Sunday, November 18, 2012

A Great November Day


Jo Swartz and I enjoyed an excellent Sunday’s birding in the Pine Falls area of Manitoba, Canada today.

The biggest highlight was this Lesser Black-backed Gull that I spotted on the ice at the edge of the Winnipeg River near St. Georges.

This first photo shows the features of this bird. I found it interesting that the primaries appeared to have no white tips although through the scope it was possible to discern the faintest of white tips at least on P8 (look closely in this photo). The dark smudge in the bill had me scratching my head at first but after the examining the bird more closely, I reconciled this feature with my determination that the bird was a third cycle individual coming into fourth year or "adult" plumage. Other features to note include the streaked nape, the pale yellow legs and the long wings that fall well beyond the tail. Click on photos to enlarge.

The second photo gives you a size and mantle shade comparison with American Herring Gull. You can see the faintest of black tip to a few of the tail feathers in this photo.
 

The next two photos show the bird in flight, offering views of the underwing and upperwing. Note the small mirror on the outermost primary for example, even though the white tips on the outer primaries are worn almost completely off. The lighting is a bit more direct in these flight shots and the legs appear more strongly yellow than in the previous photos. The combination dark smudge in the bill, pale yellowish leg colour (as opposed to bright yellow), very subtly black tip to central tail feathers and heavy neck smudging lead me to believe this is a third cycle bird (on the way to adult breeding plumage next spring).

  

As is finding one great rarity was not enough, there were more good birds on offer. Two Long-tailed Ducks, had been previously reported and they put on a great show – I was happy with this somewhat distant flyby photo opportunity. 

A Townsend’s Solitaire had been reported in Winnipeg so we made a slight detour to see this annually occurring rarity. This bird was extremely obliging! 

In addition, I took some time to photograph this Northern Hawk-Owl that was actively hunting on Maple Creek Road.  This series of photos shows the owl coming in for a landing, balancing, posing and then taking off in their typical plunging style…  the first photo is my favourite from a fantastic November day!




A beautiful day to be birding and a well deserved break from proposal and report writing!

Saturday, November 3, 2012

The World of Nuthatches

Nuthatches (Sittidae) are a northern hemisphere family that are most commonly found in temperate forests. Of the 28 species of Nuthatch in the world, only two have ranges that extend south of the equator (Blue Nuthatch and Velvet-fronted Nuthatch, both of which occur in Southeast Asia and also on Sumatra and Java).  Only four species occur in the Nearctic, the remainder occurring in Eurasia (one, the Algerian Nuthatch, occurs in northernmost Africa but only within the Palearctic Ream and not within the Afrotropical Realm). As you can imagine, that means that a large percentage of the world’s nuthatches occur in Asia and this family is thought to be “Old World” in origin. Of the 28 species, 14 occur in the Oriental Ream and 10 in the Palearctic Realm of which 6 in Asia, hence there are no less 20 species of nuthatch in Asia. The Himalayan region, with a total of eight species, has the greatest number of species of nuthatches of any area, although the ranges of all eight do not overlap.

Although not a particularly large family, and not very diverse in their size, plumage colouration and morphology; wherever they occur, the most distinctive feature of nuthatches is their behaviour, especially the way they climb both upward and downward on branches. This immediately distinguishes them from all other “climbing” birds such as woodpeckers and treecreeper, that only move upward on tree trunks and branches (or at least position their bodies upward), although woodpecker and treecreepers, like nuthatches, will forage along the underside of branches. The difference is in part anatomical: since the majority of the “climbers” including most woodpeckers and treecreepers, have pointed stiffened tail feathers that act as a brace when climbing. Nuthatches on the other hand rely on their exceptionally strong toes to grip to the bark, whether going up or down. There is also a behavioural difference in that nuthatches have evolved a unique “stride” to accompany their anatomical adaptations, i.e. when walking downwards they are able to place one foot directly below the other and hence walk in a straight line downward. This technique is presumably important for balance and for maximizing the effectiveness of their toe grip. These anatomical and behavioural characteristics are illustrated by four photos below: a Sulphur-billed Nuthatch of the Philippines (note large toes and ability to “hang”), followed by a Blue Nuthatch of Southeast Asia (note downward motion), a Pygmy Nuthatch of North and Central America (note downward-pointing posture with the legs aligned in a straight line one below the other and hence ability to hang on while walking down the tree trunk) and a female White-breasted Nuthatch of North America (note how the large hallux toes clings to bark).





