Tuesday, August 23, 2011

Grassland birds of the Carden Plains IBA

Carden Plains Important Bird Area, near Kirkfield, Ontario (image courtesy of Bruce Wilson)

Nature Canada and Bird Studies Canada have been moving forward strongly on their Important Bird Areas program, working with local naturalist organizations and birders to conserve the ecosystems and monitor the birds on some of Canada's most critical pieces of avian habitat. Here in Saskatchewan and in other provinces, local naturalists are signing up to be volunteer caretakers for the IBA in their part of the country.

One IBA I hear a lot about is the Carden Plains in Ontario. Among naturalists in that province, there seems to be a fair bit of pride in the remnant populations of grassland birds at what many simply call the "Carden Alvar." What is an "alvar" was my first question. I hope to get to see the Carden Alvar some day, but while I was on Pelee Island this spring I visited a small alvar there and learned that it is a rare landscape on a base of limestone or dolostone that gives it a distinctive character and matrix of plant and animal species. Amazingly, Ontario is home to 75% of all North American alvars.

The Nature Conservancy of Canada (NCC) considers the Carden Alvar to be "an internationally significant natural area." Carden is even more imporant because it hosts rare and endangered species, including the Eastern Loggerhead Shrike and several declining species of grassland sparrows.

Bruce Wilson, a birder friend from Barrie, Ontario, recently agreed, after minimal arm-twisting, to write up a piece for Grass Notes explaining a bird banding project he has undertaken at Carden, along with his banding trainer, Nigel Shaw.

Bruce Wilson

Nigel Shaw

Their work caught my eye because they are taking advantage of the high number of birders who come to Carden by fitting banded birds with an additional plastic alpha-numeric band that can be read either in a spotting scope or digital photo. With this approach, any subsequent sightings of individuals will help Bruce and Nigel find out more about nest site fidelity, movement and distribution of the birds they band. Seems like a good idea to me, and it is always heartening to hear of people giving up their time and spending money out of pocket to gather data on our declining grassland birds.

I will let Bruce give you the full details on the project. Here is the report he graciously wrote up for me to post. (All bird photos by Nigel Shaw.)

The Carden Plain Important Bird Area near Kirkfield, Ontario, less than two hours northeast of Toronto, is southern Ontario’s premier area for grassland birds. It is a rare alvar habitat that supports a number of grassland birds including a breeding population of the endangered Eastern Loggerhead Shrike, as well as Bobolinks, Eastern Meadowlarks, Upland Sandpipers, Sedge Wrens, Eastern Bluebirds, Eastern Towhees, and Brown Thrashers. The typical grassland sparrows, Vesper, Savannah, Grasshopper and Field as well as Clay-colored also breed in the area as do Golden-winged Warblers.

The majority of land in the area is privately held with the exception of some areas that have come under the control of the Couchiching Conservancy. Major acquisitions are the Cameron Ranch, Windmill Ranch and Bluebird Ranch totalling some 5000 acres. These properties will eventually become an Ontario Provincial Park thus preserving portions of this unique area. The Couchiching Conservancy is also working with landowners in the area to encourage conservation of important habitats.

It is well-known that many species of grassland birds have declined rapidly over the past few decades. Once common species such as the Bobolink are now listed as threatened by COSEWIC. The decline of the grassland bird species is of concern.

Although some data are collected by means of annual point counts carried out on the Cameron and Windmill Ranches, typically in late May and early June, there are no data with respect to the ages of birds and the number of birds returning to nest each year. To obtain additional data Nigel Shaw licensed master bird bander from Alcona, Ontario and Bruce Wilson of Barrie, Ontario have undertaken a banding study with the permission of the Couchiching Conservancy and the Ontario Ministry of Natural resources. In particular they are focusing on several of the grassland species known to nest on The Ranches, namely: Upland Sandpiper; Clay-colored Sparrow; Savannah Sparrow; Vesper Sparrow; Grasshopper Sparrow; Bobolink; Eastern Meadowlark and Horned Lark.

