Bird song; copycats (part two)

Whilst some birds have a beautiful repertoire of songs, others go one step further and steal, or mimic, tunes.  The lyrebird is an interesting example of such a bird:

David Attenborough describes it’s song as elaborate and complex and it most certainly is.  As well as borrowing melodies from other birds, it incorporates other sounds of the landscape into it’s tune, including manmade sounds such as camera shutters.

How birds learn to sing is covered in numerous scientific papers and textbooks but from what I’ve gleamed, most birds combine nature and nuture.  That is, they have an innate song within them but they enhance this throughout their lives starting with the songs they hear from their parents and adding to this as they get older and have more life experience.

Take for example the lyrebird.  If they lyrebird from the video clip had babies then they would hear the collection of sounds and would learn to sing them.  As the lyrebird chicks get older, they will hear different sounds, perhaps a mobile ringing, a car speeding past or a differernt species of bird.  They will then incorporate these sounds into their own song.  This means that each lyrebird potentially has a slightly different collection of noises at their disposal, a map of their life as it were. And the transmition from parent to child means that the song of the lyrebird could be considered a cultural history of the lineage of that particular bird.  I love that idea.  Of course, some of this is just my own speculation but it is this concept which is behind the phrase genetic memory on the oracle card.

Other birds which imitate calls include mockingbirds, starlings and marsh warblers.

But why do they mimic?  Well, hypotheses have been made that it makes the bird more attractive to other birds as it increases their range of songs.  It could also be to protect against predators – if you can made a noise that the predator would fear then you’re going to be a lot safer.  It might be related to territory, if you pretend to be a more dangerous species you might face less competition (assuming of course they can’t see you).  In the case of birds, like cuckoos, who lay their eggs in the nests of other birds, mimicry would mean that the babies would be less likely to be evicted.

Talking birds

Pet songbirds and parrots have been shown to mimic human speech but it’s not confined to captive birds.  On occasion when these birds have entered the wild, other birds have picked up words and phrases from them.  There are also cases where wild parrots in Australia have mimicked human speech picked up from the park where they reside, resulting in the odd “Hello darling” and “What’s happening?”.

Some birds have been forced to perform their talent repeatedly and have been promoted as talking but whether they understand what they are saying is another issue all together.

Human copycats

Humans have long been fascinated by birds and their songs and human imitation of birdsong dates back millennia.  In the early 20th century, with the advent of recording equipment, records began to be released of both bird song and of human imitations.

Composers such as Beethoven have created pieces which intentionally imitate bird song, others have incorporated recordings of birds into their work and some musicians have even duetted with birds.

Next time I’ll be looking at how bird song has influenced human culture including our music and literature.

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Bird song; who, why, when (part 1)

When I started to think about what to look into this month, bird song was an obvious choice.  There’s been many a morning when, at 3am, unable to sleep, I’ve had the pleasure of hearing a little tweet coming from outside and it has been very comforting.  What I didn’t realise is just how many subtopics there are when it comes to bird song…

Why do birds sing? How do they sing?  How do humans interact with bird song?  How are bird songs represented in music, poetry and literature?  How do birds hear songs?  Do they hear them the same as we do?  What is it like for bird watchers who lose their hearing?  How else to birds communicate?  What about birds who can’t sing?

So many questions!

Spoiler: I won’t be answering them all!

Today I managed to photograph the allotment robin

Who, why and when?

I was going to include how but it’s very technical and there’s lots of websites out there that will explain it much better than I can…

Who?

Well, firstly, there’s a common misconception that it’s only the female birds which sing.  In the UK in general, it isn’t.  And as a disclaimer, everything I’m saying here is generalised, there are a lot of birds out there and there are exceptions and I’m sure there are still many bird species left for science to discover.  So yes, in general, it’s the male birds which sing.  In the UK.  Well, in Europe and the Americas.  In the tropics and parts of Australia and Africa, females often sing as much as males.  And some of this is to do with why birds sing.

But not all birds sing, or call.  Some communicate in other ways or complement their vocalisations with other displays.

Why?

This question has some straightforward answers but I’d also like to add a note that we aren’t inside a birds mind so we can’t know why it does everything, perhaps some birds just like the sound of their own voice.  The scientifically researched answers are to attract mates and to hold territory.  There are also alarm calls.

