How are animals adapted to the cold of winter? Why do some escape it, and are their migrations being affected by climate change? And as for the most important winter journey of all – are reindeer really the best animals to pull Santa’s sleigh? These are all questions we will be looking into in our Winter Wildlife: ZoologiCOOL livestream on Wednesday 1 December. Join us live on our YouTube channel at 7pm and put your questions to our winter wildlife experts!

Ask the Scientist is back for ZoologiCOOL!

We are excited to welcome some brilliant scientists ready to take your questions during our Winter Wildlife: ZoologiCOOL livestream.

Want to learn more about migratory birds and the challenges they face? We will be joined by Dr Carles Carboneras and Dr Guy Anderson from the RSPB who work to protect some of our most iconic and threatened migratory birds, including turtle doves, cuckoos and swifts. Find out more about the amazing journeys these birds undertake every year, and how scientists are working to better understand and conserve them.

We will also be joined live by animal locomotion expert Dr Matt Wilkinson, author of Restless Creatures: The Story of Life in Ten Movements, to take a playful look at what it would take for reindeer to pull Santa’s sleigh and answer your questions on the ways in which animals move.

Put your questions in the comments on YouTube during the livestream and we can put them to our experts live.

Did you ask our scientists a question that we didn’t get time to answer? We are working hard to get answers together for you! Scroll down to the end of this blog post to find them, and keep checking back as we update them!

Wonderful Waxwings

We have been working with our Young Zoologists Club members to create a waxwing irruption to feature as part of the Winter Wildlife livestream. Why not get involved yourself! Download the template and follow the instructions to make your own winter wildlife waxwing to fly alongside the livestream, and upload pictures or videos of your model to our community gallery so we can make a flock online too.

Watching Winter Wildlife

Inspired by Winter Wildlife: ZoologiCOOL to get outside and watch some winter wildlife? Here are some of the sights and sounds of winter in East Anglia, from the Whooper Swans visiting Welney Wetlands Centre and wading birds feeding at Titchwell Marsh to the starlings you might here in the trees on your doorstep:

Ask the Scientist: Your questions answered!

Did you ask a question during our livestream on December 1st that we didn’t have time to answer? We are working hard to get answers for you! Keep checking back here as we upload answers over the coming weeks.

(of the tracking devices used to monitor bird movements) Those satellites are HUGE! How can the birds function with them?

Dr Guy Anderson replies:

Satellite tags are very light weight compared with the bird to which they are attached, and they should be designed not to cause any significant problems with aerodynamics. There is a generally rule of thumb that if a tag is going to be fitted to a bird for a long time, then it should not exceed 3% of the bird’s body weight.  Slightly higher percentages may be acceptable for short-term tag attachments.  The use of electronic tagging devices on birds, and – importantly – how they are attached to a bird, is very carefully considered beforehand, and very tightly controlled in most countries.  The UK for example has a stringent procedure for checking,  authorising, and licencing the use of any electronic tags on wild birds, involving an independent panel of experts who consider each proposal for a tagging study. This is important, for both bird welfare reasons and to ensure that the study produces meaningful information. Tags are fitted to (usually a small number of) individual birds to help us understand what whole populations of birds do.  So, if a tag affects the behaviour of an individual bird significantly, it no longer tells us anything useful about the whole population, and the study would be pointless.  So, the answer is that every possible effort must be made to ensure that fitting tags to birds has minimal impact on them.  From the point of view of the conservation scientist, it is critically important to weigh up the value of the information that a tagged bird could provide that could help safeguard a population, versus the impacts that the tagging process might have on the individual.   For example, if satellite tagging a few individuals of a long-distance migratory bird reveals the location of previously unknown migration stopping points – at which direct threats to that population are subsequently discovered (and these threats can then be tackled and hopefully eliminated) – then that is a very high value outcome, for the population.  This has been exactly the case for the satellite tagging of spoon-billed sandpipers that I talked about in the livestream – without the tagging we would be unaware of several key threats to these birds at migration stop-over sites. Threats that we have now been able to identify, and successfully deal with. 

Do you envision an increase in resident hen harrier population resulting from a lack of persecution due to lockdown?

Dr Guy Anderson replies:

I’m afraid the evidence is that persecution of birds of prey in the UK has increased during the covid-19 pandemic period, not reduced. Travel and movement restrictions hindered surveillance efforts to combat wildlife crime. So more illegal behaviour went un-noticed.  People intent on persecuting birds of prey are already breaking the law in doing so, so we cannot expect them to adhere to any laws governing travel and movement either.

Which bird migrates the closest?

