Still Waters

Friday, March 30 presented itself with a brief window of south winds.  Winds began quite strong at first, before leveling off after the trailing thunderstorms moved through.  The rest of the morning would prove still and cloudy, with very little passerine movement.  Today was the lightest migration morning recorded thus far this season.  592 birds were recorded.

Two new species added to the ranks of birds seen from the Green Tower site this year.  Flyby Blue-winged Teal and Pectoral Sandpipers give us 115 species for the year.  The Long-eared Owl that has been present for the last two days was not seen today.

On the water, a few Gadwall and American Black Duck, joined a low count of 63 Red-breasted Mergansers.  However, both loons were logged again today, with 3 Red-throated and 8 Commons being seen.

With this likely to be the last count of the month, before some strong south winds on Sunday, April 1, here’s some unique season totals logged from the Green Tower this season:

Wood Duck: 108
White-winged Scoter: 61
Red-breasted Merganser: 1,833
Red-tailed Hawk: 150
Sandhill Crane: 24,977 (23 more needed!)
Killdeer: 515
Ring-billed Gull: 17,238
Great Black-backed Gull: 25
Northern Flicker: 1,432
Eastern Phoebe: 84
Tree Swallow: 284
Eastern Bluebird: 736
American Robin: 35,572
Lapland Longspur: 604
Red-winged Blackbird: 52,737
Common Grackle: 37,894
Purple Finch: 61
House Finch: 893
Common Redpoll: 57

One last bird for the day, the park’s first Louisiana Waterthrush arrived in the Dunes Creek swamps today, just shy of the record early date of March 27.


A Little of This and That

Wednesday, March 28 brought another light morning in migration.  The southerly winds throughout the night shifted to west at dawn.  A west wind from the high dune top travels over a small sliver of Lake Michigan before chilling the counters.  It also helps create small waves on the beach.

Today’s flight consisted of 1,428 individual birds.  Clearly, the earlier bang of blackbirds and robins have been bottled up.  We have many more of them to see throughout April, so the weather is evidently restricting their movement.  Gulls were again moving again, with 14 Herring Gulls noted and 3 Great Black-backed Gulls.  The now well known Great Black-backed (Glaucous?) hybrid gull made it’s near daily flight past the green tower.  We believe  it now waves when it goes by.  Flickers made an attempt to migrate today, with 39 being seen.  A few sapsuckers were flying with them.  But, compared to recent counts, these numbers were small.

Yellow-bellied Sapsucker male on March 28, 2012

Two new birds were added to the season totals today for the old Green Tower site.  The first, a well seen, flyby female Hooded Merganser was near the shoreline moving west.  The second, technically within spittin’ distance to observation area, a beautiful Long-eared Owl was located in the nearby pine stands.  This bird stared intently at visiting birders carefully throughout the day, and was still present roosting in the park as of this writing.

Long-eared Owl in Dunes State Park, March 28, 2012.

113 species have been seen from the Green Tower area in March of 2012.  We hope to wrap up the week with some more counts, but the March lions may prevent it.  April 1 looks good, with a strong south winds.  Let’s hope it’s not an April Fools joke.


The Grube Magnitude Index

Tuesday, March 27 was one of March’s lions, rather than lambs.  After several days of north winds, last night brought an abrupt shift of winds, with gusts to 30mph.  These winds would continue at dawn for one of the windiest mornings on the old tower site since the first days of the count season. Temperatures were also similar to early March, with a morning start of 37 degrees.

The day’s flight would finish much like the flight before the front.  Slow.  Only 1,564 birds.  The day was more reminiscent of a north wind morning, with few passerines moving, and more longshore lake birds moving.  The gulls would provide a nice diversity, with a season high 36 Herring Gulls, and both Glaucous and Great Black-backed Gulls being logged.  The day screamed for a passing Thayer’s or Iceland, but none flew past.

Other highlights included 2 Snow Geese, White-winged Scoter, Great Egret, Lapland Longspur, and Purple Finch.  The biggest highlight was an amazingly early Chimney Swift.  According to eBird, there have been no sightings north of Nashville TN.  However, the funneling along Lake Michigan continues to provide new surprises every day.

After a single day of birding, how do you best quantify the the magnitude of flight witnessed?  Enter the Grube Magnitude Index (sounds like a Big Bang Theory episode).  Developed by Dr. Ken Brock, and later refined through many permutations, it essentially produces a magnitude score based on the total diversity of birds seen in a morning, while also taking into account the total individuals seen.  For total individuals seen, each species is compared to the mean average of previous counts, creating an index point for the 60 most common green tower migrants.

