A Local Peregrine Falcon Nest

A few days ago, I got a tip from another birder about the presence of a local Peregrine Falcon nest. So yesterday morning I went to the site and checked it out. I had been waiting less than five minutes when one of the parents flew into sight and perched nearby (shown above). The chicks started calling and the adult called back in response. Around the same time, I got a brief look at what I assume was the other parent flying a short distance away.

Changing my position a few yards, I was able to get a better view of the nest. Unfortunately the angle was such that I was not able to see into the nest, but two of the chicks were perched at the edge. (I heard there are three, but I only saw two myself.) One of them was especially vocal and was flap-hopping around the ledge. Its wings looked developed enough that it probably will not be in the nest much longer. The adult made one delivery to the nest in the few minutes I was there, accompanied by even louder screaming.

Unfortunately my photos of the nestlings are not so good. I probably would have gotten better results on a sunny afternoon. I am not giving the exact location for this nest since it is still a state endangered species.

Oriole Constructing a Nest

Last week, on one of the days that I walked around my patch, I happened to see an oriole that was scolding and carrying nesting material in its bill. I stood still and watched it, and the bird eventually approached its nest site. After scolding a bit more, it flew down to the branch above its nest and placed the material into the nest.

Unlike birds that build cup nests, orioles prefer hanging nests. The top of the nest is connected to a branch, often at a fork, and usually on the outer tip. The rest hangs below like a basket, wider at the bottom than at the top. This bird is a female oriole, and usually female orioles build their nests without help from the males.

House Wrens Nesting Again

The House Wrens that nested here last summer returned to the same nest box for a second breeding season. I am not sure exactly when the eggs were laid, but the chicks hatched this week, as evidenced by a chorus of hungry voices coming from the box. House Wrens usually incubate for about 12 days, so these eggs were probably laid during the first week of June. Based on average clutch size, there are probably 4-6 chicks in that little nestbox, assuming all eggs hatched.

While only the female incubates and broods, both parents participate in feeding. The parents of these chicks have been busily flying to and from the box. On most visits, a parent enters the box with a food item, feeds it to a chick and leaves. Occasionally, the parent will exit the box carrying something.

The white thing in the wren's bill is a fecal sac. The feces of young nestlings are encased in a mucous membrane. This makes it easy for parents to keep the nest clean by removing feces. A parent will usually carry and drop the fecal sacs at some distance from the nest to keep the nest's location less obvious to predators.

House Wren chicks usually stay in the nest for a little more than two weeks before fledgling. If that holds true for this group, they should fledge during the first week of July.

Group Building Nest Boxes Around Gowanus

A group of young architects has been installing yellow nest boxes for birds around the Gowanus Canal in Brooklyn.

With growth has come sophistication. At first their boxes were built with the rough idea of attracting a common songbird, the Eastern Bluebird, but since working with John Rowden, this changed. Rowden, an ornithologist with the New York City chapter of the National Audubon Society, suggested a more targeted approach.

“Most of my work is in areas a bit more natural than Gowanus,” Rowden joked. He advised the team against attracting bluebirds, which are not typically found so close to water, and to focus instead on birds such as chimney swifts, known for their insect-eating abilities, and on a small falcon called the kestrel.

A dramatically patterned bird with contrasting gray wings and a copper-colored back, the kestrel doesn’t build its own nest, but instead uses natural crevices or manmade boxes it finds. It’s a predator that hunts rats, patrolling its domain by hovering in place on outstretched wings.

“If people know wildlife is in the area, they’d appreciate it more,” Rowden said. “If people see wildlife, they’d know industrial areas are not as dead as everyone thinks.”

Since the spring of 2009, the Nest Colony group joined the Gowanus Canal Conservancy, and their members started participating in the Conservancy’s monthly volunteer cleanup events on the canal. There, they demonstrate their birdhouse-building techniques while encouraging the public to think of other ways to benefit the canal. Also, with the Conservancy’s support, they were able to secure grants that allowed them to build more birdhouses over the course of last summer.

So far the group has installed 21 nest boxes; their next goal is to build five 12-foot nesting chimneys for Chimney Swifts. They also hope that Tree Swallows will use some of the smaller boxes.

