Biscayne favorites

I have my favorite places to photograph. One of them is on Biscayne Bay near Matheson Hammock. From the launch site south, there is about a mile-long unhindered shoreline guarded by several small red mangrove trees that have spread out into the water. If I am not photographing birds, I am photographing the mangroves. At low tide, this area becomes a feeding ground for egrets (great whites and snowys), herons (tricolor, green, great blue, little blue) and white ibis. Low tide at 7 am, was right where I wanted it to be. The east winds were brisk somewhere between 10-15 knots and when I did not see a single bird upon arriving near the mouth of the creek, I thought I might paddle south a few miles to the hidden lake where a cormorant rookery sits. I was not wanting to paddle much distance with the winds, but with no wading birds around, it seemed to be the best alternative. I continued paddling and felt letdown to not even see a flock of ibis flying over. I paddled past the creek another 1/4 mile or so and all of a sudden, the birds appeared.

This was not going to be easy. The birds have endless space and can stay away from me without compromising their breakfast opportunities. The low tide grasses made it difficult for me to approach and I could only hope for one or two brave birds to feed where the grass meets the water. Often, I get my boat into shallow ground where I can only move if I push off with my paddle. If the birds decide to move away, I am stuck and have to push myself out before I can paddle over to the birds. It's painstaking sometimes, but today, the birds were relatively cooperative. I approached slowly while the sun eventually rose above the morning clouds. Once the sun came out, the white birds began to glow in the grasses of Biscayne Bay. I noticed a couple snowys but they never got close enough to be more than specks. Most of the white birds were juvenile little blue herons.

Little blue herons are quite common in this particular area; typically if I see one I see a half dozen or more. They are generally not too shy and often allow me to get close enough. Today, most of them were juvys, still mostly white feathered. During its first year, the juvy little blue begins its life all white and gradually turns blue in a calico kind of way. It takes about 1 year before the white-blue juvy turns completely blue. The little blue heron is the only heron that changes feather colors in such a dramatic way.

Some white ibises were about, but not as many as I usually see. My experience is that these birds begin to appear in greater number in this area towards mid to late summer. I think they are still nesting right now. I enjoy photographing white ibises, especially the beautifully patterned juveniles. The juvy ibis is similar to the little blue heron in that its feathers turn from brown to white, giving it a speckled brown and white appearance (see first photo above). But, they lack the aqua blue eyes of the adult white ibis. For the ibis, foraging is all about touch and not sight. This is one reason I like photographing these birds because they move their beaks around the water constantly. This makes for very nice poses and reflections that go well with the mangrove scenery. I follow an ibis with my continuous auto focus as it moves around the water, poking its peak in and around the grassy waters and frequently pulls out a crab or crayfish. I wait for the right moment to rifle off a few shots as the bird quickly captures its prey. The heron, on the other hand is a sight feeder. The little blue heron, unlike the great blues moves around constantly and is quite busy at feeding by moving its neck sideways back and forth before jabbing the water. It's feeding technique makes this bird one of my favorites to photograph. Once it hones in on its prey, you can be certain that the next move will be a precise jab at the water and the bird will almost always pull something out of the water.




The incoming tide rolled in quickly, which was good for me. I can bring my boat closer to the birds. After about 2 hours, most of the birds had moved toward the shoreline. As the tide moved in, I stayed with a juvy white ibis that was working a mangrove tree, looking for food among the oyster encrusted roots.

A tricolor heron flew in near the shoreline and with the sun now at a steep 45 degree angle, I followed the bird around for about 20 min. A couple great white egrets worked the shoreline and I captured a late morning shot of one of them. The mangrove roots compliment the birds that stand with their curvey long necks.

Not a bad morning at all. What am I saying? It can never be a bad morning on Biscayne Bay. Soon, the creeks will contain my favorite non-bird subject, the golden silk spider. Today, there were none, too early in the year for the females to be seen with their large webs that cross high over the creeks. In the meantime, I will try to get back to the pelican rookery in the Everglades and see how those babies are doing.

The Brood Reduction Hypothesis

Hypotheses are created from observations. Field ornithologists have a hypothesis concerning brown pelican nestling survival rates. It is referred to as the brood reduction hypothesis. Anyone with at least a small sense of bird behavior knows and is usually horrified that the smallest, weakest nestling does not survive and often dies from sibling bullying. Or as the experts describe it: "starvation, aggression and/or expulsion".

