In addition to all the stream hopping, nest searching, colour banding and biothon-ing, we are also well into our third consecutive season of the Monitoring Avian Productivity & Survivorship (MAPS) program. Our three stations have been a wellspring of data and ideas for the FBS program and a fundamental monitoring scheme for measuring the health and viability of local breeding bird populations. We launched the stations in 2009 and were pleased to find high numbers of adults at the sites. However, unusually wet and/or cold conditions in late spring/early summer of that year and again in 2010 appeared to contribute to low productivity (nest success) for two consecutive breeding seasons. This has been backed up by an apparent high nest failure rate detected by our nest searching efforts in both years. We hoped that things would begin to turn around in 2011 but unfortunately our results from the first of seven visits this year indicates record low numbers of adults – not unexpected given the lackluster output of young birds into the population in the preceding two years.
Blue Lakes (BLAK)
We began the season on June 4 at BLAK and found a mostly quiet woodland – far from the exuberant activity of even a year ago. We ended the day having captured just 10 individuals, although four of these were returns from previous years, which gave us some encouragement. For comparison we captured 24 individuals here during visit 1 on June 8, 2010. Numbers were down for most species with Red-eyed Vireo, Ovenbird, Black-throated Blue Warbler and Veery being the most lacking.
Rock Ridge (RRID)
On the following day, June 5, 2011, we made our way to Rock Ridge in Frontenac Provincial Park. Once again, overall bird activity was considerably lower than in previous years, especially in the forest interior. A total of 10 birds were captured – again with 4 returns. This total is identical to that for visit 1 in 2010 but significantly lower than the 25 recorded in 2009. Black-and-white Warbler, Red-eyed Vireo, Scarlet Tanager and Field Sparrow are the species that seem to have declined here most heavily.
Maplewood Bog (MABO)
Our final stop for round one was to Maplewood Bog (MABO), which tends to be our busiest of the three stations. We captured 26 birds here during visit 1 in 2009, followed by 21 in 2010. After six hours of banding we arrived at, remarkably, yet another tally of 10 individuals!! We banded just four new birds and recaptured six returning individuals from previous years. The woods, once so abundant with thrushes, vireos and tanagers, were very quiet indeed.
Our data from the MAPS program and our other studies appear to indicate a widespread downward trend in forest bird populations in the FBS study area since 2009. Factors driving populations are highly complex so we won’t be sounding any alarm bells or hitting the panic button just yet. Also, we know that populations are subject to periodic highs and lows in sync with naturally occurring but variable weather phenomena. We expect (and hope) that bird numbers will be gradually restored following breeding seasons with more favourable weather. Speaking of weather, the MAPS program is very well positioned to shed light on effects of climate change on breeding birds at the landscape, regional and even broader scales. It is unfortunate that there are so few MAPS stations in Ontario as it would be instructive to compare regional patterns and trends in vital rates in anticipation of shifting climate “normals”. All of this being said, there is still six more visits to each station in 2011 and a great deal more to learn.