Who’s Coming To Dinner?
Or Life is a Buffet
As different birds land on the feeder, you might be wondering why it is that there are certain species of birds that come to enjoy your offerings, while others don’t. If you live in a city, or live in the woods, who is “a coming and calling for dinner”, may be very different from one place to another, even if it is only a short distance separates the two. Other birds may only show up at certain times of the year or may only stop by for a short visit of a day or week. You hold a handful of soil and you know or have been told that millions of living things are right there in your hand, are they be the same if it were handful of a forest soil verses a handful of a city lot soil? What kind of creature are making holes in your maple or rhododendron leaves? As you discover the leaves of some of your plants have eaten, yet the plant next to it hasn’t been chewed on at all and why is it many times you never see them, but you surely know they were there. What we are observing is species requirements and types of different habitats. From microorganisms, fungus, lichens and mosses to plants and trees and from insects to birds, reptiles, amphibians and mammals.
We might think to landscape for wildlife whether for ourselves or for our clients, who have expressed a desire for butterflies or hummingbirds to frequent their gardens with a colorful display. So what is it we need to do attract a particular species or wildlife in general. We all know the 4 basic requirements for a habitat: food, water, cover and space. It sounds simple, at least for the first three and the forth (space) is the area that is required to fulfill the first three including cover which is a place to seek shelter from the weather, protection from predators, cover for predators seeking prey and for reproduction and raising young.
So when we think about ‘space’ we might look from our own point of view; for we might consider that our homes and our yards as being our habitat; a source of water, food and cover. Yet our water comes from a larger area, even if we have well water that is taken from the ground under our feet. For our ground water is that of a the watershed where all of the moisture that is received in the form of rain and snow slowly peculates thru the soil and recharges our aquifers and ground water. Even if you are on public water, the area that is required to supply its’ residents, may be well beyond your town or city’s limits and may cover hundreds of sq. miles and in some areas in dryer climates it they might be drawing on water from thousands of miles away. Our food may ideally be local, but even that would be regional rather that from our own food sources that we grown or raise at our homes. And for most of us, it isn’t ideal and the food we eat comes from thousands of mile away and today most likely some of it comes from the other side of the planet. The other factor of space for us is that we need to travel in our work in order for us to make the money that allows us to buy the food, the electricity to power our pumps, to have water at our faucets and to keep that roof over our heads. So our space requirements when we think about it , is a series of habitats that would have be considered part of our individual habitat that cover our base needs.
All living things have their own type of habitat and yet for almost all habitats they are dependent on other habitats for their own survival. It can be direct or indirect but they are interdependent and influence by each other. All living things fall within a range of their ability to survive different habitat requirements, from generalist that can survive in many different habitats to species can survive only in very narrow range of moisture requirements, to types of food and cover it requires. From the smallest such as what lives in that handful of soil, what life is there is dependent on the larger habitat where that soil comes from. The handful of material in your hand might be a fine particle base such as clay, silt or the larger particles of sands and gravel and stone and what microorganisms that can live there are dependent on the same 4 basic requirements water, food, cover and space. So with water (or moisture) with each of these different particle sizes interact in different ways; from clays ( poorly draining to very poorly draining) where there is very little space between particles that when the water table is high those spaces are fill with moisture pushing the air out. and on the larger scale of habitat what plants and trees that can survive seasonal water saturation and for how long it remains that way. The other characteristic of clay soils is in periods of dryness it takes a lot of rain or snow to re-moisten it again for much of the rain runs along the surface because of the smallness of space between particles and the water it follows the path of least resistance. Sandy and gravelly soils are generally well draining to excessive well draining and tend to dry out quickly, especially if sand particles are deep in the soil horizons. (As a side note these areas are where many our aquifers are located). Food the next requirement of microorganisms which are dependent on the larger living organisms that can live in the different types of soils for they provide the food for the microorganisms both directly and indirectly. Either they consumer other living organisms or the organic waste from other species consuming other living organisms within a given habitat and in turn they provide the food for other living things.
So given the different soil habitats from very wet to very dry and those different habitats in between. What each habitat can support for life in the whole range of living things. Starting with wet such as lakes, ponds, marshes, peat lands, wetlands, swamps, river riparian areas and floodplains. To the dry habitats of alpine and sub-alpine, shallow soils on bedrock, rocky ground, cliffs and talus, upland dry forest to sand dunes along the coast. Each of these habitats are unique, they may share species that can survive such different conditions, but there are also species that can only exist in a particular habitat and the layering of species, one dependent on the other that make each of these habitats unique. There are other habitats that fall between the range of wet and dry and all of these habitats may be approximate to each other the are separated by the conditions of soil, topography, weather and exposure.
I guess I’ll end for now where I started, at the bird feeder. I live in a residential area within a small city, but before had lived in woods, and what I notice is that many of the birds I seen in one location I see at the other, from chickadees, to nuthatches, fitches and tufted titmouses and one of the things and I wonder is where do they all live in my neighborhood? How far do the travel to feed upon the seeds I provide? And because I have squirrels who certainly aren’t going to give up a meal that I offering to other species (no matter how clever I think I am in trying to stop them) and with their messy eating habits, they wind up providing seeds for ground feeding birds such as mourning doves and dark eye juncos and for the rodents the tunnel under the ground and the snow to enjoy easy pickings. There are other birds that I never had before, such as wrens and house fitches that come with living in an urban environment. Yet there are many other species that never come to the feeders, like the robins or cedar waxwings that even in the dead of winter when have very little food sources other than the little fruit there is on a crabs or a pears and winterberries, they never consider sunflower seed even with raisins and berries that are mixed in? So the fact that I have bird feeders and a heated bird bath for winter and there are trees on the surrounding the edge of my property for shelter, have I created a habitat? Would they not be here if I didn’t keep the feeders full?