Chimney Swifts over Downtowns

Nature Notes for August 19, 2011

You’ve probably heard them as you go about your business in downtown Port Hope or Cobourg in the summer. Chimney Swifts chattering overhead are a welcome sign of summer. They are still around, though, foraging for insects on the wing.

The Peterson field guide describes them as being shaped like “a cigar with wings” and most subsequent field guide authors have quoted this description. They are small, dark oblong-shaped birds with long curved wings. Their flight style is quite distinctive, since they fly with stiff, fluttery wing beats.

Although they superficially resemble swallows, and are often found foraging with swallows, their closest relative is thought to be the hummingbird. They spend most of their time in flight where they feed on flying insects and a few ballooning spiders.

Chimney Swifts often nest in chimneys, hence their name. Before buildings were available, they nested in hollow trees or caves.

Their nests are a small, rather flimsy, flat saucer of twigs glued together and to the supporting vertical surface with swift saliva. The birds collect the uniform sized twigs in flight.

The nests of an Asian species of swift are prized as the main ingredient of birds nest soup. This very expensive soup is really just cooked swift saliva!

Swifts have very short, weak legs. Their toes are specially adapted for clinging onto vertical surfaces and the edge of their nests. As well, they have stiff projections from their tail feathers which aid in keeping balanced when they perch.

As with all aerial foragers, Chimney Swift populations showed a definite population decline between Ontario’s two Breeding Bird Atlases. As with many other species, this decline is thought to be due to habitat loss.

However, some Chimney Swift habitat loss has to do with modifications to human built chimneys. Many chimneys built in the nineteenth century are no longer in use and many have been taken down or closed off. Changing fire codes require metal chimney liners. Many chimneys are capped to prevent access to animals and birds which humans consider pests.

In some places, artificial structures are being erected to provide Chimney Swifts with suitable nest sites. Two have been erected in Ferris Provincial Park in Campbellford.

As a bird bander, I have had the opportunity to view many species of small birds up close. However, my one close encounter with Chimney Swifts was in a decidedly non-naturalist setting. On September 4, 2002, Northumberland Players held a reception at the Firehall in Cobourg to publicize the upcoming season. At that time, the Firehall was not air conditioned. It was a warm evening, so all the windows were open. Suddenly into the midst of the wine and cheese reception flew two Chimney Swifts. They were a bit confused and crashed into the wall opposite the open windows.

Most of those present thought that they were bats and became a bit hysterical. I leapt into the fray, picked up the frightened birds and carried them downstairs to the parking lot. One flew off immediately. The other one needed a bit of time to recover its senses, but after a few minutes, it, too, recovered and flew off to join the other swifts swirling around Victoria Hall.

Chimney Swifts have started to migrate and most will be gone in about a month. Most winter in South America, in Peru and western Brazil.

In Praise of Presqu'ile Provincial Park

Nature Notes for August 5, 2011

It is easy to take for granted natural areas that are near at hand. I have spent more time than usual in Presqu’ile Provincial Park this summer.

This park contains a large variety of habitats in a rather small area. It has mature mixed woods, good quality marsh, sand beaches, Pannes, old field, open lake, the more protected Presqu’ile Bay and offshore islands.

Since records have been kept, 333 species of birds have been recorded in the park. Some are rare and would be unusual to encounter more than once in one person’s lifetime. Some are regular visitors during the passage of migration. Some breed in the park and raise their families here.

Presqu’ile’s new Marsh Boardwalk allows visitors a good look at many marsh birds which would otherwise only be seen from a canoe. Regularly, Least Bittern have been reported this summer from the area of the first observation platform. This small heron is very secretive and one is lucky to get even a fleeting glimpse.

The larger American Bittern could also be heard, and sometimes seen, from the boardwalk. This heron is also somewhat secretive, but it has a loud voice. At dawn and dusk, a number of them could be heard singing their “chunk-a-lunk” song.

Presqu’ile’s marshes have quite a high density of MarshWrens. Throughout the season, they could be heard singing their loud trill. If an observer was willing to wait for a little while, he was almost certain to catch sight of this active little bird. While canoeing in this marsh, we were able to approach many Marsh Wrens quite closely.

There is also a good population of Swamp Sparrows in Presqu’ile Marsh. These males sing a different sort of trill than the wrens, but also have a loud song.

To our surprise, we found a family group of Common Loons just off the Fingers in Presqu’ile Bay. Until this summer, I was unaware that a pair of loons has been nesting for several years somewhere in the marsh. I had thought that they preferred the smaller lakes in cottage country. This indicates that there are areas of the marsh that are undisturbed by motorized watercraft.

Over the marsh, many swallows could be found hunting. Most were Barn and Tree Swallows, but there were a few Purple Martins.

