My pond and the cycle of life

Undergoing cardiology exams can bring up thoughts of mortality and a life lived; perhaps they also made me more attentive to the cycle of life in my yard, particularly in the vicinity of my backyard pond.

Several years ago, a local garden center went out of business and they had a 175-gallon black plastic pond for sale. It was a good deal, so I invested in it and then had to dig a large hole in the rocky Piedmont clay ground of my backyard (with a bit of help from a neighbor teen). At a certain point, the ground was so hard we couldn’t penetrate it with shovels so the pond now sits a bit above ground level; the rocks I piled up around it have offered a home to Eastern chipmunks (Tamias striatus).

 

I transferred some of my beautiful koi and goldfish from a smaller pond, only to have a great blue heron (Ardea herodias) come by to clean them all out.

On the recommendation of the garden center staff, I had positioned a heron statue by the pond – they said herons don’t like competition, so the intruder would keep flying when s/he saw the one by the pond. It didn’t take long for the bird to figure out the stationary bird was not real, however.

After the heron had eaten all the koi and goldfish, I still had some tiny baby fish. At first, I thought they were from my now deceased koi but apparently the intruder heron had had fish eggs on its feet from a nearby natural pond and left them behind. So for a time, I had unidentified native fish in the pond. They were extremely shy, however, and I only got a brief look at them when they surfaced early in the morning; as soon as I came near, they dove down under the water plants (no good photos).

Then some green frogs (Lithobates clamitus) moved in this past summer and ended up being extremely prolific reproducers. Before I realized it, there were at least 500 tadpoles in the pond!! They were eating the fish food and at the same time I noticed that I wasn’t seeing the fish at all anymore. Going online, I found out that tadpoles will eat fish – their sheer numbers had to have spelled doom for the fish.

 

 

I collected lots of the tadpoles, gave some to a friend for her water feature and released hundreds into the local creek (they are native animals after all). A few of the tadpoles grew into frogs and the pond became a residence for some very loud croakers.

 

  

The next chapter in the story came a couple days ago. I had seen a pair of red-shouldered hawks (Buteo lineatus) visiting my yard recently. I thought they were after the chipmunks, numerous squirrels and songbirds populating the area. The other day, however, one hawk took up a position in the crepe myrtle tree next to the pond and just sat there calmly not bothering with any of those creatures. Numerous Northern cardinals (Cardinalis cardinalis) perched in the tree above her and many other species of birds were at the nearby feeders;  none of them were concerned at all with the hawk’s presence. The squirrels didn’t seem perturbed either.

She sat fairly still and I took some photos through my kitchen window. Then I ventured out into the backyard, sure she would take off as I left the porch steps. But Ms. Hawk just sat there, sometimes stretching a leg or engaging in a little grooming.

     

   

Occasionally, she looked up but often her gaze was fixed on the area around the pond.

She would stare intently down at the ground – I thought she might have spotted one of the pond chipmunks.

Then after a while, I noticed her shifting her stance – suddenly she plopped down into the pond with spread wings. It happened too fast for me to get out from behind dried plants to get a good photo, so I watched as she climbed out of the pond. Then it became apparent what she had been hunting – she had caught one of the green frogs.

  

It looked like she bit its head to kill it as soon as she got on dry land; the frog wasn’t moving.

Then she spent time ruffling and shaking out her feathers which had gotten a good soaking.

She spent a little time looking around and then abruptly took off with her prize, closely followed by another red-shouldered hawk who suddenly swooped in.

He chased her but she got away with her meal and he ended up sitting in a neighbor’s tree, somewhat disgruntled with his failed thievery attempt.

  

Ms. Hawk returned yesterday and spent quite a bit of time in a high tree surveying the yard and gazing down at the ground. Red-shouldered hawks sometimes eat birds, such as sparrows, doves and starlings (which are all numerous around my feeders) but more often they go after snakes, mice, toads, frogs, lizards and small mammals such as voles and chipmunks. They will also eat insects and earthworms. Since I’m leaving the leaf litter, there are undoubtedly more insects hiding there than in neighboring yards. I’m not sure what Ms. Hawk is seeking in my yard, but I hope she doesn’t get all the pond frogs. In any event, I’m sure new ones will find the water in the spring and in the meantime, I have a beautiful bird of prey to watch this winter.

Avian generations in the making – part 3B: fledgling and post-fledgling care

The number of days after hatching when young altricial birds leave the nest is fairly predictable for many species; knowing those approximate dates is helpful if you want to plan a day to watch fledging happen. I can often arrange to sit and watch a nest box on the appointed day for several hours.This has enabled me to see several broods of Eastern bluebirds and brown-headed nuthatches make their leaps to freedom on the path to adulthood.

When it is time for fledging, parent birds encourage their babies to leave the nest. They may entice them by perching nearby with some food but not bringing it to them. Or they fly to the box with food and then go to a branch instead of feeding. The Eastern bluebirds (Sialia sialis) in my yard will hover in front of the nest box like a hummingbird, sometimes with food in their mouths; perhaps they are showing the young ones that flight involves flapping wings.

While in some species, parents appreciate help from older children in caring for a current brood, Eastern bluebirds apparently do not. This may be because they see the previously fledged young as competitors for food. In my yard, father bluebird especially was chasing the young of earlier nests away from the feeders, not only when they begged but also when they fed themselves.

 

When fledging day arrived for the bluebirds’ third brood, one of the older siblings (I’m not sure if it was a female or male) was very interested in seeing the third brood fledge. He imitated his parents, hovering in front of the nest box so the young ones could see him.

