What warblers are expected in the New Orleans area in winter?

Yesterday I was driving behind the Walmart in Chalmette, to check out the eagle nest in that vicinity*.   As I drove along the woodland edge, I chanced to notice a mixed songbird flock foraging low in the roadside scrub.  I abruptly halted the car, backed up a bit, and rolled down the passenger side window to "spish" and see what was there.  Yellowrumps charged the car, and with them came a few Orange-crowneds and a drab female Pine.  To my delight and surprise, a Prairie Warbler jointed the group, showing off its bright yellow underparts and neatly-streaked face and side.

The first three species are regular winterers around New Orleans, but Prairie is somewhat atypical.  I generally divide our wintering warbler species into several "tiers" of abundance/likelihood:

TOP TIER
Yellow-rumped Warbler
(Undeniably the most numerous species here in winter; a half day's birding our usual target winter habitats -forest, scrub, and marsh edge- will commonly produce dozens)

SECOND TIER
Orange-crowned Warbler
Pine Warbler
Palm Warbler
Common Yellowthroat
Wilson's Warbler
(All widespread and numerous enough to be found on most such half-day efforts)

THIRD TIER
Black-and-white Warbler
Nashville Warbler
Northern Parula
Yellow Warbler
Yellow-throated Warbler
Black-throated Green Warber
Prairie Warbler
Ovenbird
Northern Waterthrush
(Regularly occurring trophy birds; an active birder might expect to find around half of these in the course of a given winter; if you find one on a Christmas Count, it will probably be a count exclusive)

FOURTH TIER
Everything else that has ever turned up!  This list is long, and ranges from species a relatively small step down from those above (e.g., American Redstart) to some seemingly impossible vagrants (e.g., Lucy's and MacGillivray's Warblers, and Painted Redstart).   

*an adult was sitting low in the nest, evidently incubating.

Apparent Tree Swallow roosts in the River Parishes, visible on radar

One highlight of each November is the formation of Tree Swallow mega-roosts in the cane fields of the River Parishes.   A roost in Vaccherie has been estimated at a million birds in years past, but locations change somewhat from year to year.  I have seen them as far downstream as Luling.  They last only until the cane is cut, generally around early December.

The roosts are impressive at dusk, when huge clouds of swallows cover the sky.  Their roost entry is very strange, as the birds do not descend into the cane over a broad area, but instead "drain" from the cloud through a small funnel-shaped pathway they create.  For this reason, this phenomenon is often referred to by local birders as a "swallow tornado."

Cane fields are generally private property, so viewing options may be limited.   Sometimes a nearby river levee provides the best viewing, but sometimes engaging a farmer in conversation can open a door to driving out into the heart of the event and standing next to the funnel.  

The roosts are generally visible on the Slidell radar, when accessed online at a site that does not filter out birds.  The image below is from rap.ucar.edu, taken this morning (the 12:29 UTC on its label indicates 6:30 local time).  There are two obvious donut echos, one of which appears to be between Paincourtville and Belle Rose along (east of) Bayou Lafourche, and the other just east of Laplace, perhaps visible from Hwy 61.  Hidden between them (partially covered by the Belle Rose echo- only the southeast edge of the donut is visible) is  a third one, seemingly near Vaccherie or St. James.

Roseate Spoonbill among waterbirds at Shrewsbury Flats

Just made a brief swing through the Shrewsbury Flats- the water retention ponds beneath Causeway Boulevard, adjacent to the Earhardt Expressway. 

An immature Roseate Spoonbill was nice, hanging with the 25 or so White Ibis and a scattering of other large waders.

The most surprising bird was a female/immature Hooded Merganser- not a species that was on my radar to turn up here.

The muddy edges are extensive, and shorebird numbers have grown to 80 Least Sandpipers, 35 Black-necked Stilts, and 4 Lesser Yellowlegs.

An adult Common Gallinule was present, which makes it easier to explain the presence of three juveniles that I saw there a few weeks back.  Looks like they nested.

