Author: danderbyshire

The July-early August period of the Monitoring Avian Productivity & Survivorship (MAPS) season is important to our annual assessment of productivity rates. During this time a critical shift occurs from the main nesting period for adults (May-June) and the post-breeding dispersal/pre-migration period (July-August). Some species are still nest building and incubating – mostly late breeders (Cedar Waxwing, American Goldfinch) and those raising second broods or first broods after nest failure. We are able to sample the year’s productivity (nest success) for many species during visits 4-7 when the juvenile or hatch-year birds are first introduced into the population.

Blue Lakes (BLAK)

On July 7 we operated BLAK for the fourth session this season. We ended the day with 13 individuals captured, all of which were newly banded. Notable amongst the birds banded were four Ovenbirds, which have been relatively scarce this year, and two adult Yellow-throated Vireos. Only two of the birds captured were young birds, a Rose-breasted Grosbeak and a Hairy Woodpecker.

Visit 5 was completed on a calm, clear mid-July morning. We were a little shocked by how quiet it was as just three birds had been captured until the final net check when a young Black-capped Chickadee was extracted from net 12. The lone highlight of the record slow morning was our second-ever Pileated Woodpecker!

Maplewood (MABO)

Activity at MABO has been a little higher than at BLAK, although markedly less so than in previous seasons. We captured 22 birds on July 8, which was followed by a total of just 11 on July 20. We’ve banded a decent number of young birds during the two visits including individuals of Veery, Scarlet Tanager and Yellow-bellied Sapsucker, among others. Since we started in 2009, MABO has produced substantially more recaptures than any other station. So far this year we’ve recaptured 13 at BLAK, 13 at RRID and 34 at MABO.

Rock Ridge (RRID)

While MABO always seems to perform best of the three stations for adults in June, Rock Ridge typically outshines the others for dispersing adult and young birds in July and early August. A total of 13 birds were sampled on July 9, which was followed by a season-high total of 28 on July 19. This site is located on a high ridge along a peninsula that is bound by a large lake on three sides – attributes that naturally funnel birds on the move. An excellent diversity of species were detected and captured on July 19, which included a respectable number of young birds. Common Grackles, Red-winged Blackbirds and American Robins have been the primary species involved so far but this should changeover to warblers and other small passerines during visits 6 and 7, which are due in the next two weeks.

The third round of visits for the 2011 Monitoring Avian Productivity & Survivorship (MAPS) season were completed on June 27 (BLAK), June 29 (MABO) and June 30 (RRID). The weather in June has actually been rather normal and lacking in extended periods of unusual temperatures or precipitation – good for us and good for all the passerines raising young! A total of 17 (9 new, 8 recaptures) birds were captured at MABO during visit 3, the highlight of which was the second-year Sharp-shinned Hawk pictured above – a first for our MAPS efforts to date. Also of note was the recapture of five Veery from previous seasons, including three from our first couple of visits in June 2009.

The BLAK station was the “winner” of Round 3 as 25 birds (20 new, 5 recaptures) were captured here during the visit. All five recaptures were of birds banded earlier in the 2011 season. We banded a nice variety of species, including another male Black-throated Blue Warbler, a Yellow-rumped Warbler and a Hermit Thrush. The highlight though was the male Purple Finch extracted from net 7 around mid-morning – another first for our MAPS program! This species does occur regularly at all three stations but are so strictly attached to the upper canopy that they will always be only rarely captured.

Weather at RRID was calm and clear with pleasant temperatures. A total of 17 birds were sampled by our mistnet array (15 new, 2 recaptures). We recaptured a Field Sparrow that was originally banded on June 20, 2010 as an After second-year male. It’s becoming clear that the return rate of adults is very low at RRID, especially compared to MABO. Habitats and species composition differ greatly between stations, which will certainly present some interesting topics for further study once a few more seasons of data are compiled.

Here is a quick chart that describes an apparent decline of the adult population at all three stations since 2009 (Only 2010-2011 for BLAK). The graph was generated using total captures (newly banded birds and recaptures) for visits 1-4 by year and station. It would be such a tremendous resource if we had more MAPS stations across Ontario to facilitate local and regional comparisons of vital rates. Unfortunately, in marked contrast to the United States, participation in Canada and in Ontario has been very low. The development of a coordinated and standardized effort to monitor breeding bird demographics in the province would be a major asset for biologists to detect and understand forces affecting landbird populations – now more than ever with advancing climate change.