The many goldfinches which visit our garden and feast on sunflower kernels consume very much more than any other small garden birds e.g blue, coal and great tits. Could it be because they have a higher metabolic rate and need more food?
Hello - I found where I had heard about this topic, I think it's from a reputable site ornithology.com/.../ In part it is too scientific for me but basically the author says some do have a higher rate than others and why this may be so. It made me have a look to see what else is out there. There are similar articles/studies etc - but alas no specific mention of our goldfinches that I can see. It's generated quite a discussion - but I think by finding out and learning about these things we can help look after our birds. Thanks for posting your question Danny.
I've just had a reply from someone in the garden ecology group responsible for the goldfinch survey I mentioned in an earlier message. Whist the group do not have hard evidence to answer the question he adds: 'I suspect there will be a difference [in metablic rates], but other factors will play a part, such as the different fats in the seeds and how the birds are able to process them, along with the amount of energy different birds use. For example, goldfinches are more mobile than the tits, and will likely spend more energy moving between sites and even migrating to Europe.'
Yes, exactly. It was evidence on that which I hoped for when I posed the question. But, whilst an unusually high metabolic rate was the first hypothesis that came to my mind in trying to explain what looks frenetic eating on the part of our goldinches, it's obvious that there are a range of other plausible hypotheses which could explain why they far out-eat our other small bird visitors.
Great that the garden ecology group responded, their comment/explanation makes sense to me. A good outcome Danny.