This past week I finished up the remaining point count routes, which included a route through coastal mixed forests along the extreme eastern edge of Frontenac Provincial Park. I accessed the habitat via a lengthy stretch of the Cataraqui Trail. Weather was perfect for surveying and it was fabulous to get and see this area of the park. Dominant species encountered during the morning were Yellow-rumped Warbler, Pine Warbler, Chipping Sparrow, Black-and-white Warbler and Red-eyed Vireo with a few “goodies” mixed in here and there.
Atop a ridge looking to Buck Lake
The survey route passed through a wide variety of habitats but the main target was mature mixed forest occurring along shorelines of large lakes in the area. Most lakes around here are steep in slope along the perimeter and lined with a high percentage of Eastern White Pine and Eastern White Cedar but I wanted a route that could be accessed relatively easily on foot.
Waterfall near Slide Lake
I was impressed with the high number of clear, gravel bottomed, moving streams in this area of the park. Since early June I’ve been logging locations of suitable stream habitat for breeding Louisiana Waterthrushes with the intention of returning in May, 2009 to inventory populations of this species in Frontenac Park. This particular stream was quite a torrent along its length, ending with a flourishing waterfall as it emptied into South Bay of Buck Lake.
Prairie Warbler habitat
The most significant finding of the morning was of a small colony of Prairie Warblers along the sloped and scrub-bearing banks of Slide Lake!
Prairie Warbler habitat
This is fairly typical habitat for this rare warbler in Ontario-rocky shorelines of lakes with a large component of successional scrub habitat.
I recorded this video with my ancient Canon A70 point and shoot camera to try and capture some audio of the singing males. A male flew into the small tree directly behind where I sat for a break at the end of the day and sang repeatedly at close range. I wish I’d had my HD camera as this particular male remained very close for about 10-20 minutes.
Nidiologicals (from Peck and James 1987 and Van Horn et.al 1994)
Habitat=deciduous forests Microhabitat=nest built in sparsely vegetated forest floor with dense leaf litter, often in forest clearings Spring arrival=May Average nest height=ground Nest builder=female Nest building period=5 days Average # of broods/season=1 (rarely 2) Average Egg Date=June 6-June 20 Area sensitive=yes Average clutch size=4-5 Incubation period=12 days Egg colour=white with speckles of gray, brown or hazel forming a wreath at large end Incubation=female Fledgling stage=young leave nest 8-10 days after hatching Parasitized by cowbirds=yes
The Ovenbird is a common species inhabiting both dry and mesic deciduous forest types throughout our study area in the northern Frontenac Arch. Our point counts suggest that they are one of the most abundantly occurring species in contiguous tracts of deciduous and mixed forest, both mature and younger stands, where the understorey is sparsely developed and canopy closure is high. The Ovenbird, a ground specialist, is an area sensitive species, which means that productivity is adversely affected by forest fragmentation. Data from the Breeding Bird Survey and the Ontario Breeding Bird Atlas indicate a significant population decline in southern Ontario where most large tracts of forest have been reduced to isolated smaller fragments unsuitable for reproduction of this species. The Ovenbird winters in southern Florida, Mexico, Central America and the Caribbean islands.
Nest contents
This Ovenbird nest was discovered at our Maplewood Bog MAPS station on June 14, 2009. This species is notoriously cryptic in its habits during the breeding season, often walking slowly along the forest floor to its well concealed nest. The species gets its name for its domed nest that resembles an oven. I was rather exstatic to find this nest as I had spent a good few hours tracking adults in two other territories in nearby Frontenac Park, both of which led me to recently fledged young instead of active nests. The eggs are heavily speckled with reddish-brown marks that are concentrated at the larger end.
The Oven nest
So here is the weird part. The nest was built at some point between our first and second visit to MABO in a 12m long net lane that was cleared in late May! The female will only flush from the nest if your foot comes to within perhaps 10 inches or so of the nest, which is an extreme example of an incubating bird “sitting tight” to avoid exposing the nest to an intruder. It was remarkable that we hadn’t either stepped on the nest or flushed the female earlier that morning as the nest is almost directly in the middle of our foot path for checking the net.
microhabitat
It was only when I took the net down at the end of the day that I sensed that something small and quick had just dashed from the ground near my feet. I then had a quick look around in the thicker ground cover but didn’t find anything resembling a nest. I then turned to a small and rather odd looking clump in the grass underneath a juniper seedling and noted the classic domed shape of an Ovenbird nest and then four eggs! The nest is not unusual in being located in a clearing but it is unusual to be positioned in such an exposed context with direct sun beaming on its roof during late morning and much of the afternoon. There is however, a decent layer of dead leaves, which female Ovenbirds key on for nest site selection.
