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For us, 2013 will be remembered as the year of the point count. We’ve now finished up the last of a whopping 260 stations. This includes our own established suite of 164 on and offroad stations but also a new set conducted for our collaborative assessment of Cerulean Warblers with Bird Studies Canada. We’ve yet to enter and mine the data but a few things are clear: a) an overall decline in forest bird abundance has occurred; b) trends are positive for some species but negative for more; and c) You can almost always count on a Red-eyed Vireo or two to liven up a survey!
From 260 Point Count surveys this summer, a total of 576 Red-eyed Vireos were tallied. So often we tend to focus on less prodigious species and those showing signs of decline. However, the stability and ubiquity of the Red-eyed Vireo in the Americas is compelling and worth appreciating. Here at home in the Frontenac Arch they seem to be thriving in forests where others have thinned out if not vanished altogether. This round of surveys struck a note – these are prolific, feisty, robust survivors serving an important ecological role in hardwood forests. They are also the current record-holder amongst world bird species for most songs in a day – 20,000!
I’m beginning to let go of the notion of “normal” with respect to weather. We’re now in the middle of our fifth spring/summer season and we’ve yet to have a complete season without at least one extended period of extreme conditions. This year has been “abnormally” wet. In fact, water levels have never been so high since we began our studies in 2009. This boom and bust weather must take something of a toll on breeding bird productivity. Cerulean Warblers are clearly down from levels detected in 2009 and we’ve talked at length in the past in a similar vein regarding Louisiana Waterthrush and Prairie Warbler. However, the picture isn’t quite so gloomy across the board. A number of species are actually up from previous years including Blackburnian Warbler and Brown Creeper. It will be very interesting to dive into the data in the coming months to get a better handle on what’s happening – stay tuned for more details in the future.
Our fourth consecutive season of Monitoring Avian Productivity & Survivorship (M.A.P.S) is well underway; nearly half finished, actually. We’ve now completed our third of seven visits to each station. As previously discussed results from our first three years of M.A.P.S indicated a sharp, incremental decline in abundance and diversity of terrestrial avifauna in Frontenac woodlands and rock barrens since 2009. The breadth and severity of the decline was foremost in our minds as we walked the trodden paths from usual empty net to empty net in 2011. Hope springs eternal and a new season began in early June 2012. Below is an update on this year’s results to date for Maplewood and Rock Ridge.
First the good news. Numbers of birds are up from last year at MABO, although still considerably lower than in 2009. For comparison, in 2009 we captured 91 birds total through visits 1-3 (72 new/19 rec) while we’ve captured 60 (39 new/21 rec) for the same period in 2012. Very pleased to see that Nashville Warblers and Northern Waterthrushes have returned to the site. We banded a whopping eight Northern Waterthrushes here in 2009 but didn’t even hear or see one a year ago. We’ve banded two adults of each species so far in 2012. Annual totals of Veery and Wood Thrush have been relatively consistent in abundance since 2009 and have returned in expected numbers again this year. Two new species have been recorded for the site; a singing Brown Creeper was detected on June 7 and White-throated Sparrows have been recorded singing on each visit. Notable absentees so far include cuckoos, Hermit Thrush and Field Sparrow.
It’s been a strong year for Yellow-rumped Warblers at MABO. I’ve also observed an unusually high number of adults feeding fledged young in Frontenac Provincial Park this spring/summer – good signs for this northern species in the region. While it’s still too early to judge this M.A.P.S season at MABO, with less than half of the work completed, we are seeing some positive signs of a possible rebound. Weather conditions have been closer to normal during this breeding season than any previous season since our studies began.
American Redstarts are one of the most commonly sampled species at MABO, although they are infrequent nesters within the station boundaries proper. They mainly occupy habitats at the edges of the station but we do manage to capture them later on in the summer when adults and young disperse. In 2009 at least two pairs nested along the shrubby perimeters of small wetlands within the station but they’ve not returned since. Gorgeous bird – one of my favourites.
Rock Ridge (RRID)
While things seem promising at MABO, the same cannot be stated for Rock Ridge (RRID) where numbers are a little down from last season and at least a few species seem to be struggling: most notably Eastern Towhee and Field Sparrow. Both are species of conservation concern due to significant negative trends evident in continental BBS and MAPS data. At our stations these species have consistently decreased in abundance annually since 2009. Urban expansion and changing rural landuse practices seem to be the most commonly suggested causes for the declines in both species, although these issues are less applicable in our region. On the other hand, White-throated Sparrows appear to have rebounded nicely after a near no-show in 2011. Also, the only Pine Warbler that we’ve banded during M.A.P.S was spotted feeding fledged young on June 28, 2012. The bird was originally banded as an immature male on July 18, 2010.
2011 was not a good year for cuckoos. For the first time we failed to capture one during a M.A.P.S season. This Black-billed was a welcome capture on June 18, 2012 at RRID. However, their numbers are clearly down from our first two seasons. This is true for most species at the station – present but substantially fewer in number. Rock Ridge begins to shine in July when birds abandon territories in search of food with their young so it will be interesting to see how the year will pan out at the station.
