Download the pdf of this lesson!
When the felt on the head of the sealed glass bird is wet with water, the bird pivots back and
forth into a glass of water. It gives the appearance of drinking!
Wet the head of the Drinking Bird, and place a full glass of water near it so that when the head
tips forward, only the beak comes in contact with the water. Most Drinking Birds work without
adjustment! Sometimes a small adjustment to the pivot point of the bird is needed. Carefully
move the metal clip up or down the glass tube, (ca. a millimeter), until the Drinking Bird just
balances in a vertical position.
Water requires heat to evaporate. In this demonstration, water from the wet felt on the outside of the head evaporates, causing the vapor inside the head of the bird to cool. This reduces the
pressure of the vapor at the top, allowing the higher pressure in the lower bulb to push up the column of liquid. The pressure of the vapor in the top bulb decreases for two reasons:
- As the vapor cools, the vapor contracts. Notice the top volume of gas decreasing, and
- As the rising liquid near the top cools, less liquid evaporates into the head and more vapor returns to the liquid state. Since this demonstration only works with a sealed liquid that has a high vapor pressure, this is a major factor.
As the head cools further and more liquid inside the bird rises, the center of gravity of the bird rises, causing the bird to become unstable and tip forward.
Eventually, the beak of the bird tips forward enough to rewet its head. When this happens, the bottom end of the glass tube in the lower bulb is above the remaining liquid. Vapor from the bottom travels to the top until the pressure is equalized. At the same time, liquid in the column flows to the bottom. As the center of gravity of the bird is lowered, the bird tips vertical and the cycle starts over.
Suggested Classroom Activities:
I) Classroom Discussion
Q. Is this an example of perpetual motion?
A. No. The cycle repeats itself only as long as the water evaporates from the head
Q. What is needed in order for the Drinking Bird to work?
A. A difference in temperature between the head and body.
II) Student Challenges
- Observe the operation of the Drinking Bird and explain how it works.
- Discover a way to make the Drinking Bird cycle faster.
- Predict what will happen if a fan blows air toward the Drinking Bird. Does it
make a difference which direction the air blows?
- Predict the result of using warmer or cooler water in the glass.
- How long will the bird cycle without needing a refill of the water in the open
container? Can you find a way of causing the bird to cycle longer?
- Is there a difference in the cycle rate on a humid day vs. a dry day? Can the bird
be used to determine the relative humidity in the air?
- Predict the result of placing a small inverted aquarium over the bird. Does this
cause the bird to cycle more or less? (Note: as soon as the water in this closed
system reaches its vapor pressure, water from the felt can no longer evaporate
and the bird stops.)
- Can you attach a thread to the bird so that it does useful work, e.g. lifting a small
Write a review
Sep 25, 2017 | By Marco Mantellino of Pescia, Italy
May 15, 2017 | By Sian of Walnut Creek, CA United States
Feb 5, 2015 | By Janie M. of Beaumont, TX United States
Sixth Grade Social Studies Teacher
Apr 2, 2014 | By Ruth Beller of Dalhart, TX United States
Owner Response:Ruth, someone from customer service will be contacting you today. Sometimes the bird's fulcrum needs to be adjusted by sliding the bird's neck up or down through the metal sleeve, which changes the center of gravity. If this doesn't work, we will send you out a replacement.
Dec 19, 2013 | By Dr. Ann Abraham of Ashtabula, OH United States
Aug 2, 2013 | By Rfletch of altamont, NY United States
Owner Response:We are terribly sorry for any inconvenience. One of our customer service representatives will contact you regarding your purchase of the Drinking Bird. The problem is most likely with the placement of the fulcrum, however, if we cannot get your bird to work, we will replace it immediately!
Awesome item from the past!
Apr 4, 2013 | By Ruth of Dracut, MA United States
Jan 23, 2013 | By Christine of Stanwood, WA United States
Romantic Drinking Birds
Jan 18, 2013 | By Sweet Perfume of Casper, WY United States
Awesome Dippy Bird
Sep 17, 2012 | By Kim Dickey of Greenbrier, AR United States
As a child, as an adult
May 30, 2012 | By Guillermo Nery of Bayamon, PR United States
May 29, 2012 | By Kim of Murfreesboro, TN United States
Class is Stumped
May 29, 2012 | By Stacey Militello of Shrewsbury, MA United States
Fun to watch
May 22, 2012 | By C Chino of San Marcos, CA United States
We love our bird!