Good birding,

Peter

Mississippi River skywatch- no tropical cyclone waifs

After leaving Holy Cross this afternoon, I took a short detour to scan the river from the levee adjacent to Tulane's Hebert Center.  Because a load of frigatebirds had come inland not far from this spot during Cindy in June, and Harvey had made landfall in approximately the same location as Cindy near the Texas border, I figured what can happen once can happen twice.

Winds were strong in my face from the (more or less) south- making whitecaps on the water and causing my pant legs to flap vigorously.   I only had binoculars, but a scope would have been useless.  The weather service reported gusts to 35 mph at nearby Alvin Calendar Field while I was there, but it sure felt more like a sustained 30-35 to me!

For the entire half hour I was there (1:40-2:10 pm) there were a dozen or so Black Vultures kiting at various heights along the shoreline to my east, evidently buoyed by winds blowing up river and deflecting up the levee there, where the river makes its sharp turn.  I kept scanning them thinking a frigatebird might be coaxed into enjoying the same updrafts (I have seen this in storm-waif frigates before), but none appeared.

An Anhinga came northwest across the river fairly high up, scarcely making any effort to do anything but let the wind carry it.  Ten on so Chimney Swifts also came across riding the gale, one seemingly on the verge of losing control as the wind bullied it forward.

Several Barn Swallows fought the wind to cross the river southward.  A buffeted Spotted Sandpiper flew by along the shore.   A handful of Laughing Gulls glided up and downstream.  One Caspian Tern flew downstream.  It was the only surprise of the visit- though only mildly unexpected.

The enigma of species missing south of Lake Pontchartrain

Yesterday, Fox 8 posted this video of a beautiful male American Kestrel on one of their cams:

https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.facebook.com%2FFOX8NOLA%2Fvideos%2F10155849050679610%2F&data=01%7C01%7CPYAUKEY%40UNO.EDU%7C8956ab8c8d14495c605508d4e687fc01%7C31d4dbf540044469bfeedf294a9de150%7C0&sdata=TR3TwqrpUx6V%2Fct%2B%2FP5YU25l1zokjgMXo5lXqA2RbG8%3D&reserved=0


Apart from being a real looker, this bird is also of interest because it is here at a curiously early date-  the species nests on the North Shore, but is normally absent on the South Shore in the nesting season.  Being here before the normal fall migration period suggests it may have wandered down here after it finished breeding.  Such post-breeding dispersal in late summer is pretty widespread in North American birds.

But back up a bit.  Why would Kestrels nest on the north side of Lake Pontchartrain, but not the south side?  Isn't there plenty of acceptable habitat down here?  There does appear to be.  However, fully seventeen other species of North Shore nesters are also absent down here despite apparently suitable habitat:
Bobwhite
Wild Turkey
Swallow-tailed Kite
Broad-winged Hawk
Red-tailed Hawk
Belted Kingfisher
Red-headed Woodpecker
Yellow-throated Vireo
Eastern Wood-Pewee
Wood Thrush
Swainson's Warbler
Kentucky Warbler
American Redstart
Yellow-breasted Chat
Summer Tanager
Eastern Towhee
Blue Grosbeak
This used to be true of Eastern Bluebird and Northern Rough-winged Swallow as well, but they have become more regular nesters on the South Shore in recent years (or so it seems to me).  In reverse, the Bobwhite and Kentucky Warbler were more regular as nesters on the south side decades ago than they are today.

Why aren't all these species on the South Shore?  I and others have pondered this for many years, without a really plausible explanation yet emerging.  A biogeographical mystery under our noses!

Peter

Fall migration milestone: first Yellow Warbler reported

Although some migratory shorebirds are usually reported back weeks earlier (see my late June post), to me one of the pivotal moments of each fall migration is the first report of a Yellow Warbler.

One was reported in St. Tammany yesterday, by Jane Patterson in her back yard.