Several species of birds that breed on the offshore islands pass over on their way to and from foraging areas. The largest proportion of these birds are Ring-billed Gulls. Other colonial birds nest here too: Herring and Great Black-back Gulls, Caspian and Common Terns, Great Blue Herons, Great Egrets, Black-crowned Night Herons and Double-crested Cormorants.

Caspian Terns, large fish-eating, gull-like birds with a raucous voice and a huge orange bill, were often seen fishing in the open channels of the marsh.

Numbers of their smaller relatives, Common Terns, have experienced a precipitous decline in recent years. Presqu’ile used to have a very large colony of Common Terns, but they are mostly gone now, pushed out by Ring-billed Gulls. The Ring-bills winter further north, so arrive back on the breeding colonies earlier than the terns, and grab all the good nesting sites.

At this time of year, birders head to Presqu’ile in hopes of finding south-bound migrant shorebirds. Twenty-five species of shorebirds are regular in the park; forty-two have been reported over the years. Presqu’ile’s beaches provide habitat for these birds, a habitat that is rather scarce in Northumberland County. So far, there have been very few shorebirds reported this summer. By the time this column appears, their numbers may have increased.

The knowledgeable staff naturalists at the Park provide interpretive programs all year for those who want to learn more about the natural features of this park. This column has mentioned only birds in a couple of habitats. There are also butterflies, dragonflies and damselflies, a great variety of vascular plants, turtles, frogs…… The list is very long.

For more information about programs in the park, check out www.friendsofpresquile.on.ca

Birding on My Local Patch

Nature Notes for July 22, 2011

I hadn’t been to the A.K. Sculthorpe Marsh Trail in almost a month. Since I consider it part of my “local patch”, it was high time that I made a visit. This spur of the Waterfront Trail at the east end of Port Hope runs between Lake Ontario and a small cattail marsh.

The east end of the trail is the mouth of Gage’s Creek. There are large trees along parts of the trail while other parts have primarily red osier dogwood shrub.

Of course, I seldom walk without carrying binoculars, so this was also a birding outing. I have often written that you never know what birds might be around the next corner. Last Saturday evening (July 16) produced a bonanza.

Before we got out of the parking lot onto the trail, a Belted Kingfisher made his presence known by his loud, rattling call. These birds dig nest holes into dirt banks. He might have been nesting either along the Lake Ontario shorecliff or in the much lower banks along Gage’s Creek.

A Swamp Sparrow, which has been singing at the west end of the marsh all season, was still in full song. There has also been one at the east end of the marsh, but on this evening, his area was quiet.

The marsh itself now has very low water levels, quite a contrast to earlier in the spring when the water was as high as I have ever seen it. On closer inspection, a bump in the pond proved to be a fairly large snapping turtle. Quite small frogs could be seen as little shining bumps in the muck. Probably because of the frogs, a Black-crowned Night Heron and a much smaller Green Heron were found hunting along the edge of the cattails.

The low water levels had forced the normally secretive rails into the open. For the first time in several years, both a Sora and a juvenile Virginia Rail could be seen among the cattails here.

The only shorebird in evidence was a single SpottedSandpiper. This muddy marsh is now quite good shorebird habitat. Since there is not much of this type of habitat locally, we will be keeping a close eye out for southbound migrant shorebirds here.

A few Northern Rough-winged Swallows and Barn Swallows were foraging for insects over the marsh. Suddenly, every small bird in the area was in the sky making a terrific commotion. This is the birders’ cue to look for a raptor. Sure enough, there it was: a Northern Harrier flying through.

On the lake and at the mouth of Gage’s Creek, we found a total of eleven Bonaparte’s Gulls. This small gull with pointed wings has been quite scarce on this part of Lake Ontario’s shore line for the past several years. It was good to see them back. Bonaparte’s Gulls nest in the Boreal forest and the Hudson’s Bay lowlands, so are seen as migrants in our area. These birds were the young-of-last-year, and would not have bred this year.

On closer inspection, one bird in this gull flock was a bit different: slightly smaller, finer bill, a dark “cap” on the head. It was a Little Gull. Although Little Gulls are common in Europe and Asia, they are rare in North America. Although a pair did nest in Second Marsh in Oshawa about fifty years ago, most North American Little Gulls probably nest in remote areas where they are not easy to detect.

The Little Gull was the sort of treat that all birders hope for when they take to the field. This one was quite close to shore and on the water, so it was easy to study.

It might not be there now, but perhaps some other bird will arrive to gladden the heart of an observer. All you have to do is visit often and pay attention.

Answers to Some Readers Questions

Nature Notes for July 8, 2011

One of the interesting things about writing this column in the faith that readers have that I can answer all questions related to birds and their behaviour. This column consists of a number of things I have been asked recently, along with my best attempts to respond.

“Is it the same robin that has nested in the same place in my yard for several years?”