I am glad to see that the group is taking advice from some ornithologists, as that should make it more likely that their efforts will be useful to birds. The target species seem appropriate for an urban setting. The American Kestrel is declining in much of the northeastern U.S. and might benefit from some assistance. Likewise, Chimney Swifts have been in decline because changes in chimney design have reduced nesting sites.

The choice of color for the nest boxes seems a bit odd. While bright yellow does look cheerful against the decaying industrial buildings, most advice I have read suggests using plain, untreated wood for nest box construction. I am not sure if painting the boxes will discourage birds from using them or increase nest predation in an unnatural setting like the Gowanus Canal. It still seems inadvisable.

The article mentions that American Kestrels will eat rats. Perhaps some New York City kestrels have been observed eating rats, but I would expect kestrels to pursue smaller prey. According to Birds of North America, an average kestrel's diet is composed of 74% invertebrates, 16% mammals, 9% birds, and 1% reptiles and amphibians. Major prey animals include grasshoppers, cicadas, beetles, dragonflies, spiders, butterflies, moths, voles, mice, shrews, bats, and small songbirds. I did not see any mention of rats, either in Birds of North America or in my raptor books.

Webcams Provide a Window on Bird Nests

In the last few years, more and more refuges have set up webcams so that birdwatchers can monitor daily nesting activities online. Most of the webcams are placed over established raptor nests, but there are some for other types of birds as well. (For a full listing, go to Little Birdie Home and scroll about half way down the page.) I just read an article about the Bald Eagle webcam operated by the Hancock Wildlife Foundation and what makes it so appealing. Their webcam has been accessed by people in 43 countries and maintains a steady viewership.

Hancock thinks the eagle cams reach an audience jaded by the highly produced footage typical of nature programming. "We always know it's canned and edited," he says. The nest footage, transmitted 24/7 from a grainy webcam being blown about in the wind is the antithesis of Discovery Channel fodder. "It's the real wildlife," he says.

"It may be that the bloody animal will sleep for four hours," Hancock says. Those moments of sheer boredom add to the connection the viewers have with the birds. Like human life, it's rarely glamourous. Most of the time, it's just sitting on a couple of eggs. But Hancock says he's learned more from watching the nest cams than he did over 40 years standing on the ground looking up at nests.

...

Brian Starzomski, a community ecologist at the University of Victoria, admits he's no expert on wildlife voyeurism, but he can't see any harm in the nest cams. "It's certainly nice when people are engaged with nature," he says.

He points out that viewing wildlife on computers opens doors for people who couldn't, or wouldn't, otherwise access a nest site. Having millions of viewers online also means less traffic into sensitive areas and disruption of the nesting birds.

Parts of this article are weirdly written, as if the reporter felt there was something wrong with wildlife webcams or was trying to apologize for it. However, I think it captures why people watch. Webcams provide an intimate view of nesting activities that would be difficult to replicate, even with hours spent in the field near a nest site. Much of the footage is rather mundane, with just a parent sitting on eggs or the nestlings waiting patiently for their parents to return from hunting. But then there are also bursts of activity when the male and female switch incubation duties or one of the parents returns with food.

The image at the top of the post comes from the Bald Eagle webcam at Blackwater NWR in Maryland. It shows the mother eagle with both chicks in view at the same time. The Friends of Blackwater have been running live webcams on an Osprey and a Bald Eagle nest there for several years and have an excellent blog on the eagle nest and YouTube channel.

Bald Eagle Chicks Hatch at Philadelphia's Tinicum Refuge

Bald Eagle Nest at John Heinz NWR / Photo by Bill Buchanan (USFWS)

A pair of Bald Eagles have hatched chicks at John Heinz NWR (also known as "Tinicum") for the first time in the history of the refuge. Tinicum is the most urban refuge in the National Wildlife Refuge system, close to major highways, an international airport, and industrial sites. The presence of breeding eagles there is symbolic of the bird's resurgence across the country, even in urban areas. The Tinicum nest was one of two active eagle nests in Philadelphia this winter. The other may have failed.

Eagles' nests are in all seven of the region's suburban counties, and the urban eagles have been touted as even more dramatic proof of the species' comeback.

In 2007, a pair of eagles were discovered nesting in the Navy Yard - the first in the city in two centuries. Their nest failed then, but the next year one eaglet survived.

