Tube Bird Feeders
Looking for a tube bird feeder? There are a couple of types of tube feeders. the first type is basically dedicated for serving thistle seed, while the other is for mixed bird seed.
Tube feeders of course get their name from the shape of the feeder, as it's long and narrow, and the body of the feeder is usually clear, allowing you to see the level of the seed supply easily. The seed capacity is determined in part by the length of the tube, which can run up to 36 inches.
Thistle seed is great for attracting small birds like finches, but because of the small size of the seed the feeder needs to have a port that will handle this small thistle seed (otherwise known as nyjer seed). This seed is imported, and is favored for its high oil content, which is a source of energy for the birds. Most "thistle seed" sold today is actually nyjer seed.
Nyjer feeders have a unique design to use the nyjer seed. They will have long slots in the body of the tube, instead of the traditional holes at the bottom. Some will have the slots under the perch which is a favored way for some goldfinches to feed, but keeps other birds away from the feeder.
For those feeders using a traditional mixed seed, or dedicated to larger seed such as sunflower seed, there will typically be pairs of perches and ports. This also attracts some pests such as squirrels and larger birds, so there are some tube feeders that include a wired cage to keep the larger animals out of the bird seed.