It might be, but without marking the bird in some way, it is impossible to tell. Many banded birds have been known to return to the same place to nest several years in a row. In the fifteen years that I have been monitoring Tree Swallow nests, several females have come back to the same nest box in successive years.

It is thought that if a pair of birds successfully fledges nestlings, they will return to the same place again. That place is safe from predators and has enough food resources for the birds to raise a family.

“The baby robins/blue jays/starlings (Readers can fill in the species.) in may yard can’t fly. They are sitting in the middle of the front lawn and I don’t see the parents anywhere.”

This is the time of year that many young birds are leaving the nest and learning about the world. In the nest, safe behaviour is be still and be quiet. When the fledgling does that in the middle of your lawn, it seems rather odd behaviour for a bird. If the youngster survives for a few hours and can make it to cover or to the branches of a shrub, all will be well.

It is true that many of these fledglings don’t fly very well at first. They flutter and scramble about on the lower branches of shrubs or trees. Last week, my husband and I found a newly fledged American Robin on the top of the front tire of a parked car in a parking lot – not a safe place to be if the owner of the car decides to drive off. To the accompaniment of much scolding by the adult robins, we placed the chick on the lower branches of a nearby tree, where it would be somewhat safer.

Please believe me when I assure you that the adult birds are around. They don’t spend any more time with the young ones than is necessary to fly in and stuff food in their mouths. When the adults approach, the youngsters make a terrific commotion. This has the potential to attract the attention of any interested predator, which is not in the best interest of the fledgling. The adults make frequent, brief feeding trips to the chicks and then quickly leave.

“What has happened to the young Blue Jays from the nest in my garden? I have enjoyed watching them and now they are gone.”

The young Blue Jays are probably not far off. The adult birds will have taken the young to a safe place with good foraging. Once the young birds are somewhat independent, you will probably see them again.

In some species which raise more than one family per year (Blue Jays usually have only one brood), the male tends the fledglings while the female starts the next nest.

“What has happened to the hummingbirds? I had several at my feeder from early May until about June 12, but I haven’t seen any since.”

There are a couple of possibilities here. Perhaps the birds at the feeder were migrants which were just passing through to nest somewhere else. If a hummingbird finds a convenient feeder, it would take advantage of the extra energy provided.

The other possibility is that some of the local Ruby-throated Hummingbirds may have lost their nests. There were several severe storms in our area in early June with extremely high winds. These storms might have destroyed the nests, so the birds went somewhere else to try again.

There is much to learn about the other creatures which share our space, if we just take the time to observe.

Monitoring Tree Swallow Nests

Nature Notes for June 24, 2011

Over the past two weeks, I have been spending a lot of time with Tree Swallows. For about 15 years, I have been monitoring their nest boxes and banding the young.

Tree Swallows females are quite synchronous in their egg laying. That is, all females in an area will lay their eggs at almost the same time and start incubating at the same time. That means that I am very busy in mid-June. This year, chicks were ready to band starting on June 8 and almost all have been banded as I write. Many young birds have fledged already. There are only a few nests that still have nestlings in them.

One of six species of swallow that nest locally, Tree Swallows are cavity nesters. Prior to European settlement, they used old woodpecker holes, often in dead snags around beaver ponds. However, like the bluebird, they nest readily in man made nest boxes. This has made them a good species to study, since the nests can be found easily and Tree Swallows are quite tolerant of disturbance.

Tree Swallows nest throughout most of North America. They winter from the Gulf coast to Central America. They can winter further north than most swallows since they are not completely dependent on flying insects for food. They can digest the berries of the wax myrtle, a common coastal shrub.

The plumage of adult Tree Swallows is iridescent blue/green above and white underneath. They have a slightly forked tail, but not the long tail streamers of a Barn Swallow. Female Tree Swallows take two years to acquire their iridescent plumage. This is unusual for female songbirds. In their first breeding year, they are primarily brown above, with sometimes a few scattered green feathers.

Nests of Tree Swallows are made of a neat cup of grass lined with finer grasses. If pine needles are available, they may make a nest of them instead of grass. They also always contain feathers which act as insulation for the chicks. I have found body feathers of ducks, gulls, Ruffed Grouse, Wild Turkey and domestic chicken lining Tree Swallow nests.

Tree Swallows lay small white eggs, typically five or six to a clutch. When the female is laying, she lays one egg per day until the clutch is complete. Only then does she start incubating. Sometimes incubation does not start immediately. Incubation can be delayed for up to two weeks and the eggs will still be viable.

Incubation typically takes about 14 days, with the entire clutch hatching on the same day. Newly hatched chicks are naked and helpless. They seem all mouth and stomach with very truncated wings and legs. It hardly seems possible that in three weeks they will grow enough to have feathers and be able to fly. “Eating like a bird” takes on a whole new meaning when you see how quickly they grow. It takes a lot of flying insects to fuel that growth.

