Mockingbird in the Rain

Northern Mockingbird (Mimus polyglottos) recorded at Centennial College Ashtonbee campus parking lot near Wexford Woods, 07:52 2020-04-13 (rain, handheld phone, noise filtered)

I went out for a very soggy bike ride this morning just to get out of the house. There were a few more people out than I expected, as it’s a regular work day for most people in Ontario. COVID-19 meant that most workplaces were shuttered.

Splashing through the puddles at Centennial College’s deserted Ashtonbee campus (round about here, if you need a precise location) I heard this mockingbird giving its very best performance. I only got a little over a minute of it, but in that time there was some American Robin, Gull, hawk of some kind and best of all (starting just after 40 s) car alarm.

Centennial’s got a big automotive section, and the empty parking lot’s usually full of cars. Mimus was just repeating what it usually heard. I wonder how long they’ll remember and replay car alarms after we’re gone?

birb chirper v2.0

This is one of those toys that you whirl around on a piece of string and it makes a chirping sound like a flock of sparrows. I have no idea what they’re called, so I called it birb_chirper.

Print Settings

Printer: Reach 3D
Rafts: Doesn’t Matter
Supports: Doesn’t Matter
Resolution: 0.3 mm
Infill: 0%

Notes: This is a thin-walled model, so use at least two shells and no infill for smooth walls.

Post-Printing

Take a piece of thin string about 1 metre long (I used micro-cord, very fine paracord), pass it through the hole in the tip, then tie off a jam knot that’s big enough to stop in the hole in the top but still pass back through the slot in the side. Now whirl the thing around fast by the string, and it should start to chirp.

This is intended for the amusement of small children and the annoyance of adults.

How I Designed This

The tip of this thing is an ogee curve. I’ve included my library for creating simple ogee and ogive profiles in OpenSCAD.

// ogive-ogee example
// scruss, 2018
use <ogive_and_ogee.scad>;
ogive(20, 35);
translate([0, -5])text("ogive(20,35)", size=3);
translate([30, 0])ogee(20, 35);
translate([30, -5])text("ogee(20,35)", size=3);

Download: Thingiverse —birb_chirper by scruss. Local copy: birb_chirper.zip