Tuesday, April 26, 2016

International Migratory Bird Day + “The Messenger”

International Migratory Bird Day is celebrated here every year on the second Saturday in May and this year there are some great activities to help you celebrate on May 14th!

Join us at Oak Hammock Marsh on May 14th for any of the following:

* 8 - 10 a.m.:       Birding Marshwalk with Christian Artuso and Tim Poole - Birds recorded on the walk will be entered in eBird

* 10 - 11 a.m:      IBA Program and Data Entry – Learn how to record birds in eBird with Tim Poole and Christian Artuso

* 11 a.m. - noon: Manitoba’s Returning Songbirds presentation by Christian Artuso

* 1 - 2 p.m.:         Birding by Ear Workshop with Paula Grieef - Learn some basics for identifying bird songs in this beginner workshop.  $5 plus admission

* 2:30 - 3:30 p.m.:  Buying Binoculars presentation - What to look for when buying binoculars with Paula Grieef and Ricky Ryan from Zeiss. Binoculars will be available for testing. Enter to win a pair of Zeiss binoculars.

During the week of International Migratory Bird Day, the superb documentary “The Messenger”, which chronicles the struggles of songbirds in the face of habitat destruction, climate change and industrialization, will be featured at Winnipeg’s Bandwidth Theatre on May 13 – 19, playing at 7 p.m. daily with 5 p.m. matinées on Saturday and Sunday. On the “auspicious” Friday May 13 I will be there to introduce the screening.

I will also be leading a birding workshop at St Leon on April 30th for any of you in that neck of the woods who might be interested. On the evening of May 12th I will be doing a condensed Birding By Ear Workshop at FortWhyte Alive.

Good birding all; May is just around the corner and such a wondrous time in Manitoba!

Here are two photos of a male Baltimore Oriole I photographed recently in Costa Rica — one of many birds getting ready for the northward trek to brighten our lives up here in the temperate zones!

Tuesday, April 5, 2016

Comparison of Campephilus and Dryocopus:

The four photos used in this collage are:
Top left: Pale-billed Woodpecker (Campephilus guatemalensis), female, Bahía Drake, Costa Rica.
Top right: Pale-billed Woodpecker (Campephilus guatemalensis), female, Playa de Oro, Colima, Mexico.
Bottom left: Lineated Woodpecker (Dryocopus lineatus), male, Río Lagartos, Yucatán, Mexico.
Bottom right: Lineated Woodpecker (Dryocopus lineatus), male, Chaparri, Lambayeque, Peru.

I have posted previously about the differences in toe structure and perching posture of woodpeckers (see: http://artusobirds.blogspot.ca/2015/01/why-woodpecker-lost-toe.html); however a recent photo opportunity in Costa Rica reminded me that I now have a chance to comment further on the postural differences between two of the largest woodpecker genera: Campephilus and Dryocopus.

Pale-billed Woodpecker and Lineated Woodpecker are quite similar in appearance and most people look to the facial markings to distinguish them. If the head is turned away or you don’t have a good look at the facial markings there is one quick aspect of GISS (general impression, shape and size) that helps distinguish them and it relates to a major difference between the Campephilus and Dryocopus woodpeckers (and one that helps us understand why such similar looking woodpeckers belong to different genera).

The Campephilus woodpeckers include many of the world’s largest woodpecker species and they have a neat trick to support their weight and large bodies. In addition to gripping with their toes and stiffened tail feathers, they also spread their trasometatarsus wide with the joint resting against the trunk as an extra support. The top two photos of a Pale-billed Woodpecker shows how this works on a vertical trunk (top left) and an angled branch (top right). Notice how the tarsus and “joint” rest against the trunk such that the bird appears to be resting on them (which many of us might think of this joint as a bird’s knee but it is technically the ankle). Even though the Dryocopus woodpeckers are almost as large, they perch in a more “normal” woodpecker fashion, gripping with their toes and using their tail as a brace as these Lineated Woodpeckers show on a vertical trunk (bottom left) and on an angled branch (bottom right). In each case, notice how the joint does not touch the tree and the tarsi are held at more of a 45 degree angle to the body and to the surface they are resting on (as opposed to resting on the surface as in the Pale-billed Woodpecker examples). This difference is visible from a distance and can be a useful identification clue in situations where lighting or distance makes it hard to observe plumage details with clarity.

To give a more complete, broader picture, following IOC taxonomy, there are six Dryocopus species: Black-bodied Woodpecker, Lineated Woodpecker, Pileated Woodpecker, White-bellied Woodpecker, Andaman Woodpecker and Black Woodpecker. There are 11 Campephilus species (all confined to the Americas), with the two largest presumed extinct: Powerful Woodpecker, Crimson-bellied Woodpecker, Red-necked Woodpecker, Robust Woodpecker, Crimson-crested Woodpecker, Pale-billed Woodpecker, Guayaquil Woodpecker, Cream-backed Woodpecker, Magellanic Woodpecker, Ivory-billed Woodpecker (presumed extinct) and Imperial Woodpecker (presumed extinct). Note that Helmeted Woodpecker has now been moved to the genus Celeus.

Saturday, April 2, 2016

The many faces of the devil - Stygian Owl (Asio stygius)

The collage below shows Stygian Owls (Asio stygius) from Sinaloa, Mexico (top left, top centre), Cuba (top right), São Paulo state Brazil (bottom left) and Quito, Ecuador (bottom centre and bottom right). This shows shows some of the variation in three of the six subspecies: the nominate subspecies in the bottom row (although some have argued that the southern Brazilian birds should be in the A. s. barberoi subspecies) is described in most literature, the A. s. lambi subspecies from western Mexican is said to be a little paler, and the A. s. siguapa subspecies from Cuba apparently smaller with whiter markings. You can judge for yourself from these photos.

With their dark, almost black, plumage and long, close-set ear-tufts (that look like horns), the Stygian Owl is arguably the most “diabolical” of owls. The Stygian Owl (Asio stygius), is named after the River Styx, which of course in Greek mythology was the gateway to the afterlife. Indeed, in part because of their nocturnal haunts and human-like faces, owls have a symbolism of death and/or the afterlife in many cultures from all around the world; but the Stygian Owl arguably best demonstrates that imagery. As with other owl species from around the world, this species faces persecution in areas where it is believed to be a witch or an evil spirit and the population on the island of Hispaniola (A. s. noctipetens) is considered vulnerable for that reason. Despite persecution based on fear, this is surely one of the most handsome little devils anyone could encounter on a dark night!

The Stygian Owl is a member of the genus Asio, related to the Long-eared Owl and Short-eared Owl that many of my North American, Asian and European friends will be familiar with. The Stygian Owl is a couple of inches larger than either of those two species but you can certainly see the resemblance; for example, note the close-set ear-tufts as opposed to the widely parted, sometimes sideways ear-tufts of Bubo (“eagle-owls” and “horned owls”). The Stygian Owl has a deep hooting call similar to Long-eared Owl except that the notes have a hint of a disyllabic slur and slide down the scale a little. Although thought to be mostly resident, there may be some nomadism or short migratory movements since there are at least two winter records in southern U.S.A.

Nature Blog Network Birdwatching Blogs - BlogCatalog Blog Directory Fatbirder's Top 500 Birding Websites