Grasshopper Sparrow, just after banding

Banding studies have shown that many birds show a site fidelity and return to the same breeding area each year. The Carden IBA study will help determine if the same is true for the target species on The Ranches. The banding program will provide additional knowledge about movements of birds and will help determine the dynamics of the population trends of some of the typical grassland bird species by assessing the numbers of breeding birds and production of young. One advantage of carrying out a study on The Ranches is there are a large number of birders who frequent the area and will be able to report sightings of banded birds.

The study will be carried out over a number of years to collect the data necessary to better understand the breeding populations on The Ranches. The birds are attracted with audio lures and captured using conventional mist nests. When a bird is removed from the nets it is banded, wing chord measured made, weighed, moult patterns recorded, photographed and released. The birds are tagged with the standard bird bands as well as a plastic alpha-numeric band such that each bird will have a unique number. Studies of Green Finch in Europe using the same type of bands show the band numbers can be read with a spotting scope or by examination of digital photographs.

Adult Field Sparrow, showing alpha-numeric band

The program got off to a late start this years due to having to wait for delivery of the bands from overseas. On July 25 Nigel and Bruce went out to the Windmill Ranch hoping, given the late time, to be able to get a few birds but were pleasantly surprised with the results. In about 5 hours time they managed to band a total of 13 birds of which 10 were the target species. Although there were not many birds actively singing they responded well to the audio lures.

Clay Coloured Sparrow, just after banding

Target species banded:

Grasshopper Sparrow 2 adult, 1 hatch year
Clay Colored Sparrow 3 adult
Savannah Sparrow 1 adult, 1 hatch year
Vesper Sparrow 1 adult
Field Sparrow 1 adult

Other species

Yellow Warbler
Gray Catbird
Song Sparrow

An Upland Sandpiper responded to the call by coming into the net are but flying over. This bird was a different one than one heard a few minutes earlier.

Based on the results the birds will still respond to the audio lure despite the apparent lateness of the season. This bodes wells for work next year.

Next year's early efforts will focus on areas that lead to the various point counts on the Ranches hoping birds trapped there will be more likely to be seen again.

This is an interesting project and it is hoped it will give us more information about the little brown jobs most people do not give a second thought to.

Friday, August 12, 2011

Ducks need grass too

Drake Ruddy Duck displaying in late July near Grasslands National Park, Sage Herriot

This wet spring and summer has made for as ducky a breeding season as I can remember. There are ponds and sloughs everywhere on the prairie and in late June and July every one of them seemed to host a brood of mallards, wigeon, scaup or redhead.

I often report alarming and discouraging statistics in this space, but here are some we can all celebrate. According to an outdoor column I read today, U.S. Fish & Wildlife waterfowl surveys are estimating 45.6 million breeding ducks in the North American population this year. That means they believe we will have 11 percent more ducks than they estimated last year (40.9 million) during the spring survey. They have been keeping data on this since 1955 and this year’s estimate is 35 percent above the long term average! In fifty-six years, the estimate has exceeded 40 million only five times. (See below for the U.S. Fish and Wildlife estimates on the common duck species that breed on the northern Great Plains.)

According to this same column, the aerial pond counts in the United States and Canada showed 8.1 million ponds, a 22 percent increase from last year’s estimate and 62 percent above the long-term average. Only one other time in the history of the survey has the figure gone beyond 8 million.

Redhead landing at a dugout near Lanigan

As terrific as these figures are (you knew I would have something to qualify all the good news), they would have been even better if our wetlands were surrounded by wider margins of grassland. Too many of our sloughs are cultivated right up to the water’s edge. Ducks don’t ask for a lot of grassland habitat, but many species need to have some upland grass beyond the water’s edge to nest in.

Unfortunately, nesting cover has been declining in both the Canadian provinces and the American states on the northern Great Plains. In the U.S., grassland formerly protected by the Conservation Reserve Program has recently been converted to cropland in response to high corn prices driven by federal subsidies for biofuel production. According to Ducks Unlimited, North Dakota alone has lost 22 percent of its CRP acres since 2007. They estimate that another 387,000 acres will be lost in 2010-2011 and more than 1 million acres will be lost in 2012-13. (For more on this concern about losing native grassland in the duck-breeding prairies of the northern states, see this excellent column by Minneapolis Star-Tribune writer, Dennis Anderson.)