I normally expect to hear of a Yellow somewhere in the state at the very tail end of  July, but this one was a few days earlier than I anticipated.   It is the onset of a larger movement-Yellow Warbler normally seems to me the most numerous August migrant in the New Orleans area.  Because it is also one of our migrant species with the greatest propensity for "morning flight" (active migration in the early AM), it is not unusual to hear one giving its seet note overhead on any morning during the month.  I have spent many hours listening for these birds in many locations on August mornings, and have on occasion observed movements of up to 100/hour both on the lakefront and in Old Jefferson.  Most such birds appear to be westbound, and presumably are bound to circumnavigate the Gulf.  They do also stage larger corrective flights at South Point on August mornings with northeast winds, but such winds are hard to come by so early in the season, since we are generally still out of range of the cool fronts that create them.  I have long tried to figure out when during August the peak of Yellow Warbler numbers occurs; my best guess is that it is in the last few days of the month, but because substantial flights can occur earlier, I am still wondering.

First fall migrants have returned!

What?  Fall migrants?

Yes, three Lesser Yellowlegs have been reported together in the northwestern corner of the state, fresh down from their nesting grounds in Canada.

Although it seems crazy, since we are barely past the solstice and into "summer," this is actually a pretty typical time for our first fall migrants to show up.   And it is quite typically a shorebird species that leads the pack.

What happens now?  Purple Martins are at peak numbers right about now in their pre-departure roosts (including under the Causeway bridge), and will be among the first breeders to disappear.  However, things get started slowly- some martins will be around until the end of August, about the same time our Mississippi Kites vanish.  At that point fall migration as a whole will just be getting up steam.  The waves of Neotropical migrants (i.e., species that winter in the tropics in our hemisphere) will build in size  through September.  Around mid-October, movements will become dominated by species that winter in our area.   Finally, major flights will end at the close of November, with just a small variety of species with atypical migratory patterns actively migrating afterwards, such as Yellow-rumped Warblers and Cedar Waxwings. 

Changes are on the way!


Peter

Brown Booby on the Causeway Bridge

Today as I was driving southbound on the Causeway at 7:25 PM, I was treated to a Brown Booby at mile marker 16.3.  It was just off the bridge, and turned in such a way as to approach the side just as we passed.

This is the exact spot where a roost of this species has been located for the last few years.  Birders crossing the bridge had been seeing small numbers occasionally, but it wasn't until a boat trip in June 2015 that allowed better viewing of the bridge structure that we discovered that there were many more there than suspected.  The peak count I know of was of 37 on one boat visit last October.   To my knowledge, there have not been any recent boat trips- a similarly large number could still be roosting on the bridge there every day.

How crazy- this species was an extreme rarity in Louisiana waters up until a few years ago.  Then they inexplicably started appearing with greater frequency- including on near-coastal lakes and even once flying with geese over the rice country!  This tropical species has been turning up in other parts of the country- and even Canada- with increased frequency at the same time as this has been happening in our own state.  These odd appearances out of range and out of habitat together pose one of the most fascinating and enigmatic ornithological mysteries I have ever heard of, and I have yet to hear an explanation that is even remotely convincing.

So the next time you cross the Causeway, keep alert!  These birds can turn up anywhere along it, but are most likely to be seen near mile marker 16.3 on the west side.  When roosting, they are invisible from the roadway- thousands of cars pass these rare birds every day, completely unaware of their presence!

Good birding, Peter

Hundreds of Mississippi Kites migrating through South Point!

This morning I took a walk out to South Point, which is the point of land from which the railroad bridge leaves New Orleans East and heads across Lake Pontchartrain to Slidell.  This is the railroad bridge visible to your left as you cross the twinspan.

South Point is interesting because it is the logical jumping off point for birds that are wanting to cross from the south shore of the lake to the north shore- by sticking northward from the southern shore, it cuts that overwater distance to 5 miles.

I had hoped for a migratory movement of some sort to be going on, but was unsure what to expect. We know big migratory movements  happen here in fall, but know virtually nothing about spring.

The point is only accessible via a mile or so walk, which starts at the "fishing bridge", which you may have noticed on the lake side of I-10 more or less across from the Irish Bayou castle.

As I walked out, I noticed  a flock of 21 Mississippi Kites negotiating the wind, which was howling from the west-northwest.   Lakefront Airport says 23 mph, gusting to 32  Felt stronger than that to me!

They made their way up to the point at about the same pace as I was walking, and we arrived there at 845 AM.

