MATH IS FOR THE BIRDS! Part 2

Crow photo on pixabay.com

 

A Murmuration of Starlings

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A photo that I took of crows in January

As I sat on my back porch, I noticed a group of about fifteen crows flying around the top of a tall tree and making a lot of noise. I know that they do this when a racoon is up in that tree. But today, I heard the sound of a bald eagle. I wondered if the crows were working together to chase away the eagle. Sometimes a large group, or flock, of crows is called a murder of crows.


This made me think of another grouping of birds, a murmur of starlings. Starlings fly together in large numbers for safety; they are less likely to be prey for other larger birds. 

This video is taken near Vancouver by Pacificnorthwestkate. 

The flight velocity and direction of one bird affects 7 around it which multiplies throughout the group.

Like the movement of schools of fish, murmuration is an example  of scale free behaviour correlations. 

No matter how large the flock of birds is, the action of each bird will affect and will be affected by the action of all the other birds.

This means that each bird's range of perception is much larger than if they relied on direct interactions.

Murmuration has been compared mathematically  to magnets.

A three dimensional computer model shows an attempt to understand the mathematics in this flight patterning.

Dunlin birds can also form murmurations.  This video was created near Vancouver, BC for DVWildlife.

publicdomainpictures.net

Another reason that birds form patterns in flight is for migration. For example, Canada geese fly together in a V shape when travelling north in the spring and south in the fall.

JOURNAL ACTIVITY:

Observe groupings of birds. Record what you see with drawings, photos, or videos.
Why do these birds form groups?
Do all birds form flocks?
Do all birds form mating pairs?

Continue to identify and add more kinds of birds to your journal.

Do people form groups that are similar to flocks or murmurations? 
How has social distancing changed how people interact in groups?

MATH IS FOR THE BIRDS! Part 1

Black Capped Chickadee

An Invitation to 
Urban Birdwatching

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Sitting on the back steps of my home in East Vancouver earlier this week, I was visited by four different kinds of birds. I identified them using a guide to birds in Vancouver.

European Starling

Bushtit

House Finches

The house finches appear in a pair. The male has salmon coloured feathers. The female is mainly brown and grey to help her go unseen when she sits on a nest. The two of them like to sit and feed on the top of my kale plants that are going to seed. 

I listen to the birds sing and call and when I see them. I want to try to identify them by their sounds even when I can’t see them.

ACTIVITY: START A BIRD JOURNAL

Start with three or four birds that you can see from your home or on walks close to your home. Using drawings and writing, record what you notice. 

Which birds do you see?

What do they look like?

Are the male and female different?

Identify them by name? 

What do you notice them eating?

What calls and songs do you hear?
Do they move about alone, in pairs, in groups?


Start a routine of recording when you see or hear these birds. How will you record over time?

Identify and describe more birds as you notice them.

Outside Listening: Mapping Soundscapes

In May the hummingbirds arrive on Haida Gwaii. One afternoon my good friend and I sat out on her deck and were entertained for hours by the hummingbirds. We counted 17 hummingbirds sipping the nectar from two feeders stationed on the deck corners. Listen … can you hear their calls? Can you hear the beating/buzzing sounds of their wings? 

 image: Amanda Kariella on Unsplash

Soundscapes, like landscapes, tell us a story about the place. Soundscape ecologists like Bernie Krause and Hildegard Westerkamp have recorded sounds in the natural environment for almost 50 years. Over time they have mapped how the sounds of the environment have changed. In some cases the hum or buzz of urban life on land, shipping traffic on sea, and air-traffic have transformed our soundscapes.

You can participate in being a soundscape ecologist by listening to and mapping the sounds outside in your backyard, or at a nearby park, or wherever you are.

Here’s one activity you can try by yourself or with others. You will need a piece of paper, pencil, and clipboard.

Find a spot outside to sit or stand. Draw a big circle that fills your page and place a dot in the centre. The dot represents you. Now along the edge of the circle mark nearby objects in front of you, to the right and left and to the back of you as a way to record your position. In this example the tree is front the building behind, mountains to the left and a deciduous tree to the right. 

Now close your eyes and listen. Listen. Listen. Mark on your map what you hear. How far from you is the sound and from what direction? Maybe you hear the wind rustling in the trees, or a bee nearby, or the sound of bicycle, or the call of an eagle. Mark both the distance from you and the direction of your sounds.

Try making soundscape maps at the same place over different days. What do you notice? Try making soundscape maps at the same place over different times of the day. What do you notice? What do you wonder?