Ring-necked Duck pair in early spring, beaver pond in Upper Indian Head Creek

All the water we have this year and are likely to still have in the next couple of years could produce even more waterfowl if Canadian and American governments would stop subsidizing biofuels and instead begin to subsidize carbon sequestration in perennial grassland.

Having said that, these reports of high duck numbers and pond counts are as encouraging as anything I have heard this year in conservation circles. Like many prairie naturalists, I'm feeling grateful for the recovery of our prairie waterfowl, and looking forward to seeing some large flocks this September and October as they begin to gather for the flight south.

Northern pintail near Strawberry Lake Community Pasture

Here is a breakdown of estimates for this year species by species:

Mallards — 9 percent increase compared with 2010 estimates; 22 percent greater than long-term average.

Gadwalls — 9 percent increase compared with 2010 estimates; 80 percent greater than long-term average.

Wigeons — 14 percent decrease compared with 2010 estimates; 20 percent less than long-term average.

Green-winged teal — 17 percent decrease compared with 2010 estimates; 47 percent greater than long-term average.

Blue-winged teal — 41 percent increase compared with 2010 estimates; 91 percent greater than long-term average.

Shoveler — 14 percent increase compared with 2010 estimates; 98 percent greater than long-term average.

Pintail — 26 percent increase compared with 2010 estimates; 10 percent greater than long-term average.

Redheads — 27 percent increase compared with 2010 estimates; 106 percent greater than long-term average.

Canvasback — 18 percent increase compared with 2010 estimates; 21 percent greater than long-term average.

Scaup — 2 percent increase compared with 2010 estimates; 15 percent less than long-term average.

Source: U.S. Fish & Wildlife Service

Friday, August 5, 2011

Photo journal of Grasslands NP trip

yellow coneflower, by Sage Herriot

Last week I made a quick trip down to the West Block of Grasslands National Park and back to work on an assignment for Canadian Geographic. My second oldest daughter, Sage, a photography student at Ontario's Sheridan College, came along for the drive to take some photos. She had to use my camera, which is a bottom of the line Canon Rebel with a stock lens and a 100-400mm zoom (5.6), but even so many of the shots Sage took came out very nicely--mostly because she knows how to use a camera.

Here are the results--all of these shots were taken by Sage--except the fuzzy ones of the weasel and the prairie falcon.

Half way to the park, just as we were coming off the Missouri Coteau, we came across this abandoned farmyard swarming with hundreds of tree, bank, cliff, and barn swallows.

On the road into the West Block ecotour we found a number of Chestnut-collared Longspurs still in song and perching on rocks and fenceposts.

This shot Sage took of the Frenchman River shows how extensive the Yellow Sweet Clover is this year. Let's hope this introduced species does not become a permanent problem in the park.

This fledgling meadowlark sat still for a photo--mostly because it wasn't that confident flying yet.

Lark Buntings were easy to find outside the park on the return portion of the Ecotour road.

We spotted this fellow, a fairly large Western Painted turtle, along a road south of the West Block.

The park's buffalo were off in a remote coulee during our visit, but this small herd of longhorns was just west of the western edge of the West Block.

Here is my weasel photo. Again on a road outside the park, we found this Long-tailed Weasel trotting into the ditch carrying a Richardson's Ground Squirrel ("gopher") in its jaws.

This Prairie Falcon sat atop a prairie dog mound in the grey light of dawn. Here it is in flight:

Another view of the West Block. Sage took some landscape shots but, like most photographers, found the park's wide open landscapes challenging to shoot.

I think this is a young Krider's Red-tailed Hawk.

Then there is the one that got away. On the drive home we skirted the northern edge of Old Wive's Lake, which is a vast inland sea this summer, and I am pretty sure we had a glimpse of a Swift Fox. It trotted along the trail in front of us but when I stopped to try and get a photo it vanished into the cropland as I held the camera and watched the wheat sway to its hidden passage. If it was a Swift Fox--and I am not sure what else has a small fox body with a black-tipped tail--it was pretty far north. The recovery of the Swift Fox in Canada has been one of a few success stories in our grassland species at risk--thanks to the vision of Miles, Beryl, and Clio Smeeton early on, and the more recent efforts of the Environment Canada and the Calgary Zoo.

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