Capture Methods

Why During Molt

The molting season was identified for large scale banding efforts of scoters due to several factors:

Large numbers of scoters flock up into molting groups
Molting scoters do not have the ability to fly, thus making them easier to capture (they can not fly away)
The effort necessary to capture large numbers of scoters during this season is far less than other seasons
Molt occurs before the harvest season

Project Vessels

On a typical day we utilize 4-5 boats for the capture efforts.


17' Boston Whaler - This is our primary net boat that guides the capture efforts.	2 - 14' Rigid Hull Inflatables (RHB's). These boats work with the Whaler in herding scoter flocks.

R/V Harlequin and two other inflatables.
Harlequin is our primary processing and staging vessel, as well as serving as the main personel transport.
The other two inflatables are used either for herding scoter flocks during the capture drives, or transporting scoters to R/V Harlequin from the capture locations

Procedures

After we have arrived at the molting site, and R/V Harlequin is anchored, the capture boats go to where we expect to find concentrations of molting scoters. Once a workable flock is identified the boats begin to split around the target flock.

Whaler and RHB-2 move to opposite ends of the flock, as Whaler prepares to get into position to deploy the capture net. RHB-1 guards the gap between Whaler and RHB-2 to keep the flock from coming back through that gap.

Once Whaler is in position the net is deployed from the stern of the vessel. The ends of the net are marked with decoys, and there is a small set of decoys marking the center of the net. This string of decoys will also give the scoter flock a target to shoot for as they swim away from the boats.

Once the net begins to be deployed RHB-2 continues quickly moving ahead to turn the direction of the scoters around towards the net. RHB-1 backs off to fill in this gap between the net and RHB-2, while keeping the gap between the end of the net in control so the scoters do not see this escape route.

Once the net is deployed whaler moves away from the net, and closes the gap between their position and RHB-2. RHB-2 pushes the flock towards the net, while RHB-1 guards the gap between the end of the net and RHB-2.

Whaler and RHB-1 slow, guarding the gap to RHB-2, while protecting the ends of the net. RHB-2 continues to push the flock towards the net.

The push is continued, keeping the scoters focused on the "escape route" towards the center of the net.

Once the flock is at the net, and before they begin to react to seeing it, a cracker shell is shot over the flock to induce them to dive. It is important that this is done when the scoters are facing the net, as the direction they are facing is likely the direction they will swim while under water. All boats move in towards the net to encourage the flock to swim towards it (away from the sounds of the boats).

All boats wait to see where the birds surface.

Once the scoters begin to surface a decision is made if we have enough birds captured, or if un-captured birds need to be pushed back to the net. Once enough birds are captured, or the un-captured birds have scattered, Whaler and one of the RHB's will go to either end of the net for retrieval.

We will bring the entire net into the two boats with the birds in the net. If the net is left in the water while scoters are extracted, there is a risk of drowning, injury, and greater individual entanglement.

When puling on the net to bring it into the boats very little strain is put on the net. If the net were pulled it could injure entangled scoters. As the net comes into the boats the empty sections of net are stacked and moved back into the boat. When sections of net with scoters come into the boat the scoters are supported by their bodies to prevent injury - the birds should not be lifted by the net if possible. These birds are then placed in the boat, alongside the empty net pile. Then the next empty net pile comes in, alongside the birds, but not resting not the birds. This process is continued until the two boats meet at the center of the net.

This season we should have special "wicking" platforms installed on the boats retrieving the net to keep the scoters off the hull of the boat (if we do not have platforms we will have special pads on the hull of the boats holding the scoters above the water coming off the net). This will keep them from getting excessively wet, and allow the water from the net and the birds to drop down into the hull of each boat.

Post Capture

Once the boats are secure the process of scoter extraction occurs. most people on board the boats will assist in removing birds from the net. The first batch of scoters, that satisfies SFU's sampling needs for more detailed processing, blood draws, and VHF transmitter deployment, will be shuttled back to R/V Harlequin, either by the RHB that did not pull the net in, or the 4th boat (smaller inflatable).

The scoters that are transported back to R/V Harlequin will be placed in crates modified to keep scoters dry and contained. There will be two processing teams of two people as well as a 5th person to weigh and then re-crate processed scoters. Once these scoters have been processed they will be moved back to the capture area for release. If there is another set of newly captured birds, more of these will be transported back to Harlequin for processing.

The birds that remain on the capture boats, after the capture, will be processed and released on location. There will be two banding teams, of 2-3 people each, processing these birds - information collected will include band#, species, sex, age, and 9th primary (9th primary may be omitted if there are more birds than anticipated. Once a scoter is banded and these data are collected, it will be released. While this is occurring, people on board that are not processing, will continue to extract entangled scoters from the capture net.

Depending on how many scoters we capture, if there is time the capture net may be cleaned and re-spooled. Once the processing is complete, another net spool will be loaded, and another capture will be initiated.

A few important notes regarding injured birds and bird safety:

If you notice an injured bird, or a bird becomes injured while you are handling it, bring it to our attention right away.
This will help insure the injury is minimized by allowing the most experienced handlers to work on the bird. This can not be overemphasized, as the rare injuries we get have the potential of becoming much worse if the bird is not restrained, and does not get the focus it deserves.
If you see larger waves coming towards the capture boats (and you are on one of these boats) let everyone know a wave is coming, and brace yourself to make sure you are in a position you will not fall. At times waves will come by, and for your safety, and the safety of the birds below you, injuries can be avoided if everyone maintains awareness of the surroundings.