One of the most widespread of the nuthatches is the Eurasian Nuthatch. The first photo is from South Korea, but this species occurs across temperate Asia and Europe and even a tiny amount into the northernmost Africa. The first photo shows their remarkable ability to seemingly hang off the side of tree trunks using their strong toes. The second photo shows the western European subspecies for comparison (note the difference in underpart colouration).  The second photo also shows a behaviour of food storage – ramming a food item into bark crevices either to assist in cracking them open or for storage – a habitat that presumably earned this family their name.



Of course the short, straight, chisel-like bills of nuthatches are designed for probing into bark but several species show a willingness to forage on other substrates (as opposed to just probing into tree bark). This Eurasian Nuthatch is picking tasty morsels off a rocky outcrop. Other species such as the two “Rock Nuthatch” species (Eastern and Western) are more specialized in this technique.


Some of the Old World nuthatches are very similar in appearance and require a little care in identification. This is a Chestnut-vented Nuthatch (photo taken in China) that is similar in appearance to Eurasian Nuthatch (the distinctive undertail coverts not visible in this photo).

Another similar species, whose range partially overlaps with similar species like the Chestnut-bellied Nuthatch is the White-tailed Nuthatch shown here. This species has a predominantly Himalayan distribution and I took this photograph in northern India.The white base to the tail feathers that gives this species their name are seldom visible in normal field conditions.

The identification of nuthatches is simplified by the fact that in most parts of the world there are no more than two or three species that coexist. This is presumably due to similarities in foraging niche. Nonetheless, there are certainly differences in niche that reduce competition where overlap occurs. Where I live in North America, for example, the ranges of the Red-breasted and White-breasted Nuthatches overlap partially and you do sometimes see them together at a feeder in winter. Nonetheless, the former is primarily a bird of boreal/coniferous forest and the latter primarily of deciduous forest. Here is a photo of a Red-breasted Nuthatch on a pine tree and a White-breasted Nuthatch on a riverside deciduous tree, both taken in southeastern Manitoba, Canada. The White-breasted Nuthatch in this photo is a male and, if you like, try comparing with the photo of a female White-breasted nuthatch above to see if you can spot the differences.



In Central Asia, the White-cheeked Nuthatch is remarkably similar to the White-breasted Nuthatch of North America, although the more eastern subspecies, like this one shown from western China, have more extensive rufous below. If you can imagine this bird without the rufous underparts, you’ll understand what I mean.


This Yunnan Nuthatch, endemic to southwest China, is a small species, but this series of three photos illustrate their ability to probe into large seed cones to retrieve large seeds. 





North American observers will recognise this behaviour – in this case, the diminutive Pygmy Nuthatch illustrates the same technique…


One of the most distinctive species is the Velvet-fronted Nuthatch shown here. This is a widespread Southeast Asian species (this photo taken in India). The Sulphur-billed Nuthatch shown above was once considered conspecific with this species, though it differs in having a yellow as opposed to a red bill.  This photo further illustrates the utility of the probe-feeding strategy (in this case for prying open a tree wound) so typical of this fascinating family.



So ends this glimpse into the life of the Sittidae…

Sunday, October 28, 2012

Red-bellied Woodpecker

I found this male Red-bellied Woodpecker today along the north shore of Gull Lake, Manitoba. I located this bird by their distinctive call and managed to get a few record photos like the one shown below (heavily cropped). The Red-bellied Woodpecker is still rather rare in Manitoba, although they do seem to be moving northward and there are now one or two sightings in southern Manitoba every year.

Happy fall birding all!

Friday, October 5, 2012

Highlights of the Manitoba Breeding Bird Atlas to date

After only three years of fieldwork (2010, 2011, 2012), the Manitoba Breeding Bird Atlas (www.birdatlas.mb.ca) is already turning up plenty of surprises. This post offers a glimpse into what we are finding thanks to:

   870 registered volunteers, who have put in
   over 21,000 hours of survey effort consisting of
   over 160,000 records of
   287 species breeding in
   over 2100 atlas grid squares (a grid square is 10 km X 10 km)
   and with over 16,000 point counts in over 1,100 squares….

For a “small” province like Manitoba (in terms of human population), chalking up this much effort is a phenomenal achievement and we have two more years to go to get even better!

