Laura Erickson's For the Birds

Friday, May 4, 2012

Heron Cam: Science and Emotions Both

This is the transcript of a two-part For the Birds for May 3 and 4, 2012. Production of these programs was made possible in part by a generous grant from an anonymous donor.

Great Blue Heron nest cam

When I started keeping track of the Great Blue Heron nest via the Cornell Lab of Ornithology’s streaming nest cameras, I never imagined how emotionally intense the experience would be. It was so scientifically fascinating to observe so many behaviors at such close range. I saw how they add sticks to their nest, wedging and weaving large ones on the outside and setting small twigs flat on the floor. The male brought more sticks more often than the female, and brought many before mating with her each time, and after she laid each egg.

Great Blue Heron nest cam

I got to watch them mating, seeing close up how the male grabbed onto the female’s long spiky head nuptial plumes to hold his balance on her back.

Great Blue Heron nest cam

Four times, I watched live as the female struggled and contorted her body and suddenly stood up to reveal a brand new beautiful blue egg. I missed seeing it live but did get to see a video showing the fifth egg’s arrival.

Great Blue Heron Laying Egg

Watching the birds take turns incubating eggs and working on the nest was enlightening, both because we always knew which bird was which close up, which had been hard to do when I was watching the birds from the Lab in 2009, and also because the two birds share roles fairly equally yet each has slightly different ways of doing everything.

But familiarity leads to affection. I wasn’t online in the middle of the night when something attacked the female as she was incubating—the people watching were horrified when something seemed to collide with her and she stood up squawking. Her loud distress calls awakened people who had been sleeping with their computer on to hear the soothing sounds of spring peepers in the background. No one was quite sure what had happened in the darkness, but we soon had a grainy but decipherable video clip showing in slow motion a Great Horned Owl headed straight for her head.

Great Blue Heron after owl attack

The following day she was clearly stressed, and there was another middle-of-the-night attack. The only visible damage to her was that her head’s spiky nuptial plumes were gone, but she looked visibly shaken, and seemed entirely diminished. The owl came back a third time, when the male was on the nest. We hoped his larger size and strength sent it elsewhere for good. A few days later we noticed a cracked dent in one egg, which we think happened when she lurched up too quickly in one of the attacks. The cracks made it seem unlikely that that egg would ever hatch.

Ithaca had such warm weather in March that this pair started producing eggs over a month earlier than they’d even started building the nest in 2009. But well into incubation, on April 23rd,  I woke up and turned on the cam to see four or five inches of snow piled up all around the incubating male.

Nesting Great Blue Herons in snowstorm

He stayed hunkered down all day, not getting up for more than a few moments, but when he did, the five eggs looked so bizarrely out of place surrounded by all that snow.

Nesting Great Blue Herons in snowstorm

The female stayed away all day, and we started wondering whether she had decided to cut her losses and move on, but the male steadfastly incubated hour after hour. It was already evening when finally, after 22 ½ hours, he flew off, leaving the eggs. It seemed pretty certain that he, too, was cutting his losses, but less than a minute later he returned, and within another couple of minutes, the female came back and took over so he could finally get a bite to eat.

At each triumph, over an owl and over deep snow, we became increasingly aware of just how many bad things could doom the eggs and even the birds, even as we became increasingly attached to these tenacious creatures and those beautiful eggs. And there were more intense events still to happen..

(Part II)

Last time I told you about the emotional roller coaster I’ve been on since a pair of Great Blue Herons started nesting in full view of the Cornell Lab of Ornithology’s nest cam. I’ve been learning so much that the experience is extremely satisfying intellectually, but I’ve found it impossible to maintain emotional distance from this little family.

After owl attacks on three nights, leaving the mother missing some head feathers and one egg dented, and after watching the male sitting faithfully for 22 ½ hours during a deep snowstorm, I’d not have been surprised if the eggs didn’t hatch at all, and certainly expected them to hatch few days late after the extended cold snap. But no--the first and second both hatched on Friday, April 27, and the second egg to hatch happened to be the one with the dent.

Pips in Great Blue Heron eggs


The third hatched on Saturday, and the fourth on Sunday. The birds didn’t feed them much over the weekend—I wonder if they were trying to delay maturation of the first to hatch so that the last to hatch wouldn’t be as far behind.

Everything would have been idyllic except that the owl returned three times that weekend, and I kept collecting more information about how Great Horned Owls kill and eat more adult Great Blue Herons than I’d realized. The male was on the nest for these attacks, but on Sunday night the female was squawking from a branch on the nest tree, and then she disappeared. We didn’t see her at all Monday morning, even with four hungry chicks. I was pretty sure that if she had been injured or killed there would be some noticeable evidence, but no one at the Lab reported anything. Hour after hour the male stuck it out, well after his stomach was too empty to regurgitate anything to feed the constantly begging chicks. Finally in the afternoon one of my friends at the Lab spotted her, safe and sound, in another area of the pond, and people trained the moveable cam on her to show her fishing. When the male finally left the nest, he flew right past her and she immediately returned to the nest and regurgitated a nice big meal for her hungry young.

At each point, whether it was the dented egg or the snow or the female’s long disappearances, a lot of people in the heron chat room assumed the worst. The fifth egg didn’t pip until May 1, which was exactly right since it was laid 2 ½ days after the fourth egg, but people constantly asked why it hadn’t hatched yet and was the chick dead? I can usually be pretty calm about how nature works, and I had already been well aware of the many dangers that could suddenly destroy this nest filled with vulnerable chicks and the parents who were giving their all to raise them. I’d been taught in graduate school to look at birds as populations, not individuals, and it’s very true that protecting birds at the population level is what is critical in managing natural resources. But watching the hard-working parents and their five chicks, I couldn’t see any as expendable. It made me appreciate how much work is involved in creating and sustaining life even for a bird as common as a heron.

Great Blue Heron feeding chicks

This pair of herons has raised a broods of four chicks all the way to fledging each year since 2009. As I was working on this on May 3, a thunderstorm raged over the pond. The female had flattened herself with wings spread a bit to keep the force of the rain and hail on her, not the chicks. Every time lightning filled the sky over the nest and thunder rumbled, I told myself there have been many, many storms over Ithaca during the past three years, and this would be no different.  But when I awakened this morning, I felt a flood of relief to see the birds safe and sound. I’d love to be a zen-like person, learning from these birds patience and a wisdom surpassing understanding. Instead, I’m learning how valuable each individual life is, and what a triumph every day truly is.

Great Blue Heron chicks

Production of these two For the Birds programs was made possible in part by a generous grant from an anonymous donor.