- This video was taken in a small stream near Mendenhall Glacier in Juneau, Alaska.
- A male threespine stickleback builds a nest by sucking up sand or mud and depositing it away from from the construction site.
- In the resulting depression he glues together pieces of vegetation with mucus secreted by his kidneys, until a dome-shaped structure is formed.
- He wiggles into the structure to form a tunnel.
- He then attracts a female to enter the nest to deposit her eggs and then he enters the nest and fertilizes the eggs.
- The female leaves and the male has the responsibility of maintaining the nest and raising the young.
- This video show the effort that the male stickleback goes through to protect the nest with the eggs and developing young.
- You can see several instances when he removes caddifly larvae from the nest area and one instance of him attacking a water beetle.
- Most other fish that swim near the nest are attacked, you can see him attacking coho salmon fry.
- Notice how he fans the nest with his large pectoral fins.
- Why does he do this?
- This creates a flow of water that improves the supply of oxygen to the eggs.
- Once the eggs hatch if a young emerges from the nest he catches them in his mouth and spits them back into the nest.
- In this video he does this twice but the newly hatched stickleback are very tiny and difficult to see.
- He will do this for about 10 days before he no longer attempts to retrieve them.
- Stickleback are an important food for several other creatures.
- Great Blue Herons and Greater Yellowlegs seem to specialize in eating them. I have seen Belted Kingfishers, Arctic Terns and dragonfly larvae eating them. River otter scat usually contains many discarded stickleback spines.
- Look at this essay by Mary Willson on Sticklebacks
- For more information about threespine sticklebacks look at /sites/default/files/Threespine%20sticklebacks.pdf
