After Friday’s big fallout on the Eastern Promenade, my birdwalk group on Saturday morning headed there as well. Interestingly, very few sparrows – or anything else – was present in the brush. Upon returning to the store, I downloaded the radar, and it showed what appears to be a great flight, but a great flight of birds heading out – and little coming in. Do you see how much was moving on the 10:00pm and 1:00am radar images?:

As opposed to the relative paucity of echos on the 5:00am image:

I interpret this to mean lots of birds left the area – and our “ground-truthing” on the birdwalk certainly reflected that. (Luckily, the walk was still a smashing success thanks to the Semipalmated Sandpipers: nearly twice as many – about 1,500 – were roosting on the rocks and the seawall a mere 15-20 feet away! Quite a spectacle. An early – and molting – Dunlin joined the group, as well)

Saturday’s fog never did burn off, and continued well past sunset. A weak, and dry, cold front finally passed through overnight, but the winds didn’t switch the to northwest until around 2:00am. (I use this NOAA page to see what winds were over the last 24 hours)

The radar from last night and this morning shows relatively little. Here are the 10:00pm, 1:00am, and 5:00am images. (Ignore those patches of bright reds, oranges, etc – that’s some sort of clutter).

So, there seemed to be little on the move last night. But, let’s look a little closer to be sure. In addition to the images that I have been including in the blog – these are the “reflectivity” images (Essentially, it means there’s something in the air) - we then check the “velocity” image, to see if this stuff is birds. Take a look at the Velocity Image from 3:00am on the big flight of Thursday night/Friday morning:

Things are moving from the NE (represented by the blues and greens) to the SW (represented by yellows and oranges). This is an expected direction of migrants on a W or NW wind at this time of year. Therefore, we can conclude that this is mostly, if not all, birds (bats and insects could also be part of the return).

Then, last night, although we see there were returns on the radar (see above), a check of the velocity image shows a SW to NE movement. In the fall, our birds don’t move in this direction at night, so the radar was not picking up birds. Maybe it was picking up the fog and light mist falling ahead of the approaching cold front?

So, last night we saw little activity on the radar, and that radar activity didn’t seem to represent birds. But luckily, I look at the radar AFTER I go birding. Otherwise, I probably would have looked at those images and gone back to bed. Instead, I was at Sandy Point at dawn once again, seeing if anything had moved last night and wandered over Casco Bay.

Apparently, they had, as a decent flight was enjoyed. Not huge numbers of birds, but very good diversity (14 ½ species of warblers, for example, counting the two subspecies of Palm Warblers) and a good mix of early (first Pine Siskins of the season here) and late (Northern Waterthrush). Complete list and totals below.

So, we have learned that radar-birding is not infallible! Of course, this is assuming that I am interpreting things correctly – which certainly may not be the case. (Many thanks to my friend David at woodcreeper.com for helping along this radar-greenhorn!) Either way, birding without binoculars – or even daylight – from the comforts of a soft, cushy office chair certainly doesn’t make up for being out in the field, enjoying a beautiful sunrise. Besides, I’ll get some sleep in January!

For more information, here's a good FAQ from Air Sports Net.

Meanwhile, migration doesn't occur only at night. A number of birds move during the day. We know hawks do, but so do some passerines. During my one-hour of hawkwatching in front of the store (8 raptors, despite warm and very blue skies, making very high birds very tough to find), I noted some diurnal migrants as well: 11 Double-crested Cormorants, 1 Ruby-throated Hummingbird, 21 Blue Jays, 1 Red-breasted Nuthatch, 4 American Robins, 6 Pine Siskins (a LONG overdue addition to our store's Yard List; #114!), and 14 American Goldfinches. Why do some passerine migrate during the day (finches, for example), while most migrate at night? Good question!

But, enough science for now - it's a weekend afterall. Therefore, I'll leave you with a little entertainment. Check out this amazing video of displaying Red-capped Mannikins from South America doing the moonwalk!

And, the totals from this morning:

Location: Sandy Point Beach, Cousin's Island, Yarmouth
Observation date: 9/23/07
Notes: 6:24 to 8:45 am. Weak, dry cold front passing after dark,
clearing out fog. Lt-mod NW developing by 3-4am, and lt WNW with clear
skies at dawn. 286 Unidentified.
Number of species: 55

American Black Duck X
Greater Scaup 1
Common Eider X
Common Loon 2
Double-crested Cormorant X
Great Blue Heron 1
Laughing Gull 2
Ring-billed Gull X
Herring Gull X
Great Black-backed Gull X
Rock Pigeon X
Mourning Dove X
Belted Kingfisher X
Red-bellied Woodpecker 1 Likely individual that has been
frequenting feeders on Cousin's Island for about 2 years now.
Downy Woodpecker X
Hairy Woodpecker 3 One high fly-over, one low fly-over, and one
"thinking about" flying over.
Northern Flicker 8
Eastern Wood-Pewee 3
Red-eyed Vireo 11
Blue Jay 19
American Crow X
Common Raven 2
Black-capped Chickadee 36 Beginnings of a flight?
Red-breasted Nuthatch 10 The flight continues
Brown Creeper 4
Carolina Wren 1 Singing from mainland
Ruby-crowned Kinglet 1
Gray Catbird X
European Starling X
Cedar Waxwing 24
Nashville Warbler 2
Northern Parula 2
Magnolia Warbler 1
Black-throated Blue Warbler 2
Yellow-rumped Warbler 18
Black-throated Green Warbler 9
Palm Warbler 1
Palm Warbler 1
Bay-breasted Warbler 1
Blackpoll Warbler 105
Black-and-white Warbler 1
American Redstart 4
Northern Waterthrush 1
Common Yellowthroat 2
Wilson's Warbler 4
Chipping Sparrow 3
Song Sparrow 2
White-throated Sparrow 30
Dark-eyed Junco 5
Northern Cardinal X
Bobolink 4
Rusty Blackbird 1
Purple Finch 11 flight continues
Pine Siskin 2
American Goldfinch 3

This report was generated automatically by eBird v2(http://ebird.org)