Field Notes: June 3, 2013

Daryl Christensen adding hay to
Forster's Tern nesting platforms

Wildlife

So far there are no Common Terns nesting on the rafts, but several adults, and non-breeding birds are still hanging around.  Daryl Christensen and I placed 20 small platforms for Forster's Terns, at Pancake Island among the River Bulrush that grows there, on Friday. The birds are either nesting or have staked their claim on them.  Daryl has been placing these platforms for many years.

Update: 19 of 20 platforms had nests

Forster's Tern Nest Platforms

Habitat

I began some experimental plantings of cuttings of common reed (canes).  If these are successful it will be a great way to establish and expand existing cane beds for very little cost.  

Underwater photo of wild rice in its
submerged growth phase.

So far it is looking like a good wild rice year up the Dead River.  Wild rice is a fragile annual grass, so sudden changes in water level could change that overnight.  

Last year's emergent plantings are struggling for light even though the water is somewhat clear in places.  Plants are coated with algae, sediment and other debris.  This can cause stress, and may end up killing some of the plants.  

Fish 

It is interesting to see massive schools of tiny fry, of several unknown species.  These are being preyed upon by Northern Pike, which just hatched in April, but are already 2-3 inches long.  I have seen several at our planting sites and take full credit for these fish.   :)

Common Tern Nesting Raft: May 24, 2013 update.

Too many terns???

Lake Puckaway has been home to the endangered Forster's Tern for decades; now the District is attempting to get the endangered Common Tern to nest on the lake as well, by placing the nesting rafts made from old pontoons.  Apparently, the Forster's are a big fan of this beach property too.  On Friday, approximately 37 Forster's terns were busily preening or leisurely resting on railings or on the pea gravel inside Raft A (Western).  Three Common Terns were also there.  While I watched the raft, terns kept coming and going, leading me to believe Raft A is being visited by 60-100 of these endangered birds each day.  The raft itself could probably only hold the nests of 15 pairs, and that would be a dense nesting population.  No nests on the raft.  I was curious to see how disturbed the birds were after I had spent 15 minutes attaching new signs, so I counted how long it took for a tern to return:  29 seconds.

I also saw something I wasn't really expecting, and that was a flock of 16 Ruddy Turnstones, members of the sandpiper family, attempting to land inside the raft.  Some saw my ugly mug and floppy hat and flew off, but others landed and were the last birds to leave when I approached within twenty feet of the raft.  Ruddy Turnstones are only passing through on their way to their nesting grounds within the Arctic Circle.  While they are here they are neat to see, but unfortunately they will also eat tern eggs.  Fly on, Turnstones.

Raft B (Eastern), which is closer to boat traffic, has fewer birds on it, only 2-3 at a time, but maybe this will give the Common Terns some needed space to nest.  For those who like to fish the small cane bed nearby, casting into it from the channel side should not disturb the birds too much.  Thanks for giving them some space.

Common Tern Raft Update:  For 2014 tern rafts are both located behind "Bird Island" and raft B is now east of raft A .

Sorry for the up and down from the rocking boat.

New signs on nesting Raft B.  Each raft has two signs. 

Raft A, before new signs and loaded with Forster's, and a few Common Terns.
A flock of Ruddy Turnstones rocket into view on the right.  

Common Tern Nesting Rafts

The Lake Puckaway Protection and Rehabilitation District has placed two modified pontoon boats along the central dredge bank of Lake Puckaway.  The Common Tern is an endangered species in the state of Wisconsin because their natural nesting habitats--beaches and sand bars--have disappeared due to development and dam building.  The rafts placed on the lake simulate this habitat, while being less susceptible to fluctuating water levels and predators.  Lake Puckaway is already home to another endangered species of tern, the Forster’s Tern.  Forster’s Terns and Common Terns look very similar, but the Forster’s Tern typically nests on mats of vegetation.

Please only observe terns at a distance to avoid disturbing the birds.  If the rafts are visited too often, the birds may abandon the colony.  Keep at least 100 yards distance, and never enter the rafts.  Wildlife watchers can get a good look at these 4.5 ounce terns when they are resting on buoys, posts, rocks, or exposed sandbars.  They are fun to watch as they search and catch fish throughout the shallower regions of the lake.  When they spot a fish they hover and go into a dive, plunging and briefly disappearing into the water.  Males will often give their catch to their mate. 

Common Tern on nesting raft railing

 Rafts will be placed in early May and be removed after the breeding season in late summer.  Funding is provided by a Wisconsin Department of Natural Resources Lake Protection grant and the Lake Puckaway Protection and Rehabilitation District.  Check the Lake Puckaway blog for weekly updates during the breeding season.

UPDATE: 5/19/2013

Up to ten Common Terns, and two Forster's Terns have been seen using the raft simultaneously  and least for loafing purposes.  The western raft sees most of the use, and appears to have a nest on it with no eggs yet.  Common Tern nests are often just scrapes in the sand, but sometimes they add nearby sticks and grasses.  Rafts will soon get official looking signs.

Click for more photos

Forster’s Terns Nesting Fails

The Forster’s terns nesting on Lake Puckaway came to an end June 22nd when high water destroyed many of the 143 nests, causing the rest of the colony to abandon the site.  These birds nest on floating mats of vegetation, which are susceptible to wind, waves and water level increases.  Nesting was late this year because of high water, and there is a chance that they may nest again, but given that I only saw 10 individuals on the lake Thursday I don’t think it is likely.  It has been a bad year for these terns in our area.  They normally nest in large numbers on Lake Poygan in Winnebago County, but that colony had all of its nesting material taken away by this spring’s flood and high winds.  The LPPRD is keeping tabs on Forster’s terns and their habitat and will develop a program to stabilize the lake’s population.