Before I look at this in a bit more depth, I want to consider what bird song actually conveys to the bird who is listening.  Firstly, it tells the listener who is singing, that includes what species they are and can include which individual is singing.  It also says where the singer is, giving detail about direction and distance.  And it gives the listener information about the quality of the singer.  All of these are important things if you are a bird.

When it comes to areas where females sing as well, we find that there is less seasonality and this means there isn’t a breeding season as such.  Because some years food can be scarce, these birds need to mate when conditions are right, regardless of the time of year.  It is thought that singing, especially duetting, brings both the males and females into ‘season’ and hence they can reproduce.

In areas where the males are the ones who sing, they do so to attract mates – and hence it’s useful for the female listener to know that the male is the same species.  Their singing advertises their attributes and the best singer gets the best mate.  Experiments suggest that the quality of a males song is related to their sexual fitness and hence an indicator of how well his young will fare.  It’s also been shown that parasites and diseases may affect his song and thus are a helpful sign of his health.  Songs can also signal other characteristics such as their exploration behaviour which gives insight into their boldness, dominance, their foraging skills and their ability to learn.  In Great Tits, the repertoire size and singing activity (the number of songs) have been shown to be important in mating selection, with the latter being a reflection on the males exploitative behaviour.

When it comes to territory, the information shared in the song is crucial.  If you hear a bird singing nearby, you need to use the location information to establish if it’s within your territory.  There is no point wasting energy fighting off another bird who isn’t actually a threat to your land.  If it’s borderline then knowing who is singing is important.  If it’s a neighbour, you will react differently than if it’s a stranger.  Long term neighbours are probably not a threat to your territory – you’ve got a mutual understanding that you don’t push the boundaries if they don’t.  If it’s a stranger on the other hand, you’re going to need to get ready to confront them.  And singing is one of the tools in your toolkit.  If your song tells the intruder that you’re strong and tough and ready for a fight they will hopefully back down before further measures need taking.

When it comes to alarm calls, the message can be specific with one type of call to warn of a ground predator, another to warn of aerial ones.  Sometimes other species of birds have learnt to react to these alarm calls.

Another use for song is to help birds ‘see’ in the dark.  These types of vocalisations are used by species which live in caves like swiftlets.

When?

Obviously some of the answers to why birds sing will answer the question of when they sing.  We know now that birds sing to attract mates, so will sing during breeding season.  They also sing to stand their ground or warn of threats and this are going to happen to some extent all year round.  But in terms of time of day, the most popular time for birds to sing is the dawn chorus, about 40 minutes after day break.  Having said that some species start before this including the wren, robin, song thrush and blackbird.

Of course, nocturnal birds will sing at night and in the UK, this includes owls, nightingales, corncrakes and nightjars.

In part two, I’m going to be looking at mimicry and after that, bird song in human culture.

A history of birds and humans

Way, way back in time, when dinosaurs roamed the earth, birds evolved.  But our story starts a little bit before that with dinosaurs who had feathers and who could fly.  This was several hundred million years ago and these dinosaurs were huge. They had massive wings made of skin, think of a bat’s wing, and had feathers.

Then, over time, evolution led to the bird and then circumstances would result in the reign of the bird.  When dinosaurs were wiped out, birds could take to the stage.  At this point mammals were quite small and birds could be quite big.  In fact one vulture had a wingspan of over twenty feet so its no wonder birds essentially ruled the world for a while.  There were also huge flightless birds which dominated the land.

For those birds who could fly, this allowed them to travel far and wide and world domination is only a slight exaggeration.  Birds can be found all over the world – at their southern extreme, the snow petrel breeds 270 miles inland in the Antarctica.  Over 120 million years, they have adapted to very specific climates and environments and have lived very successfully ever since, possibly in part due to their very versatile beaks.  Whilst different species use them differently and have evolved different shapes and styles, they allow the bird to carry out actions they otherwise couldn’t; cracking open food, moving stones, pecking into trees and ice…

Today there are thought to be over 10,000 species of birds ranging range in size from the 5 cm bee hummingbird to the 2.75 m ostrich.

The success of birds has, of course, been impacted by the increase in human activity… Since the 17th century, 120-130 species of birds have become extinct and human activity is threatening at least 1,200 species today.  Of course, birds did become extinct before human activity but we are certainly having a significant impact on them and I’ll be looking at that later this month.

