I live with a cat. I know my cat has an in-built clock, my body clock is not as accurate as her’s.
The rooster’s morning crow is driven by an internal clock. That clock also gives an accurate time. No dawn, no light, it’s roosters’ biological clock that tells when it is time to crow.
A new study has been published about cock’s clock.
LA Times says :
The scientists put three different groups of four roosters in light- and sound-tight rooms, recording their “cock-a-doodle-doo” -ing — or “ko-ke-kok-koh” -ing, as the Japanese would say — with sound recorders and video cameras.
When the roosters were subjected to cycles of 12 hours of light and 12 hours of dim light, the birds crowed about two hours before the lights came on. In conditions kept constantly dim, the roosters also continued to vocalize early in the “morning,” suggesting that their internal body clocks, or circadian rhythms, were involved in timing their crows at dawn.
Hoping to also gain insight into the relationship between body clocks and external stimuli, the team investigated further, checking to see if shining lights on the birds or piping sound into their enclosures also caused them to crow. It did — but again, the roosters were more likely to sing in the early day than later on, again suggesting circadian rhythm involvement.
In a statement, the researchers said they hoped to understand the innate calls of a variety of animals that don’t learn their vocalizations as humans or songbirds do.
I am thinking why roosters have a biological clock that controls crowing! Why is it so necessary for roosters to crow in the morning? Why don’t hens have an internal clock for clucking every 24 hours?
my clock tells me put the rooster in the soup pot and go back to sleep! lol
cock + crock pot = clock stopped.
On a side note, our cats are fed at exactly 6pm every day. Around four-ish one of the cats starts to nag about it being nearly six o’clock. Uncanny.
Er… hens do have an “internal clock”. The daily changes in vocalization patterns might not be as obvious (to us) as those of roosters, but they’re still there if you care to quantify them 😉
From a functional standpoint… Chickens are diurnal, foraging primarily during daylight hours, so it makes some sense for them to stake their territorial claims as early as possible each day, to allow them to maximize effective foraging while still getting sufficient sleep time. The same daily pattern of behaviour typically holds in other territorial species, and in species where the males are communal/social but vocally competitive for mates. It can also expose their location to predators, of course… but hens aren’t territorial (or at least, not nearly as much as roosters are), so there’s little incentive for them to advertise their presence to conspecifics at the risk of exposing themselves to predators.
Of course it also makes some sense for them to be able to crow when prompted by relevant external stimuli, so it’s interesting (but not really all that surprising, particularly given what we know about circadian rhythms in general) that the behaviour can be triggered by either internal or external cues, and that internal cues modulates the amplitude of the response to external cues.
Pigeons are known to navigate by magnetic fields, and dogs have incredibly sensitive senses of smell. Many animals have unusual traits, and can specialize and change with their environment, including us.
http://www.nature.com/news/pigeons-may-hear-magnetic-fields-1.10540
It doesn’t surprise that to learn that these animals are attuned to the Earth. Animal behaviour has long been linked to earthquakes anecdotally, though it’s still unproven.
http://www.bbc.co.uk/nature/15945014
http://earthquake.usgs.gov/learn/topics/animal_eqs.php