Crunch time has arrived as we make final preparations for the start up of the Frontenac Breeding Birds program in early June. Establishing the MAPS sites has been the main task on the agenda but we’ve also been delving into establishing over 180 point count stations, getting ready for Project Whip-poor-will and the usual administration duties. Things should clear up by early next week and I should be back to regular blogging by the end of the weekend. I have yet to start nest searching in an “official” manner but have already found nests of a dozen species. I was very pleased to find a Winter Wren nest yesterday evening and have since added Red-eyed Vireo, Rose-breasted Grosbeak and a second Hairy Woodpecker nest to the list from this afternoon. No sign of a nest yet for the residing pair(s) of Ruby-throated Hummingbirds at the FBS headquarters….
Returned to the Hemlock Lake site yesterday to begin searching for mistnet locations and to get a better picture of the breeding bird community for our study. The visit was considerably more comfortable than my last when black flies were particularly menacing! This latest visit was cool with very few biting insects, which afforded me a great opportunity to get to know the site a bit better. What a difference a couple of weeks can make in the late spring! The emerging foliage was substantially further along, which created a much different looking landscape. Site visits in winter and early spring gave me a solid understanding of the scale, topography and structure of the site but I knew that it wouldn’t be possible to even consider positoning net locations until the canopy and understory had matured.
Upon entry to the site, I heard Eastern Towhee, Scarlet Tanager, Nashville Warbler and a concert of voice-battling Ovenbirds. Further along to where the forest turns from deciduous to mixed-coniferous, I encountered Black-and-white, Magnolia, Black-throated Blue and Blackburnian Warblers, all species we were expecting at the site. Also of interest were at least two territories of Winter Wren, one of the most vocally adept species on the planet! I was able to record a few seconds of one of our talented males holding territory in the site along with one of the unavoidable male Ovenbirds (click play to listen).
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Evidence of active nesting by many species included alarm calls, adults carrying nesting material and territorial disputes. I didn’t find a great number of nests but I did mark locations where a nest was suspected. I will have to return in a few days to a week to confirm presumed nest sites of Ovenbird, Black-and-white Warbler and Eastern Towhee among others.
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However, I did manage to find the nest of a Brown Creeper, which was discovered by patiently watching movements and behaviour of a pair in the standing dead timber at the edge of Hemlock Lake. After sitting quietly for about 45 minutes, I was finally rewarded with the observation of an adult entering a tree with nesting material. The Brown Creeper places its nest almost exclusively in dead trees, between a loose flap of bark and the trunk. They build a hammock shaped nest of sticks and fibres, which is secured to the bark with insect-egg casings and spider silk. The nest will now be monitored with the goal of deriving a nest outcome. The information will be important to our demographic studies of breeding birds in the FBS study area and will be submitted to the Ontario Nest Records Scheme and Project Nestwatch for province-wide monitoring efforts. A closer view of the nest site is provided below.
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Brown Creeper nest site
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The most exciting discovery of the day led to this short video of a waterthrush carrying material to a nest in roots of an upturned tree along a clear moving stream. Northern Waterthrushes were quite vocal in the vicinity but this particular pair were all but silent except for some occassional contact calls between male and female. The calls were diagnostic of Louisiana Waterthrush but I will have to confirm identify of the nest owners at a later date. Northern Waterthrush are very similar in appearance with some subtle differences. It is best to distinguish the two by song, which are distinct. The Louisiana Waterthrush is a Species At Risk and a specialty of the Frontenac Arch region where an abundance of mature forest and clear moving streams provide suitable nesting habitat. The video is of less than ideal quality but one can clearly see an adult entering the roots about halfway up the screen to the left of the small tree trunk. The bird is more clearly seen at the end of the clip as it cryptically runs through the stream and out of the frame. Click here for HD version of this video clip.
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The Hemlock Lake MAPS station will begin operating in early June and continue with one visit per ten-day block through the final visit in late July. We will also be conducting a standardized nest monitoring study at this and the other two MAPS stations in the FBS study area. The site is turning out to be a terrific find and hopefully a long-term home for our research and monitoring programs.