Then another flock of 22 approached, along the same tack as the others.  They headed out over the water toward Slidell and gained altitude until they were beyond range of my unaided eye.  

Around 930 the sky to the south suddenly became filled with kites- 185 in one flock!  This was far more Mississippi Kites than I had ever seen at one time before.  They were mostly low, dipping and tilting in the stiff wind.  They eventually headed out across the water, gaining height like the previous flock of 22.  I watched them through binoculars beyond naked eye visibility.

Another 10 minutes passed, and another flock- 155- appeared to the south and again headed toward me.  Shortly thereafter, another flock of 85 doing the same.

That's 468 Mississippi Kites in an hour.  That's crazy- quite likely a new record high count for the state of Louisiana, and something I never would have anticipated.

Two brief snippet videos are below, of parts of the flocks, taken by cellphone.

Good birding!

Peter

Birding opportunity at City Park- tomorrow!

Spring is a time of boom and bust migration here in New Orleans.  According to reports, there is a little "boom" happening today in the Couturie Forest on Harrison Avenue in City Park- the city's premier migrant trap.  James Beck reported today that he and a handful of companions found 15 warbler species, accompanied by numbers of other passage migrant species, including 20+ each of Red-eyed Vireo, Great Crested Flycatcher, Scarlet and Summer Tanagers, Rose-breasted Grosbeak, and Indigo Bunting.  Warblers were let by 15 Bay-breasted, 12 Tennessee, and 3 of the hard-to-find Cerulean and one harder-to-find "Brewster'" Warbler (Golden-winged x Blue-winged hybrid).

Because winds are still from the northerly half of the compass, chances are that many or most of these birds will hang tight and still be there tomorrow- continuing migration would require departure into a head wind.  All these species migrate at night.  If you go, focus on both the live oaks and whatever fruiting mulberries you can find in more open sunlit areas.

This fallout is a puzzling.  At first glance it appears sensible- we know cold fronts precipitate fallouts by inducing birds to stopover instead of passing over us, and one came through last night.  However, this front was still hours away when the birds would have arrived across the Gulf yesterday.  This arrival is typically around mid afternoon, and the front didn't reach us until around 3 AM- about 12 hours too late to hit the birds with a headwind and induce them to ground.  There was no rain ahead of the front, so that couldn't have caused them to stop.  Could it have intercepted last night's flight instead?  No- James reported the fallout as already underway at 930 am, before birds from last night's flight across the Gulf should have reached us.

Just when you think you have migration figured out!  Sheesh.

Peter

Black-bellied Whistling-Ducks mobbing Mississippi Kite!

This morning I stepped out my front door to see seven large birds wheeling above the trees across the street.  It was a Mississippi Kite pursued by six Black-bellied Whistling-Ducks that were equal it in size (and I am sure quite a bit heavier).  

I have seldom seen a Mississippi Kite mobbed by anything- there is little reason to, since they eat insects and have unimpressive talons.  Mobbing is usually engaged by birds against larger species that pose a predatory threat.  But these six whistlers were on its case in a major way,  tracing its circles and keeping on its tail.  

I pulled out my phone to take a video, but it took too long to go through its booting steps.  The birds moved south and were blocked from sight.  Aargh!

Mississippi Kites are a common and widespread nester throughout residential New Orleans, wherever there are trees of sufficient stature to nest in.   From now through August, they will be the most common raptor in our urban skies- with the possible exception of the two vulture species, in some parts of the city.  They are one of our last migrants to return from the tropics each spring.  The first I saw in my hood was yesterday.

Black-bellied Whistling-Ducks have a puzzling history here in New Orleans.   They had been gradually expanding in our direction from Texas for decades, and had reached south-central Louisiana.  Then, a few decades ago, they seemingly jumped eastward over lots of potential habitat and suddenly established a presence in, of all places, Audubon Park.  Before long there were thousands loafing in the lagoons there.  They have continued to expand throughout southeast Louisiana.  While still reported in largest numbers at urban sites, they are becoming a common site in our rural surroundings as well. They have taken to nesting in residential areas of the city, presumably in tree cavities.  The birds harassing the kite this morning were presumably local nesters in my hood.

