurred to me that they nested in trees. I always assumed that they nested along the shore.
Great fix on the strap!