Monday, 30 April 2012

Amazing foraging behaviour by Hermit Thrushes

When I got home from work today I came inside and noticed a Hermit Thrush on my lawn.  The bird appeared to be shivering, which I thought was perhaps the cold weather (it was about 5 degrees Celsius).  However, I quickly realized the whole bird wasn't shaking but it was just very quickly tapping the ground with one foot.  I watched the bird (and noticed another Hermit Thrush doing the same thing) for about 45 minutes off and on.  I remember seeing the same behaviour once before at Bird Studies Canada Headquarters by a Semipalmated Plover and Ron Ridout at the time told me it was a foraging behaviour used to draw prey up to the surface.  I've heard second hand that Wood Turtles actually employ a similar technique!

Anyways, I did some searching and found this paper from the Wilson Bulletin that documents the behaviour in some of the other Catharus thrushes and also suggests that the "foot quivering" is a foraging behaviour - something that seems well supported by the video I took:

The Birds of North America Online account for Hermit Thrush also references "foot quivering" as both a foraging technique and an aggressive behaviour between birds.

Sunday, 29 April 2012

More from Pelee Island

Spent most of today again on Pelee Island with Ken.  We racked up another decent list considering the persistent cool temperatures and north/east winds putting a damper on migration.  New birds for me for the year were Sora (Fish Point first thing), Ovenbird (singing at Sheridan's Point), Black-and-white Warbler (along west shore road), and Red-headed Woodpecker (along west shore road).  You can have a look at the full eBird checklist for the day.

The highlight of the day was again one of the Yellow-throated Warblers that have been present since Ken arrived.  Ken heard the second one just before we saw this one at the pump house:

Here are some other photos of actual birds from the island today.
You know it's slow when...

Some nice and close Red-breasted Mergansers today

Ken claims there are "lots" of pheasants this year but I didn't see that many

Decent numbers of Hermit Thrushes this weekend

A few vultures around

A woodcock camouflaged with its surroundings

young eagle

And a few non-birds:
Fox Squirrel

Fair numbers of Question Marks and Red Admirals today

Syrphid to identify...

Got a couple more shots from the plane too:
Middle Point

Lighthouse Point and Scudder

Point Pelee

I'm back on solid land so hopefully things don't get too crazy this week...

Saturday, 28 April 2012

Welcome to the Island

I made a quick trip down to Pelee Island to visit with Ken and do some birding for the weekend.  As expected based on the weather the birds have been slow but lots of new stuff for me for the year (about 30 year birds in the last two days).  The best bird was one of the Yellow-throated Warblers that Ken has had near his cottage for the last few days.  Here's our eBird checklist for today.  Be sure to check out Ken's blog to follow sightings on the island this spring.

The ferries that normally service Pelee Island are both broken down/ being maintained so right now service is only by plane, which was actually quite a nice and quick (15 min!) way to get to the island.  I took advantage of the flight and snapped some pictures of the island from the air.
View of Essex Sewage Lagoons from the air

Lighthouse Point (NE part of island)
trail at Lighthouse Point (summer)
the lighthouse (summer)
Lighthouse Point from the air (Point Pelee in the distance)
Sheridan Point and the Pelee Club from the ferry a couple years ago
The municipal campground (centre of east shore of island)
Middle Point (Brandon Holden's least favourite spot) in the distance
West dock, where the ferry would normally drop me off!
Fish Point sign (SW part of island)
Fish Point from the air

Fish Point interpretive sign
 And I couldn't resist some Pelee Island scenery from a couple summers ago:
Lightning over Lighthouse Point

Sunset from Lighthouse Point
 And a Pelee Island post wouldn't be complete without a Fox Squirrel from the island today:

 With a little luck I'll have some bird pics to post tomorrow!

Saturday, 21 April 2012

Guide to spring arrival dates in Ontario

*: I originally posted this in April 2012 using 1900 to 2011 data. I have since updated everything to include up to the end of 2013.*

I've wanted to put something like this together for a while now but it wasn't until I read the "Changing Seasons" piece in Volume 65 Number 3 of North American Birds that I had a good way to do it.  So what is it?  Following this short introduction you'll find a list of 198 of Ontario's fairly common birds and the dates you can reasonably expect to find them returning.

Background: in the article I mentioned above, Marshall Iliff, Brian Sullivan, and Chris Wood (AKA eBird HQ) proposed that we should start using 20% of the peak arrival frequency for a given species to indicate the day that a species arrives on a broad front (I'll refer to this day from here on out as the "mass arrival date".  The eBird team showed that this is really a good measure of arrivals since it is largely independent of outliers (exceptionally early individual birds), independent of sampling effort (since it is based on percentages of checklists, not raw number of checklists), and adjusted for species' rarity. Email me if you want a scanned copy of the article.

