- Description
- Nest Box Summary
- Nest Boxes Map
Land Department staff have installed 127 bluebird boxes and 19 wood duck boxes on SMSC land. Nest boxes are intended to provide nesting habitat to secondary cavity nesters, birds that use existing cavities to build a nest. A primary cavity nester, like a woodpecker, excavates a new cavity. Many secondary cavity nesters experienced low population levels during the 20th century as settlers cleared forests for fuel, building, and agriculture. We have observed many species nesting in our boxes including American Kestrel, Hooded Merganser, Wood Duck, Eastern Bluebird, House Wren, Tree Swallow, Black-capped Chickadee, and House Sparrow.
Our nest box program has increased nesting of target species on SMSC lands (see [Nest Box Summary] tab). We have bluebird boxes at several locations on SMSC lands (see [Nest Boxes Map] tab). We survey bluebird boxes once per week to remove undesirable species such as House Sparrow and to check on the health of nestlings. House Sparrows are a non-native bird introduced from Europe that out-competes bluebirds and other native species for cavities. They destroy eggs and have been known to remove chicks from established nests. Removal of House Sparrow nest material and eggs creates an open niche for other native cavity nesters like bluebirds. We also encounter problems with Tree Swallows. Although native, they’re aggressive and usually take over nest boxes before bluebirds have a chance to occupy them. One strategy to mitigate this problem is to place boxes in groups of two approximately 15 feet apart. Tree Swallow pairs claim one box and defend the other box from other Tree Swallows. Oddly, they do not drive away other cavity nesters like bluebirds from the spare box.
Staff check Wood Duck boxes in the winter when frozen water allows easier access to wetland locations (see [Nest Boxes Map] tab). One management problem with Wood Duck boxes has been that Grey Squirrels nest in the box before Wood Ducks. Grey Squirrels also destroy nests and eat eggs. We partially solved this problem by placing boxes further out in wetland locations but staff have actually observed Grey Squirrels climbing out over the cattails to get to a box. We will continue to explore ways to prohibit squirrels entry by removing cattails from nearby boxes, installing baffles, and placing boxes in open water areas. Another, often ignored management problem, is to limit the number of boxes that one places on a wetland and to install boxes in such a way that they are not visible from one another. Wood Ducks will "dump nest" if give the opportunity (see [Photos] tab). This happens when a hen lays her eggs in another female’s nest. The host female then is forced to incubate the intruder’s eggs as well as her own, and if she is successful, she must tend to an exceptionally large brood. This extra work places undue stress on the hen and is not good for the population as a whole.
Staff also conducted annual breeding bird surveys from 2000 – 2006. A breeding bird survey is designed to identify the presence and likelihood that a species is breeding within a given area. We used literature to determine what species are likely breeding on or near SMSC lands, designed datasheets for field surveys (see BreedingBirdDatasheet.pdf), and created field maps using aerial imagery and sample unit boundaries in a Geographic Information System (i.e., GIS).
Workers conducted surveys approximately three times from sunrise to 10 a.m. CST from late-April to mid-July but we also recorded observations made during other time periods. We surveyed for owls at night during late winter and early spring because of their early breeding season, and we also conducted evening surveys for Common Nighthawk during the regular April to July breeding season.
Observers recorded bird species using a behavior-based system of codes. For example, the behavioral code "S" represents a singing male [observed in suitable habitat during the breeding season] and this is a possible breeding indicator. On another day, the worker may observe the same species on the same sample unit as a "NY", Nest With Young, and this represents a confirmed breeding indicator and the highest possible evidence of breeding. The second record supersedes the first record, and the sample unit has confirmed breeding for that species.