On a different, but important, note:    The next two weeks are usually the fortnight with the highest volume of bird migration through our area in the spring.  How many of the birds will land rather than passing over will depend on the weather- a cold front usually provides the best birding.

Peter

Great Crested Flycatcher back from the tropics...

This morning I stepped onto my doorstep to be greeted by the reeeep! of a Great Crested Flycatcher, my first of the spring. The species nests on my block, as it does widely in residential areas in and around New Orleans where there are large shade trees.  They are quite noisy from the time they arrive back until mid summer, after which they quiet down (as is typical of most nesting species in late summer).  After that, they can be surprisingly good at escaping detection- I might hear or see the local nesting pair only a handful of times from then until they leave in September.

The Great Crested is one of only a handful of neotropical migrants- the technical name for birds in our hemisphere that travel all the way to the tropics to winter- that spend their nesting season in residential New Orleans.  The others are Chimney Swift, Purple Martin, Mississippi Kite, and Bronzed Cowbird. Martins and cowbirds have been back for some time, and I heard my first report of a swift today, in City Park.  Mississippi Kites are likely to take a couple more weeks to make it up to our latitude. 

Several other neotropical migrants nest within our urban landscape but typically avoid residential yards- such as the Cliff and Barn Swallows under some of our bridges, the Eastern Kingbirds in some of our open spaces, and the Least and Gull-billed Terns on a handful of our large gravel rooftops.   Outside the city, in shady hardwoods especially, there are many more- a host of flycatchers, vireos, warblers, thrushes, buntings, and others, which turn places like the Honey Island Swamp or Jean Lafitte Park into a smorgasbord of song during the nesting season.

Tornado skirts (?) Night-Heron colony off Chef Hwy

Yesterday, I took a small group of my students to examine the impacts of the Feb 7 tornado on bird populations in the residential neighborhoods through which it tracked.  The EF3 tornado is estimated to have had winds of c. 140 mph and ran more or less parallel to Chef Menteur Highway in New Orleans East, cutting nearly perpendicularly across an array of residential side streets that run north from Chef.

Shortly after we began walking up one of these side streets from Chef (Knight),  we encountered Yellow-crowned Night-Herons in the live oaks that arch above the street, singles and pairs huddled around nests that are scattered through the trees.  One pair was copulating.  As we progressed, we counted 32 birds before we ran into the tornado damage a little over a block off Chef.  When we came back to Chef on the next street east, we saw another ten.  

Though incomplete, this count makes this a larger colony than any other I know of for this species in Greater New Orleans.  At first I thought that the tornado narrowly missed the birds, less than a block away.  However, one homeowner we spoke with smack in the middle of the tornado path said she had formerly had birds "pooping crawfish" on her property, so it sounds like the nest trees did previously extend up the block into the impact area.  Presumably there were no herons there when it came through- the species did not return on migration until March.  Hopefully the birds that would have nested in the trees taken by the tornado will just move to adjacent areas.

For some idea of the damage caused by the storm, here is a pic (with a European Starling on the wire).

Peter

Visiting birder Alan Crockard took these cool photos of a Red-cockaded Woodpecker flying across a marsh in Big Branch Marsh National Wildlife Refuge in Lacombe on Lundi Gras.  Not a view one usually gets of the species- traversing open air space.  Way to be fast on the draw, Alan!

The Red-cockaded is an endangered woodpecker found only in particular types of pine stands.  The only two reliable places to find them in southeast Louisiana are on this refuge, where pine flatwoods are managed by controlled burn and nest/roost boxes are inserted into trees- both strategies to improve habitat for the species.

Peter

First Yellow-crowned Night-Heron back

Just now I was cutting drywall in my front yard in the dark (don't ask!), and heard my first Yellow-crowned Night-Heron of the spring.  It gave its typical skeow several times.  The species nests throughout the metro area in residential neighborhoods with lots of large trees, especially oaks.  In my 'hood, a pair typically nests in my neighbor's yard next door or across the street, and several (in some years 20+) nest a few blocks away on Dodge Ave just off Jefferson Highway.