habitat
This last photo shows the location of the nest within the net lane and the habitat of choice for this particular pair of Ovenbirds. Incidentally, we captured presiding male and female in the net that goes here on the first net check of visit three! They both seem to be doing well as the male sings throughout the morning, no less than 30m from the nest at any time and the female incubates the four eggs despite our comings and goings. We won’t be revisiting MABO until next week, which will give these expecting parents some quality alone time to take care of business.
The mid-season “switch” was turned on at MABO this past week. We were plodding along at about 25 birds/morning during the first two visits in early to mid-June. This period of the breeding season is known as the adult “superperiod” when adult males and females tend to nests with eggs or young within defined territories. Capture rates tend to be a little lower at this time as there are few young in the area and just a sample of the adults are mistnetted. Young birds appear in numbers around mid-late June and suddenly the site is alive with adults either dispersing or establishing new territories in different spots. Visit three was a perfect example of this as a total of 45 birds were captured during the morning, which included the first wave of youngsters and many new adults banded including the striking Scarlet Tanager pictured above.
Habitat at Net #9 (aka waterthrush highway)
This is one of the net sites at Maplewood Bog MAPS station, net number nine of ten. Net nine is located in a wet shrubby clearing within mature deciduous forest. This wet area is actually part of a long and narrow band of flooded shrub habitat within the interior of the forest that connects two wetlands. Northern Waterthrushes seem to use this habitat feature as a sort of highway between territories and foraging areas. We have captured and recaptured a high number of individuals in this location. The photo was taken in late morning when light begins to scatter down to the forest floor but this net site is quite shaded for most of the morning.
Forest floor at MABO
The vegetation on the forest floor indicates an uneven canopy closure where enough light passes down to sustain a fairly dense layer of ferns, tree saplings and other herbaceous plants. This type of deciduous forest is preferred by Wood Thrush, Veery and American Redstart among others. Too dense for Cerulean Warblers however, as the singing males recorded here in late May and early June must have opted to look elsewhere for more mature forest with primarily grass/forb understorey.
Maple saplings in the understoreyFemale Northern Waterthrush starting to moult
We captured four waterthrushes, including this adult female in the early stages of a complete moult. The new primary feathers are coming through in the center of the wing, which are noticeably darker and crisper than the adjacent primaries and secondaries feathers from 11-12 months ago. This individual was sexed as female based on the appearance of a waning brood patch, indicating that this was likely an early nester somewhere in the area.
Second-year male American Redstart
We also banded two new redstarts, including this second-year (SY) male that was captured simultaneously with an adult female in net ten. After-second year males have vivid orange and black plumage while the younger males, born last summer, have an unusually delayed plumage maturation for a warbler. SY males are distinguished from the females by the patchy black feathering around the eyes and bill.
After-second year male Common Yellowthroat
Overall it was a terrific outing and the results certainly give great confidence that the site can yield viable indices of both productivity and survivorship rates for several commonly breeding forest birds of the area. We still have four visits remaining for the MABO site in 2009 as well as a thorough Habitat Structure Assessment of the 20 hectare plot. It is still a bit early to make a final call but I think we can stamp the station with a shiny gold star for its performance thus far. The experience of establishing this and the other two sites will be crucial to setting priorities for expansion of our MAPS network in 2010. Results from visit three to MABO are posted below.
[I should be back to nest profiles and other blog topics tomorrow as I have a ton of content that I want to share with our faithful readers]
Maplewood Bog Results-Visit 3 of 7
New birds banded (36 of 14 species)
American Redstart-2
Black-capped Chickadee-5
Black-and-white Warbler-1
Common Yellowthroat-2
Ovenbird-1
Northern Waterthrush-3
Red-eyed Vireo-1
Veery-4
Song Sparrow-6
Swamp Sparrow-1
Scarlet Tanager-1
Gray Catbird-4
Rose-breasted Grosbeak-1
American Robin-4
Recaptures (9 of 6 species)
Black-capped Chickadee-2
Ovenbird-2
Northern Waterthrush-1
Red-eyed Vireo-1
Veery-2
American Robin-1
The first of two point count survey routes through rock barren environs in Frontenac Park was completed this past week. It has been tough going for scheduling and conducting surveys this season as the weather has been largely uncooperative for both roadside and off-road surveys of breeding birds. Cool temperatures, high winds and precipitation limit bird activity, which greatly reduces the validity of the data being gathered. This is the main reason why these surveys have yet to finish, however they should be wrapped up by the weekend (fingers crossed).