If I am going to go out of my way to paddle a canoe to areas where birds roost, loaf, breed, feed, and grow and develop, than I am obliged to learn as much as I can about them. With my observations of these pelicans for the past 3 years, I have many questions. These have led me to research brown pelican nesting and from that, I have learned a few things. I didn't expect to see only beauty and joy in nature when I signed on for this amateur pursuit of bird watching and photography. But dang if nature doesn't get more harsh and often times cruel as I learn and observe more of it.

Here's what I have learned so far. Brown pelicans of the gulf coast began breeding sometime around February. The span of time is about 4 1/2 months, beginning with 2 weeks of courtship and nesting followed by 1 month of incubation. It takes about 3-4 mon before the nestlings fledge and are no longer dependent on the adults. The breeding season varies and is greatly affected by temperature (last year's freeze delayed the season noticeably). It also appears that brown pelicans are smart enough to avoid hurricane season, enough so that the young pelicans are well fledged before a big blow.

Nestbuilding continues during incubation and after hatching. Here is a shot from mid-March this year showing a parent bringing in nest material while the other parent incubates. Both males and females incubate the eggs. Nest building is quite vigorous during this period. However, I've noticed less stick delivery going on after the hatchlings arrive.



During the first 3 months of breeding season, most of the eggs have been laid, but egg laying can continue for another 3 months. Adaptive brood reduction is the name of the game for the brown pelicans and this appears to be a parental strategy for dealing with unpredictable food supplies. Here's how it works. Within about a 40 hr period, the mother lays 3 eggs, the second egg comes about 24 hrs later and the third one about 40 hr following the first. When the second hatchling appears, the first one is 16% larger. When the third one appears, it is 33% larger! This initial size difference is a competitive asymmetry that gives the first chick a head start and much better odds of survival. The mortality rate is greater for the second and third hatched birds, they feed less and grow more slowly. In the photos below, notice the one that appears smaller than the other two. In the first photo, you can barely see the smaller bird shadowed by its larger siblings.


Brown pelicans are atricial birds, meaning the hatchlings are dependent on parents for long durations. During the first 10-12 weeks, both parents care for the babies that require nourishment and thermoregulation from them. It is during the first month that nestlings experience the highest mortality rate. Success rate of initial clutches is about 50%. Mortality rate in the nest depends on several things including the parents' success at foraging, tick infestion which can lead to nest abandonment, human encrouchment (primarily ground nests) and predators. Feeding the babies requires about 1 lb of fish per day for each nestling. Feeding is a fierce competition for the siblings as seen here.


The nestlings grow in size, and feathers begin to replace the downy white. As wings grow, nestlings exercise them by flapping them vigorously before the bird can even get itself out of the nest. Space becomes an issue as the larger siblings demand more of it, while the smaller birds hang on to whatever is leftover. The pelican must also keep its pouch flexible and does so by stretching it, as seen in the third and fourth photos below. This highly vascularized pouch is the pelican's life blood for many reasons; heat dissipation through fluttering, capturing fish, and as a breeding display.




Brown pelicans are colonial nesters, as few as 10 pairs to as many as 1500 have been observed within a rookery. Typically, there is about a 4-ft distance between nests; but from what I can see, egret nests fill in some of that empty space between, leaving very little room for the large gular-pouched pelicans. Group activity is quite robust as parents tend to their babies while many juveniles and adults hang around seemingly not attending nests. I see many pelicans in juvenile plumage among the adults and nestlings. Brown pelicans do not reach full adult plumage until about 3 yrs and typically do not begin breeding until age 3-5 yrs. But, juvenile pelicans have been known to breed (although not as successfully as their older counterparts) and I have seen juvenile pelicans flying with nesting sticks. What I observe at the rookery seems to be a combination of non-breeding and breeding juveniles mixed with the adult breeders and their young. As a result of the dense population of birds, there is plenty of interaction going on as can be seen here.




Once fledged, the pelican's mortality rate is about 70-75% during the first year, but then declines to about 15% after that. Last year in late May, I watched several young fledglings in the water and flying small distances around the nest islands. Here are a few photos of some of these birds as they learn to care for themselves.