By 2009, they were gone - perhaps, like generations of suburbanites, to New Jersey, officials figured.

But by then the city was seeing eagle action aplenty elsewhere. Another pair built a nest near the Pennypack Creek in the Northeast, and two young survived.

Yet another nest was under construction that year at the Heinz refuge in Tinicum, but those eagles were like bumbling newlyweds, producing a clumsy, rickety nest. And there were no eggs.

This year, both pairs returned, one to Pennypack, the other to Tinicum, and laid eggs.

Perhaps the Tinicum pair learned from last year's mistakes to build a successful nest this year. The eagle family may be helping with one of the refuge's management problems.

Refuge manager Gary Stolz said the eaglets were active. He has seen them stretching their tiny wings. Better yet, they're helping out.

The refuge has had an ongoing problem with carp, an invasive fish that has turned out to be an eaglet delicacy.

"Besides being the gorgeous, magnificent birds that they are," Stolz said, "they're helping us remove problem fish and restore native species."

The nest at Tinicum is on an island, but visitors to the refuge can see it with binoculars from a safe viewing distance.

Last Summer's House Wren Nests

Yesterday I cleaned out two nest boxes that were used by a pair of House Wrens last summer. (I have a Birdcam image of a wren entering one with nesting materials.) House Wrens are cavity nesters and will take advantage of artificial structures such as nest boxes or openings in buildings. Male wrens may build multiple nests, with only some being used for breeding. In this case there were at least two nests, a dummy nest and a real nest. You can see the remains of both nests above, the dummy nest in the foreground and the real nest in the background.

Above is the dummy nest in its box. House Wren nests have a base of twigs and other materials under and around the nest cup. A foundation of sticks may keep the nest cup dry even if water leaks into the cavity and collects on its floor. A male wren starts building as soon as it claims a nest site, and a female will complete the nest after mating. In the case of this dummy nest, there is only the twig foundation that a male placed in the box.

I was not able to extract the entire real nest intact because the opening in the box was too small. However, the nest cup did survive and is pictured above. A nest cup is built by a female wren and is lined with soft materials like grass and feathers. There appears to be some sort of foam and cotton-like materials in this nest. Some of the soft white materials look like spider egg sacs, which may be placed in nests to eat parasitic mites. I found feathers that I think were from a Blue Jay, a Northern Cardinal, and a Northern Mockingbird among the nesting materials.

Last summer I heard nestlings chirping in the box, but I never saw any fledglings. I found no signs of dead chicks when I extracted the contents, so I assume they all fledged safely. House Wrens should return fairly soon. They may nest here again, as House Wrens tend to return to the same sites year after year.

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Some information in this post comes from A Guide to Nests, Eggs, and Nestlings by Baicich and Harrison and the excellent Birds of North America.

Bird Nests from Cape May County

In keeping with the nest theme from yesterday's post, here are a few nests that I encountered recently. The first is the nest of a Marsh Wren pair at Stimpson Island Road in Cape May County. That road runs out through fields into a salt marsh; at the end of the road you can look out over acres of marsh and follow a few short trails. All around the parking lot there were singing Marsh Wrens, and a few of their nests were openly visible.

Like other wren species, Marsh Wrens often build dummy nests. A male will start construction of several and then his mate will finish the job on one of them. A pair will often raise two or three broods per season. It was not clear if this nest was currently active, no longer being used, or just a dummy.

The second nest was one that I found at Beaver Swamp WMA. This one was about four feet off the ground in a small bush. The nest is about five inches wide, and it contained two eggs, each about an inch long.


No birds were visible either in or around the nest, and I could not hear any scolding coming from nearby bushes. So I think that this nest was probably abandoned after these two eggs failed to hatch. Based on the size of the nest, its location, and the appearance of the two eggs, I think that this nest probably belonged to a pair of Northern Cardinals. Usually cardinals lay 3-4 eggs, so it is possible that there were other eggs that either hatched or got carried off by a predator.

Finally, I may have posted both of these already, but here are two osprey nests. The first is at Brigantine.

The second is in Cape May Harbor.

A useful guide for identifying nests and eggs is A Guide to the Nests, Eggs, and Nestlings of North American Birds by Paul Baicich and Colin Harrison. The egg illustrations in that guide were very helpful in identifying the nest from Beaver Swamp. Of course, other guides are available as well.