Fieldwork has kicked into full gear as the action-packed month of June is just a week away. Our Louisiana Waterthrush surveys are nearing completion for the 2012 season. Soon I will be racking up the mileage while scouring the barrens for Prairie Warblers and other goodies in the southeast section of the park. It’s such a wonderful contrast to transition from damp mature forests to the hot and dry expanses of bedrock, poverty grass and junipers. Yesterday I found this Barred Owl in a wooded swamp about 40m from where my truck was parked on Salmon Lake Road. Barred Owls are easily the most common owl species in the area. Great Horned Owls are comparatively rare in the hardwood forests but are found with some regularity in mature mixed coniferous zones. Owl populations would be an excellent subject FBS in the future.
Louisiana Waterthrushes have been very scarce this spring, even more so than last year. The species was recorded at seven sites in 2010, our first year, but only evident at two sites so far in 2012. Fortunately, they are paired and probably nesting at the two sites. The steep sided stream corridors seem so empty without their voices.
Many species are well into their nesting cycles. While observing the Barred Owl I tracked a female Black-throated Green Warbler, which had just finished bathing in the swamp. After a bit of preening and some flitting it plunked itself into a fork at the main trunk of a young Yellow Birch. Raising binoculars to the spot revealed a surprisingly deep and bulky nest. The earliest nest record for this species in Ontario is June 5 so a nest with eggs on May 24 is quite early. This particular record is also somewhat unusual in its location in a deciduous tree species within purely deciduous forest. In Frontenac Provincial Park the Black-throated Green is more typically found in woodland with tall Eastern White Pine and/or Eastern Hemlock. However, a quick search of our point count data revealed that they are present, albeit in low numbers, within hardwood stands as well.
Below is a photo of habitat suitable for Golden-winged Warblers. This was taken just southwest of Westport, ON where there are many small, family-run farms with low-intensity agricultural practices. The presence of dense shrub cover at edges of property lines provides appropriate conditions for Golden-wings, which were designated as Threatened by COSEWIC in 2006. A total of six male Golden-winged Warblers were located yesterday morning with relatively little effort. The Frontenac Arch and the southern shield ecotone are important regions for the protection of this species. In these areas, the rugged terrain and shallow till have been effective deterrents to large scale/intensive agriculture, so far…..
Land O’ Lakes indeed! Frontenac Provincial Park lies at the southern tip of the great Canadian Shield with its astounding proliferation of lakes, wetlands and rivers. The map clipping above provides a glimpse of the difficult terrain here and also the number and distribution of lakes. The landscape is rich and beautiful but often very harsh too. The park has an impressive history – of miners, farmers and loggers who endured extreme hardship eking out a life here. The route I took this morning passes by abandoned homesteads and mines as well as the old log roll way at Hardwood Bay on Devil Lake. A century ago the land was mostly cleared and the air would have been filled with the sounds of men and women working the land. Decades of regeneration later, the area provides mature oaks, maples and hickories for troubled bird species, Cerulean Warblers and Red-headed Woodpeckers.
Very pleased to find that the Red-headed Woodpeckers have returned! Hopefully this means that they were successful rearing young last summer. I watched the pair fending off Common Grackles from a nest site and also observed the pair copulate twice. I’ll make a point to return to locate the nest later on in the season and hopefully get some footage of the young being fed at the nest.
I sought out this fantastic forest swamp for our ongoing project to inventory Louisiana Waterthrush habitat in the study area. This was a site that had not been visited before. I took the liberty of naming it Devil’s Swamp in my records. Northern Waterthrushes were present but no Louisianas today. This would be a high priority site for future monitoring, especially in years when the population is healthier in the region. Once again, Louisiana Waterthrushes are present this year at only a few sites in the region but we are also finding a dearth of unmated “wanderers”.
Great to be back in Frontenac this week! My first memorable observation of the season was of two black bears encountered along Devil Lake Road on an early morning commute – interesting start. This week I began revisiting stream and swamp woodland sites for Louisiana Waterthrush (Parkesia motacilla). This will be our third and final season of inventory and monitoring for this species of concern. In spring 2010 and 2011 we emphasized the maximization of coverage for potentially viable breeding sites in the study area. We have a handful of hitherto unexplored locations to check this year but most of our available time in May will be dedicated to historically occupied sites to procure assessments of breeding status in 2012.
These West Virginia Whites (Pieris virginiensis) have been faithful companions on my travels to mature forested ravines and swamps in the region. Once considered a Species at Risk, they remain quite rare, known to occur in only about 50 sites in Ontario. They are common in Frontenac Provincial Park on warm days in April and May. West Virginia Whites are threatened by habitat loss and the invasive Garlic Mustard (Alliaria petiolata), which is a close relative of their host plant, the Toothwart (Dentaria diphylla). Adults will lay their eggs on Garlic Mustard but the hatched larvae will not feed on the invasive plant and perish.
The birding was excellent this week thanks to the recent warm front. Cerulean Warblers were particularly numerous. Eleven males were counted en route to one of our Louisiana Waterthrush sites. Over the years I’ve amassed an impressive collection of hopelessly blurry photos of Ceruleans or the perches they left behind. This is the best I’ve managed to come up with so far – sadly. It was pleasing to find that Louisiana Waterthrushes have returned to the breeding site we first described in 2010! A pair has been detected here for three consecutive years, which makes this site in Frontenac Prov. Park one of just a few annual breeding locations in the region. High fidelity to these sites make them important “footholds” at the range limit where contraction and expansion can be marked. These Frontenac louies are true pioneers!