Saturday, December 11, 2010

More than a glimpse...

Bird banders generally expect the rewards from band returns to be few, far between and more "vignette" than "mini-series", but within months of receiving a band on South Padre Island (SPI) in Fall of 2009, Joe's Hag began sharing more of her story than could be told from that first encounter.

That day, her weight and size told us she was a "she"; her plumage indicated that she was at minimum in her third year of life...and the long history of banding peregrines on SPI suggested strongly that she was a tundra peregrine. But from where exactly had she come? And where was she going? Had she bred successfully the previous summer? Would she survive the remainder of her migration, that winter and the subsequent return trip to the breeding grounds.

She did survive, produced 4 young, and we confirmed our suspicion that she is a tundra peregrine. In July 2010, she was captured again - this time in the Canadian High Arctic on the Melville Peninsular. She was fitted with a GPS satellite transmitter, and we "watched" as she foraged up to 40 miles from her eyrie, and on occasion remained more than 20 miles away from her nestlings for as many as 36 hours, except for brief visits presumably to deliver prey.

The male paired with Joe's Hag feeds a Lapland Longspur to 4 nestlings

In the latter half of September, we watched further as she left her breeding territory traversing Southampton Island and much of the Hudson Bay, presumably intent on reaching the Texas Gulf Coast where she'd been captured 11 months earlier. But Joe's Hag, it seems, had other ideas in mind...bearing SE from the Churchill shelf, she made decisively for Florida never coming closer than 1000 miles from Padre resulting in 2 entirely different migratory routes south in as many years.

Via Florida rather than Texas

Five weeks and over 5100 miles after leaving her breeding territory, Joe's Hag arrived on her wintering territory in northern Colombia. With a little luck, we'll watch her fly north and see her once again at the cliff on which she breeds.

Alastair


Friday, December 10, 2010

A summary for Scott

Few would likely argue that a band fixed to the leg of a bird is a cause for worry by those who band birds...but attaching a satellite transmitter to a bird is a different matter. Yes, guidelines exist that help to resolve the conundrum, and good arguments can be made that do or don't tip the balance in favor of securing a tracking device to a bird that migrates several thousands of kilometers twice annually.

Banded Peregrine (Todd Kemper)

Most reasoning rests on the trade-off between risks that accrue for the individual and the benefits that can applied to the population...but the "recipe" that ultimately governs our insights into both obligates the use of a sufficient number of individuals - i.e. go big or go home.

Peregrine with PTT (V. L'Herault)

Some time ago a colleague interested in what effect the Deepwater Horizon oil spill may have on Peregrine Falcons that migrate through the Gulf of Mexico with millions of songbirds, shorebirds and waterfowl asked me for a summary of the tracks for peregrines that we've followed.

The following southern migration tracks of 12 individuals hint that the Gulf Coast of Louisiana, Mississippi and Alabama receives a high proportion of the tundra peregrine population migrating to wintering areas further south, and the coast serves as a "decision point" with some birds simply choosing to overfly the Gulf, while others choose an eastward route through Florida or a westward one through Texas. While most (7/12) opted for a route that took them directly into the Florida peninsular, the remaining 5 spent 1-3 days along a 400 mile section of the Louisiana, Mississippi and Alabama coastlines.

Southern migration tracks of 12 tundra peregrines

Any effect of Deepwater Horizon on Peregrine Falcons remains unknown, but two organizations (the Peregrine Fund and Earthspan) have partnered to study the issue.

Alastair

Wednesday, September 29, 2010

Joe's Hag Heads South

Joe's Hag left her breeding cliff in the 3rd week of September and started south for a yet-to-be-determined wintering location somewhere on the South American continent...maybe through Padre Island in the middle of October again as she did last year.

Southward, first stop South Hampton Island

If success is measured in terms of life-time reproduction, 2010 was a pretty good year for Joe's Hag and the male (24 C) with which she raised 4 young. Some pairs fledge a chick or two...for many breeding aged adults the long journey north is just a long journey north...

For some, one storm interrupts a breeding attempt completely

However, if prey is abundant and the weather cooperates, providing for and producing 4 well-fed offspring is routine for an experienced pair of breeders...and from the relative safety of an eyrie that overlooks any prey-rich landscape, hatch year birds need only to eat whatever is brought to the nest ledge to roll the dice in their favor.

The landscape below Joe's Hag's cliff (photo B. Robinson)

Alastair






Saturday, September 11, 2010

"Crews-in"

Margins for Peregrines breeding in the Arctic are narrow…in some years, certain individuals are too narrowly restricted and some of what’s supposed to happen just doesn’t.

