Ontario Breeding Bird Atlas, Region 24 (Ottawa)
Region 24 (Ottawa) Report for 2005 (draft)*
by Christine Hanrahan
* This report is a draft only. We are still awaiting data from one square, and casual observations continue coming in, thus the figures given here are not final by any means. Furthermore, species such as Double-crested Cormorant, herons, terns and gulls are still being evaluated to determine correct breeding codes. Other species may be added or deleted depending on further review by the Region 24 committee and the Atlas Significant Species Subcommittee. Final results will be available at the main atlas website in 2006.
Remarkable results have come out of the last year of atlas work, building on the excellent results through 2004. Point counts were done in all squares, confirmations were bumped up considerably and the total number of species per square was greatly increased. In most cases, our criteria for considering a square complete was exceeded. Atlassers really outdid themselves and a core group not only worked in their own squares but spread throughout our region and into neighbouring regions to help out in all possible ways. A big Thank You to those who worked so hard in 2005, and to everyone who participated over the five years and contributed so much to the success of the atlas project.
Atlassing Results – 2005
Breeding evidence has been found for 182 species with a further 4 species requiring the input of the Atlas Significant Species Subcommittee for a final decision (they are included in Table 1 but listed in italics). Confirmed breeding was found for 161 species. Note that provisions exist on the Breeding Evidence Form, and therefore also in Table 1, for species that are heard only (Black-billed and Yellow-billed Cuckoos and Blue-winged and Golden-winged Warblers).
Confirmed breeding evidence can be tough to find for many species, with some simply eluding all attempts. For example, we were unable to confirm species such as Long-eared Owl and Northern Saw-whet Owl, found on 12 and 27 squares respectively, or Sedge Wren (15 squares) and Ruby-crowned Kinglet (19 squares), or a handful of others. The surprise is that we were able to confirm breeding for as many species as we did given the tremendous challenges this presents. Once again, it points to the skill and hard work of atlassers in this project.
Fortunately some species are much easier than others to confirm. Robins, Common Yellowthroats, starlings, Rock Pigeons, Mourning Doves, Song Sparrows and Red-winged Blackbirds are all quite accommodating!. Finding nests with young or eggs,, the ultimate in confirmed breeding evidence, is also relatively easy for somespecies but next to impossible for others. We have only one report of a Ruby-throated Hummingbird nest (18VQ19), although this species is confirmed on 19 squares.
Abundance estimates give a more accurate reflection of the numbers of breeding birds in our province than simply noting the presence of a species on a square. A species may be widespread but present in very small numbers. Alternatively, it may be restricted in range but relatively abundant within this range. Of course, knowing how many squares a species was found on is very important, but it is not the whole story. Point count data helped to fill in the gaps.
Sixty-three squares had 100 or more species. The highest total was 130 species in 18VR52, which also had the highest number of confirmations, a whopping 93 species.
Sixteen species were recorded in every single square, while 13 other species were recorded in 85 squares.
Our guideline for considering a square complete was 90 species per square west of Ottawa, 80 species east of the city, with 30 species confirmed breeding per square. Partial squares (those less than 50% the size of a full square) were to match or come close to figures set by the last atlas. In many cases the number of species and confirmations per square exceeded results from the first atlas, sometimes significantly. In others, results were astonishingly similar (see Table 2).
The habitats in our region are varied to say the least, from vast forests and wetlands, to small villages and towns, large urban areas, and the infamous corn belt east of Ottawa. Not surprisingly the lowest species numbers come from the agricultural areas, while those with high habitat diversity are the richest in terms of numbers of species. Yet even within the corn belt there are pockets of woodlands, streams, riparian zones, even small thickets along roadside ditches where nesting birds may be found, and then there are the sewage lagoons (the saving grace for many birds – and birders!).
The first record for this atlas of Blue-gray Gnatcatcher was recorded ( possible breeder) on 18VR13. Some of you will remember that this species was found on four squares, including VR13 during the last atlas (1981-1985). It has nested sporadically in the Ottawa area but this was the first record during the present atlas period.
