Swallow tornado

Tonight I tried to track down a Tree Swallow roost that has appeared to be visible on radar on the West Bank near the St. John/St. Charles parish line.

These annual November roosts are one of the great wildlife spectacles of Louisiana, with hundreds of thousands of swallows gathering in a massive flock before descending into the cane in the gathering dusk.   The roost entry is in the form of a strange tornado-like funnel (made of birds) that extends from the swallow cloud down into the cane.  The birds "drain" through it as darkness falls.

I had never visited this site before, but located it on radar- an expanding donut ring (or one side of a donut) visible at dawn on rap.ucar.edu, a site that does not filter out bird echos.  When I arrived tonight I found birds streaming over the fields toward the river, and so I followed them and climbed up on the levee to find hundreds drinking (or catching bugs?) on the surface of a pond in the batture.  Large numbers seemed to be gathering higher in the air upstream from there, so I drove a ways in that direction on the River Rd.  I ended up going too far, passing the birds, but could see 100,000 (very rough estimate) high up in the air with binoculars (beyond unaided vision) back in the direction from whence I had come (see photo below).  A falcon of some sort was now maneuvering within the flock, very high in the air, but I could not afford the time to try to identify it to species. 

I returned a bit downstream and could not relocate the flock (how can it be hard to relocate that many birds?!?), until I saw their entry funnel coming down out of the then fairly dark sky a bit farther back downstream toward their drinking pond, blocked from view somewhat by a woodlot.   I moved farther downstream to get closer and saw the last minute or so of the roost entry, the final pulse of birds swirling down through the "funnel" into the cane.  It was surprising how short a time it took for the whole entry to be completed for so many birds.

A local resident came out and couldn't stop talking about how she and her husband had watched these birds in awe for the last couple of weeks and wondered who she should call to report them to.  Blackened the sky, she said.  I told her the roost in Vacherie had been reported at a million in years past and she said she thought that was a low estimate for what she had been seeing.

She said that earlier in the month the birds were streaming overhead toward cane fields upstream at dusk, and only in the last couple weeks had relocated to the cane just off the end of her street.  The street is private, so viewing might only be from the river levee across from it around 350 yards away.  I am not sure the attitude of the St. Charles Parish levee board toward people being up on the levee.

The exact coordinates of tonight's funnel entry point are 30 deg 1 min 10.5 sec N, 90 deg 29 min 48.2 sec W.  This is in the town of Killona.

I managed to snap one picture of the gathering flock, from a great distance (still beyond naked eye detection), posted below.  I felt there were probably 100,000 in an initial count (the picture only includes a part of it), but it seemed it grew afterwards- maybe several fold- but I would hesitate to hazard a guess until I get more optimal viewing conditions.  Unfortunately, this roost location will probably only persist till the cane is cut, which is ongoing.

Peter

Birds overhead tonight

Birders:

I just came in from a 5 minute moon watch at around 10:45 pm- four small birds crossed the lunar orb, which is conveniently near full tonight.  Of course they were actually migrating a couple thousand feet overhead, and were made visible by passing between me and the lit orb.  I watched with binoculars.

There is also a good density of flight calls- average spacing between them probably 3-5 seconds in my hood, which is rather noisy.  It seems like mainly thrushes, which make medium-low short notes that sound like "heep" or "urp" or something similar.

The bird silhouettes seem way too far up in altitude to be the source of the call notes- interesting.

The movement tonight is in response to the tail winds following the cold front passage- migrant birds normally wait for such circumstances, and then migrate in droves.

Peter

Amazing shot of booby underwater- from Carnival Cruise ship!

Local New Orleans birder Steven Liffmann just came back from a Carnival Cruise with an amazing shot taken near our shores, of a Masked Booby underwater after its headfirst dive in pursuit of prey:

To give you a better idea what the bird looks like under more normal conditions (if looking down at a seabird is normal!), here is another shot of the bird:

Boobies are not related to gulls, despite their superficially similar appearance.   Before the Brown Booby incursion of the last decade (or so), Masked Booby was the presumed booby species to see in the Gulf.  Now Brown is also found regularly.  Their close relative, the Northern Gannet, is also regular in winter and often seen from shore.

Steven's bird was 80 miles off the mouth of the River.   Masked Boobies are generally not visible from land- finding them requires going out in a boat.  The way most Louisiana birders get them is by participating in an organized  trip, in which a group of birders pitch in to hire a boat.  Recently a few birders on the LA-Bird listserve have reported on working the cruise ship angle- James Holmes and now Steven.