During this trip to the rookery, I noticed several juvenile pelicans flying about. There were lots of flying adults too, some bringing nest sticks back to the nest. I also noticed that the adults no longer had the bright yellow tuft of feathers on their crowns, which are noticeable during the courtship period. Here are a few pelicans lovely in flight.





And finally, knowing that the young nestlings have a low chance of reaching full adulthood (adults, by the way, can live as long as 20 yrs), here are a couple photos to compare. The soon-to-fledge bird in the first photo has less than a 50% chance of getting through the next year. With good genes and luck, this bird will come back to this rookery next year in its juvenile plumage and will then likely grow up to be a parent one day, such as the adult in the second photo.


I can't put all this information into this blog without giving credit where credit it due. Sources of information are the following:

Blus, LJ, & Keahey, JA. Variation in reproductivity with age in the brown pelican. The Auk, 95, 1978.
National Audobon Society's The Sibling Guide to Bird Life & Behavior, 2001.
Saches, EB, & Jodice, PGR. Behavior of parent and nestling brown pelicans during early brood rearing. Waterbirds, 32, 2009.
Schreiber, RW. Nesting chronology of the eastern brown pelican. The Auk, 97, 1980.
Schreiber, RW. Growth and development of nestling brown pelicans. Bird Banding, 47, 1976.
Shields, MA. Establishment and persistence of mass hierarchies in broods of the brown pelican. Wilson Bull, 112, 2000.

Summer is here

And that means more time on Biscayne Bay. It's been over five months since I had seen the bay near the Deering Estate. Going there this morning was the first day of my summer and I can't think of a better way to spend a morning than on Biscayne Bay. It Mother's Day and it seemed very quiet at 6:45 am at the launch site. With a mostly cloudy sky, the sun shown on the horizon only for a short while before it hid behind a large splay of clouds that would disappear an hour later. Low tide was about 8 am, so I expected to see birds on the water.

I headed toward the bird rookeries with calm waters and barely a breeze. There were a few wading birds, a great blue, a great egret and not much else. Ibis and cattle egret flocks flew over and cormorants were flying about. Once at the rookery, I noticed that my rookery island was no longer being used by the cattle egrets, or any egrets from what I could tell. Only cormorants were nesting. It was 3 years ago that I spent many mornings at this little island photographing cattle egrets and cormorants. For the past 2 years, I have had little opportunity to photograph the white birds. Now this year, the egrets are no longer using the island. Seems the cormorants have taken over. Such is life in the city.

I paddled the short distance over to the other rookery islands that are not located in as secluded an area as the previous island. There are 3 tiny islands separated only by about 15 feet from each other and this is now where the egrets are nesting. I caught on to them a couple years ago, but this is not my favorite place to hang out and photograph, so I don't come here often. First, the islands are adjacent to a boat channel, although not often used. And the lighting is such that I need to anchor on the channel side, rather than the more protected west side. Second, the water is relatively deep, so anchoring is the only way to go; the stake out pole is useless here. And third, it is close to several condominium buildings, thus lacking privacy.

Once I got over my complaining, I was glad that the sun was no longer hidden in clouds. The morning was not burning white light yet, so there was a good hour of warm morning light to play with. Cattle egrets mostly, but several tricolor herons were flying about, often with sticks. There were many cormorants here, but clearly, the egrets outnumbered them. Once I got the birds' flight patterns figured out (of course they altered them as soon as I arrived), I stayed in one or two spots for awhile and captured some incoming flights. Here are a few shots of the day.

Later, I paddled past the cormorant island and then headed over to the sponge farm where several cormorants were resting. The sun was high and it was time for some high key photos. Looking for the right cormorant wing spread or combination of birds on sticks, I staked out and captured some shots. This has been a fun experiment lately and the black and white images have turned out quite well. These shots, by the way, are pretty much what came out of the camera. I overexpose by 1 2/3stops or more. Depending on how rough the water is, I may have to remove some blue streaks from the water area in post processing. For fun, I played around with some of the artistic filters in photoshop. The second one you see below has a filter added to it, rendering the subjects completely black.

