Nebraskaland

62 Nebraskaland • November 2022 MIXED BAG Birds make nests to raise their babies, and do not use them outside of breeding season. Different birds make different types of nests, and during this time of year, the falling leaves will uncover a range of shapes and sizes. The construction of each nest corresponds with species-specific factors, including bird size, clutch size, time and energy needed for nest building, and the availability of cover, warmth, habitat and resources. For example, bald eagles are known for their huge nests, which they return and add to year after year. Eagle nests typically measure 5-6 feet in diameter and 2-4 feet tall, but they can be significantly larger. The largest bald eagle nest recorded weighed a shocking 2 tons. In stark contrast, the smallest nest we have here in Nebraska is that of the ruby-throated hummingbird. These thimble-sized nests seem fairy-inspired, made with whimsical materials such as thistle seeds, spiderwebs and lichens. When complete, these cup nests are only approximately 2 inches wide and 1 inch deep. So, how can you identify the nest you find? Unless the birds or eggs are present, this can be tricky business. However, there are a few clues to help narrow down the field. Hanging Nests When trees shed their leaves, one nest many people notice is the woven hanging "socks" of orioles. Often suspended from the edge of branches, these nests are designed with strands of grass, vine, hair and even manmade materials, such as twine and fishing line. Cup Nests Cup nests are a very common form of nest. When trying to determine what species built a cup nest, there are three clues that can help: size, materials and location. For example, a barn swallow builds a 3-inch cup nest made primarily of mud and lined with feathers. The nest will be found attached to a manmade structure such as a barn. On the other hand, a brown thrasher creates a slightly larger 3.5-inch cup nest of twigs, leaves, dead grass and rootlets. They hide their bulky nests in the branches of bushes, with preferences for bushes with thorns. Platform Nests Platform nests are the style of choice for birds such as ospreys, bald eagles and herons. The platforms are constructed by layering twigs and branches. Materials such as grass or feathers are sometimes added to soften and insulate the structure. Platform nests can be found in trees, cliff edges or on manmade structures including wooden platforms that are placed to encourage nesting. Cavity Nests Cavity nesters place their nests inside a chamber of a tree, rock face, chimney or bird house. Primary cavity nesters are the birds that can excavate their own home. A great example of a primary cavity nester is the woodpecker. Secondary cavity nesters, which are birds that use already excavated chambers, include chickadees, kestrels, wood ducks and others. The nest placed within the cavity can vary greatly. For example, mountain bluebirds make a shallow cup of grass in their cavity. The house wren takes a more "stuffed" approach, packing in twigs between the eggs and entrance for extra protection. These birds may also welcome the presence of spider sacs in their "house" design. When the spiders hatch, they help eliminate pests such as mites. If you are interested in learning more about identifying bird nests, visit NestWatch.org. It also is home to NestWatch, a community science project that invites participants to report nest-related data from their backyards to the Cornell Lab of Ornithology. WHOSE NEST IS THIS? By Alie Mayes, Community Science Education Specialist An orchard oriole's hanging nest. JUSTIN HAAG, NEBRASKALAND Barn swallow's cup nests on a bridge. JEFF KURRUS, NEBRASKALAND A bald eagle's platform nest in a tree. ERIC FOWLER, NEBRASKALAND A woodpecker's cavity nest in a tree. ERIC FOWLER, NEBRASKALAND

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