Although at the beginning of the nestling period, the adults remove the fecal sacs from the nest, as the chicks grow, they stop doing this. The result is that by the time the chicks fledge, the nest is a matted mess which needs to be scraped from the box. Successful Tree Swallow nests, that is chicks survived to leave the nest, are disgustingly filthy.

Although there are a few exceptions, most Tree Swallows have only one brood per year.

So far this year, I have captured 3 previously banded adult females. One was banded as a chick in 2007, one as a chick in 2008, and the third as an adult in 2008. The third bird is at least 5 years old, although she could be older. The oldest known Tree Swallow on record is a male which hatched on a long-term study site at Long Point on Lake Erie. This bird was a little over 12 years old when last captured, alive and well and at an active nest on Long Point.

The last Breeding Bird Atlas for Ontario reported a significant population decline in Tree Swallows since the preceding Atlas, as with all aerial foragers. The reasons for this decline are probably many and include habitat loss, drainage of wetlands, changes in farming practices, competition with other species for nest cavities and pesticide use which reduces their food source.

Since this species is quite tolerant of humans, it is really unfortunate that human activity is the main cause of its decline.

16th Northumberland Summer Bird Count

Nature Notes for June 10, 2011

On Saturday, June 4, I awoke to gentle rain. This was not good news, since this was the first day of the 16th Northumberland Summer Bird Count. I ate breakfast and drove to my assigned area near Castleton in the rain. By the time I arrived, the rain had stopped but the skies were still very gray.

Even without rain, the weather was going to be a problem. On a bird count at this season, observers find birds mostly by sound – songs and calls. Overcast skies tend to suppress bird song, so birds can be very difficult to detect.

I donned my rain gear and started down the road allowance. This is a very interesting route, since there are treed hedgerows along both sides of the road. Part of the length has forest on one side and open agricultural fields and pasture on the other.

The variety in habitats houses a good variety of landbirds. In the hedgerows were such species as Indigo Bunting, Brown Thrasher and Chestnut-sided Warbler. The forest held Veery, Ovenbird and Rose-breasted Grosbeak. In the open fields, I could hear Eastern Meadowlark, Bobolink, Grasshopper Sparrow and Savannah Sparrow.

There is one wet field with a small pond. Here I encountered swarms of mosquitoes. In an area that is generally high and dry, I am assigned the “buggiest” walk. Thanks goodness for the rain gear!

I returned to my car and drove slowly up Jakobi Road, stopping from time to time to get out and count the birds I was hearing. Next stop was another unmaintained road allowance, where I startled a group of people checking the transformer for their solar collectors. I’m sure they thought I was a bit odd when I told them I was doing a bird count. Who would walk into that valley with thunder rumbling from increasingly dark clouds?

This time, I used the environmentally friendly bug spray that I had purchased at Port Hope’s Living Green Fair. I also donned my mesh bug shirt. As I ventured down the road, light rain began to fall. By the time I had walked to the river bottom and back to my car, it was raining hard.

This seemed a good time to have some lunch and wait for the storm to pass. It didn’t. The rain fell even harder. I decided to drive slowly with the car window open along several secondary roads to see if I might hear or see any other birds. I learned that not only robins sing in the rain, but so do Baltimore Orioles. Since the rain seemed to have settled in, I ended my day at 11:45 and headed for home.

On Sunday,  I had a friend birding with me. I picked Katsu up and drove to our starting place, this time in fog. There was intermittent sun and cloud, so the birds were singing more. Our first walk was another buggy walk (for which Katsu wasn’t prepared) along a different road allowance to Piper Creek. This walk yielded Mourning Warbler, Alder Flycatcher, Black-throated Green Warbler, Black-and-white Warbler, Blackburnian Warbler, Northern Waterthrush, Yellow Warbler, Common Yellowthroat, and Swamp Sparrow, as well as other species.

On a drive in an agricultural area we found Horned Lark, more Bobolinks, Savannah Sparrows, Grasshopper Sparrows and a pair of Northern Harriers. These were the first raptors I had seen. They don’t like to hunt in the rain.

Next was a walk through a pine plantation in search of Red-breasted Nuthatch (success) and Red Crossbills (no joy), but we did find Blue-headed Vireo. Then another walk along a wooded trail through the forest. This walk added Scarlet Tanager, seen as well as heard.

The last bird of the day was a Ruby-throated Hummingbird.

Why do we do these counts? It is mainly to monitor breeding bird population trends. Data from this count has been used by the Nature Conservancy of Canada in their conservation work on the Rice Lake Plains and is available to other agencies.

This count is organized by Willow Beach Field Naturalists. The data from past counts is posted on the WBFN web site, www.willowbeachfieldnaturalists.org. The 2011 data will be added when it has been compiled.

Let’s hope for dry weather in 2012. We’re due. It also rained on the 2010 count.