Boat birding is essentially the only way to get several other truly pelagic species that are seldom visible from shore.  Audubon's Shearwater, Band-rumped Storm-Petrel, and Bridled Tern are three of the more regularly seen such "pelagics"  on these trips, but a range of others are possible.  As a general rule, such Gulf outings are not as birdy as comparable trips out of the well known East and West Coast pelagic birding hubs, but they are a must-do for birders serious about building up big personal Louisiana lists.

Birding Opportunities Produced by Weather

The approaching cold front has prompted me to contemplate and categorize various ways in which particular weather phenomena can produce birding opportunities.  So here goes an attempt at delineating them, with an emphasis on south Louisiana.   All of these, however, are pretty well known to experienced birders across the continent.

1.  Cold front passages

Cold front passages produce concentrations of migrants.  In spring this is crucial in coastal areas along the Gulf, where trans-Gulf migrants are induced by these fronts to stop in our area instead of overflying the coastal belt and heading inland.  A cold front produces a headwind (and often rain) that makes the Gulf crossing a struggle, inducing them to stop on the immediate coast or somewhere in the coastal belt.  These "fallouts" are best viewed  in the Nature Conservancy properties on Grand Isle, but can be impressive even in New Orleans (where the best spot to experience them is usually the Couturie Forest in City Park).  The grounded migrants will often linger for some days until wind directions change to give them a tailwind to continue north.  If the front arrives at the coast in time to intercept the arrival of migrants from across the Gulf (usually around midday), the fallout can happen that same afternoon.  If not, the next day is a better shot.

In fall, cold fronts often usher in waves of migrants utilizing the northerly tail winds that occur in the days that follow them.  The pulse of migrants is usually greatest on the morning following the first night dominated by northerly winds after the front passes.

Because cold fronts are more frequent in the cooler months, cold front birding opportunities are most common early in spring and late in fall.  However, most years we will get a front as late in spring as early May, and as early in fall as August.  At these times they may not usher in much change in temperature, but will still produce the desired wind direction change that can produce good birding.

2. Intense and widespread rainstorms

These can produce fallouts just as cold fronts do in spring, with the birds wanting to pause because they have been struggling through the rain (vs.  bucking a headwind after a cold front).   Rain-grounded birds will usually depart more rapidly than after a cold front, often at first nightfall if the rain has abated.  This is because wind direction is usually southerly and thus favorable for continued migration at times when a lot of non-frontal rain is in our area.

Major regional rain events in spring are generally considered the best conditions for grounding shorebirds.  The rain not only grounds them, but often creates rain pools in large open grassy areas, into which birds will gather.  The "Exxon Fields" at Grand Isle are well known for this.  Before the construction gobbled up so much of the University of New Orleans campus lawns, they also were famous for this.  Sometimes rain pools can have birds along Lakeshore Drive.  There are a few other lawns around, but they are owned by private interests who have not yet been courted to gain permission for general birder use so I will not name them.  However, during a rain event earlier this month, lawns on the West Bank of Jefferson Parish produced gatherings of Greater and Lesser Yellowlegs, and Pectoral, Least, and Solitary Sandpipers, and a Dowitcher sp.  Shorebirds do not generally stay grounded long- it is best to get out and find them while the rain is still falling.

3.  Tropical weather

Ah, the love-hate relationship of birders with tropical weather systems!  We love 'em for the birding they create, but we fear their destructive potential!  Tropical weather regularly displaces coastal and oceanic birds inland, sometimes hundreds of miles (I recall a Cory's Shearwater in Oklahoma).  For this reason many birders key in on them and get out and about searching for storm waifs as soon as they are able to do so safely.

The most predictable outcome of a tropical weather event in New Orleans is that Magnificent Frigatebirds and Black Terns will appear around the city.  These occur on the coast in numbers, so they may have merely been displaced inland by tens of miles- though we don't really know from whence they came.  Overall in the Eastern USA, Sooty Tern may be the most common truly pelagic species to be displaced inland after tropical systems make landfall, although it seems like just about anything is possible.  Jaegers, shearwaters, petrels, storm-petrels, phalaropes, tropicbirds- have all been reported in the last few years somewhere in the eastern USA after tropical systems passed inland.

