Tuesday, July 28, 2009

Yellow-bellied Sapsucker nest

A wonderful treat this summer field season at one of our camp sites west of Lake Manitoba (Manitoba, Canada) was a nest of Yellow-bellied Sapsuckers right near our tents. The young were not large enough to be visible but they made an incessant racket and the parents fed them almost constantly throughout the day.

As you can see from this photo, when you spot a bird carrying (as opposed to eating) a mouth full of food, chances are they may be nesting. This is the male, about to fly to nest to feed the hungry youngsters.

He flies to the nest they have excavated in a large aspen and lands just below it

Then hops around towards the cavity before landing on the rim

Sometimes he would turn his head sideways as if he were trying to see into the cavity or maybe looking up. I wasn’t sure if this behaviour was a type of vigilance. In this shot you can see well the pointed stiffened central tail feathers that most woodpeckers have. These serve as a prop to help them in climbing and bracing against tree trunks.

Of course mum was hard at work feeding as well. In this photo you can see her pale, as opposed to red, throat and duller crown. She looks a little ragged from all the hard work...

Sometimes the pair would arrive at the nest at a similar time

On some occasions the male would make a straight line approach from in front of the nest

And land right on the cavity rim

When they left the nest they would dive low – a technique I have seen other cavity nesters use too. This is perhaps in part for ease of take-off but may also make their entrances and exits less conspicuous.

On this occasion she is carrying something in her bill. This is the fecal sack, i.e. the dropping of the chicks. In this way they keep the cavity clean and reduce the risk of predators detecting the nest by scent.

In the next 3 shots, the male shows the whole process – and he’s loaded (devoted parenting!)

He would usually fly to particular rotting tree a certain distance from the nest with deeply crevassed bark and get rid of the feces by hitting his bill sideways against the bark and sometimes scraping his bill against the tree. Here he is pausing after doing just that.

And then he would often give himself a good preen

Including rubbing the bill against his feathers. Presumably this helps to clean his bill before he brings more food back to the nest.

A little stretch and a mewing call or two and he was ready for action again...

Now you may have notices that these Yellow-bellied Sapsuckers don’t look particularly yellow in the belly. In worm plumage in fact their belly often looks more off-white than yellow. This photo shows you what they look like in the spring with fresh (brighter) plumage.

And you may also have wondered why “sapsuckers” always seem to be feeding mayflies and flying insects... as with many birds that vary their diet at different times of year, bugs are a wonderful food source to meet the high energetic demands of growing chicks (and maybe a little easier to feed to young than sap). So here’s an older shot of a Yellow-bellied Sapsucker making the characteristic sap wells that this species is so well known for…

And this what an immature bird looks like, also demonstrating the sap-feeding technique on an introduced tree species, locally referred to as "Russian Olive"

More photos of sapsuckers and other woodpeckers at: http://artusophotos.com/

Thursday, July 23, 2009

Blue-spotted salamander

Nopiming Provincial Park (or “Noopiming” as I prefer to spell it because this is an Anishinaabemowin (Ojibwe) word meaning “in the bush” and the first vowel is long – indicated in some orthographies by doubling the “o”) is one of my favourite places for watching wildlife in Manitoba. I do a breeding bird survey here every year, on which I have encountered many wonderful sights including Canada lynx and nesting Trumpeter Swans. Situated in southeastern Manitoba, Canada and straddling the Ontario border (just north of Whiteshell Provincial Park), Noopiming is a wonderful example of the boreal forest of the Canadian shield. Normally, when I talk about Noopiming I go on for hours about owls or boreal birds or some exciting mammals but this post is about a smaller resident of Noopiming – the beautiful blue-spotted salamander.

Since I am more typically looking up in the trees I don’t often see salamanders but when I accompanied Shauna Hewson on an amphibian survey a few days ago I learnt a trick or two about looking on the ground. Blue-spotted salamanders are quite small (<14cm) and not easy to find. The first photo shows two salamanders from above. You can see the extensive blue spotting on the tail with less on the body, although there is considerable variation in individual markings.

These next shots show them from various angles on moss. In some of these shots you can see the grooves on the side of the body that are characteristic of the North American Ambystoma salamanders, sometimes called “mole salamanders”.

And here is a close up to show the features of the head such as the protruding eyes

The Ambystoma have some fascinating tricks. Maybe the most famous is the Axolotl, in which adults develop from aquatic larvae without the usual metamorphosis by developing lungs but retaining gills (actually the Axolotl is not alone in this). The blue-spotted salamander exhibits another fascinating phenomenon – they can hybridise with their sister species, the Jefferson’s Salamander, but this amazingly has resulted in two completely female hybrid populations, which lay eggs that contain cloned material, i.e. asexual reproduction. Genetically speaking the whole population is one hybrid cloned many times. Females in these all female populations still go through mating rituals with males of the parent species even though they don’t actually breed with them. These hybrids don't occur in Manitoba though - we are on the westernmost edge of the range of blue-spotted salamander and far from any populations of Jefferson's salamander.

Another highlight of the day was seeing two common snapping turtles – here is one of them. These enormous turtles have a formidable bite and can pluck unsuspecting prey from the surface with a dazzling speed that belies the turtle/tortoise reputation.

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