I am adding an additional post today to respond to two comments I had about :What is the deal with the ducks?
In my job as a Waterfowl Technician, on July 1st till till mid September I band wood ducks. I catch the wood ducks with a rocket net. I put out corn to get them up close to the net and then shoot a ~60'x40' net over them. It has three rockets attached to the net that pulls the net out VERY quickly. They are incredible flyers and even though they are 3 foot from the net many of the birds are caught on the outer edge of the net when it comes out. The US Fish and Wildlife Service provides aluminum bands that we put on each duck...it goes on their right leg. Why do we do this? Wood ducks...as their name implies live in woody areas...like swamps and small streams. They spend most of their time in areas where you can not count them easily. Other ducks can be counted with aerial surveys because they spend their time in open water areas. Because of this we band wood ducks so that the US Fish and Wildlife Service can better estimate the population and other stuff using statistics. When a hunter kills a wood duck in the coming hunting season they will report the band number to the USFWS. The USFWS uses these banded birds to find out about migration, life-span and survival rate, reproductive success and population growth. For a much better explanation please check out the link to the Bird Banding Laboratory: http://www.pwrc.usgs.gov/bbl/ That site covers Why Birds are banded?,History of Banding, Who bands birds?...etc. It is very interesting.(atleast to me it is)
I am now finished with banding wood ducks. My next job duty is to maintain, clean and record data from the 550 wood duck nest boxes that we take care of. Wood ducks are cavity nesters and we put out boxes to help boost the population since many larger trees are being cut down. The boxes are located on ~35 rivers,streams,etc in ~13 counties. It takes me about 2 months to check them all.
When the ducklings hatch out of the egg they pull the egg membrane out. This membrane drys and is left in the box. When I check a box I count the membranes...which lets us know how many ducklings were hatched and left the box. I also record eggs left in the box and also dead ducklings.
A hazard to this job is that wasps love the boxes also and I have killed hundreds of wasps in a single box. Also there is an occassional black snake..which is no big deal. We also get other birds that use the boxes like: hooded mergansers, flickers, screech owls, prothonotary warblers...etc.
Most of these boxes are checked by using a boat but some are on retention ponds or beside a stream in the swamp and we use waders to walk to them.
Hope this post has answered some of your questions....let me know if I need to explain anything further. Have a great day.