It is no surprise, given their range of habitats, that people and birds have a relationship that almost certainly dates back to the start of humanity.  Birds are prominent in the environment, they are a source of food in themselves and the eggs they lay and I can’t help but imagine that our ancestors would have been in awe of their ability to fly.

Stone age drawings and bones found in settlements provide evidence of this relationship.  Sometimes the relationship is mutually beneficial, sometimes birds benefit from human activity and sometimes humans benefit from bird activity. This close relationship has seen its way into our languages with phrases such as nest egg, bird brained and birds eye view.  We also find birds throughout folklore, mythology and literature, areas which are so vast they need their own blog posts.

Modern threats from human include hunting, egg collecting, poisoning (accidental or intentional), predation from pets, habitat disruption and threats such as roads and wind turbines.  With this in mind it can be easy to overlook threats that birds pose to humans, a key example being diseases.  Because of the long distances birds can cover, they can spread diseases around the world and some of these can be transmitted to humans.  There are also incredibly violent birds such as the cassowary which can cause a lot of damage if threatened.

Ornithology

Perhaps one of the more obvious ways that birds and humans interact is through bird watching and the study of our feathered friends.  The study of birds began with Aristotle who had some interesting thoughts, especially about swallows.  He started the long lasting myth that they hibernate in winter, an idea that was still noted in the 19th century.  After Aristotle, things went fairly quiet until the 17th century and then in the 19th century, things really took off.

The Victorian era saw the field of natural history revitalised.  It was the time of Darwin’s concepts and his work on sexual selection encouraged interest in birds.  Bird collecting was encouraged as a pastime for young men as it got them outdoors and into the fresh air.  Given the camera was in it’s very early days, the best way to examine birds and to learn about them was through dead specimens and through eggs.  Birds would be shot and preserved, neither easy tasks especially prior to the 1820s when a more reliable method of preservation was made popular.  This allowed collectors to build up larger numbers of higher quality specimens but despite this, many remained unattractive and storage became a problem.

We also have to note that this was a time when British explorers were heading out to “discover” new places and find new specimens.  The early 1800s was a time of colonial expansion and expeditions regularly involved amateur or professional natural historians.  These ventures would return with drawings, details about sightings, dead and live specimens.  These were destined for private collections but the idea of public museums was coming alive and by 1830 they would feature major bird collections.

Other factors fed into this interest in birds and ornithology including the development and refinement of field glasses, first used in the 1820s but used more widely towards the end of the century.  The rise in field guides was another factor.

Bird watching grew in popularity, including amongst amateurs and over time the scientific community began to value the knowledge and data that the former could provide to advance discoveries and findings.

Bird watching had been revolutionised by the impact of easier travel, better technology, increased knowledge and ability to share this knowledge.  Today, bird watchers can use apps to identify species, to mark sightings and to share photos, and some of this is used by scientists to track birds and monitor changes.

Birds and humans have had a long history, some pretty and some considerably less so, and it is that relationship that I hope to focus on this month.

Humans and Birds

We’ve already looked at humans and plants and humans and animals but I wanted to look at birds separately (as I hope to also do with insects and water creatures).

Birds experience the world so differently from us, as a basic difference of course they fly.  They ‘see’ the air currents, some of them live in trees and other high places, some of them migrate epic, unimaginable distances.  And despite this amazingness, I bet most of us have seen a bird today.  We might not have consciously noticed the pigeon, blackbird or crow but I bet you saw one.

robin2 e

Birds have been around so long that they saw the dinosaurs, possibly as long as 150 million years ago.  They predate flowering plants, bees, great apes and of course humans.  They probably evolved from flying dinosaurs, becoming more aerodynamic and feathered.  Once the dinosaurs were wiped out, birds took to the stage, or rather the skies.  At this point mammals were quite small and birds could be quite big.  In fact one vulture had a wingspan of over twenty feet so its no wonder birds essentially ruled the world for a while.  There were also huge flightless birds which dominated the land.

Birds have evolved and changed and can now be found pretty much world over including the harsh climates of the arctic and Antarctica as well as deserts and cliff edges.

This month I’ll be looking at birds through a number of lenses as well as focusing on specific species but in the meantime, you might want to check out the birds I’ve already written about.  Or perhaps, given the rather long list, pick your favourite birds or those you’ve not heard of before.  If I was going to recommend a bird to read about I’d go with the crow (and its relative the raven).