Update - sibling's return

Late in the afternoon on 2 April 2016 a familiar bird started running towards the garden door when it saw us.

Sibling had returned, after nearly 2 years of absence. The memory these birds have is truly amazing.
Its coat still has immature colouring, and when it run towards me I could not help but put a few sunflower seeds out and take a video of the event.

Interlude - more about magpies

Magpies adapt quickly to our urban environment and the free rides that can be had. At the same time they have to overcome the obstacles created by uncaring attitudes, such as when waste and fishing wire is carelessly discarded into the environment.

As well as adapting to the urban environment, magpies must learn how to deal with intruders who may be stronger and larger than them, a daily reality in magpie life. In neighbourhoods with strong permanent magpie residents, status tends to be equal and fights are rare. While neighbours are still potential threats, in a stable neighbourhood many battles do not need to be fought, because the groups have worked out their needs and have become familiar with one another. 

Magpies are also very collaborative. When they have adequate resources they occasionally collaborate in locating food and raising young. When magpies spot a predator they issue alarm calls and often follow and harass a raptor to a distance well outside their own territory. Magpies warn others of cats, snakes and birds of prey. Countless species benefit from such cooperative, vigilant magpie behaviour. Most other birds will hide when they see danger, instead the magpie will go out and actively, even fearlessly, pursue it. It is their strong group cohesion and collaboration that helps magpies survive.

A story

Once upon a time, early 2014 to be precise, a family of magpies came to visit our garden. There were the parents and their two young, who we later named Hoppy and Sibling. When they were fledglings, fresh out of their nest, Hoppy and Sibling walked close to their parents to learn how to forage and listen to the sounds made by earthworms and larvae underground.

This ‘listening for food’ has been proven in a study in 1981 (Floyd and Woodland), where the researchers had recorded the minute sounds of movements made by scarab larvae, and then, using tiny speakers buried underground, they played back the recorded sounds. The magpies detected the sounds, located the speakers, and dug them up! They must have been very disappointed to find that they were not edible.

Anyway, I detract from our story. One day in March 2014 we saw that Hoppy had fishing wire wound around its right foot and the family seemed to have ostracized it and left it to its own devices. Even though it could only hop on one leg – yes, that’s where it got its name from – it was still a great flyer and managed to outwit us each time we tried to catch it to remove the wire.

We called Wilvos and other experts and were told to put out some food, such as minced meat and bacon, to train the bird so we could get close enough to catch it.

It took a couple of weeks to catch Hoppy, and by that time its leg had become infected, so I took it to a friendly local Vet who snipped off the fishing wire and treated the infection. Within a day or two I saw Hoppy walking around the garden with Sibling again, and every time Hoppy spotted us it would draw up its right foot and look at us hoping to get free food again.

Then, a few days later, Sibling’s foot had become entangled in fishing line that had been left laying around in the open somewhere. Thankfully we managed to catch Sibling quickly and removed the fishing line.

Over the next month or two the family carried on foraging in the area, and especially Hoppy and Sibling often walked around our little garden, catching earthworms, larvae, spiders, and all kinds of insects.

One day in July 2014 three very large magpies started to show up and survey the area by foot, the way developers might do. We called them the bullies. I remember our magpie family sitting on the power line next to our garden, carolling. Carolling is a kind of song magpies use to reaffirm territorial ownership. But the bullies totally ignored their territorial claims and carried on walking around unperturbed.

In the days following, magpie wars had broken out, and in particular Hoppy and Sibling were swooped on relentlessly, day after day. The dispute culminated in a very ugly scene with much noise, and it seemed that there were fatalities, and we never saw Hoppy again. Sibling was pushed out to a small neighbouring area, and driven from its familiar childhood territory.

The parents moved to a smaller area up the road, and raised just one young in late 2014. We have not spotted them since.

The bully parents were firmly established until late 2015 and in total control of what was 'our' magpie family’s territory. They too only had one young, but it quickly got bigger than its mother, and confidently pulled worms out of our lawn.

