It’s been a tough Fall banding season: nights of hopeful anticipation followed by days of great disappointment…..repeated over and over again. It’s difficult to put your finger on “why”. The only consistency was the long stream of unseasonably warm, “great”, weather. A telltale indicator of this is a picture in the Hamilton Spectator – in the second week of November! – highlighting magnificent Fall tree colours. Usually you would look for this type of picture, and the phenomenon it is highlighting, a month earlier…at least. Although we had a few cold days (with frost at night) in October, we had temperatures in the mid- to high-teens right through the end of October and up to the end of the banding period on November 7th.
While we realize that banding numbers at an “inland” banding site like Ruthven, with no physical features to concentrate birds (like the shore of a big water body or desert), is a bit of a crap shoot – sometimes you’re lucky, sometimes you’re not – there are features that can fuel “hopeful anticipation”. For us, the presence or absence of wild grape clusters has proven to be a good predictor in the past several years (ever since Wild Grapes began to proliferate at the Ruthven site). This year we had a VERY good grape crop so, naturally, we were thinking that we would get lots of fruit eating species, especially Cedar Waxwings…but the capture of birds that feed on them was still low. In fact, there are still large clusters of grapes, untouched, which will possibly provide sustenance for overwintering bluebirds, waxwings and robins.
When I began to crunch some of the numbers, the results were even more disheartening. The average number of birds, in total, banded during the monitoring period over the past 15 years is 3, 297; our total this year was only 2,328 (969 below the average). And month by month our catch was below average: September: 793 vs 969 (-176); October – our biggest month of the year – 1277 vs 1972 (-695); and November: 258 vs 264 (-8).
And then, really wanting to get depressed, I looked at the numbers of various species captured and banded against the average going all the way back to 1998. We were below the average for flycatchers, kinglets, all thrushes, catbirds, many warblers, and many sparrows. We were above average for all vireos and a number of warblers….and Tufted Titmice (which are a relative newcomer). But when I say we were below average for a number of species, it masks the fact that we were WELL below average for common ones: Golden-crowned Kinglet: 41 vs 106; Ruby-crowned Kinglet: 120 vs 168; Yellow-rumped Warbler: 213 vs 318; Chipping Sparrow: 4 vs 41; Song Sparrow: 47 vs 151; White-throated Sparrow: 123 vs 230; Dark-eyed Junco: 143 vs 193. But the kicker was Cedar Waxwing: the average number banded in the Fall since 1998 is 215; the average since 2010, when Wild Grapes began to proliferate, is 520; this Fall we banded only 44!!
I wish I could tell you what the problem was but I just can’t make sense of it. I do know that, generally, in periods of “good” weather (warm, clear, dry) we tend not to catch nearly as many birds as in periods of “bad” weather (cold, overcast, wet). The common thinking is that birds on migration tend to “fly over” inland sites in their hurry to get south – making hay while the sun shines so to speak.But in October we tend to band good numbers despite good weather…. except this year.
We had a great grape crop…and fruit generally (eg, dogwood berries). But Cedar Waxwings (and thrushes and other fruit eaters) didn’t show up. There were reports that there were grapes everywhere in the area so maybe the birds were more spread out. Even so, a drop from 520 to 44 birds is hard to explain by a more diffuse food source.
Top Ten
1. American Goldfinch – 493
2. Yellow-rumped Warbler – 213
3. Dark-eyed Junco – 143
4. White-throated Sparrow – 123
5. Ruby-crowned Kinglet – 120
6. Northern Saw-whet Owl – 80 (as of November 7th; we’re above that total now – 87)
7. Blackpoll Warbler – 75
8. Red-eyed Vireo – 59
9. Black-capped Chickadee – 58
10. Magnolia Warbler – 50
Rick