I have also heard a report of Barn Swallows back in the state- also newly returned migrants.

It's March- things are starting to roll!

Peter

Second migrant species reported

A pair of American Golden Plovers, passing through en route from southern South America to the Arctic, was reported yesterday near Shreveport.

This, the second species of migrant reported, comes about four weeks after the first- Purple Martin. This gap of weeks between the first martin and the next species to follow is pretty typical- although it remains baffling why the vanguard martins always show up long before anything else.

The plover observers also reported an apparently departing group of migrating Greater White-fronted Geese, northbound.  A few additional species should be reported back in the next week or so.....

Peter

The first spring migrant has returned- right on schedule!

Every year, the first species that is detected returning from parts south of us is the Purple Martin.  They seem to always get reported from somewhere in the last week of January, when we are still in our coldest month.  And this despite relying entirely on flying insects for their food!  

Right on schedule, Martins were reported a few places over the weekend, as close as East Baton Rouge and St. James Parishes.  However, the earliest bird reported this year, spotted sometime last week, was in Oak Grove in the far northeast corner of the state (!).

The fact that the first martins are back, however, does not mean their nesting boxes will be full this week.  There is usually a time lag of several weeks between the first report and the bulk arrival of the species.

Usually the first birds back are males, which is actually a widespread pattern among songbird species.  Males precede females in spring migration, so as to have an edge against rival males of their species in procuring nesting territories.

One of the oddities of our spring migration schedule is that it is likely to be a solid month before any other species arrives back.  The next returnee to be reported is less easy to predict- a Swallow-tailed Kite or Northern Parula perhaps?

Peter

Brazen Cooper's Hawk at Harahan Walmart

Yesterday afternoon I was at the Walmart in Harahan, pulling out of parking space in the crowded lot.  The local flock of panhandling Boat-tailed Grackles took flight in apparent alarm, so  I stopped to scan for a raptor.  Sure enough, an adult Cooper's came bombing through.  However, it was not flying at normal height, but weaving and maneuvering among the cars and shoppers.  It then dove into one of the small ornamental trees near the store front, scattering several House Sparrows from its foliage, and quickly reappeared, heading back along a row of cars.  It flew at eye level ten feet in front of two oblivious shoppers, and swept up to the top of a rather short light pole.  

I pulled up that aisle, trying to get close, when it dove back to near ground level and zipped between two parked cars.  It seemed to be using these to conceal itself as it hunted, but came up empty, and flew across Jefferson Highway to park on a wire in front of the Chisesi Ham warehouse.

I say it was hunting, but I suppose it may have just become frustrated trying to find a parking space.

Cooper's Hawks are one of our most frequently seen urban raptors, but it was not always so.  As recently as the 1990's, urban Coop nests were noteworthy and sightings still pretty infrequent.  Its recent increase in numbers and urban occurrence have been reported in many parts of the country, begging the question what could cause these changes in such widespread areas essentially simultaneously.

Peter

Blue Jays imitating...Cooper's Hawk?!?

Vocal mimicry is well known in the bird world, but prominent in relatively few taxa- most famously parrots and mynas in the realm of pets, and in members of the family Mimidae (most notably Northern Mockingbird) among our native species.

One additional case of local relevance to birders has always been the penchant of Blue Jays for imitating one particular hawk species, the Red-shouldered Hawk.  Jays are quite good at rendering the strident kyah notes made by the hawk, and do so a lot.  Because both species are common in our area, birders hear a lot of both the hawk and its impersonator.   The jays can be very convincing-  usually sounding a little more frail than the real raptor- but I find myself sometimes uncertain of whether I am getting duped.

At any rate, I had never heard a jay imitate another raptor until today.  On my way out to my car in the driveway, I heard an apparent Cooper's Hawk in my live oak.  Coops make a series of short chants, quite different from a Red-shouldered.  The sound appeared to be coming from the exact location in the tree where a Blue Jay was moving about, seemingly unconcerned about any nearby predator.  I became suspicious.  The jay then moved fifteen feet through the crown of the tree, and the Cooper's Hawk call moved with it.

Another identification complication to add to the list!  Bring it.

Peter