Saturday, June 8, 2013

Yellow-crowned Night-Heron babies

South Florida has two seasons. Simply stated they are the Dry and the Wet seasons. Some would call them the Tourist and the Hurricane seasons. Fall and winter nights are usually cool and there is no great threat of rain, allowing us to sleep with the windows open, while air conditioning becomes a necessity during the hot and muggy summer. By any name we have entered the second season, which begins by late May and lasts into late September.
  • Red sky in the morning, sailors take warning;
  • Red sky in the night, sailors' delight.
There are opposing theories about the source and usefulness of this old poem. Some say that the red sky at night is caused by high pressure and good weather (in the west), while red in the morning indicates a storm system to the east. Another explanation is that a reddish sunrise is caused by particles suspended in the air, foreshadowing an approaching storm from the west. Here in coastal Florida, the storm clouds often move in from the ocean, which is east of us, and red sunrises are common this time of year. This is the view from our back yard, showing a bank of clouds along the oceanfront, some 18 miles away.

Sunrise HDR 20130531

  • Mares' tails, sailors furl your sails
Cirrus clouds, long streamers high in the sky, usually mean that bad weather can be expected within the next 36 hours. Sailing vessels are well advised to take in their sails. Mary Lou is up ahead of me, walking north along the gravel road that leads to the heron rookery near our home. 

Cirrus clouds HDR 20130601

At the rookery, it was interesting to see this interaction between a pair of Yellow-crowned Night-Herons. The male (on the right) had just flown into the nest tree and the female appeared to be greeting him in what I believe to be a mutual recognition display.

Yellow-crowned Night-Herons display 20130524

Notice the bright reddish legs, characteristic of the male during the early part of the breeding season.

Yellow-crowned Night-Heron display 20130524


Nest #22 is out in the open, providing some nice photo opportunities. The pair at this nest posed with their two offspring on May 24.


Yellow-crowned Night-Heron family 20130524


The two little herons have plenty of character. I called them "Mutt & Jeff," after cartoon characters that were popular when I was a child. Younger folks called them "punk rockers."


Think of a caption 20130525


They struck some comical poses....


Yellow-crowned Night-Heron nestlings 20130525


...or at least I thought so (May 27). Maybe I looked just as funny to them.


Yellow-crowned Night-Heron nestlings at nest 22 20130527


They grew quickly (May 31).


Yellow-crowned Night-Heron chicks nest 22 20130531


Their parents kept watch and ignored them as they begged to be fed..

Yellow-crowned Night-Heron nest 22 family 20130602


Here they look like unruly teenagers (June 2).


Yellow-crowned Night-Heron nest 22 nestlings 3-20130602

One of their free-flying neighbors, of the same species, is probably a week or two older.


Yellow-crowned Night-Heron immature 20130602


There also were several juvenile Green Herons in the rookery.


Green Heron juvenile COREL 2-20130602

On the walk back home, a Killdeer, flashing its conspicuous tail feathers and feigning serious injury, tried to draw me away from its eggs or young, hidden at the side of the road.

Killdeer distraction display 20130524


I took notice of other interesting creatures, such as a distant Great Crested Flycatcher...

Great Crested Flycatcher 3-20130602


...the persistent singing of a Northern Cardinal...


Northern Cardinal 20130527

... the coos of Common Ground-Doves...


Common Ground-Dove 20130525


... a Eurasian Collared-Dove at the fruit of a Royal Palm...


Eurasian Collared-Dove 2-20130524


... a dragonfly, which I believe is a Golden-winged Skimmer...


Dragonfly 20130519


...a White Peacock...


White Peacock 20130525


...and a Gulf Fritillary..


Gulf Fritillary 20130525


The next morning it was cloudy but the weather forecast said that there would be no rain for the next 4 hours. We only walked out about a quarter mile when the skies darkened and we had to hurry back home. Folk wisdom trumped the science of the meteorologists!


196th Ave Canal HDR 20130603

That little red dot is Mary Lou moving away fast. She was smarter than I and turned around earlier as I lingered to snap a couple of photos of the gathering storm. I got wet, but a garbage bag protected my camera equipment! 


Miramar Parkway HDR 20130603

Saturday, June 1, 2013

Nighthawks and Night-Herons

These two birds illustrate a convention in the use of capitalization and hyphens in their names. Why not Night-Hawk and Nightheron, or nighthawk and night heron? In preparing an article for a popular publication I encountered a problem when I wrote of the Black Rosy-Finch, but the proofs came back as "black rosy finch," suggesting that I must have had difficulty in deciding the color of the finch.

The simple answer is that, in North America, the American Ornithologists' Union (AOU) has established "official" common names. They are capitalized if used to describe a distinct species, and follow general rules. For example, if the compound name of a bird describes its taxonomic classification it is hyphenated, but if it describes a characteristic (such as the behavior called "hawking" insects), there is no hyphen. Hence, we have "night-heron" and "nighthawk," and "Yellow-crowned Night-Heron" and Common Nighthawk. There are exceptions for some names that have been in use for a long time (such as goldfinch instead of gold-finch).

