Last year in these classes we focused on orca communities, food and habitat. This year we shifted the focus a bit to discuss sound underwater and orca families. I'll share a bit about each class:
The intent of this class was to introduce students to the science behind studying sound underwater while also discussing how orcas use sound to communicate. We begin by covering the basics of WHAT sound is (using visual demonstrations to show that it's not a wave like we normally picture but instead is a vibration). We then have the students play a game to become the compression wave; passing a "vibration" around the circle either as slowly or quickly as possible. We follow this game with a discussion of what makes sound in the ocean; students brainstorm about all the living and non-living things that produce sound underwater. They then get the chance to listen to recordings of many of these; shrimp, fish, harbor seals, cargo ships, a zodiac boat and OF COURSE; Resident and Transient calls.
So how do we know all of this? How were these recordings captured? Time for the hydrophone's entrance! Here at PTMSC we're fortunate enough to have two hand-held hydrophones available for educational demonstrations, (this is is addition to our permanent hydrophone that is a part of the Salish Sea Hydrophone Network: http://www.orcasound.net/pt/). We use one of these portable hydrophones in conjunction with a glass aquarium filled with water to demonstrate how they function as underwater microphones.
Next is a game where students sing out a "signature orca call"; aiming to find the other members of their pod amid the ruckus of all the students calling out like orcas. We complicate the game by adding background ship noise; something killer whales have to contend with in the wild on a daily basis. Just like real orcas, the students unwittingly demonstrate the Lombard effect; lengthening their calls and raising their volume just to be heard. It's thought that this is a stressor on whales and the students certainly would agree; yelling over the ship noise certainly complicates the game's task of finding one's pod.
1. What is an orca?
Students list off every possible (relevant) characteristic that they know about killer whales
2. Inherited vs. Acquired Traits
Here we introduce these two vocabulary terms ("inherited" refers to hereditary traits the animals are born with while "acquired" traits are learned during their lifetime). We then separate the characteristics they just listed into the two categories.
3. Resident vs. Transient Orcas: This is where students learn about the many differences between our local Resident and Transient Orcas. We briefly mention their dietary and range differences and then launch into a family tree game. During this game students are assigned specific orcas and must determine their family relationships based on their information card. The Residents have far more complicated family trees and therefore must communicate more (which is the case in the wild; but is more about their prey and less about determining who their siblings are) while the Transients' family relationships are frequently unknown and their groups much smaller.
4. Vocalizations
We conclude with a discussion of further differences between Residents and Transients (range and amount/type of communication is largely dictated by their prey choice). Since we do have the fantastic resource of the Salish Sea Hydrophone Network we are able to play orca calls that were recorded here at PTMSC and vividly demonstrate the differences between the resident pod's signature calls (while also teaching about how vocalizations are produced by the animals). We conclude by categorizing these calls as acquired rather than inherited.
All in all, it was yet another year of excellent Free Science Classes. We're not shying away from presenting real research but we're doing in an accessible, interactive way. I'm glad to be a part of an organization that puts significant effort into reaching students that otherwise would not be exposed to this type of interactive science. Hopefully we've inspired a few blossoming marine scientists!
Jess Swihart
AmeriCorps
Natural History Exhibit Education Coordinator
* Big thanks to all our generous donors that made it possible for us to offer these programs:
First Federal,
George and Patricia Ann Fisher Foundation,
The MacRae Foundation,
U.S. Bancorp Foundation,
Wells Fargo Bank
So how do we know all of this? How were these recordings captured? Time for the hydrophone's entrance! Here at PTMSC we're fortunate enough to have two hand-held hydrophones available for educational demonstrations, (this is is addition to our permanent hydrophone that is a part of the Salish Sea Hydrophone Network: http://www.orcasound.net/pt/). We use one of these portable hydrophones in conjunction with a glass aquarium filled with water to demonstrate how they function as underwater microphones.
Heather illustrating the sound air bubbles make underwater (the student helper is holding the cord of the hydrophone) |
ORCA FAMILIES
This class covers four main topics:1. What is an orca?
Students list off every possible (relevant) characteristic that they know about killer whales
2. Inherited vs. Acquired Traits
Here we introduce these two vocabulary terms ("inherited" refers to hereditary traits the animals are born with while "acquired" traits are learned during their lifetime). We then separate the characteristics they just listed into the two categories.
Introducing the main topics of Orca Families |
3. Resident vs. Transient Orcas: This is where students learn about the many differences between our local Resident and Transient Orcas. We briefly mention their dietary and range differences and then launch into a family tree game. During this game students are assigned specific orcas and must determine their family relationships based on their information card. The Residents have far more complicated family trees and therefore must communicate more (which is the case in the wild; but is more about their prey and less about determining who their siblings are) while the Transients' family relationships are frequently unknown and their groups much smaller.
Figuring out the family relationships |
We conclude with a discussion of further differences between Residents and Transients (range and amount/type of communication is largely dictated by their prey choice). Since we do have the fantastic resource of the Salish Sea Hydrophone Network we are able to play orca calls that were recorded here at PTMSC and vividly demonstrate the differences between the resident pod's signature calls (while also teaching about how vocalizations are produced by the animals). We conclude by categorizing these calls as acquired rather than inherited.
"Inherited or acquired?!" |
All in all, it was yet another year of excellent Free Science Classes. We're not shying away from presenting real research but we're doing in an accessible, interactive way. I'm glad to be a part of an organization that puts significant effort into reaching students that otherwise would not be exposed to this type of interactive science. Hopefully we've inspired a few blossoming marine scientists!
Jess Swihart
AmeriCorps
Natural History Exhibit Education Coordinator
* Big thanks to all our generous donors that made it possible for us to offer these programs:
First Federal,
George and Patricia Ann Fisher Foundation,
The MacRae Foundation,
U.S. Bancorp Foundation,
Wells Fargo Bank
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