Friday, March 4, 2011
Yeah, I checked back in on the nest this morning. I approached from within the neighborhood across the street and was able to get these shots from a distance, and without having to approach the nest in the open any more than from a ways down the street. Even so, I'll be leaving them to it for a while now. There will be plenty of activity around that site, and I'll keep from aiming a big lens at them for a bit.
Besides, there are more signs of spring showing up at Lower Church Lake each morning. Today it was a pair of Cinnamon Teal.
They were mostly keeping to the far side, and a cloud bank had blocked the direct sun by that time, so prettier shots of Mallards and Red-winged Blackbirds were kept to a minimum. I find the Cinnamon Teal absolutely gorgeous. It was too bad the sun wasn't shining brightly today, I doubt this pair will remain there through to Monday. Even so, seeing this pair on the fourth is roughly five weeks ahead of when I spotted my first Cinnamon Teal last year! That means a lot more chances to find them again and get more shots to share. I checked eBird to see what the bar charts had to show for Cinnamon Teal presence in Jefferson County, and sure enough, the first week of March is what came back for a first week in the spring - so it looks like the first arrivals are right on time.
On the other hand, here is a bird that seems really early to me:
I have seen this bird twice, once on the 23rd, and again this morning. My shots on the 23rd were worse, the tail was in line with the body and gave no impression of size. That day however the bird was vocalizing, and didn't sound anything like a Common Grackle. It had a staccato type sound to it.
This time the bird was quiet, but was perched in the same tree before it lifted off for this flight. Both sightings have made me think Great-tailed Grackle on the site, but I always labor over those judgements after the fact.
For this one eBird is a little less helpful, in a bar chart comparison between Common and Great-tailed Grackles for Jefferson County, the chart shows Common Grackle sightings beginning in March, and Great-taileds picking up in April.
To get a bigger sample I expanded the charts to pull from Adams, Boulder, Weld, and Jefferson Counties. With that change Common Grackles show about the same arrival pattern, but for Great-taileds a new pattern emerges, they have a lower frequency, but it expands and becomes almost stable throughout the year.
My counties made me nervous though, Weld County is large, and it runs well out to the east from the eastern edges of Boulder and Broomfield Counties. So, just to see if it would make a difference I then swapped Weld for Broomfield County.
A slight difference, but the pattern seems to hold up.
Moral of the story....I have no idea. I do know that I had been concerned that my instinct was completely wrong. I certainly have more experience with Common Grackles than Great-taileds, but was fairly confident after seeing the bird a second time that it was a Great-tailed. My narrow view of just the Jefferson County birds last week had led me to believe that I was pulling out a bird that really shouldn't be around. With a species that is tough to distinguish in the field I tend to the conservative choice, or just let it go as a bird that couldn't be ID'd. This one had bugged me though. Birds can be out of place, if they weren't the Ross's Gull that visited Colorado this fall would have never been here. Even so, when I check a bird and find that there are no other records of the species in the county for another month I question myself first.
The explanation....I don't know, but Lower Church Lake lies about as close to the eastern edge of Jefferson County as possible. My best guess is that because Jefferson County extends to the south, (developed) and west, (higher - eventually reaching well up into the foothills), it is not ideal Great-tailed habitat. I recall reading that the species is slowly extending its range. Perhaps these sightings will become more common over time. Either way, I feel better knowing that at least a few of these birds are being found in the surrounding counties on a regular, if infrequent, basis.
2011 Count: 73