106 point count stations are now “in the books”, the last batch of which were drawn from rock barren habitat in Frontenac Provincial Park on June 20th, 2009. It was a long day of hiking, spanning over 12 kilometers through the deep interior of the park’s southeastern portion. The habitat was stunning and full of birds and other wildlife, which made for yet another exhilarating day of field studies on the Frontenac Arch. This particular section of the park is HEAVILY laden with irregularly sized and shaped wetlands ranging from beaver ponds, lakes, swamps and sloughs. More than once I was forced to wade through the water waist high in order to stay on course-there was simply no way of getting through it without a long and wasteful detour. I don’t normally object to getting a bit wet as needed but these wetlands are very soft-mud bottomed types with imperceptible footing and a great deal of mushy unpleasantness-not to mention saturated with unseen snapping turtles! In the end though, my way was found and I took in the ordeal with a balanced sense of bemusement and humour.
blueberry season arriving
Blueberry, probably Vaccinium corymbosum or High-bush Blueberry, was a dominant ground cover species in areas with enough moisure (i.e. everywhere). The fruit is just starting to mature and should be edible soon. I have yet to associate any particular bird species with this plant but I can imagine that Nashville Warblers would find it an appropriately dense-low growing cover for their shallow cup nests. Blueberry is common throughout the park but is particularly abundant in rock barren areas running in a gradually narrowing band from the park’s south end through to Big Clear Lake in the northeast.
Prairie Warbler turf
The very first survey of the day yielded Virginia Rail, multiple pairs of Wilson’s Snipe and a distant Prairie Warbler-not a bad start! The next station, some 330m away, got me closer to the Prairie Warbler territory, which is pictured above. The male was constantly singing from the the dense shrubs lining a wet draw astride a rock wall. I had no time to investigate this particular territory any further but I’ve been pleased enough overall with having mapped several territories of this species in interior and atypical habitat associations. Prairie Warbler is a rare breeder in Canada with a very patchy and sparse distribution along the southern shield ecotone in Ontario.
Mixed-forest habitat near Slide Lake (FPP)
The route carried through a habitat I hadn’t yet sampled this season, mixed-forest dominated by Eastern White Pine and Red Pine. This area was “loaded” with Yellow-rumped and Pine Warblers, Chipping and White-throated Sparrows and lesser numbers of Blue-headed Vireo. The highlight of the birding was an adult Great Horned Owl with a fluffy youngster within 75m during a survey. Great Horned Owl is considerably less common than Barred Owl in this region.
panoramic shot of pine barren habitat
This is the last of the panoramic shots I took of the area during the day. I was hoping that the widescreen view might help in providing a sense of scale and depth of the habitat. Vegetation in the area is quite stunted, reflective of shallow till and extensive rock outcrops. This park “ecozone” is a stark contrast to the mature woodland featured earlier, with its abundant Cerulean Warblers and towering century old ash, maple and oaks. Just a few kilometres away, Wilson’s Snipe, Eastern Towhee, Field Sparrows and Common Nighthawks, among others, inhabit vast expanses of moss and lichen covered rock with ripening blueberry shrub and stunted pines. These contrasts are a defining feature of the Frontenac Arch, an undulated, ever-changing landscape of immense diversity.
The Common Nighthawk nest first discovered at our Rock Ridge MAPS site is still active. This adult, probably a female, spent the morning of June 16th incubating eggs in the blistering sun and seemed to be catching up on some sleep as well. I called in Seabrooke to sweep by on a net check with her long lens for a photograph and it turned out very nicely as usual. The eggs have been incubated since at least June 2, which means that the chicks should hatch no later than June 21 if they haven’t already. We will be back for our third visit to the site around the middle of next week and will hopefully find two “nighjarlets” at the little rock outcropping. I will also be conducting two point count routes in rock barren habitat next week. Each route will be four kilometres long, which gives me a good opportunity to turn up some more of these fascinating birds.
Whip-poor-wills, waiting for the next full moon to approach, have been quiet of late but we did flush three individuals from Canoe Lake (1 bird) and Perth (2 birds) Rds on our pre-dawn drive to Rock Ridge on the 16th.
Frontenac Bird Studies 