Other species of note
The number of species present during this atlas but absent in the first form an interesting study. A more complete picture of the spread of these species in our area of eastern Ontario can be found by comparing with the 6 adjacent regions (Regions 20, 21, 22, 23, 25 and 26) and noting that in many cases similar increases are revealed. The explosion of Wild Turkey can be easily traced to the release of the species in this area over the last 10-15 years. The spread of other species may be attributable to range expansion (for example, Cape may Warbler), or the adaptability of a species to a wider diversity of habitats (Merlin). In some cases, the spread is less easily explained.
Sandhill Crane is an interesting example of a species once considered a very rare breeder in both our region and those adjacent. Twenty years ago it was absent from all 7 regions but during this atlas has been widely recorded in all of them (12 squares in our region, 3 with confirmed breeding). Merlin is another remarkable success story. It has been found on 43 squares compared to only one in the previous atlas. Not all species new for the atlas show similarly dramatic increases. Common Goldeneye, for example has been recorded from only three squares in our region, (two possible breeders and one confirmed – a brood found in a nest box). However, it has also been recorded from a numer of squares in neighbouring regions. Last atlas it was found on only one square (Region 26). It will be interesting to see if Common Goldeneye continues its spread as a breeding species into our region in the future.
Another notable species is Palm Warbler, recorded on one square (18VR62) as a probable breeder in the first atlas. It was not until 2004 that it was reported for this atlas (also on 18VR62). In 2005, Palm Warbler was again found in the Mer Bleue, this time in two separate squares, 18VR62 and 18VR52, both with confirmed breeding. Given the accurate reports and descriptions there is no doubt that at least 2 pairs of Palm Warblers bred this year.
Several other species, whether new for this atlas or not, are counted from only one square: Peregrine Falcon, Yellow Rail, Northern Hawk-Owl, Loggerhead Shrike, Gray Jay, Blue-gray Gnatcatcher, Northern Parula, and the species awaiting review by the Significant Species Subcommittee.
Many other species have substantially increased their range and can now be found on most squares. Common Raven is one such example. In the last atlas it was largely confined to the western part of our region, present on 24 squares but confirmed on only 6. Now it is easier to say how many squares it has not been recorded on (12). Interestingly, it is now common in Regions 22 and 23 although entirely absent in the last atlas! Of course, everyone knows that both Northern Cardinal and House Finch have spread far and wide in the last 20 years, and are now recorded from across the region.
On the other hand, quite a few species were found on significantly fewer squares than in the previous atlas. Last year we tried to emphasize the importance of searching for crepuscular and nocturnal species, and many of you took up the challenge, only to report limited success. The exceptions were Barred Owl which to date has been found on 41 squares, compared to 30 last time, and Eastern Screech-Owl whose numbers have remained pretty steady, even showing a slight increase (32 squares vs 27). However, one of our supposedly common owls, the Great Horned Owl was found on 74 out of 86 squares in the first atlas, but this time on only 49 squares. Looking at the provincial atlas map for this species it is easy to see how widespread it was in period 1981-1985 and how many gaps show up now. Northern Saw-whet Owl and Long-eared Owl both show quite a decline compared to last atlas. Another crepuscular/nocturnal species recorded on significantly fewer squares this atlas, is Whip-poor-will Found on just 35 squares this time, it was reported from 54 squares last atlas .It is probable that habitat changes account in part for the absence of this species, but other factors must surely play a role. It will be enlightening to see what results and conclusions the experts come up with once the provincial data has been analysed. Habitat change, range expansion and contraction, declining or increasing populations, all account for the differences we see between the two atlasses. In our region a lot of good habitat has been lost to development, particularly around Ottawa. In the twenty years since the end of the last atlas, thousands of acres of open land have been destroyed, woodlots have fallen, wetlands and waterways diverted, filled in or changed in some way. Encroachment of development on greenspaces creates habitat fragmentation, pressures from increased human usage, incursions of domestic pets from nearby subdivisions, and myriad other problems all of which displace the native avifauna. The atlas data can help map these changes in breeding birds and perhaps help stop future development into sensitive sites.