The species chosen for the Grube Magnitude are, for the most part, well-recognized longshore migrants.  An effort was made to avoid species that breed near the Dunes State Park green tower site (e.g., Brown Thrasher, Prairie Warbler, Towhee, and Field Sparrow), as there is always uncertainty about whether these are local birds or migrants

Standards were calculated from each species mean using the below equation.  The advantage of this approach is that indexes of the less common species more closely match their flight numbers (i.e., they are not overpowered by the standard), thereby emphasizing flight diversity.

  Std = loge(4^mean)

Obviously there are other parameters not mentioned.  One such limits a single species score to 10, thus a single record flight from one species will not skew the total index score.  

Grube Index baselines for 60 common migrants.

The computer program uses the given date and location to search database files for each of the above species.  The number of each species is divided by its corresponding standard; these quotients are referred to as indexes.  The sum of all indexes involved in the flight is the Grube Magnitude.

Consider the following printout of the 25 April 2009 count at the Dunes S.P. green tower site (Table II).  The left number gives the species order in the list of 60 selected species.  Missing numbers reflect species that were not recorded on this flight. Note below that the number #1 (KILL ) was absent in this day’s count.  For the Solitary Sandpiper the count of 8 was divided by the standard (5.55) to yield the index.  The Grube Magnitude for this flight (sum of all the indexes) is 41.58.

The 20 best flights, based on Grube Magnitude, are listed in Table III.

The longshore flight magnitude is named for Brendan Grube’s leadership in guiding us all to the lakefront’s most superb watch site.  The index and it’s permutations have been developed by Ken Brock.  If you have ideas on making it better or questions, let us know in the comments box.  We can also provide a full synopsis of the Grube Magnitude Index IIIa in it’s current form.  Thanks to Ken Brock for allowing us to share this unique way to measure the longshore flight.  We’ll also try to include Index numbers for this year’s flight in various posts too.  You can see above that three of our flights this year have already made it into the top 20.

Sound the Fog Horn

Marine fog intrudes into the Green Tower Site, March 24, 2012.

As is evident from the photo, no birds were seen migrating today.  Fog drifted in and out of the counting spot throughout the entire day.  However, the territorial Pine Warbler was heard by visiting birders today.  North winds look to set in place for the next 48 hours, but we hope to be back counting birds by Tuesday at the latest.

Some Loony Weather

Longshore Rainbow, March 23, 2012

This morning greeted the counters with the first real precipitation in days, if not two weeks.  Despite the weather, it was absolutely beautiful and calm out over the high dune.  By dawn, most of the morning rain was more of a drizzle off and on.  The rain was never really hard enough to put a hamper on the birding.  Heavier rains came later in the afternoon, but for the morning, songs could be heard, and a few birds did choose to migrate.

The best highlight may not have been a bird, but the amazing full color rainbow that arched across the sky around 8:30am.  As the old birding lore goes, some mega rarity was sitting off shore at the end of that rainbow.  A Yellow-billed Loon perhaps.

A loon no doubt, as there was a good movement of loons early this morning.  The loon migration typically peaks in mid-April, but a good number are already being seen.  The dunes area hosts record counts of 1,000+ birds.  The majority of these high counts occur in the fall, but a few spectacular spring counts also exist.  Thus today’s 69 Common Loons and 5 Red-throated Loons are merely the tip of the iceberg, but quite enjoyable for folks that have never seen that many loons on the water at once.

As one can guess, the morning flight of passerines never really took off.  Perhaps 1,000 robins and blackbirds flew over the tower site this morning.  However, once again, Palm Warblers made a presence, with two more birds being seen.  One of the Palm Warblers chose to serenade the counters with it’s weak trill from the West Lot for quite a while.  A quick look on Ebird and IN-Bird shows that no other birders in Indiana have seen a Palm Warbler yet.  Odd?  Accompanying the Palm Warbler in song was the season’s first territorial Pine Warbler.  Add the two Yellow-rumped Warblers and it was the season’s first three warbler species day!

After 14 full days in a row of counting birds, it may be nice to have some breaks in the coming week.  The forecast becomes more complicated and wind shifts will occur more often.  Calm north winds don’t necessarily mean no birds, so if conditions look good, we will still be out there.

Flicker Clickin’ and the White Goose Shuffle

As projected yesterday, this morning’s longshore flight (March 22, 2012) hit a milestone in migrating Red-winged Blackbirds.  Today’s 1,770 birds surpassed the 50,000 mark for the season.  While on milestones, Red-breasted Mergansers surpassed 1,500 for the season with 111 added today, and Killdeer exceeded 500 today by adding 3 birds.

