LOCATION, LOCATION, LOCATION
As they say in the real estate industry, location is of prime importance for a good quality residence. Birds are no exception, but for them the location of their nest is a high-stake undertaking. It can mean success in raising a new generation or failure to do so, when for example predators will raid the nest.
Bald Eagles and Ospreys are known to build huge nests, such as this one below.
|Osprey near its nest, for scale, by Sjahanmi|
A good example of the latter is the Great Blue Heron. Their colony is called a ‘heronry’. Herons need large and sturdy trees due to their size. They use the same nests year after year, and because of this eventually the trees die from guano buildup and the herons need to start a new colony elsewhere.
In addition to animal predators, the heronry is vulnerable to humans during the nesting season. If chicks are disturbed and fall off the nest, they can’t fly back up into the nest and the parents stop feeding them. They will either starve or fall prey to other animals.
The photos below show a nest by a Grey Heron (ardea cinerea) and some of those birds in a heronry in Japan. The grey heron is similar to the great blue heron and has the same nesting habits.
|Grey heron heronry, Tokushima, Japan|
|Grey herons at top of trees in heronry|
Tokushima Central Park, Japan
|Grey heron, Kamo River, Kyoto, Japan|
|Spotted shags, Red-billed gulls and Black-billed gulls on rock colony, New Zealand|
|Black-billed and red-billed gull colony|
on rocky island, New Zealand
|Spotted shag juvenile, New Zealand|
|Red-billed gull, Kaikoura, New Zealand|
|Black-billed gull, Christchurch, NZ|
Bank Swallows nest in colonies along shore banks or gravel or sand pit slopes, near the top:
|Bank swallow nests, PEI, by Marie Smith|
|Kaena Point Coastal Reserve, Oahu|
|Double gate and fence, Kaena Point|
|Laysan albatross, Kaena Point, Oahu|
|Wedge-tailed shearwater, Oahu|
The Chimney Swift (Chaetura pelagica) builds its nest inside the vertical wall of a chimney. The American Robin (Turdus migratorius) can build its nest near a house or right onto some house structure, such as this one who used a Christmas wreath. (I once had a nest of robins on top of a window frame of my house in Quebec.)
Birds can also use a rural mailbox to build a nest. [When I was living in rural Quebec, one morning I picked a pale blue egg with my mail, courtesy of a European Starling (Sturnus vulgaris) that had started a nest inside the mail box.] These birds can also make a nest in the hollow pole of street lights at the top.
The Common Nighthawk (Chordeiles minor), in natural settings, builds its nest on the ground. However in cities it will settle on flat roofs with gravel. Unfortunately there is a decrease in these types of roofs, so this bird’s population also decreased accordingly.
The Barn Swallow (hirundo rustica), as its name implies, is well known for building its nest on and inside barns. However for lack of a barn, this swallow will readily use other human-built structures, as seen below. In this case the barn swallows nested on the ballasts of neon lights of a strip mall in downtown Tokushima, Japan, a city of around 250,000 people.
The Song Sparrow (Melospiza melodia) nest below was built on the ground under a hedge in front of the photographer’s house.
An interesting case is Lucy the Duck, an American black duck who has consistently built her nest over several years among the plants for sale at the Atlantic Superstore nursery in Charlottetown, Prince Edward Island, Canada. It’s a sheltered protection from predators, and the nursery staff are helping shield her from visitors as well. Every year a special police patrol helps her and her ducklings cross the busy University Street to the other side, where she lives in a nearby marsh (see video below).
|Barn swallow nest, Tokushima, Japan|
|Barn swallows on nest, Tokushima Japan|
|Strip mall with barn swallow nests, Japan|
|American robin on nest under a house|
deck, PEI, Canada, by Marie Smith
|Song sparrow nest, by Marie Smith|
|American robin nest with eggs, PEI,|
Canada, by Kathy McCormack
|Lucy on her nest|
This tendency for some bird species to use human-built structures or a natural cavity for nesting has contributed to the development of a bird house ‘industry’. Building a bird house can be a popular hobby for a school project or a family, or a full time job for some enthusiasts. There’s all kinds of models and plans available in terms of materials, size and number of ‘units’, and which bird species they are intended for. Some models are affordable and easy to build, while others are more complicated and expensive. There are a few points to consider when buying or building a birdhouse:
You or the birds? Are you buying/building that birdhouse primarily to match with your landscaped backyard, for example, or are you first ensuring the birdhouse will meet the needs of the species you’re trying to attract? (Good planning could achieve both goals.)
What birds? Many bird species nest in cavities and will readily use human-built houses if available. However each species has its own needs in terms of size, location, etc. What are the bird species around your area? Which one(s) do you want to attract with a birdhouse?
Once you have identified the species you want to attract, then it’s a matter of choosing the appropriate materials, house size, location (safe from predators including the house cat) and other needs for that bird species.
Here are some sources of information on birdhouses (that website also shows links to many other birdhouse related topics) :
The Cornell Lab of Ornithology is an authoritative source of information for all things birds including bird houses:
One particular case of this human contribution to bird nesting is the building of platforms at the top of poles for birds of prey such as eagles and ospreys (photos below). Some of those birds are also known to build a nest on top of electrical poles (see photo below), a less desirable location as the birds risk electrocution and humans risk power outages.
|Eastern bluebird pair on nest box|
|Osprey nest on platform, PEI, Canada|
|Osprey nest on electrical pole, PEI|
|Red-tailed hawk nest on electrical pole|
|Blue jay on bird house, PEI, Canada|