May 22, 2012 | By Diane W of Minneapolis, MN United States
Great Focus activity
May 22, 2012 | By Rebecca Absher of Troutdale, VA United States
May 22, 2012 | By constance maxwell of oxford, MS United States
May 19, 2012 | By Margaret Flack of Jasper, IN United States
Drinking birds spark creative hypothesizing
May 18, 2012 | By Dave Beedell of Ottawa, ON Canada
Great thought provoker
May 18, 2012 | By Charles Zierzow of Barkhamsted, CT United States
Great Item to challnge thinking!
May 17, 2012 | By Ashley Dyson of Brandon, MB Canada
A great buy
May 17, 2012 | By D Doherty of Dublin, AL Ireland
Nothing dippy about these birds!
May 17, 2012 | By Jason H. of Zeeland, MI United States
Drinking bird rocks
May 16, 2012 | By Candy Sykes of Fremont, CA United States
Beautiful Bird Breaks Easily
May 16, 2012 | By RJAD of Jacksonville, FL United States
A great introduction to heat of vaporization
May 16, 2012 | By Cathy of Richland, WA United States
Old toy, always fun
May 16, 2012 | By Martin Roy of St-Georges, QC Canada
May 16, 2012 | By LaDawn Haws of Chico, CA United States
May 16, 2012 | By Charla O'Brien of Ferris, TX United States
May 16, 2012 | By Diedre Adams of West Terre Haute, IN United States
This product will support your students' understanding of the Next Generation Science Standards (NGSS)*, as shown in the table below.
Suggested Science Idea(s)
Students can use the Drinking Bird Demonstration to use and share observations of local weather conditions and describe patterns over time.
Students can use the Drinking Bird Demonstration to make observations and/or measurements of an object's motion to provide evidence that a pattern can be used to predict future motion.
Students can use the Drinking Bird Demonstration to make observations to provide evidence that energy can be transferred from place to place by heat.
Students can use the Drinking Bird Demonstration to design, test, and refine a device that converts energy from one form to another.
Students can use the Drinking Bird Demonstration in the plan of an investigation to provide evidence that the change in an object's motion depends on the sum of the forces on the object and the mass of the object.
Students can use the Drinking Bird Demonstration in an investigation to construct and present arguments using evidence to support the claim that gravitational interactions are attractive and depend on the masses of interacting objects.
Students can use the Drinking Bird Demonstration to develop a model to describe that when the arrangement of objects interacting changes, different amounts of potential energy are stored in the system.
Students can use the Drinking Bird Demonstration to test what either minimizes or maximizes thermal energy transfer.
Students can use the Drinking Bird Demonstration as an introduction to an investigation to use mathematical representations of Newton's Law of Gravitation to predict the gravitational forces between objects.
Students can use the Drinking Bird Demonstration to refine a device that works with given constraints to convert one form of energy into another form of energy.
Students can use the Drinking Bird Demonstration to conduct an investigation to provide evidence that the transfer of thermal energy when two components of different temperature are combined within a closed system results in a more uniform energy distribution among the components in the system.
This amazing 50+-year-old science toy can be linked to physical science, earth science, chemistry and more. Effective for students of all ages. It is important before starting any of the investigations; make sure the bird is at equilibrium. A slight adjustment at the fulcrum or metal clip on the neck up or down is all that is needed until Drinking Bird just balances in a vertical position.
The speed of the bird's dipping cycle changes due to the humidity in the air. If the students watch and collect data; overtime in different weather conditions they will see a correlation. Students can use the Drinking Bird Demonstration to use and share observations of local weather conditions and describe patterns over time.
Students can use the Drinking Bird Demonstration to make observations and investigate motion. Have the students change the temperature of water and make predictions about the speed of the dipping cycle.
Water requires heat to evaporate. In this Drinking Bird Demonstration, water from the wet felt on the outside of the head evaporates, as the vapor in the head cools, the vapor contracts. This causes higher pressure in the lower bulb, allowing liquid to raise up the neck, the center of gravity rises, resulting in the bird to become unstable and tip forward. When the head gets wet, the cycle repeats itself.
Students can use the Drinking Bird Demonstration in an investigation to understand Center of Mass as pressure inside bird changes, so does the fluid moving up the tube.
* NGSS is a registered trademark of Achieve. Neither Achieve nor the lead states and partners that developed the Next Generation Science Standards were involved in the production of, and do not endorse, this product.