This small nest, which I found on my front yard, contained shed hair from my dog, Cali, and more than two feet of monofilament fishing line. (David Figura | dfigura@syracuse.com)

Last weekend I found a small bird’s nest in a forsythia bush in our front yard with a two interesting building materials – hair from our dog, Cali, and more than two feet of monofilament line.

We’ve been brushing our white-haired dog for the past couple of months on our front lawn, leaving the hair on the grass. Evidently, the dog’s scent didn’t bother the bird that picked it up.

“Birds do have a slight sense of smell, no better than ours. It most cases, it’s a little poorer,” said bird expert Laura Erickson, author and former science editor at Cornell’s Lab of Ornithology. “Birds often use hair from other animals to build their nests. It’s a natural fiber that doesn’t stretch of shrink when it gets wet.”

I described the size and location of the nest and Erickson said it could have been a tuffed titmouse or a chipping squirrel. She said she once witnessed a tuffed titmouse pluck hairs from the tail of a sleeping raccoon at Sapsucker Woods in Ithaca; and on another occasion, from the carcass of a road-killed squirrel.

The length of the fishing line, which I figure I made available by haphazardly tossing on the lawn, was troubling, Erickson said. Birds often get entangled in discarded fishing line and die, she said.

“It’s a careless and easy thing to do. A lot of people do it,” Erickson said. She noted discarded fishing line in coastal areas is the main cause of mortality for brown pelicans.

At locations where there’s a lot of fishing activity, Erickson added it’s a popular Eagle Scout project to create a monofilament disposal barrel or container for fisherman to use.

Erickson said saving and throwing junk fishing line in the garbage at home is better than tossing it on the ground on the side of a stream or into the water on a lake. She pointed out, though, it may still end up at a landfill where a bird can get at it.

She suggested using scissors to cut it up into small pieces that aren’t very long before disposing of it.

Erickson said birds use a wide variety of skins, feathers and fur from other animals to build their nests. Great crested flycatchers, for example, use the shed skins of snakes.

I asked her about the most unusual building material she’s seen in a birds nest.

“I have seen cellophane used from discarded cigarette packs. Evidently they didn’t read the warnings on the package,” she said.