Habitats and Niches

If we consider any particular bird or group of birds, the habitat which the bird/birds is/are found in can be described and information which helps us to understand something more specific about the niche it occupies and the way in which it lives can be detailed.

What we need to realise is that, especially in the case of birds which evolved a long time ago, it is inevitable that subtle changes to both habitat and niche will have taken place. At the extremes we can talk about ancestral and present day habitats.

Field guides focus mainly on features and characteristics which help "birders" to identify birds but rarely provide much information about habitats. Niches which bird species occupy are hardly ever mentioned. This is a neglected area which would benefit from discussion by like-minded "birders".


If the physical characteristics of evolving species are such that they find the particular part of the environment which they are in favourable they will prosper and this will become their habitat. The species can be identified with the habitat and this, taken with specific behavioural aspects, will establish a niche unique to that species. The habitat depends upon the circumstances at the time of evolution.

One thing we can say with certainty is that environmental circumstances change, especially when we are talking about time scales of tens of millions of years. Some birds have been able to adapt to change so they have survived and can still be seen today. We know quite a bit about the present day habitat of most birds but we can only speculate about the ancestral habitat.

I start by taking a simple view that the habitat is the place in which birds take their food. Many birds take more than one type of food and others have evolved to be adaptable and will take food in different habitats. When a favoured food is in short supply many will move to another geographic location where food is plentiful. Seasonally this can involve migration over considerable distances. Likewise some birds will move to a different location to breed.

Shared Habitats.

Many habitats will be home to two or more different groups of birds. They often eat different foods so they are not in competition with each other. The size of the habitat relates to the species involved and territory which they defend. Some birds are colonial and roost or nest close together. On the other hand the Golden Eagle defends a territory of many square miles.


Quite a few groups of birds are extremely adaptable and have evolved to fill a number of different sub-habitats and niches. It’s not unusual to find genera and species within a family which occupy totally different sub-habitats. This is one of the findings which I like to highlight.

Development of counterparts.

Birds which occupy specific habitats often have counterparts elsewhere. When I look at an Old World habitat I search for a similar New World habitat and vice-versa. It's quite pleasing when I find that such counterparts look quite like each other and behave in a similar fashion. Sometimes there is no counterpart to be found. In that case I like to understand why a particular species is not where I might expect to find it.


Ornithologists talk about niches within habitats. A niche within a habitat or sub-habitat is defined by a set of conditions in which a particular species can thrive. This is where feeding technique becomes an important characteristic. A classic example is the long billed probers where a number of different species can be seen feeding side by side. They are not in direct competition because their different lengths of beak allow them to access different aquatic organisms.

Where different species eat the same food in the same habitat their feeding strategies will be different. An obvious example is a habitat in which some birds feed by day and other feed by night. Other strategies might seem to be quite subtle but are the result of trial and error over many years.

With over 10,000 species of birds being currently listed there is no way I am going to attempt to define 10,000 niches. What I do want to do is to describe some which interest me particularly and to focus on some specific groups of niches.

Observable Characteristics.

Habitats can be observed and described in terms of geographical location, altitude, ground cover etc. These and many other factors need to be considered in relating a habitat to a particular group of birds. In many cases food and the way it is taken are the most important factors.

Safety is also a pretty high priority - it’s no good getting the food if you don’t live to eat it! For example, small, ground feeding birds, where safety requires that they nest in trees or bushes off the ground, the nature of the immediate surroundings in terms of avoidance of predators and means of escape, form part of the description of a suitable habitat.

Once I have defined a habitat for a particular group of birds I tend to try to establish other geographical locations where I might expect to find the same habitat. Habitats are rarely unique and the world is a big place. Once I find a similar habitat I try to establish whether similar birds are found there. If not I tend to ask myself why not?

Likewise when I find birds with characteristics which suit a particular habitat I look for other birds with similar characteristics. I am especially interested in cases where birds have similar characteristics but are nevertheless unrelated, and have established themselves in similar habitats in various parts of the world. Ornithologists call this Convergent Evolution.