 

13 - magpie anatomy and diet

It is a crisp, sunny winter's morning, and we have opened the doors to the garden. IA took this occasion to wander into the living room and looked if we had dropped anything edible on the tiled floor. This is a first, wandering into our house to graze. This time of year lawn beetles have gone through their lifecycle, and the magpies have spent less time foraging in our garden of late, so maybe this is why IA ventured indoors. As magpies are omnivores and as there is no shortage of food they can forage on, this behaviour could also be attributed to curiosity or opportunism. Today I am writing about some findings regarding magpie anatomy, how they find food underground, and about their diet.

IA listening-in on her food / foraging in our garden

Magpies have a hard and relatively thick, 'all-purpose' beak, with a pointed tip. Their beak works equally well for feeding on plant matter, as for crushing beetles that have a hard shell, breaking open hard soil, or fighting. Magpies can injure or even kill an intruder with their beak.

The much shorter beak of nestlings grows to adult size, by the time they are three months old.
I learned this fact from an excellent book that I just bought: 'The Australian Magpie - Biology and Behaviour of an Unusual Songbird', by Gisela Kaplan (see http://www.une.edu.au/__data/assets/pdf_file/0004/65551/MagpieBookCSIRO.pdf and/or http://www.publish.csiro.au/pid/3880.htm). Professor Kaplan is a researcher and teaches at the Centre for Neuroscience and Animal Behaviour at the University of New England, Armidale, NSW (Australia). She has studied magpies for well over ten years and has spent thousands of hours observing these birds. I can highly recommend her book, and am quoting from Professor Kaplan's findings about magpie anatomy and diet in the following paragraphs.

Even though the ability to fly imposes anatomical restrictions, it also means that flight has enabled birds to colonise nearly all habitats on earth, including islands. From  the magpie book I learned that the anatomical adaptation to a habitat is called adaptive radiation, and that restrictions have paradoxically produced a very high degree of variation: there are nearly 9000 species of birds, with a great variety of colouration, locomotion, feeding etc.

I have mentioned beaks, but did you know that birds do not have sweat glands, although water loss through the skin has been observed in some bird species. Magpies therefore control heat by rapid respiration where there is a very high load of heat. Magpies can also cool off and get rid of some heat through changes in skin blood flow, and they do this by positioning their feathers in a certain way and by lifting their wings. As an aside, because magpie nests are high up in trees and usually exposed to the elements, the female adult shields her brood by standing over them with her wings outspread, to provide shade from the sun or protection from heavy rain.

Magpies close their eyelids from the bottom lid upwards, usually only when they sleep or when they are in great pain. From Professor Kaplan's book I also learned that, in order to moisturise their eyes, birds have a third eyelid, called the nicitating membrane, that traverses the eye from the lower inner part outwards and up.

With regards to the head, magpies (like most corvids) have a very large upper hyperstriatum, also called 'wulst', in their large brain. This wulst is the area where visual information is processed and could mean that the magpie's long-distance vision is excellent and its acuity superior to that of an average human. I have observed my magpie family emitting alarm calls when they spotted eagles that were high up in the sky. The birds' hearing is also excellent, and they use it to great effect for locating food such as scarab larvae underground. This brings us to the magpie diet.

Foods consumed by Australian magpies
Magpies forage on the ground, and only feed above ground during breeding time when they feed their nestlings. Else trees are for roosting and breeding as far as magpies are concerned. When IA and IB were fledglings, I saw them walk with their parents on garden lawns and learning to forage. Magpies have a very varied diet, and substantial skills in acquiring their food items.
I already mentioned that they listen to the very slight sounds that larvae and earthworms make underground. Professor Kaplan refers to a study by Floyd and Woodland in 1981, that furnished conclusive proof that magpies find scarab larvae by sound (and sometimes vibrations) alone, and not by visual or olfactory clues. She writes that the researchers had recorded the minute sounds of movements made by scarab larvae and then, using minute speakers buried underground, playing back the recorded sounds. The magpies detected the sounds, located and digged up the speakers!

This 'listening' for food has to be learned and therefore fledgling magpies walk close to the adults, learning to link this sound to food.