Partially hatched chick at abandoned site

This breeding season is all but over; day length and sub-zero temperatures will soon urge breeding birds and, in some cases, their fledged young to leave the Arctic and fly south to their Austral wintering ranges throughout South America.

Future recruit?

Every spring our field crews arrive on the Arctic breeding grounds and try to follow every circumstance as each pair of breeding birds tries to replace themselves and more. We use every voyeuristic tool and trick we can think of to sneak a peak…bands, blood, cameras, satellite tags, feathers, rulers, scales, pencils, paper, rain gauges. But bands don’t go on and wings can’t be measured nor migratory routes traced without snow machines, quads, boats, snow pants, sunglasses, hot tea, rain gear, wrenches, twine, a place to sleep and help when things just won’t go your way. Once in every while, we actually do get a glimpse and gain a little insight, but it’s of no consequence if not summarized, written down and dispensed in ways that are useful.

None of this happens without good people.

The Rankin Crew: Frankie, Poisey, and Alex

Steensby Inlet (Baffin Island) Crew: Theo (AF missing)

Igloolik Crew: Matt, Barry and Mike (missing)

Mark Prostor (Rankin and Igloolik)

Alastair

Saturday, September 4, 2010

Joe's "Hag"

In anticipation of the start of outward migration in a week or two, I thought I'd kick things off by telling you about Joe's "Hag". Hatch year Peregrines on migration are raw, unruly and almost always looking for a meal...they’ll take a run at anything that has a meal or might be one. Haggard birds are elusive and discriminating…each potential meal, it seems, is cautiously assessed before it becomes one.

Dowitcher remains on the flats of Padre Island

At the eyrie, with young to protect, the demeanor of an old “Hag” is best described as "in-your-face" – literally on occasion. So it was without much surprise that this summer Mark Prostor was able to trap a resident female defending 3 young at her nest ledge on the Melville Peninsular near Igloolik in the High Arctic.

Unlike our study area near Rankin Inlet (550 miles to the south), there had been no previous effort made to trap and band adult peregrines in the Igloolik study area, so it was with excitement that Mark found the bird already marked with a USFW band…someone had already trapped this female elsewhere. But who…and where?

An "Old Hag"

Unbelievably, Mark recognized the number series on the band – he’d used the same series the previous fall while trapping migrants staging on the Gulf of Mexico at Padre Island, Texas. We wondered if the answers t0 “who” and “where” would be found in Mark’s field book – his field notes showed that the bands he had used were close (within 5), but he’d not been the one to trap the Hag on Padre…at least we now knew “the where”.

We e-mailed the band ID to Gregg Doney who directs the fall peregrine survey on Padre Island to let him know another Padre bird had been recaptured in the Canadian Arctic – he replied;

Great job, the connections between Nunavut and Padre are growing!

Actually, this was Joe Snyder’s first Padre bird. I remember the scenario very well, because it was Joe’s introduction to the flats (15-OCT-09) and he experienced the “black and white” of behaviors often seen.

We (Joe, Bud, myself) were just south of the silver well-head, after spending about an hour on a Hatch Year male that would never close the 10 foot gap on the trap. We finally called it quits and were in a group, picking up and going over landmarks when an adult female bumped from the flats 250 yards downwind.

I was skeptical, because the Hag seemed skittish and had probably watched our entire routine with the male…but even with 3 ATVs in the area, she came right in and bound.

Joe then worked her to hand.

Joe and 1947-00531 on Padre 2009-10-15

1947-00531 and nestlings on the Melville Peninsular, NU 2010-08-09

Alastair

Tuesday, June 22, 2010

"Blue's demise"

Three weeks ago (May 28/29) Blue roosted near the Botanical Gardens on the west end of Roatan Island, Honduras before over flying Glover Reef making landfall in Belize 30 miles south of Belize City on May 30.

West end of Roatan Island, Honduras

Glover Reef

From there he over flew the Gulf of Mexico making landfall just south of Brownsville, Texas on the Mexican side of the Rio Grande River by June 2. A total of 1150 miles in 4 days.

Blue's route May 28 - June 2

On June 1, Mark Prostor and I checked Blue's territory and found the site still occupied by only a lone female. No doubt that he would be one of the late arriving breeders, but not so late that he could not successfully raise a brood of young.

By June 5, Blue had added another 1000 miles and was located near Cunningham, Kansas. He'd been traveling 300 miles daily for more than a week, and early in the evening on the 5th, Blue found a well-treed farm yard surrounded by irrigated crop land.