At sunrise the day after we arrived back home to Florida, we walked the gravel road into our local wetlands. It was warm and humid. This and the relative lack of bird song suggested that spring was over and the summer/rainy season pattern was now in place. Mockingbirds and this Northern Cardinal broke the silence.

Northern Cardinal 20130519

The air was calm, just perfect for capturing the reflection of this Great Egret.

Great Egret reflection 20130519

I was disappointed to see that the recreational off-road vehicle drivers had not only knocked down the "No Trespassing" sign but had dragged it out into the road, as if to flaunt their indifference.

Sign - Trampling on rules 20130519

After walking the full length of the mile-long road, I pushed on to check up on the Yellow-crowned Night-Heron rookery, as I was anxious to see what had happened there since we left for Illinois a month previously. At that time I observed courtship and recorded the locations of nests under construction. I assigned a number to each nest, relating it to the position of the 30 regularly spaced live oaks that had been planted along the near side of the canal. The numbers run from north to south.

As I proceeded northward along the side of the canal opposite the rookery trees, I found four active Yellow-crowned Night-Heron nests. The first (#22) was in a new location and contained two nestlings. Look closely to see the red eye of one of them (click on photo to enlarge).

Yellow-crowned Night-Heron 22-HT female with nestling 20130519

A few days I discovered a second nest  (#18) within arms reach of a makeshift dock which had two or three nestlings. I could not get any good photos

A third nest (#13.5) was in the same location as in the previous year. I had re-found it the month before but now it was entirely obscured by vegetation, though I saw fresh whitewash and could discern some movement that indicated it was still active. My neighbor Scott photographed four chick at this nest the week before.

A fourth nest (#10) contained two or more blue eggs. Like the first, it was over the water and quite exposed to view.

Yellow-crowned Night-Heron 10- nonHT female with eggs 20130519

A fifth nest (#9) was one from last year being reconstructed by a pair when I charted it before leaving for Illinois a month before, but it had disappeared.

The sixth nest (#4.5) was near the far north end of the canal, in a new location. The month before I had found an occupied nest out in the open only a few yards north of it, but now it was gone. Perhaps a storm (or vandals) had destroyed it and the nest pictured below represented a second attempt. It also contained eggs.

Yellow-crowned Night-Heron 2-5- nonHT male with eggs 20130519

Another nest (#2.5) that was under construction a month ago had also disappeared.  Last year six pairs of Yellow-crowned and three pairs of Green Herons nested in the rookery. 

Green Herons are more secretive, and their nests are easy to miss. I found one new Green Heron nest at #5.5 but could only see movement through the leaves and hear one or more nestlings' begging cries as it was being fed by a parent. A second Green Heron Nest (#20.3) contained eggs on May 25.

Green Heron nest 20-3 non-HT with eggs 20130525

However two days later it was empty and an adult male Green Heron was roosting next to the nest but did not enter it and soon flew to a nearby branch.

Green Heron at nest 20-3 2-20130527

This male in breeding condition has bright reddish legs as opposed to the yellow-orange legs of the females. 

Green Heron at nest 20-3 20130527

Suddenly, a very young immature Yellow-crowned Night-Heron appeared on the nest and began eating something. It probed in the nest and I took many photos it an attempt to see what it was eating-- the eggs of the other species? Only one photo gave any clue, as it appears clear that at this point the young intruder was eating some kind of insect, possibly a large beetle.

Yellow-crowned Night-Heron immature eating at Green Heron nest 20-3 2-20130527

Here is a close-up of the insect in its bill. 

Yellow-crowned Night-Heron immature eating at Green Heron nest 20-3 20130527

What happened to the Green Heron's eggs or young remains a mystery. Perhaps they had been destroyed withing the past 48 hours and the  beetle was attracted to their remains

So far I have identified these five active Yellow-crowned Night-Heron and two Green Heron nests. I found three fledgling Green Herons that I could not associate with any particular nest. The streaked breast and the presence of a tuft of natal down identifies this Green Heron as a juvenile.

Juvenile Green Heron 2-20130524

At least one other pair of adult Green Herons was present. It is quite possible that I missed some nests and will keep looking.

On my way back home I observed interesting behavior on the part of a Common Nighthawk. Last month I suspected that a pair of nighthawks was planning to nest in this area, and now saw that one of them was flying short hops just in front of a walker, evidently in an attempt to lead him away from the nest. 

Common Nighthawk distraction display 20130519

I quietly watched as the nighthawk returned to a spot that I assumed may have been the nest site. Being very careful about where I planted my feet, I ventured a short distance off the side of the road and saw an empty egg shell but no evidence of a hatchling.

Common Nighthawk egg shell 20130519

Of course a baby bird could well have been right in front of my eyes as they are so well camouflaged. In the meantime the nighthawk landed a short distance away and waited for me to depart. As I left it actually walked (almost ran) in front of me before taking short flights as I followed it away from the nest area.

Common Nighthawk 6-20130519

Common Nighthawk 2-20130519