Dr Guy Anderson replies:

Bird migration takes place on whole range of different scales. At one extreme, there are the long-distance migrants. Avian athletes that always travel tens of thousands of miles each year and can rack up hundreds of thousands of miles in a lifetime. Birds like swifts, swallows, cuckoo, Arctic terns, and the bar-tailed godwits I mentioned in the livestream. Others may always migrate, but over a shorter distance. For example chiffchaffs and blackcaps that breed in the UK may winter in Spain, Portugal or North Africa. Curlews and goldfinches may go as far as France. Others my stay in the same country but move to an area with milder winters. Bird ringing studies have shown us that some blackbirds that nest in the UK have regular summer territories and different winter territories, usually further to the south and west of their breeding areas (our winter climate is milder in the south-west).  They might move a few hundred miles. Some might only move a short distance – just enough to find suitable wintering area with enough food.  Without the ability to following individual birds around by marking them (with a ring, or satellite tag) we would have not idea about any of this.  We would still think that the robin we see in our garden is the same bird that lives with us all year round. It might be, but it likely not. Your summer-nesting robin might well move south-west for the winter, and be replaced by birds coming from further north and eat.  We know we get many migratory robins coming to the UK each winter to escape the harsher winters in continental Europe.  So that robin in your garden now might be from a long way away.  It’s the same with blackbird, song thrush, chaffinch, goldcrest and others.  Even birds that we think of a very sedentary (never moving very far at all), like wren and dunnock, have been recorded crossing the North Sea in autumn to reach the east coast of the UK.  

Can migration patterns change due to global warming?

Dr Guy Anderson replies:

Yes, and we are already seeing this happen in some birds. For example, over the last few decades, we have seen the numbers of some wintering waterbirds decline in the UK. A small wader called the dunlin is a good example. Large numbers of dunlin used travel from Scandinavia and Russia to winter on estuaries around the UK, which were a safe refuge from harsher winter conditions further north and east.  But as Europe’s climate has warmed and winters have become milder, more dunlin have started to winter further north and east in areas like the Waddensea (huge mudflats, stretching along the coasts of the Netherlands, Germany and Denmark).  So not so many dunlin travel as far as the UK any more. This process is called ‘short-stopping’ as birds are stopping their migration a shorter distance along their flyway. There are lots of other examples of changes to migratory patterns linked with climate change. Migratory birds travelling shorter distances or wintering in more northerly locations as conditions there have changed. Whilst some of these effects of climate change might sound like good news for migratory birds, others are not. The same northerly-breeding waders and waterbirds that are ‘short-stopping’ here are seeing rapid climate driven changes taking place to the habitats on their breeding grounds, especially in the Arctic.  They may not have anywhere to nest in the future.  An increased frequency of severe weather events as a result of climate change is also likely to be bad news for migratory birds – particularly if they hit bad weather during their migration. There have been a series of recorded severe weather events in Europe in spring in recent years that have delayed and sometimes killed migrating birds.

Where to cuckoos go in the winter? 

Dr Guy Anderson replies:

The species of cuckoo that we know in the UK (Eurasian cuckoo, Cuculus canorus) winters all the way across tropical Africa. We know from satellite tracking studies that cuckoos that breed in the UK spend the winter in the Congo Basin forest zone in Central Africa. Just imagine – the cuckoo that you hear in spring has been hanging out with forest chimpanzees and elephants all winter! They usually stay high in the trees in the forest canopy in Africa, and remain largely silent while they are there, so they are really hard to find in winter.

How do birds know they have to migrate and do they all remember the directions or is there a leader?

Dr Guy Anderson replies:

They don’t ‘know’ in the same sense that we think and make conscious decisions. The have evolved to respond to triggers in the environment at the right time – for example, temperature, day length, their own physiology, or – in a few cases- the behaviour of other individuals.  Think of a young bird migrating south from the area it hatched from for the first time.  If they follow these in-built (‘innate’) triggers, and they successfully find a migration route and a wintering area, and survive to breed themselves, then they will pass on any genetic component to this behaviour and response to triggers to future generations.  Also that individual bird is then likely to simply repeat the same migratory pattern each year for the rest of its life.  Its worked the first time, so it will work again, right?  The route and timing becomes established as a regular behaviour pattern for that individual. Remember, it has no map or sat nav – that migration route is the only thing it has ever experienced – it has no experience or knowledge of any alternatives.  This is why protection of key migration staging points for birds is so critically important.  If you destroy a vital feeding stop on their flyway, those individual birds that have relied on that place for years have no idea where else to go, because they have never been anywhere else.  So, remember this when someone says “Oh, don’t worry about us destroying that bit of mudflat, lake or marsh – the birds that use it will just go somewhere else.” No they won’t just go somewhere else because they don’t know anywhere else.  They will lose their safe migration stop over site that they ‘know’, and some of them will die as a result.

“Is there a leader?” For many birds that migrate during the day, they often do so in groups. It is probable that young birds follow more experienced individuals within these groups. For a minority of birds, the young follow their parents on their first migration – the families staying together in close groups. Swans, geese, cranes and some seabirds do this. Very few other birds do. For most the young become independent from their parents a few weeks after fledging.