Table 1 lists the total number of squares a species was found on for this atlas and the last. For more information check out the species maps on the atlas website.
More News from 2005
The number of people who helped out in squares other than their own during 2005 was quite remarkable. These folk willingly completed point counts, helped upgrade breeding evidence, did lots of general atlassing, and in general filled in wherever help was needed or asked for. Every single person who participated in the atlas deserves recognition. But for going that extra mile in 2005 I’d like to recognize Marg Benson, Peter Blancher, Ludmilla Borshevsky, Peter Fuller, Colin Gaskell, Mark Gawn, Mark Hovorka, Paul Jones, Michael Kahn, Richard Killeen, Bernie Ladouceur, Bev McBride, Mick Panesar, Jack Romanow, Cameron Sangster, Langis Sirois, Jeff Skevington, and Kim Zbitnew. Thank you!
In 2004 we assumed responsibility for five squares from Region 25. Several atlassers continued working on their squares in 2005 and to these folk, many, many thanks: Ken & Ruth Allison, Mark Gawn, Jim Gillick, Richard Killeen, and Dick Mabee.
‘Owl Square Bashes’ were held on several weekends in April but despite some good weather few owls were heard, although those who ventured out had a good time anyway. Thanks to Mick Panesar for organizing and leading these outings.
We really emphasized completing point counts (PCs) for 2005. Atlassers were also encouraged to try their hand at them by Mike Cadman who removed some of the concern surrounding PCs by suggesting that although 25 PCs per square was the ideal, even 10 would contribute valuable data. Ten seemed a more manageable number than 25, but once atlassers found out how much fun they were to do, many carried on and did more. The end result is that most of our squares have at least 10 PCs, often more, the exceptions being the 5% squares which generally have fewer than 10 PCs.
More Information about the atlas can be obtained by checking the main atlas web site. The toll-free atlas number is 1-866-900-7100.
Atlas Volunteers 2005
As always we are supremely grateful to the volunteers who devoted so much time and energy to the atlas again in 2005. The following list includes registered atlassers, friends who helped out, as well as people who contacted us with additional observations: Ken Allison, Tim Allison, Ruth Allison, Ted Baldwin, Ron Bedford, Gord Belyea, Cliff Bennett, Lynda Bennett, Marg Benson, Ludmilla Borshevsky, David Britton, Richard Brouillet, Peter Browne, Gerhard Bruins, Emily Burton, Janet Castle, Dale Crook, Ron Curtis,, Erica Dunn, Peter Fuller, Anne-Marie Fyfe, Marcel Gahbauer, Colin Gaskell, Jessica Gawn, Mark Gawn, Carol & Alan German, Jim Gillick, Al Graham, Christine Hanrahan, Mark Hovorka, Roy John, Paul Jones, Michael Kahn, Anthony Keith, Rick Killeen, Bernie Ladouceur, Marc Latremouille, Rob Lee, Kathryn Lindsay, Dick Mabee, MacNamara Field Naturalists, Paul and Michelle Martin, Bev McBride, Joy & Ralph McGiffin, Mississippi Valley Field Naturalists, Dave Moore, Mick Panesar, Bev Peterkin, Eric Ridgen, Jack Romanow, Ghislaine Rozon, Cameron Sangster, Paul Schoening, Arnie Simpson, Dan, Chris and Shawn Simpson, Langis Sirois, Jeff Skevington, Adam Smith, Dave Smythe, Daniel St. Hilaire, Blair Stevens, Austin Taverner, Eve Ticknor, Sloane Watters, Laurie L. Wood, Kim Zbitnew, Eleanor Zurbrigg
Table 1: Region 24 Ottawa: Cumulative Results (2001-2005)
Species in bold are new for 2005. Species in italics are awaiting further review.
Table 2: Species totals and confirmations per square