Roost location June 5/6

Based on his rate of travel, I anticipated that his next set of GPS locations due 3 days later would show Blue's location to be near Lake Manitoba, and less than 700 miles from his breeding territory. Surprisingly, the location data on June 9th indicated little movement which could easily be explained by GPS error alone...worse yet, the activity sensor indicated that the PTT had not moved in 3 days.

Data we received on the 12th confirmed that the PTT was stationary, but our field crew surveys on Baffin Island, the Melville Peninsular and Rankin Inlet left little time to track down what had happened to Blue.

No activity from June 5 to 12 near Cunningham, KS

Once back in Edmonton, I contacted Kerri Steffen at Cunningham Courier. who passed me along to a couple of biologists with the Kansas Department of Wildlife and Parks. Over the next couple of days Mark Van Scoyoc, Ken Brunson (both with KS Wildlife and Parks) and I exchanged information about Blue's location data, PTT frequency, search strategies, possible outcomes and the area around the farm yard.

Yesterday morning, I received the following message from Mark...

...we found your transmitter and the remains of the male peregrine. Just a wing was left of the bird itself. Ken will be sending you some photos...

And a little later, this one from Ken (along with the images below)...
...I brought up our bat biologists who were using a radio receiver related to some transmittered bats about an hour away from us but, unfortunately, we could not get their radio to encode your frequency. It turned out that the transmitter and wing were not all that hard to find after all . Jeff Miller was the one who discovered it mixed in with some branches on top of a shed roof. Glad we were able to find it. Our best evidence is that Blue met its demise from the talons of a Great Horned Owl which had already claimed the farmstead as its territory...
Looking south to the farm yard

The yard and "starting point" for the search using PTT locations

Jeff Miller finds PTT and wing on the roof of a shed

The shed

PTT and Blue's wing

My thanks to Mark and Ken for their time and resources, and to Whitney Haskell, Jeff Miller, Mike Rader and Murray Laubhan. Their efforts have provided invaluable insight into the events that lead to Blue's demise.

From L to R Whitney Haskell, Jeff Miller and Laurie Yasui

The field crew (Alex Anctil, Poisey Alogut and Frankie Jean-Gagnon) currently working at Rankin Inlet report that a male and female are resident at the site where Blue bred last year, and that a clutch of 4 eggs was completed by June 21.

Alastair

Friday, May 28, 2010

No sign of Red...Blue still in the tropics

Blowing snow, poor visibility (fog) and gusts up to 50 mph have kept us from going out today - so I thought I'd get a note posted to the blog. Mark Prostor and I visited Red's territory on May 22, and found the resident female and an unbanded male. The nest ledge used last year is drifted in with about 12 feet of snow. To date, only about 1/3 of the sites in the study area (about 36 in total) are occupied.

Blue opted for the "safe, but longer" route having circumnavigated the Andes by bearing north until he reached the Venezuelan coast, then flying westward to Panama. His most recent location has him only 7 degrees further north than he was on May 13. Each degree of latitude is about 69 miles, so he is only 500 miles further north than he was 2 weeks ago despite having traveled more that 1900 miles.

At this rate, he will undoubtedly be one of the late arriving breeders (certainly later than he was last year) - but his timing may yet prove to be to his advantage. His territory remained unoccupied as of May 26.

Route to May 28

More next week...Alastair

Friday, May 14, 2010

Hmmm...decisions, decisions?

This week Blue traveled another 535 miles (since the May 7) for a cumulative distance of over 2800 miles thus far. Surprisingly he once again veered from the expected NW bearing to one that is now taking him NNE. If he maintains his current bearing, then it's possible that he may ignore the Andes and Panama altogether opting to take the Cuban route north as he did to come south. Alternately he could cross the Caribbean Sea from Venezuela or Columbia directly to Central America (Costa Rica or Nicaragua). Both have their risks and benefits - the former is ultimately a shorter route to Rankin Inlet, but it means crossing a minimum of 400 miles of open ocean. The latter offers the relative safety (in my mind at least) of the Central America land bridge, but is a significantly longer route to Rankin Inlet. Complex decisions when time is of the essence for those individuals breeding in the Arctic.

Route taken through May 13\

His last received data point indicated his position to be on the northern fringe of the Amazon Jungle straddling the border between Venezuela and Colombia (see image below)...


Blue's location on northern edge of the Amazon

...and that he roosted on a hill (red circles in lower left corner of the GE rendition below) overlooking the Orinoco River that divides Colombia and Venezuela . In the background, about 30 miles from the the river, you will a series of mountains...

GE rendition and most recent location (lower left)

...Panoramio photos show that the mountains include a well known table-topped mountain (Tepui or Tepuy) called Autana Tepui...I can think of worse places to stop.

