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Posted At: 16/10/2008 07:48:25
Thought you might find this of interest all you Robin lovers.
As a species the robin is doing very well and its population has increased by 45% since 1970.
Along with other small songbirds, robins are relatively short-lived. They live on average only a couple of years, but a few reach quite an advanced age. The oldest known wild individual was 11 years 5 months. Mortality is high and its causes are many and varied. Only 28% of fledglings and 38% of adults survive to the following year.
A large number of robins succumb to cold, starvation and disease, which, combined, are the biggest cause of death.
Several diseases affect robins, many of which are difficult or impossible to diagnose. The most obvious disease is alopecia, loss of feathers, often associated with a fungal infection. It is most apparent around the head, but in severe cases a bird can become almost bald, often with yellow encrustations of affected skin. Some recover, but advanced cases tend to be fatal.
Ringed birds later found dead show that the cause of death is known for only a small percentage of individuals. The domestic cat takes 15 times more birds than owls and sparrowhawks, while road casualties and territory disputes account for a similar number of birds as predation.
All mortality is more than compensated for by the high rate of reproduction, and it appears that only surplus birds perish. As a species the robin is doing very well and its population has increased by 45% since 1970.
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