Methods: I went through the eBird frequency graphs (for all data years 1900-2013) for each species reported in Ontario. Frequency is a common statistic eBird calculates - it is the percentage of checklists reported for a given date/location which have a positive observation for a given species.  I didn't include species that are very rare in Ontario during spring migration, species which don't show an appreciable widespread seasonally predictable change in frequency (i.e. resident and irruptive species), or species which are more frequently encountered during the winter season and just decrease through spring migration (i.e. they don't show a spring migration spike in frequency).  That left me with 201 species.  For each of the 201 spring migrants I collected the date and value (frequency) of the spring migration peak and then calculated what the mass arrival date frequency would be and what date the average mass arrival date in Ontario is (Figure 1).  For species which overwinter in parts of Ontario I corrected for the "winter frequency" by calculating the mass arrival date as:

M = 0.2 X (P - W) + W

M = mass arrival date
P = peak arrival date
W = winter frequency

Results: Well, first of all to most of you this information won't be new, but I think it is interesting to put some hard numbers to things.  Keep in mind when looking at the results that these results show the average date that the species arrives on a relatively widespread front across Ontario.  So, the actual date will obviously be earlier along Lake Erie but later in Thunder Bay - interpret accordingly.  Before the final results, here's a neat figure showing the number of species arriving en masse per week during the course of spring migration.

OK, here are the results, now get out there and find some spring migrants and be sure to report your findings to eBird so we can compare how advanced (or not) this year has been!

02 Feb -   Horned Lark
05 Feb -   American Crow
20 Feb -   Redhead
26 Feb -   Gadwall
Northern Pintail
European Starling
28 Feb -   Tundra Swan
American Wigeon
02 March -   Snow Goose

Canada Goose
Ring-billed Gull
03 March -   Mallard
Lesser Scaup
Red-breasted Merganser
American Coot
04 March -   Cackling Goose
Hooded Merganser
Red-winged Blackbird
House Finch*
07 March -   Red-necked Grebe

Common Grackle
08 March -   Ring-necked Duck
09 March -   Horned Grebe
Sandhill Crane
10 March -   Ross's Goose

Eurasian Wigeon
Northern Shoveler

Green-winged Teal

American Robin
11 March -   Red-shouldered Hawk
Little Gull
12 March -   American Woodcock
13 March -   Merlin
14 March -   Turkey Vulture
Northern Harrier
Song Sparrow
16 March -   Eastern Bluebird
17 March -   Pied-billed Grebe
18 March -   Wood Duck
Golden-crowned Kinglet
Eastern Meadowlark
Brown-headed Cowbird
20 March -   Red-throated Loon
21 March -   Great Blue Heron

Rusty Blackbird
22 March -   American Kestrel
25 March -   Northern Flicker
Eastern Phoebe

Brown Creeper

Winter Wren

Fox Sparrow
27 March -   Blue-winged Teal
28 March -   Pectoral Sandpiper
Belted Kingfisher
30 March -   Dark-eyed Junco
31 March -   Wilson's Snipe
01 April -   Bonaparte's Gull
02 April -   Double-crested Cormorant

Tree Swallow
03 April -   Great Egret
Yellow-bellied Sapsucker
Field Sparrow
Vesper Sparrow
04 April -   Osprey
06 April -   Common Loon
Sharp-shinned Hawk

Greater Yellowlegs
07 April -   Cooper's Hawk
Hermit Thrush
08 April -   Lesser Yellowlegs
Purple Finch
09 April -   Caspian Tern
10 April -   Black-crowned Night-Heron
13 April -   Louisiana Waterthrush
Pine Warbler

Swamp Sparrow
14 April -   American Bittern
Forster's Tern
Ruby-crowned Kinglet
Eastern Towhee
Savannah Sparrow
15 April -   Surf Scoter
Barn Swallow
Chipping Sparrow
American Goldfinch
16 April -   Broad-winged Hawk
Brown Thrasher

Yellow-rumped Warbler
White-throated Sparrow
17 April -   American White Pelican
Northern Rough-winged Swallow
18 April -   Virginia Rail
19 April -   Purple Martin
20 April -   Cliff Swallow
21 April -  
Yellow-throated Warbler*
Worm-eating Warbler*
22 April -   Black Scoter
Upland Sandpiper
23 April -   Willet
24 April -   Green Heron
Spotted Sandpiper
Common Tern