View of Autana Tepui from village of Seguera

Autana Tepui

More next week from the Arctic.

Alastair

Monday, May 3, 2010

Favorite things...

Blue has now completed a little more than 1/4 of his migration having flown 2300 miles in total. After arriving at Lake Tefe in Brazil on the Amazon River, he remained there for 6 days, then flew 190 miles taking the expected NW bearing toward Panama, which is still 1000 miles from his current location.

Route to May 7

Last week we saw Blue surprisingly retrace his route by flying south before turning north east toward Lake Tefe, which incidentally is very similar to the lake where Blue spent the winter.

Considering his dramatic change in direction, apparent preference for big lakes and the 6 day respite makes one question if he just "stumbled" across Lake Tefe.

Recall too (see April 24 post) that while wintering Blue repeatedly used a cell phone tower in a very urban setting...well the GE image with GPS locations and the photo below show that he repeated this behavior in the city of Tefe (click on each one to see and compare the full sized versions).

GE view of favored locations in Brazilian city of Tefe

Photo of Tefe (similar to GE image above)

Sure makes one wonder whether we're seeing random behavior or evidence of preference for a few favorite things.

Update on spring conditions...earlier (April 19) I posted some MODIS imagery from April 10 2009 and 2010 that show how spring conditions can differ from one year to next. The following 2 images (about 450 miles X 450 miles) below show snow cover in the region on the Hudson Bay near Churchill, Manitoba (red dot) on May 5th 2009 and 2010.

Churchill snow cover May 3 2009

Churchill snow cover May 3 2010

Sunday, May 2, 2010

Amazonia...and beyond

Blue flew an additional 580 miles between April 25 and April 30, his route has taken him to the center of the Amazon Jungle. Last October, he crossed the Caribbean Sea from Cuba and made landfall in western Venezuela - Peregrines typically perform a "loop migration", which suggests that he'll resume his path NW and through Colombia into Central America...to do this, he must first cross the Andes.

Route up to April 30

There are very few Panoramio images posted in the immediate vicinity of the GPS locations , but the two below are typical of the region...
Canopy

Tributary of Amazon River

It's a little surreal to think that in 4 or 5 weeks, (all things being equal) he'll be on territory near Rankin Inlet where it will be like this...

"Panorama Island" with Rankin Inlet in the background

Sunday, April 25, 2010

A brief rest and then...

Blue has now covered just under 1500 miles of the approximately 8500 miles it will take to get to Rankin Inlet. His route north remains somewhat similar to that taken south (purple = southern route, blue = northern route).

Route up to April 25

Acquiring 12 locations per day (1 fix every 2 hours) tells us a great deal about active and sedentary periods...for example, this peregrine habitually travels at a approximately 30 mph, starts out at about 10 a.m. on migrations days, and usually stops to roost between 8 p.m. and 9 p.m. So...generally active for about 10 hours and sedentary for about 14 hours per day. Of course, there is some variability; here's a brief synopsis of activity between the 20th and 24th...

20 - 21 = sedentary
22 = 400 miles
23 = 285 miles
24 = 229 miles

Locations on the 20th and 21st were concentrated among 4 or5 areas of about 8 square miles each that appear to be fenced and are apparently (Panoramio images) grazed by livestock (cattle and/0r goats) .

Goats

Cattle

The area appears to be quite arid, and some watering holes like the one below are artificial. These locations are probably permanent and are undoubtedly very attractive to many bird species in the area.. It's likely that Blue hunted these watering holes before resuming migration.

Livestock watering hole

...more soon, Alastair.

Saturday, April 24, 2010

Panoramio tells the tale

In mid-March, whilst wintering in Brazil, Blue began spending many hours each day and night in a very urban location as shown in the GE image below - to me it looked like he may be using the trees around which the GPS locations were scattered, but I couldn't tell from GE what was so special about the few trees he seemed to have selected when there were so many others just like it to choose from?

The "Roost" location

I e-mailed the GPS locations to my colleague, Mark Prostor, to get his thoughts on what might be so attractive to the peregrine. He took a look at the locations in GE and then started looking for Panoramio images close by...he found one of the swimming pool below(and bottom left corner of the GE image above), and pointed out the GPS fixes were located at the cell phone tower that can be seen in the top right corner of the pool photo.

The Pool

It also be came apparent after a few weeks that GPS locations would periodically be situated in the surrounding soy bean fields like the one below located half a mile from the cell tower.

Soy bean field

Looks to us like the cell phone tower served as both safe overnight roost and strategic location from which he could hunt prey in the nearby agricultural lands.

Alastair