 

Again, however, the parent bluebirds chased him away.

This did not deter the immature bird, however. He waited for the parents to go get food and again took on encouraging the young siblings. It was fascinating to watch!

 

The parents returned and drove him off with a show of bad temper.

Eventually, the babies did fly out of the nest box into a nearby crepe myrtle. There, they continued to call for food with a wide-open mouth.

    

This gaping behavior stimulates the parents to feed their offspring and the offspring can be very insistent and persistent in begging for food.

    

Eastern starling (Sturnus vulgaris)

     

Carolina wrens (Thryothorus ludovicianus)

  

Common grackle (Quiscalus quiscula)     Royal tern   (Thalasseus maximus)

This behavior can go on for days, especially when the young ones cannot yet fly, like this recently fledged Northern mockingbird (Mimus polyglottos).

 

 

The birds that feed their young ones on the ground, like the American robins (Turdus migratorius) have it a bit easier than those that feed juveniles perched on wires, like these barn swallows (Hirundo rustica).

   

I can imagine that the mother and father get to a point of thinking, “Enough already!” as those large fledglings continue to beg for food; this parent Northern cardinal (Cardinalis cardinalis) did not seem willing to go out for yet another bug for the young one.

But some young birds can be very insistent, even when it is obvious that they are now fully capable of finding some food on their own. This parent chipping sparrow (Spizella passerina) seemed willing to be a feeder for a while longer.

                        

The parent-child feeding routine that often catches people’s eye is when a young brown-headed cowbird is being fed by a (non-voluntary) adoptive parent. For example, here we see a male hooded warbler (Setophaga citrina) bringing food to a brown-headed cowbird baby (Molothrus ater) after the youngster spent quite a while loudly crying out for a meal and hopping around on branches after the parent to convince him that he needed to be fed.

  

Of course, at a certain point the parents do stop feeding and the young set off on their own. They may check out nearby nest boxes, either scouting homes for next season or looking for roosting boxes for the cold winter nights, like these Eastern bluebirds. They may groom a bit to remove the last bits of fluffy feathers, like this red-shouldered hawk (Buteo lineatus). And then they are ready to spend an autumn and winter getting ready to repeat the cycle, this time as the parent birds. And we can look forward to watching the process again. 😊

 

        

Communal nesting – the rookery at Sandy Creek Park

great blue heron DK7A5496© Maria de BruynUnlike Eastern bluebirds (Sialia sialis) and other songbirds, great blue herons (Ardea herodias) like to build their nests near one another, forming what is called a rookery, or colony of nests. The nests are often seen in the tops of tall trees and comprise large twigs and branches that surround grass, leaves and moss. As many as 135 nests have been counted in a rookery, but the one at Sandy Creek Park that I visited this spring had three nests.

The herons return to the nests for several years running. Each year, the males re-furbish the nests in order to attract a mate.

great blue heron DK7A7297©Maria de Bruyn great blue heron DK7A7367©Maria de Bruyn

You can see the nests well with binoculars from a walking path, but as I have no binoculars and rely on my camera’s zoom lens, I slogged through forest and marshy terrain on numerous occasions to get close to the pond that had their rookery pine trees on the other side. They were still a bit out of range for my lens, but occasionally I managed to get a half-way decent shot, which encouraged me to return often to follow the nestlings’ progress.I followed them from 8 March through 26 June.

great blue heron DK7A5924© Maria de BruynGreat blue heron DK7A3689© Maria de BruynThe top nest in an open-to-the sky tree appeared to have four babies, while the nest below it had three.

A nest in a tree to the right, which had much more dense foliage, seemed to be occupied by only one or two babies.

great blue heron DK7A6005© Maria de Bruyn

There were always 1-4 adults around, including both parents on the nest and “guards”, who took up posts atop nearby trees to watch the nearby skies. This is one reason for the rookeries; the herons want to ensure that there are adults around to protect the nestlings from predators, which include raccoons, crows and hawks, such as this red-shouldered hawk (Buteo lineatus) that was hanging around the nests one day.

red-shouldered hawk DK7A7354© Maria de Bruyn red-shouldered hawk DK7A7371© Maria de Bruyn

great blue heron DK7A6601© Maria de BruynGreat blue heron DK7A3495© Maria de Bruyngreat blue heron DK7A8238© Maria de Bruyn resThe parents feed their young by regurgitating food and the young birds get excited when a parent returns after being away for a time.

The nestlings make quite a lot of noise squawking loudly while they jostle to get first in line for the meal.

great blue heron DK7A3743© Maria de BruynThe young herons appear to “argue” with one another with loud calls and it seemed that they “jousted” with one another using their beaks.

great blue heron DK7A3735© Maria de Bruyn

Weaker chicks may miss out on getting enough food and can die of starvation, but that didn’t happen at the Sandy Creek rookery. Some chicks were obviously larger and stronger than others, but even the smallest fledglings survived.As they grew, the babies began standing tall and walking around the nest.

great blue heron DK7A8283© Maria de Bruyn Great blue heron DK7A3638© Maria de Bruyn

great blue heron DK7A9348© Maria de BruynWhen they were close to fledging, they stood near the edge of the nest and practiced spreading and flapping their wings. Sixty days after hatching (much longer than smaller birds!), the young herons were ready to fly and began taking short flights to nearby trees, before venturing out on farther trips. great blue heron DK7A8960©Maria de BruynThe young ones will not breed until they are two years old.

Watching events unfold at the rookery was a new past-time for me this year and likely one I’ll repeat in the future. If you have time and the opportunity, I’d recommend the experience!