The day was overall slow, with a pale 4,267 birds recorded flying over.  Today  marked the second slowest day of the season.  Having said that, conditions were near perfect, with a very light wind and glass like conditions on the lake.  The quiet chip notes of Purple Finches could be heard among the usual blackbird and robins sounds.  The slower day allowed for careful counts of migrating flocks, without having to quickly switch to the next incoming flock.  Counting flocks can be a lesson in how bad we are at counting bird groups.  Three people can count the same flock and get completely different numbers.  We tend to underestimate flocks of smaller sized birds, but at the same time want to be conservative in the number, rather than risk over-estimating the flock sizes.  Ebird had a good post here regarding counting flocks.  You can even practice at home with the Irania Bird Counting Game.

Irania Bird Counting Game.

Our counter was joined again by Bernie Konrady, who has become the “Flicker Clicker,” catching every bird heading west, both in front and behind the staircase.  287 Flickers were counted today, on top of the 229 yesterday, and 295 seen on Wednesday.

Female Northern Flicker flying west over the old Green Tower site, March 22, 2012.

On Tuesday, March 19, just as the day’s count was finishing, seven white birds with black wingtips were picked up south of the count site heading in a southeasterly direction.  Quickly getting the birds into the scope, it became apparent that these birds were not pelicans, but Snow or Ross’ Geese.   Though both are extremely rare on the lakefront, logic dictated that they would have been Snow Geese, and the birds were logged as such.

Fast forward two days to March 21, local birder Penny Starin finds seven Ross’ Geese at Hitchcock Pond in Michigan City.  The pond is west and south of the state park.  Could these have been the same seven geese logged from the old green tower two days earlier?  Not long after this morning started, an amazing seven white geese were again located flying by the tower.  This time the birds were near the shore and heading out in a northwest direction.  Again, with a quick scope swing, it became obvious that these white geese all had tiny bills and lacked the grin patch present on Snow Geese.  They were Ross’ Geese!  Did we blow the call on March 19!?  Given the likelihood now that the March 19 birds were Ross’ Geese, they will still be recorded as a Snow/Ross’ type Goose without specific designation.  The Ross’ Geese seen today are a new Green Tower site record.


A Morning of Milestones

The morning migration at Indiana Dunes State Park continued again, ready or not!  This morning saw more migrating birds than yesterday, with 8,424 birds flying by.  Several species hit some milestones for the season that may be worth mentioning.  Those being:

Sandhill Crane: 24, 947 (ok, not a milestone.  maybe tomorow?)
Killdeer: 503
Ring-billed Gull: 15,904 (actually hit a couple days ago)
Northern Flicker: 1,003!
American Pipit: 204

Tomorrow looks to be the magic day where we will have hit 50,000 Red-winged Blackbirds.  We’re at 49,741, so you’ll want to be there early for the celebration!

Aside from the usual highlights, some folks have been curious about the full list seen.  We’ve included it below for those interested.  Aside from the increased passerine flight, waterfowl were down today, as well as birds of prey.   Today’s best highlights were both expected loon species, a flyby Merlin, the first Lesser Yellowlegs of the season, and 229 Northern Flickers.  For the third day in a row, a Palm Warbler was seen from the high dune site.  We’ve now set the first, second, and third earliest spring migrants to the Dunes Area.  Not on the official count, but a Hermit Thrush was also found within the park boundaries this morning too.

The Longshore List, March 21, 2012

Canada Goose 10
Ring-necked Duck 6
Bufflehead 4
Common Merganser 2
Red-breasted Merganser 39
Red-throated Loon 5 continuing flight
Common Loon 1
Double-crested Cormorant 13
Great Blue Heron 7
Turkey Vulture 5
Sharp-shinned Hawk 3
Cooper's Hawk 4
Red-shouldered Hawk 2
Red-tailed Hawk 7
American Kestrel 1
Merlin 1
Sandhill Crane 143
Killdeer 11
Lesser Yellowlegs 1
Ring-billed Gull 419
Mourning Dove 38
Belted Kingfisher 3
Red-bellied Woodpecker 1
Yellow-bellied Sapsucker 4
Northern Flicker 229
Pileated Woodpecker 1
Eastern Phoebe 3
Blue Jay 1
American Crow 13
Tree Swallow 17
Tufted Titmouse 2
Brown Creeper 1
Red-breasted Nuthatch 1
Golden-crowned Kinglet 6
Eastern Bluebird 21
American Robin 655
Brown Thrasher 1
European Starling 49
American Pipit 37
Lapland Longspur 37
Palm Warbler 1
Yellow-rumped Warbler 3
Field Sparrow 1
Song Sparrow 1
Northern Cardinal 1
Red-winged Blackbird 4555
Common Grackle 1852
Brown-headed Cowbird 183
Purple Finch 2
House Finch 12
Pine Siskin 4
American Goldfinch 4

Lastly, we should thank Bernie Konrady for spending the last few mornings with us to gaze at the longshore flight. Today we had Bernie clicking off Flickers as they go by.