Keep the lights down low and hang feeders if you want the local birds to sleep in.
“In comparison to chemical and noise pollution, light pollution is more subtle, and its effects have perhaps not received the attention they deserve,” said Bart Kempenaers of the Max Planck Institute for Ornithology in Germany. “Our findings show clearly that light pollution influences the timing of breeding behavior, with unknown consequences for bird populations.”
The researchers investigated the effects of artificial night lighting on dawn song in five common forest-breeding songbirds. In four of those five species, males near street lights started singing significantly earlier in the morning than did males in other parts of the forest.
Further study of the effects of that behavioral shift on blue tits based on comparison of their reproductive behavior with and without street lights over a 7-year period showed real consequences. Females near street lights laid their eggs on average a day and half earlier. And males near lights at the forest’s edges were more successful in attracting “extra-pair mates,” meaning that they more often sired offspring with females other than their primary social partners.
That might sound like a bonus for those males, but Kempenaers said that doesn’t mean it’s good for the species, and it might not even be good for the males in question. read more
Feeding wild garden birds during the breeding season may delay the start of the dawn chorus sung by some species, say researchers.
Their study claims to have found a link between supplementary feeding and the observed changes in songbird behaviour.
The scientists made the discovery studying populations of great tits living in the suburbs of Oslo, Norway.
Birds with access to feeders delayed their song by up to 20 minutes, often beginning only after the sun had risen. Feeding garden birds such as tits delays dawn chorus