Bright lights make city blackbirds grow up quicker: Urban birds thought to reach maturity 19 days quicker because of way they react to extra light

Brian Williams shows his face for the first time in a month: Disgraced anchor out with his family as legendary predecessor Tom Brokaw breaks silence on 'really, really serious case'
Tom Hanks' wife Rita Wilson, 58, reveals battle against breast cancer after undergoing double mastectomy
Suicidal Air Force vet says he almost ended his life after being put on HOLD three times by VA helpline
Through the gates of hell: Horror of Belsen is captured in never-before-seen photos taken by British troops as they liberated infamous death camp 70 years ago
Hitler's last 24 hours: 'Bullseye!' shouted Goebbels' little boy as Hitler shot himself in the head
EXCLUSIVE: Why are Flight MH17 victims' personal possessions STILL lying at crash site? Families' fury as charred passport is among items found nine months after jet was blown from the sky
EXCLUSIVE: 'Mommy needs to eat more healthy. No more Coca Cola': Body-in-suitcase teen reveals she thinks her baby is going bald because of her junk food diet in Bali prison
Who would call their child AIRWRECKA? The worst baby names in the world revealed... including Lucifer, I'munique and Orgasm!
Self control is the most important a parent can teach their child: Study says skill has a major influence on children's lives
RAF Typhoons scrambled to intercept Russian bombers near British airspace after HMS Argyll monitors destroyer as Nato stages exercises off Scottish coast
Stolen Valor? Row in Florida bar as man in uniform 'trying to pick up girls' gets aggressive when he can't answer simple questions about his basic training
Norway 'is taking foreign children away from their parents because it has the highest rates of inbreeding in the world': Country forced to deny claims after Lithuanian child is taken into care
'The black models were sent home early': Abercrombie and Fitch staffer reveals shocking details about the 'racism' she has witnessed while working for the retailer
Seattle to LA flight has to turn around after shocked passengers hear banging and screaming coming from baggage handler who'd fallen asleep in the cargo hold
Man tears tendon in his thumb after playing Candy Crush on his phone ALL DAY for more than 6 weeks
EXCLUSIVE: The verdict is in! Judge Judy gets top honors in the courtroom - and the bedroom - says her salty husband of 38 years
Man, 23, 'beat his girlfriend's toddler son to death for urinating on him during diaper change'
Pictured: Mother, 24, shot dead by her Marine veteran husband in Alabama doctor's office after he wrote chilling Facebook post saying he would 'die today'
TSA employees manipulated security body scanner so male employee could grope men's genitals at Denver airport
New police brutality outrage over video that claims to show California cops CLUBBING DUI motorist as he lays on ground
Married teacher accused of 'improper relationships' with two students and having sex with a third applies for diversion program to have all charges dropped
Strong winds blow thousands of blue jellyfish-like creatures onto Oregon beaches
'I am acting here, and this d**khead wanders onto my set!' Dennis Quaid blows his top on film set... but is he in on the joke?
Millionaire volunteer deputy turns himself in after 'accidentally shooting suspect dead when he thought he was firing his Taser'

City lights cause blackbirds to think days are 49 minutes longer on average
This can affect the birds' daily and seasonal biology, scientists say
Urban blackbirds therefore reach sexual maturity sooner than usual

Published: 18:52 EST, 16 March 2015 | Updated: 18:54 EST, 16 March 2015

View
comments

Bright lights in cities may be causing urban blackbirds to reach sexual maturity sooner than their country cousins, say scientists.

They found that the extra light from artificial sources in cities caused the urban birds to perceive the days to be longer by 49 minutes on average.

This affected their 'photoperiod', the part of a 24-hour day that is light. Organisms use this to time their daily and seasonal biology.

Bright lights in cities may be causing urban blackbirds to reach sexual maturity sooner than their country cousins

As a result, in early March the city birds experienced the length of day that their country counterparts experienced in late March.

The biologists believe the city birds' perception that they were living at a later point in the year caused them to reach sexual maturity 19 days earlier in anticipation of the breeding season.

The team, from Glasgow University and the Max Planck Institute for Ornithology in Seewiesen, near Munich, fitted tiny devices to the backs of 100 blackbirds in Munich, and in a nearby forest. These light loggers tracked the amount of light birds in both environments were exposed to each day.

The research was led by Dr Davide Dominoni of Glasgow University's Institute of Biodiversity, Animal Health and Comparative Medicine.

Extra light from artificial sources in cities caused the urban blackbirds to perceive the days to be longer by 49 minutes

He said: 'Artificial light at night is one of the most obvious environmental changes affecting the habitat of wild animals. The global increase in light pollution poses new challenges to wild species, but we're very much in the early stages of understanding the effects of exposure to light at night.

'Our research suggests that light at night is the most relevant change in ambient light affecting the biological rhythms of urban blackbirds, most likely by a modification of their perceived photoperiod.

'We're keen to continue our research and learn more about the effect of human activity on animals' biological clocks.'