Some of the biggest highlights to date have been confirming four species breeding in the province for the very first time! In 2010, Ken De Smet found a nest of Black-headed Grosbeak and David Raitt confirmed breeding Western Tanagers for the first time in Manitoba. The two photos below are ones I took recently in Manitoba. All the photos in this blog post are mine but you can view the photos of other atlassers at: http://birdatlas.mb.ca/mbdata/photos.jsp?lang=en


In 2011, Ken De Smet found Manitoba’s first nest of Snowy Egret and apparently only the second breeding record in Canada. The nest was at Whitewater Lake where I took this photo.

In 2012, there was a rash of Long-tailed Jaeger reports. I found three pairs near Schmock Lake just south of the Nunavut border (photos below) and Joel Kayer and Ken De Smet found a nest at Nejanilini Lake – the first confirmed breeding in our province! 


There were some other great finds too; for example, the Wapusk National Park survey team (a joint effort of Parks Canada and the Manitoba Breeding Bird Atlas) found three Golden Eagle nests along the Broad River. These are the first confirmed Golden Eagle nests in Manitoba in over half a century although there are other unconfirmed reports.   

This male Lazuli Bunting has been on the same territory in southwestern Manitoba for three years in a row. Unfortunately, we have yet to confirm breeding although there have now been some sightings of a female.

In addition the headline makers, the atlas has produced a plethora of excellent nesting records from many out of the way places. These two photos show a Red-throated Loon and nest – this nest I found this summer was the first of two found to date.


Some waterbirds such as American White Pelican (found well north of known colonies) and others like Red-winged Blackbird have been found farther north than expected. What we don’t know is how much of this represents northward expansion or just lack of previous data in remote areas.


A suite of species normally associated with deciduous woods or mixed forest along the aspen parkland to southern boreal transition zone such as Eastern Bluebird, American Woodcock, Eastern Whip-poor-will, and Black-and-white Warbler (photos below) have also been found farther north than is indicted in guidebooks. One possible explanation may be related to habitat change associated with human land clearance in the boreal that has enabled disturbance adapted deciduous trees (especially poplar family members such as Trembling Aspen) to colonise areas following human disturbance, resulting in movement corridors for deciduous forest species. In other areas, however, we have found these species in the north in relatively undisturbed areas such as Black-and-White Warblers along the God’s River and even as far north as York Factory! 




The atlas has documented a better picture of both Northern Parula and Pine Warbler (photos below) which are typically thought of as occurring only in extreme southeastern Manitoba but which we now know have small breeding populations in the Interlake region.


Some boreal forest birds also seem to be moving north including Winter Wren and Brown Creeper. Both of these species have now been recorded several times in the Churchill area (well north of typically drawn ranges).


The atlas is not just finding northern movements however. Some species such as Bonaparte's Gull have been documented farther south than previously thought. This is a juvenile Bonaparte’s Gull shown here. Other species such as Tundra Swan, Northern Shrike and Pine Grosbeak have also been recorded south of their typical ranges.

The atlas is also gathering a lot of much needed data on species that are poorly known or for which there is anecdotal evidence of decline. For example, Smith’s Longspur, Lapland Longspur and Harris's Sparrow (photos below) have all become much more difficult to find in the Churchill area in recent years. Nonetheless, the atlas has been documenting these species in reasonable numbers elsewhere in the north. The last photo in the series of four below shows a rarely encountered Harris’s Sparrow nest.




The atlas is procuring fantastic documentation on Species At Risk in our province and working hard to augment the Manitoba Conservation data Centre. This juvenile Rusty Blackbird (just out of the nest) is one example of many Species At Risk records the atlas has documented to date. Rusty Blackbird is listed as Special Concern. 


In some cases, we have special projects occurring within the larger atlas framework. This includes the ongoing Bird Studies Canada Golden-winged Warbler Project I began in 2008 thanks to the Walter Siemens Memorial Fund. Golden-winged Warbler (photo below) is listed as Threatened. Other researchers also share distributional and nesting data with the atlas.


And then of course there are the hundreds of personal stories that make the atlas what it is. You can read about many of these stories in the various issues of the atlas newsletter at: http://birdatlas.mb.ca/newsletter_en.jsp. I will leave you with one of my favourite magic moments from atlassing in northern Manitoba – this young Boreal Owl that I found (along with other family members) near Shamattawa, Manitoba.

To learn more about the atlas, you can contact me by email at: cartuso AT birdscanada DOT org or phone 1-800-214-6497 and ask for the Manitoba Breeding Bird Atlas.  Thank you!

 
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