Warblers in Boxes

When I think of southern swamps, there are a few bird species that come to mind – Pileated Woodpecker, Red-shouldered Hawk, Barred Owl, Northern Parula. But none is more closely associated in my mind with southern wetlands than the Prothonotary Warbler. The ringing songs of these bright yellow birds are a prominent feature of spring and summer mornings in wetlands from Maryland southward.

Prothonotary Warblers are one of only two North American wood warbler species to nest in cavities. (The other is Lucy's Warbler.) This imposes a natural restriction on nesting opportunities. Even where the habitat is right, the warblers must compete for nest sites not only against members of their own species but also against other cavity nesters like Tree Swallows and House Wrens, as well as introduced species like European Starlings. While it presents a challenge for nesting warblers, it also makes it possible for people to help the species directly by providing additional nesting boxes that meet their needs.

Volunteers in Virginia have been doing just that over the past few decades. Virginia is one of the few places where the Prothonotary Warbler's breeding population has been increasing, thanks to an active program of installing and maintaining nestboxes, coupled with the protection of appropriate habitat. There are currently about 500 artificial nest sites in eastern Virginia, and volunteers continue to add more.

This year, the attempt to add an additional 60 nest boxes to the Northwest River State Natural Area in Chesapeake ran into protests from a nearby landowner.

But Luton also made it clear he wanted no part of a scientific project next door at the Northwest River State Natural Area, where volunteers want to help revive populations of a small, yellow songbird - the prothonotary warbler - struggling against a tide of predators and vanishing habitat.

Speaking before the Virginia Marine Resources Commission, a state agency debating whether to allow construction of 60 bird boxes on the Chesapeake preserve, Luton said he feared the little bird might some day be declared an endangered species.

Citing its decline across most of the United States - except in Virginia, where numbers are increasing - Luton reasoned that the warblers could jump across Smith Creek and take up residence on his land, where federal endangered-species protections "could be a catastrophe."

"I'm fighting for my property," he told the commission.

Eventually the Virginia Marine Resources Commission decided to install 60 boxes on the preserve anyway, but not along the border of Luton's property. This course of action was probably the easiest way of continuing the important conservation program while minimizing conflict. However, the case raises some important questions. There are a lot of issues to unravel in this story, and I doubt that I will do any one of them justice in this short post. But here are a few problems that I see.

First, there is a certain incoherence in fearing that Prothonotary Warblers might be listed as a federally endangered species but obstructing actions that would prevent further decline. The best way to avoid any hardships that an endangered species listing might impose is to avoid having to list a species in the first place. In the case of the Prothonotary Warbler that means preserving southern wetland habitat and maintaining adequate nesting sites for a sustainable breeding population. One of the commissioners noted this when he issued the decision.

"I hear what you're saying, Mr. Luton," said commission Director Steve Bowman. "But it seems the more you have of them, the less likely they will be on the endangered list."

Second, I have to wonder just how likely the Prothonotary Warbler is to be listed, or at least to be listed any time soon. This species has experienced a substantial decline in recent decades, as much as 30-40% since 1966. This decline, while startling, is only enough to place the species with a yellow flag on the Audubon Watchlist and as a species of Least Concern on the IUCN Red List. There are many bird species that have suffered far worse declines over the same period.

As far as I can tell, Prothonotary Warbler is not currently a candidate for federal listing. This places it in line behind other candidates (such as the rufa subspecies of the Red Knot) that have suffered even more dramatic declines yet have languished on the candidate list for years without being given the full protections that come with listing under the Endangered Species Act. In part, this was a result of the Bush administration dragging its heels on species protections, but so far the Obama administration has not shown much interest in wildlife conservation, either. This makes me skeptical that the Prothonotary Warbler would suddenly be rushed through the system, especially since the organizations that might push their cause seem more concerned with species threatened by climate change right now.

In other words, Luton probably has little to fear in terms of the Prothonotary Warbler becoming an officially endangered species anytime soon. And even if it did, this would not necessarily mean restrictions on his property. Much would depend on whether they were breeding there, how much of his property was occupied, and other factors – all of which are hypothetical at the present time. In addition, one of the warbler's biggest problems is that its wintering range in Central America and the West Indies is under pressure because of the destruction of mangrove forests to make way for other uses. Any conservation strategy for these warblers needs to deal as much with that threat as with preservation of potential breeding grounds in the United States.

