Are You Nidicolous?
By: Lee Foote
Tags: Nests, Birds

Nest-loving Northern Osprey

I emerged from my daughter’s room shaking my head and said “Our daughter is nidicolous”. Without speaking, my wife’s worried brow said “What is that? What to do?” It means she is “nest-loving”. Have you seen that pile of dirty clothes on her bed? It looks sort of like a Magpie nest. My rapid departure and closing her door suggested that I was nidifugous or “nest-fleeing”. In this case the “nidus” refers to nest and “colous” means fleeing. The young of many ground-nesting birds such as waterfowl, grouse, pheasants, and sandpipers flee their nests shortly after birth. For some, the need is to escape the noise, exposure and smells of the nest site which could draw predators. They also need to head over to the best available feeding sites. Unlike the naked pink and helpless nestlings of American Robins, Barn Swallows and Chickadees, nidfugous birds hatch out fully feathered and mobile. They are sometimes called another special word; “precocial” or ready to roll once out of the egg.

I love the language of ecology with its specialized terms drawn from Latin, French or Greek roots. On a more field-based level, next time you are walking in a winter woodland, notice how many bird nests you can see nestled in the leafless winter shrub borders. Saskatoon bushes, young aspens and dense Christmas trees make ideal nesting places. It is even OK for us to scavenge an occasional small cupped nest in mid-winter and bring them home as a natural ornament for our inside Christmas tree. A heavy spray with spray shelac or hair spray will help them stick together too. While some small perching birds will scavenge nest materials from previous year’s nests, it is rare to see a re-occupation. You too can be nidicolous.

Red Squirrels — one of the major northern nest predators

Location, location, location! The selection of nesting location is very important for birds. Nests must be carefully hidden to escape the keen eyed, egg-devouring ravens, magpies and jays. Nor should nests be built on any of the tree-limb travel lanes of red squirrels, weasels or flying squirrels, all of which relish fresh eggs or young birds for a protein-rich meal. Ideally, nests will have good structural properties so they don’t blow down, good thermal properties to gather warmth but not overheat or be exposed to cold rain.

Red-winged Blackbird on wetland fringing willow shrubs

They should be within a well-defended territory where males can alert all and mob predators but also have food within easy shuttle distance too. The cattail and bulrush nests of Red-winged Blackbirds are densest along the line where the water meets the reed bed. This is where big juicy dragonfly larvae haul out on the cattail stems to metamorphose into adults. Dragonfly larvae become the equivalent of a larvae-topped pizza delivery system for the territorial male blackbirds that select and defend territories in these ideal spots. Ultiately, that is where the females will want to be too. Similarly, although Barn Swallows may love porch eaves, barn rafters and bird houses, their site selections have a roof and are always close to hordes of emerging insects, which means wetlands. Barn, Tree, Bank and Cliff swallows all seek out wetland proximity for their on-the-wing foraging of insects dancing above water.

Common Mergansers — some of the largest cavity-nesting waterfowl

But don’t forget the other cavity nesters, including the whole spectrum of woodpeckers from the sparrow-sized Downy to the Crow-sized Pileated Woodpecker. These birds drill their own nest holes that are sometimes later re-used by all sorts of other hole-nesters like flying squirrels, owls, and pine marten among others. Many forest birds like cavities too including chickadees, titmice and nuthatches. Several waterfowl species common in Alberta are also cavity nesters; Bufflehead and Common Goldeneye, Common Mergansers and Hooded Mergansers. The cavity trees must be large enough to support such a cavity and within duckling walking distance of a suitable waterbody which means some older age-class trees need to remain near wetlands for the sake of species diversity.

Ultimately, beaver flooding will kill this birch tree

The sequence goes something like this: trees near water, beaver flooding, tree death, insect colonization, woodpecker excavation, ducks using the abandoned woodpecker cavities. It is a beautifully orchestrated chain of eventes that produces abundant duck broods. This shows one of the many ways that conserving biodiversity benefits species and us whether we are birdwatchers, nature lovers, hunters or all three.

Paraphrasing Aldo Leopold now, we need to “keep all the pieces” if these ecosystems are to continue working well.