Baby pelicans

At last, the babies are here! I paddled over to the rookery yesterday morning, with northeast winds blowing briskly and increasing slightly during the morning hours. Got to the rookery at about 8 am with cloud covered sky. This would be a challenging light as large dark clouds mixed with thin clouds, all passing quickly from east to west. For some short periods, the sun was uncovered but always a slight haze filled the sky. North of the Tamiami trail somewhere in the Big Cypress a fire burned and this created a thick fog while driving to Everglades City. While on the water, the east winds blew that smoke over the bay.

One mangrove island seemed to favor the pelicans over the egrets. Here, there were at least a dozen pelican nests with various sizes of babies. Some barely big enough to see their triangle shaped heads over the nest, others were big enough that they were already flapping their wings (barely feathered) widely. In most the nests were 3 babies. Finding a nest with a clear view was not easy and most of the well seen birds were located on the west side of the island. This would have been a perfect set up as it was also an area protected from the strong winds. Unfortunately, it is the least desirable for lighting. I moved to the other side and with the sun behind me, I tried to stake out so that my boat stayed firmly in one spot while I face the birds. Having a strong wind makes this very awkward. Here's a shot of a nest; in the first photo the parent had a wary eye on me. After a few minutes, she decided I was not a threat and went back to her nap while keeping her featherless babies warm.



I had a challenging day both winds and lighting. For most of the morning, I kept the flash in the pelican case, attempting to shoot when the sun was not covered. I paddled around to various islands, some where most great white egrets were nesting. I noticed something different this year compared to last; there are many more snowy egrets nesting here. The problem with those guys is they hide low in the trees, so rarely do I see a nest clearly. And they do shy away from me moreso than the other birds.

Later, I paddled over to the island that contained the most baby pelicans. I staked out on the west side with the intent of simply watching the babies, as I had an excellent view of a couple nests. An adult flew into one of the nests to feed the starving babies. With that I decided to set up my fill flash to attempt some shots, to overcome the shadows as the sun provided a severe side light. Feeding time is quite an act to see; at times 2 baby heads are inside the parent's pouch and appear to reach far into its neck. It is my understanding that both parents take the responsibility of feeding the babies about 6-8 times a day. Feeding on regurgitated fish, the babies grow quickly and in about 4 weeks from birth are about ready to fledge. That's when it becomes fun to watch them as they learn to fly. I think in 2 weeks, I should see much more fledging activity and if I am lucky, maybe watch a parent teach its baby to dive for food. I read somewhere that this endeavor is so dangerous for a young pelican fledgling that the parent will interrupt its dive before it hits the water if it is doing it wrong. Here are a few flash shots of the feeding scene, not ideal light but at least you can see what is happening.



I will be back in two weeks, hoping to see the baby egrets as well. One thing to add here, I have been audio recording while at the rookery. Yesterday, I captured the loud screeching sounds of baby pelicans. In this audio, you'll also hear a plane fly over, a typical sound. Between the low flying planes and the airboat tours to the Brown island near by, the bird rookery sounds are continually interrupted. Be patient, and try to listen the entire audio (about 4 min). Here is the link to the audio file.http://www.plunder.com/Rookery-4-min-wma-download-4caeebe7c8.htm

Brown pelican spa

I visited the bird rookery for a brief time last weekend. I and some paddling friends of mine were on our way to Camp Lulu for the night. We passed through the rookery at an early enough time of day to have some good light. Clear skies dominated and the south winds had not yet picked up as they would get to 20-25 knots later in the day. Egrets and pelicans were busy with their nest activities as usual. I noticed a few snowy egrets, but they are more difficult to find among the mangroves and big birds that dominate them. The snowys were definitely there in number because their distinct voices were heard clearly among the cacaphony of cormorant croaks and egret squacks. The snowys have this funny gurgling sound, quite amusing.

Since there were other paddlers and no time to hang out, I didn't anchor and had no intention of staying more than 20 minutes or so. Some adult brown pelicans were in the water near the nest islands. This meant that they were bathing, having a bit of spa, a reprieve from their nesting duties. This meant fun photo opportunities while the birds luxuriated in their baths. The pelicans splash their wings fully into the water with very rapid beats. The water spray is great as they continue this action for a few seconds, rest a few and start over again. it begins with a full head dunk and then the wings start flapping madly. With several frames per second, I can capture various positions and find some of them to offer exquisite feather display, like this one.

Enjoy these shots from the short visit with the brown pelicans.