Apart from earthworms, beetles and larvae, magpie also eat invertebrates such as snails, millipedes, mantids, crickets, grasshoppers, weevils, bees, at least eight varieties of ant, moths, crustaceans, spiders, scorpions, and all manner of insects.

They also eat reptilians and amphibians such as skinks, and frogs, and mammals such as mice and other small rodents.

To round up magpie diet, being omnivores they also like plant matter, such as seeds, grains, tubers, walnuts, figs and prickly pears.

12 - a duet and a territorial dispute

Today was exciting. First, IA and IB were duetting, see attached video. Duetting is a form of communication where one bird initiates a call, IA in this instance, and another one, his sibling IB, answers. This form of song is useful if the birds cannot see each other and want to establish visual contact. In this case IB sat in a tree nearby, just out of view of IA, who was perched on a chair in the garden. The siblings duet regularly, and it may also function as a way to reinforce bonding between the two birds.

Duetting is a sequential song. If birds sing at the same time then this is referred to as carolling.

Carolling is usually harsher and is used to reaffirm territorial ownership. This happened today as well, but later in the afternoon, when I suddenly heard a lot of calling and saw wings flapping in the garden. On closer inspection I found that two large magpies had intruded on the family's territory, and were dive-bombed by the adults in the garden.

By the time I grabbed a camera and started shooting a video, the magpie family sat on the power line and it started to rain shortly thereafter. The siblings stayed close together throughout, with IA flying off from the power line last, already drenched. One of the adults held the fort just a little longer, sitting on the fence, and looking at the intruders who carried on foraging in our neighbour's garden quite unperturbed, before flying off to join the rest of the family.

11 - brief update

Our neighbour's dog has been escaping and camped in our garden, so the local wildlife has kept a respectful distance. However, a faulty gate has now been fixed, and the magpies are slowly returning. I should have some time over the weekend to observe the magpie family, and will soon report more.

10 - wiping the beak

Having observed IA just now, I am quite convinced that one of the reasons why magpies wipe their beak is to clean it. Have a look at the video clip. At the beginning you can see that IA has been eating something really messy and is wiping its beak on the back of the old outdoors seat. IA then forages on the lawn and wipes its beak again in the grass.

09 - flying up a brick wall

I noticed IB flying up the brick wall, but when I went outside to explore, I could not see any prey animal on the wall such as an invertebrate, or maybe even a gecko, that might have prompted this behaviour, and wonder what it was IB saw and/or wanted to catch.

08 - juveniles at play

IA and IB sat on the power line this morning at dawn, singing and preening. The brown colouring of the immatures is clearly visible.
I did not see or hear any adults. As far as I remember, IA and IB only voice this particular song (an audio recording can be found on day '07') when the adults are not around, and I wonder whether their songs are a practice to address future territorial disputes, reinforcing their territory as the dominant male does whenever he is sitting on the power pole. Maybe the immatures are even 'forbidden' to utter any calls other than begging for food when the parents are around. Further observations may provide a provisional answer / theory.

Later in the morning I took the photographs below of IA foraging in the garden. I wonder why the magpies wipe their beaks on the grass, and at times on the palm tree stump. Is it to clean their beaks and to sharpen their beaks? A quick google has not brought up a scientific explanation. I will take a video of this beak wiping soon.

Magpies are extremely playful, as was shown on the youtube video that I posted on day '05'. We can easily picture bear or lion cubs playing, and associate play with mammals honing the survival skills that they will need in their adult life, but magpies are very playful too. I have not seen them play hide-and-seek yet, but have observed IA and IB playing shortly after IA's foot had been released from the fishing wire, and before IB entangled his foot. They were rolling around on the ground, pulling on each other's wings, play fighting, and running after each other. I hope that I will see something similar again soon, and maybe even get a chance to video it.

I just googled Australian magpie behaviour and came across a post called Play behaviour of Australian Magpie  . This blog includes some great pictures that illustrate magpie playfulness. It looks very similar to IA's and IB's play that I observed a couple of months back.

07 - magpie song audio

This morning I recorded some magpie calls. The *.wav audio is embedded below and can be downloaded by right-clicking on this link . I have also converted this file for download to an iTunes ringtone . Enjoy! More soon.