22 July 2011
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 around 40 per cent of fledged birds will survive from one year to the next. High levels of mortality are compensated for by high productivity and the robin population has increased by 45 per cent since 1970.
Severe winter weather can have severe impacts on robins. A bird can use up to 10% of its body weight during one cold winters night, and unless able to feed well every day to replenish its reserves, a prolonged cold spell can be fatal.
In normal circumstances the fat reserves built up by the bird will keep it going for a few days, but mortality tends to increase rapidly if a cold spell continues into a second week.
Birdtables can make a big difference to the survival of urban and suburban robins. The favourite birdtable treat is mealworms. Other useful foods are meaty kitchen scraps, fat, cheese, cake and biscuit crumbs, and dried fruit. Peanuts are also taken, but they are better shredded or crushed than whole.