Saturday, January 20, 2007
Where would I roost?
Where would I roost?
I have been fascinated by the number of birds that fly up from the valleys around Ashdown Forest, Kent, UK to roost on the heathland on the top of the Weald. Maybe I would have expected the opposite, as its quite a bit colder up there.
Protection or avoidance of predators, and Conservation of Energy are clearly elements to be optimised, and maybe the height and heathland nature can indeed aid these factors.
Heathland is not a fertile place, almost by definition, and therefore does not of itself support many local predators. Local territories will also be larger, and unlikely to be an issue of competition.
From an energy point of view, there are a number of items that counter the obvious problem of being exposed to worse weather.
The sun is more available in the morning and evening, allowing longer active days, despite the commute. Better visibility for feeding opportunities and predator concerns.
More speculatively
- it provides a visible focus for populations, allowing concentrations to form more easily.
- it provides "potential" energy, allowing a downhill commute to work, rather like the building of underground stations above the general level of the track. And morning thermals will not be so essential for larger birds.
This may be particularly important if you are a large predator. And this does happen.
- It provides a variety of slopes that might provide protection from the prevailing weather.
- Naturally a roost will eventually be predated, and random moves over time may be a good idea, which can be easily achieved because of the natural focus that will allow pre-meetings and last minute changes of site.
MartinW
I have been fascinated by the number of birds that fly up from the valleys around Ashdown Forest, Kent, UK to roost on the heathland on the top of the Weald. Maybe I would have expected the opposite, as its quite a bit colder up there.
Protection or avoidance of predators, and Conservation of Energy are clearly elements to be optimised, and maybe the height and heathland nature can indeed aid these factors.
Heathland is not a fertile place, almost by definition, and therefore does not of itself support many local predators. Local territories will also be larger, and unlikely to be an issue of competition.
From an energy point of view, there are a number of items that counter the obvious problem of being exposed to worse weather.
The sun is more available in the morning and evening, allowing longer active days, despite the commute. Better visibility for feeding opportunities and predator concerns.
More speculatively
- it provides a visible focus for populations, allowing concentrations to form more easily.
- it provides "potential" energy, allowing a downhill commute to work, rather like the building of underground stations above the general level of the track. And morning thermals will not be so essential for larger birds.
This may be particularly important if you are a large predator. And this does happen.
- It provides a variety of slopes that might provide protection from the prevailing weather.
- Naturally a roost will eventually be predated, and random moves over time may be a good idea, which can be easily achieved because of the natural focus that will allow pre-meetings and last minute changes of site.
MartinW
