This video from North America says about itself:
Black-Capped Chickadee Vocalizations – Did You Know?
19 April 2014
The “Chickadee dee dee” call by Black-capped chickadees is one of the most complex vocalizations in the animal kingdom and is said to be language -like. This call is used in many social interactions such as, contacting members of the flock, or giving information about an individual’s identity, other slight changes in the phrase of this call can relay other specific messages.
Who’s who?: How chickadees figure out dominance hierarchies through song: here.
From daily The Morning Star in Britain:
Animal noises ‘more closely linked’ with human speech
Tuesday 19th August 2014
ANIMAL vocalisations have more in common with human speech than previously thought, scientists claimed today.
Research published by the Royal Society in its Proceedings B biological science journal suggests there may be a missing link between sounds animals use to communicate and the more complex linguistic abilities of humans.
“Language is the biggest difference that separates humans from animals evolutionarily, but multiple studies are finding more and more stepping stones that seem to bridge the gap,” said lead scientist Dr Arik Kershenbaum of the National Institute for Mathematical and Biological Synthesis in Tennessee, US.
“Uncovering the process underlying vocal sequence generation in animals may be critical to our understanding of the origin of language.”
It has long been recognised that some species of animals possess distinct vocabularies.
Some monkeys have a range of cries distinguishing between threats, which is useful since the evasive action appropriate for a snake attack is different from that for a bird of prey.
But linguists have so far held that animals lack the ability to use grammar to change or extend the meanings of individual sounds by reordering them.
Their vocalisations were believed to follow a structural system known as the Markov process, where sound sequences could easily be predicted by listening to a finite number of preceding elements.
The sounds produced fitted statistical models for human language instead, the scientists concluded.