Bank Swallow
25 April -   Long-billed Dowitcher
Blue Jay
26 April -   Solitary Sandpiper
Blue-headed Vireo

Blue-gray Gnatcatcher

Palm Warbler
27 April -   Wilson's Phalarope
White-eyed Vireo

House Wren
Marsh Wren
Northern Waterthrush
28 April -   Sedge Wren
Grasshopper Sparrow
30 April -   Common Gallinule
Chimney Swift
Red-headed Woodpecker
American Pipit

Black-and-white Warbler
Nashville Warbler
Kentucky Warbler
Black-throated Green Warbler
01 May -   Eastern Whip-poor-will
Warbling Vireo
Wood Thrush

Gray Catbird

Blue-winged Warbler

Orange-crowned Warbler

Hooded Warbler
Lincoln's Sparrow
White-crowned Sparrow
Rose-breasted Grosbeak
02 May -   Ruby-throated Hummingbird
Least Flycatcher
Eastern Kingbird
Yellow-throated Vireo

Golden-winged Warbler

Prairie Warbler
Blackburnian Warbler
Orchad Oriole
Baltimore Oriole
03 May -   Great Crested Flycatcher

Prothonotary Warbler
Common Yellowthroat
Northern Parula
Black-throated Blue Warbler

Yellow-breasted Chat
Clay-colored Sparrow
Scarlet Tanager
Indigo Bunting
04 May -   Black-bellied Plover
Semipalmated Plover
Least Sandpiper
Swainson's Thrush
Cerulean Warbler
Magnolia Warbler
05 May -   Cape May Warbler
06 May -   Least Bittern
American Golden-plover
Short-billed Dowitcher

Black Tern
Gray-cheeked Thrush
American Redstart
Kirtland's Warbler
Summer Tanager
07 May -   Common Nighthawk
Tennessee Warbler
08 May -   Ruddy Turnstone

Black-billed Cuckoo

Philadelphia Vireo

Red-eyed Vireo
   Connecticut Warbler
   Bay-breasted Warbler
Canada Warbler
Wilson's Warbler
09 May -   Semipalmated Sandpiper
Cedar Waxwing
10 May -   Yellow-billed Cuckoo
Eastern Wood-pewee

Acadian Flycatcher

Blackpoll Warbler
11 May -   Brant
12 May -   Olive-sided Flycatcher

Willow Flycatcher
Mourning Warbler
13 May -   Yellow-bellied Flycatcher
15 May -   White-rumped Sandpiper
17 May -   Red-necked Phalarope
18 May -   Whimbrel
20 May -   Red Knot
Alder Flycatcher

*these species are barely calculable due to a pretty weak peak

Anyways, I hope you find this information interesting/helpful.  Please let me know of any errors you see.  It will only get better as more eBird data comes in.

Last updated March 1, 2014.

Sunday, 15 April 2012

Scissor-tailed Flycatcher

Wouldn't you know it, we get a weekend with lots of south winds and I am stuck in a classroom attending a course all day Saturday and Sunday.  Well, I managed to finish early today and headed straight for the Scissor-tailed Flycatcher that was reported yesterday by Terry Sprague, near Demorestville.

When I arrived I was told by the friendly lady who owns the property the bird was south across the field by the small lake and I was welcome to walk across!  After walking across the field I quickly saw the bird - beauty! Also got my first of the year Swamp Sparrow here, bonus!  Here's the full eBird checklist and some photos:

I am pretty sure this is an adult (definitive alternate) male.  Definitely a male by the bright red underwing and the large notch on the outer primary (P10).

Friday, 13 April 2012

Good migration conditions tonight

Sorry it's been so long since the last post.  I'm working on a couple things that I should be able to put up on the blog soon...

In the meantime there was a link posted on the Frontiers of Identification list serve for this awesome wind visualization map.  It is a pretty nice simple look at the current wind patterns in the US, very handy for figuring out whether it will be worth looking for new arrivals the next day or so. 

As for tomorrow, I'd say it should be good....! Here's the current windmap (better if you go to the site and see the moving version):

You can see there's a nice conveyer belt of south winds coming right up from Texas and up the Mississippi flyway.

The current radar shows lots of bird movement across the entire eastern US (the green blobs around the radar stations are birds, the blockier yellowish blobs in the midwest is precipitation):

eBird did a good story recently about interpreting weather RADAR for looking at bird migration, check it out!

PS, way to go Ontario eBirders, we're sitting in third place for number of checklists submitted for April (although Texas is catching up)!