Here at the park our little colony of Humboldt Penguins are not only very popular, captivating both kids and adults alike, but they are also aiding the survival of their species. We’ve been breeding them successfully here at the park since 2013 and right now our birds are well and truly into their breeding season.
It is fantastic to witness all the behaviours and processes that come along with this special time of year, so in today’s blog I’d like to answer some of the most frequent questions we get asked during their daily feeds at 1 and 3PM.
Humboldt Penguins in the Wild
But first, let’s talk a little about their wild counterparts. Humboldt Penguins are native to the west coast of South America along the coasts of Peru and Chile but sadly their population is currently decreasing with an estimated 32,000 mature individuals remaining across their range. They are now classed as Vulnerable on the IUCN red list and a huge reason for this concerns their peculiar nesting habits. Did you know that Humboldt Penguins like to build a nest out of their own poo?!
The coasts and islands where these Penguins live are very rocky so they prefer to nest in areas with guano deposits where they can excavate a burrow to nest in. It might seem sad they build a nest out of excrement, but the true tragedy is that guano makes a very effective fertilizer. Historically, in the mid-1800s the guano was extensively harvested causing not only a removal of suitable nest sites but causing huge disturbance at the same time, causing a huge decline of Humboldt Penguins. Thankfully their breeding grounds are regulated today, but their numbers do not seem to be recovering due to other factors such as overfishing, invasive species, pollution and climate change.
Penguin chicks at the Park
But hopefully that is the depressing stuff out of the way, let’s talk about the Penguins here at Wingham Wildlife Park. One of the questions we get a lot is “when do the Penguins have babies?” Most eggs are laid in February and March with chicks hatching from March to April. But the truth is, they can potentially lay eggs any time of year, except when they are moulting in the Summer. The first signs we see is that each pair of penguins starts to get very cosy and defensive of a nest box.
Most penguins become mature and are able to reproduce at around 2 years old but can sometimes take up until they are 7 years old. We have 6 pairs of penguins here which take the same partner each year. Some also take the same nest box every year like Pingu and Mumble, whilst others sometimes fancy a switch like Isobel and Hurricane often do.
At the start of the breeding season we see an obvious change in our male penguins. Along with defending a nest box comes a lot of testosterone fuelled behaviours, and the boys seem to size each other up by posturing and braying. These display songs sound a bit like a donkey, but they can help attract a mate or re-establish bonds with their existing partner. Sometimes I get the feeling they are also sizing each other up as they have sharp beaks and can potentially do a lot of harm to each other if they did have to fight, something we rarely see here at the park.
(Kermit’s love song; Kizzy and an immature male respond.)
My favourite part of these early stages are the males’ perseverance as they collect nesting material. Every morning we give our group of penguins an opportunity to leave their enclosure if they want to and walk around some of the park. Sometimes the girls will bring back a small twig or leaf for the nest, but I’m always impressed with the materials the boys try to lug home again, sometimes they even attempt a branch twice the length of them! No matter how many leaves are on the ground they all seem to want the same one which makes for an eventful outing. Sometimes they have gathered so much nesting material in their bills that surely they can’t even see where they are going. If you have any photos of the penguins doing this, our team would love to see them on Facebook and Instagram.
Another question we often get is “how long are penguins pregnant for?” Birds don’t really have a pregnancy like us and other mammals. Chickens are a great example; once the egg has left the ovary it only takes about 24 hours for the egg to gain it’s thick calcium shell and be laid. Birds instead have an incubation period which is different depending on the species. Whilst chickens have an incubation period of around 21 days, for Humboldt Penguins their eggs have to be incubated for 39-42 days. Here at the park we again see a change in the behaviour of our female penguins during this time. A day or two before laying an egg she will stay in the nest box and refuse food.
Two eggs are usual with the second being laid two to four days after the first, and she will start incubating them straight away, meaning one chick will hatch a few days after the other. Both parents will take it in turns keeping the eggs (and chicks when they hatch) warm, and do so by parting the feathers on their belly and sitting on the eggs so they touch the bare skin. This is called a brood patch which you can just about make out on Isobel in the picture above.
Another common question we get is “how big are their eggs?” Hopefully the picture above gives you an idea of scale. They’re quite large eggs for birds, measuring on average 73mm long and 52mm wide. Here at the park we keep a close eye on our penguins but try not to disturb them too much during this time. Once the hatch day approaches we check the egg for signs of life and if the egg is fertile we should expect to see a “pip” where the chick has broken through the shell. Interestingly, baby birds have a special “egg tooth” at the tip of the upper part of their bills to help them crack open the eggshell. You can just make this out in the picture below
If we can’t see any signs of hatching we can sometimes listen and hear the chick calling to it’s parents from within the egg. Amazingly as the chick develops an air sac inside the egg forms and when it is ready to hatch it will take its first breaths of air there before it starts to break through the shell into the outside world. This is very hard work for the chick and occasionally they are not strong enough to fully break out of the shell and become stuck within the egg. Thankfully for our hatchlings we are on standby to help them past this last hurdle if needed.
The parents shouldn’t need to feed their chicks for the first 24 hours or so as like other birds the yolk sack that was in the egg is now inside the newly hatched chick and will sustain it for some time. When it is hungry it will start chirping and asking for food. Each parent will then take it in turns guarding their chick, keeping it warm and regurgitating partially digested food for it. During the first few days we carefully monitor any new penguin chicks by weighing them every day and checking them over until we’re happy that mum and dad are feeding their chicks well.
Baby penguins grow really fast! When they hatch they weigh around 90g and are blind. At ten days old their eyes will open and they will start to move around a bit more. By day 15 they already weigh between 500-800g, over half a kilo!
They don’t stay small for very long; at three weeks of age they are more than a handful and are often seen sitting up in the box and looking more alert. By day 25 they should approach the 1kg and both parent’s appetite would’ve increased dramatically as they need to feed their growing chick more and more as it grows.
As the chicks explore their nests more around this age they will also suddenly seem to realise that there is a big wide world outside the nest box. Often you can catch a glimpse of a chick as it peers out of the nest entrance before one of the parents ushers it back in.
During the middle of their time in their nest, when we are weighing the chicks they seem to reach a point where their flippers are growing faster than the rest of them! At around 40 days the chicks reach 2kg and we start to see differences in each chick’s character too and start to guess at whether they will be a little girl or boy. This is another popular question but we can’t tell a penguin’s gender just by looking. When the chicks are old enough we can take a feather sample to send off for DNA testing.
They will keep their fluffy down until they are fully grown around 3 months old and at this age, they will have reached a weight of around 3kg. They soon moult into their waterproof feathers before fledging where they enter the water all by themselves. They usually spend a few days in the pool where they can test their swimming skills. They are brilliant to watch as they learn to dive, at first they seem to need some practice at controlling their buoyancy, they can’t seem to keep themselves underwater very well at first.
(Humboldt Penguin juvenile takes it’s first swim at Wingham Wildlife Park)
The juvenile in the video above hatched two months earlier than expected and can be seen out on the penguin beach. He or she is very distinctive as the youngsters are much greyer and lack the distinctive band markings of the adults. The adult plumage will appear when the chicks go through their first moult at one year old. Hopefully it won’t be long before he has some playmates, the other chicks in the nest only have a few more weeks before they are ready to fledge. I hope you have enjoyed learning all about penguins and their breeding season and hope you can spot some of our youngsters on your next visit.