Notable Species at Hemlock Lake (May 18,2009)
Great Blue Heron
Red-shouldered Hawk
Eastern Kingbird
Brown Creeper
Winter Wren
Wood Thrush
Swainson’s Thrush (migrant)
Northern Parula (migrant)
Nashville Warbler
Yellow Warbler
Chestnut-sided Warbler
Magnolia Warbler
Cerulean Warbler
Black-throated Blue Warbler
Black-throated Green Warbler
Blackburnian Warbler
Black-and-white Warbler
Ovenbird
Northern Waterthrush
Louisiana Waterthrush
Common Yellowthroat
Scarlet Tanager
Eastern Towhee
Field Sparrow
Song Sparrow
White-throated Sparrow
Rose-breasted Grosbeak
Baltimore Oriole
The Red-shouldered Hawk (Buteo lineatus) occurs across much of the eastern half of North America with a northern limit of central Ontario and Maine. Formerly Ontario’s most abundant hawk species, Red-shouldered Hawks declined sharply in the last century due to habitat loss and fragmentation and resulting inter-specific competition with the Red-tailed Hawk. Red-shouldered Hawks are an area-sensitive species, preferring large tracts of mature, contiguous and primarily deciduous forest cover. This species also prefers a closed canopy of 70% or greater for successful breeding (Badzinski 2005). Territory size for the lineatus subspecies averaged 192 hectares in a Maryland study with distance between nesting pairs ranging from .37 km to 1.27 km (Steward 1949). Interestingly, this species is considered a partial migrant as it is only those individuals that breed in the northern portion of the continental range that are known to migrate south. These migrant Red-shouldered Hawks that breed in Ontario migrate relatively short distances to the United States.
The rather unimpressive photo above was taken of a incubating parent, probably a female, along Canoe Lake Road on April 27, 2009. A pair returned to this nesting location from previous years in late March and were highly vocal during the first two weeks of courtship. The male and female were often observed together coasting on thermal updrafts around mid-day near the nest site. The pair have been nearly silent since that time and are much more inconspicuous in general since eggs were laid in the last week or so. The nest itself, compacted and disheveled by the winter, was extensively renovated by the pair in the first few weeks, and has nearly doubled in overall size since late March. It is located in a mature ash between two small ridges. The presiding male has been observed on multiple occasions bringing food (mostly small mammals) to the incubating female. The incubation period is about 33 days, which suggests that young will hatch around late May (Palmer 1988).
Cruising Red-shouldered Hawk
The Red-shouldered Hawk was listed as a Species At Risk (Special Concern) in Canada (COSEWIC) and Ontario (COSSARO) until 2007 when it was delisted largely based on results of a pioneering citizen science project. Bird Studies Canada (BSC) and Ontario Ministry of Natural Resources (OMNR) completed a thorough assessment of the population status of this uncommon raptor species by conducting annual roadside counts in southern and central Ontario from 1990-2006. The Red-shouldered Hawk and Spring Woodpecker Survey concluded that populations during that time period seemed to be stable in regions of Ontario with suitable habitat (central) and that the species was expanding northward. Of over 141 survey routes conducted during the project, there were a few that stood out in terms of the average number of hawks per route. Canoe Lake, Opinicon Lake, Otty Lake and Christie Lake, all routes located within the northern portion of the Frontenac Arch, had significantly higher counts of this species than anywhere else. This pattern of high population density in this region as well as The Land Between ecotone is also indicated by abundance and breeding evidence maps of the Ontario Breeding Bird Atlas.
Protecting the ecological integrity of the Frontenac Arch and the Southern Shield region of Ontario is important to a vast array of species, including the Red-shouldered Hawk. The contributions of the Red-shouldered Hawk and Spring Woodpecker Survey and the continued efforts of the Kingston Field Naturalists have been of considerable significance to our understanding of this species in the Frontenac Arch region. While not a focal species at this time, Frontenac Bird Studies will be conducting surveys and nest-monitoring to lend further support for this remarkable hawk in Ontario’s woodlands.
Frontenac Bird Studies 