Something that has crossed my mind many times is why are birds more colourful in hot countries?
Being originally a pohm and visiting the UK regularly I notice that the birds there are much plainer in colours than say, Australia or Africa or Asia. Likewise when I have been snorkelling, the best places (with the most colourful fish ) are hotter countries.
I would be having a guess Heva but here it goes. Perhaps it is due to a lot of factors such as abundance or shortage of food, Migrational factors, and even breeding habits. Another crucial factor could have occured over millions of years - the evolution and adaptation of species in an aim to pro-create etc.
Warm climates may have a prolonged period of fruiting/flowering plants, this would lead to a strong resident bird population. Perhaps over time birds have adapted their different bright colours in order to stand out from other species and indeed from competitiors from the same species.
Blending into ones surroundings may play a factor in regards to avoiding predators. Most marshland or desert birds (not all) are drab in colour and suit their surroundings, could not the same rule be used for birds that frequent areas with colourful tropical plants. (the same rule could apply to tropical fish) Counter this arguement with the need to be seen... this could explain the brighly coloured birds in the darkness of a dense tropical rainforest.
Finally colouration could be due to the lack of mating display or voice!!! I know it sounds a bit strange but I am thinking of some of the birds of paradise and their elaborate dances, bower birds and their ability to build, lyrebirds and their ability to mimic, and even butcherbirds and magpies and their ability to sing; All of these birds aren't vibrant and colourful and obtain a mate by other means. Colour could be a mating display for those who live in food abundant tropical areas and just don't have the time to make the effort and sing!
As I said I am only hypothosising here. Would be very interesting to see what other members think.
Well I researched it when Hev posted it, and could find nothing really substantive on the net. I did read that the reason for tropical birds having the green backs & wings predominantly is to blend in with the surrounding foliage. Underneath they can be really bright at times.Camouflage is an obvious reason, I agree.
but thinking of Pink and Grey Galahs and white cockatoos for example I can't see it following.
The pro creation theory is an interesting one, and the beautiful singing birds being plain too. I remember being incredulous that the beautiful morning serenade was from a plain old black and white bird!!!!
Sunshine Coast Queensland
I think the ice ages would have a lot to do with it. The northern hemisphere was covered with ice in many areas until 20,000 years ago. The retreat of the ice was very recent and hasn't allowed much time for evolution of colours etc. I know that for example the uk has only about 40 native tree species, less than exist in 1 square km of rainforest. Evolution in the southern and tropical areas has been uninterrupted for millions of years so lots of colourful birds have evolved.
For Australia anyway Hev, I would say an evolutionary fluke- the flora and fauna present at the time, Australian flora and fauna evolving in isolation for 40 M years or more and we have a rich array of flora adapting and evolving in mostly poor soils where you generally don't get a dominant species (WA wildflowers for instance- thousands of different flora in a hectare). The fauna is also evolving with this flora, so to get an 'edge' on other fauna they need to stick out, i.e. colour, mimicry, mating displays. We also have so many different climates within the country. The amount of species in an English wood is much less than a comparable area in Australia, the soils and climate are not as poor or harsh, flora species dominate (less overall diversity) which form specific relationships with the fauna and there is less evolutionary pressure to stand out. Remember, when evolving there can be a trade-off- colour can also make you stand out to predators, trade-offs can further set the evolutionary wheel in motion. It is such a fascinating topic and theory.
Oxalis is not my friend