The best place to search for storm waifs is large bodies of water- such as Lake Pontchartrain.  Birders saw a Great Shearwater from the Causeway after one recent storm.  There is some indication that birds may also be found following the Mississippi River back out to sea up to several days after a storm, but this needs further study. 

At this point it is not really clear how much of a correlation there is between numbers of waifs carried inland and strength of the storm.  Birds appear to show up mostly on the track or to its east.  While it seems reasonable to think some have become stuck in the eye (kept within it by their avoidance of the eyewall), and others merely pushed onshore by the winds, we don't really know. 

Sometimes other weird phenomena accompany tropical weather.  For instance, Hurricane Juan in 1985 lingered in late October on the northern Gulf, and resulted in unusual numbers of tardy land bird migrants occurring along the Gulf Coast- species that should have been in the tropics by then.  Even flamingos have occurred along Gulf and Atlantic shorelines after tropical systems.

The widespread rain of a tropical system can in itself produce fallouts that are similar to those described in the rain events under # 2 above.  Waterbirds and shorebirds are often in good numbers in flooded grassy fields during tropical weather.  One fancy record I recall:  Hurricane Opal in 1995 induced a Sabine's Gull to pause at Southshore Harbor on the New Orleans lakefront. 

4.  Extended drought

Less of a weather event than a prolonged pattern, extended dry periods produce low water levels in ponds and impoundments.  This can produce extensive shorebird habitat, often otherwise hard to come by in the immediate New Orleans area.  It can draw birds like a magnet.  The place with the best track record in this regard in our area is the impoundment on Recovery Rd in Bayou Sauvage National Wildlife Refuge- especially the pond accessed by walking beyond the landfill mound, or via the levee from Chef Highway farther east.  At such times this spot can have thousands and thousands of birds, ranging in size from herons to peeps.

Good birding!

Great Horned hooting in my urban hood

Last night I walked out my front door in Old Jefferson at a few minutes before 10 PM on a late grocery run, and before I could open the car door heard the resonant hooting of a Great Horned Owl just across the street. 

Four rapid breathy hoots followed by two more spaced out.

I have only heard Great Horned hooting in urban residential New Orleans a handful of times previously.  Closest woods are about 0.4 miles away in the batture.  This species is scattered through the metro area, but they have always seemed to me to be less vocal here than in "the country."

This bird was a tad higher pitched than I am used to, so I actually was able to do a decent (to my ears) imitation back at it.  I have been practicing Barred and Screech imitations since I was a pre-teen, but have always given up on Great Horned because I couldn't get my hoots low enough.  This one was within my range, or nearly so, suggesting it was a male (higher pitch than female).

It seemed to pause in response to my hooting, so I gave up and started back into my car- only to have it hoot again.  So I hooted back, and it flew over my car, underside visible in the adjacent streetlight.  Looked on the small side (at least, for a  Great Horned)- cementing my impression it was a male (males are generally smaller in birds of prey than females- reverse sexual size dimorphism!).

I drove off on my milk run, decidedly happier than when I walked out the door.

Whistler Horde at Ninemile Point

On Monday I visited the Ninemile Point grain elevator, for the purpose of estimating the massive duck flock.

I ended up walking the length of the flock, and estimating 15,000 Black-bellied Whistling-Ducks were present, with another 1400 Lesser Scaup.  The whistlers were pretty much on land, the scaup out in the water.  Careful inspection of the couple hundred scaup that were close in did not show any Greater Scaup mixed in (Greaters are often mixed into Lesser flocks in our area, in small numbers).

I used to bird this site twenty years ago, before the Whistler invasion.  Back then thousands of scaup were regularly in attendance in late winter, but there were of course no whistlers around yet.  My how things have changed!

These Whistlers presumably share time between the elevator area and Audubon Park,which is more or less across the River, and where local birder Dan Purrington reported counting 10,000 in the lagoon system fairly recently.  The species is also numerous (though not in such crazy numbers) at Lafreniere Park in Metairie, at the Monticello water treatment plant in New Orleans, and can be found in smaller numbers widely throughout the metro area.  As spring progresses, you may see them showing up in residential areas with tall trees- where they nest in cavities. 

As far as birding the Ninemile Point site, the mass of birds is both cacophonous and odiferous.  For parking, I pulled over at the Entergy plant just upstream where there were other cars pulled off on the left, but have not yet done any legwork with respect to asking how they feel about birders parking there.  I walked the river levee to count the birds.

The pics below are just small segments of the area.  The third picture has scaup in the foreground.