Sunday, April 25, 2010

Back to the Rookery on the bay

Sometimes, I look at my photos as archival data for amateur field research. Last year, I visited the rookery in ENP three times, February 22nd, Mar 31st and May 17th. From those photos, I can see the growth of young birds. I know that both great white egrets and brown pelicans were mating and preparing nests in February (and were doing so in great number), were raising their babies in March and some brown pelican babies were almost as large as the adults at that time; and in May, some of the young pelicans were already flying. The great white egrets did not appear to be fledging at that time but by then, there were several groups of young ones throughout the canopies of the rookery island.

This year, we have barely recovered from one of the longest sustained cold snaps experienced in south Florida. I believe it was this rare event that delayed the nesting of the birds. Consequently, during my visits this year, Feb 20, Mar 21 and Apr 25, I've witnessed a very different timeline of nesting. In February, there were only a handful of GWEs and even fewer pairs that appeared to be settling in with a nest. The brown pelicans were in large number and busily nesting. In March, the brown pelicans looked much the same, maybe with more active nest building, but the GWEs had finally grown in number. But still, compared to last year, there were much fewer of them. This weekend, I finally saw the rookery teaming with both browns and great whites, and even a few snowy egrets. But only one baby pelican did I see. It was very small compared to the larger version witnessed a year ago in March. There were some baby egrets, but still too small to be sticking their long necks outs. I did see the baby pelican feeding from its mother's very large pouch and got a photo to prove it. But other than that, it was very difficult to see the young one.

In the meantime, some of the adults were busy flying in and out, still trying to score a stick here and there. Losts of squabbling among the adults, mostly within species, but sometimes I would see a pelican and egret go head to head. It appears that the egrets are much more aggressive and probably more dangerous with their sharp beaks. I noticed a dead adult pelican hanging from the trees. It had been there for some time; all that was left were the feathers and a few bones. There it hung and I wondered how it happened. I imagined an egret causing great injury to the bird. What else could it be? Old age? Sickness? Nevertheless, among the thriving nests comes death for one of the adults.
I watched a few snowy egrets flying about and landing into the mangroves where the great whites and pelicans mostly took up the space. Cormorants were in great number as well, but they were mostly in other small mangrove islands; not mixing with the others as much. One island houses mostly brown pelicans and cormorants, with maybe one or two egrets. But the primary islands were all egrets and pelicans.

Turkey vultures began flying around a bit later in the morning, at one time there were 3 of them. The vultures (as well as crows) are not uncommon among these rookeries, I suspect they find lots of food here, obviously. Today though, I watched them swoop down toward a couple nests. One cormorant nest located at the peak of the canopies was the primary target for the vultures. I didn't think vultures raided other bird's nests, but there they were.

I had arrived at the rookery at about 7:45 am, and would have to leave before 10 am. The southeast winds had increased to 15-20 knots by 9:30 am and that meant a head wind all the way back to the rangers station. What normally only takes about 30 min took an hour. Dang, this wind has been a killer this season. Despite the bow breaking waves, the trip was worth it. I plan to get back, I do want to see the babies and hopefully watch them fledge. The birds seemed to have survived this cold winter, despite the high cost to the fisheries. The Everglades lives on, passing from one generation to the next.