Third, there is the problem of the intrusion of private interests onto public property. Luton wanted to block a conservation program on state property on the basis of a hypothetical future presence of a hypothetically endangered species on his own private property. The species is not on his property now, and we cannot be certain that any future presence of the species there would be caused by the nestbox program. The implication in all this is that the concerns of private landowners should trump the legitimate management decisions made by public officials, even when the harm claimed by the landowner only involves some possible future land use, not current conditions. In my opinion this sets a bad precedent for future wildlife management on public land.

Fourth, even on private land, property rights are not absolute. Landowners are not free to develop their properties as they see fit. Instead they must comply with a variety of laws from zoning regulations to fire codes to noise and nuisance ordinances. If a property is needed for a project that benefits the public, it can be seized (with compensation) through eminent domain. Endangered species protections are simply one set of regulations among many and not inherently more onerous than restrictions on building height or requirements for off-street parking. Compliance with such regulations costs money and limits how a property might be used, yet they are subject to far less opposition and paranoia than endangered species (and other environmental) protections.

The good news is that the nestbox project will continue, at least for this year, despite Luton's opposition. It has been very successful; this year alone 108 nestlings were banded in the 38 boxes at Northwest River Park, near the preserve in question. The program's success makes me think that other states within the Prothonotary Warbler's range would do well to follow Virginia's example and implement nestbox programs if they have not done so already.

(Top photo by Birdfreak.com; second photo by Robert Mussey. Thanks to long-time reader Peter Doherty for alerting me to this article.)

Osprey Nest

Osprey nest on a channel marker in Cape May Harbor

DC Bald Eagle Nest Threatened by DHS Project

For a long time, I knew or suspected that there was a pair of Bald Eagles nesting within the District of Columbia, but I did not know the location. Well, I finally learned where it is, but for unhappy reasons. The nest is located on the grounds of the former site of St. Elizabeth's Hospital, a 19th-century psychiatric hospital located in southeast Washington. In the winter of 2001, a pair of bald eagles built a nest at the site and have nested each year since then. This pair was the first to nest in DC since 1946. I think it likely that these are the adult eagles that I often saw perched or flying along the Anacostia River, at places like Haines Point and the National Arboretum.

Now that nest may be at risk. A few years ago, the federal government decided to reuse the abandoned federal facilities as a new national headquarters for the Department of Homeland Security. That, by itself, makes some sense. Abandoned historic buildings are more likely to be maintained if they are being used actively rather than sitting empty, and a new federal building could potentially bring jobs to the surrounded neighborhoods, which are among the poorest in DC. The problem is not so much the headquarters as the access road.

The government says a centralized control center would streamline its response to a national emergency by bringing thousands of federal workers under one roof, with a new access road to handle most of the traffic.

But the road would run through 200 acres of protected wildlife habitat, wiping out a dozen acres of trees. That, some fear, could drive off the only pair of eagles intrepid enough to call Washington home. "They used to be here, they weren't here for many years and now they're back. It makes me feel better knowing something is coming back," Stephen Syphax, a National Park Service ranger, said one morning as he walked through the woods near the eagles' nest....

The two are what scientists call "urban eagles," displaying an unusual willingness to tolerate levels of human activity they avoided for decades -- understandably, considering the threat man posed.

The question of just how much more noise and habitat destruction the eagles will withstand has been simmering for months, putting the emblem of America's strength at the center of a post-Sept. 11 dilemma: balancing natural resources and national security.

That indeed is the question: how much disturbance these urban eagles are willing to tolerate before abandoning the nest. Since this pair has stayed at the site for eight years, they are clearly tolerant of human activity and have the skills to survive and breed in a dense urban atmosphere. However, given that the hospital grounds have seen very little activity for most of that time, it is difficult to predict how the eagles might react to sudden changes to the landscape, especially a change as drastic as the construction of a long access road. I would prefer not to see this question put to the test, especially when there are viable alternatives. The department ought first to try refitting one or more of the hospital's existing entrances to meet current standards. This would provide them with the security they need and avoid harming our national symbol in the process.

Even if you do not click through to read the article, make sure to take a look through the accompanying photo gallery.