Tag: brooding

Mountain Bluebirds Attending To Nesting Duties

On my recent Montana camping trip I was pleased to note that the good folks of Big Sky Country care deeply about their bluebirds. Nest boxes of every description and age seem to be abundant on both private and public land and along road corridors. Nesting season was in full swing, as were the traditional spats between Mountain Bluebirds and Tree Swallows for nesting rights to the boxes.

On these trips I can never resist photographing the bluebirds in particular as they perform their domestic duties.

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Brood Patch In A Female Short-eared Owl

One of the primary functions of feathers is insulation and they’re very good at preventing heat loss.  But this efficiency presents a problem – how to keep the egg(s) sufficiently warm during incubation, since feathers act as a barrier to heat transfer from parent to eggs.  Typical bird body temperature is about 104 degrees F. and the ideal incubation temperature for their eggs is very close to normal human body temperature – 98.6 degrees F. That dilemma has been solved by most bird species through the evolution of the “brood patch” – an area of belly skin that loses its feathers near the end of the egg-laying period.  As the feathers are lost, supplementary blood vessels engorge the skin of the “patch” so that hot blood is brought to the surface.  Amazingly, the parent can even shut down blood flow to this region when that bird is off the nest.  When the incubating parent returns to the eggs for incubation, he/she typically goes through settling movements that bring the brood patch into gentle contact with the eggs. The patch may be large or small, depending on a variety of factors including how many eggs are incubated.  Some species have a single patch in the middle of the belly, others may have one each side or even three.   Typically the patch is difficult to observe in wild birds, particularly in flight but I have several images of a female Short-eared Owl where it is visible.  This female had two chicks that she was trying to keep warm during a typically cold Montana spring.   The male…

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Western Grebes – Aggressive Speed Demons

I’ve spent a lot of time over the years watching and photographing the behaviors of Western Grebes and I’ve been impressed by both their aggressive tendencies toward other birds and by their incredible acceleration and speed in “running” across the water at those same birds.  In my experience that aggression is most often directed toward other grebes in defense of mates, chicks or feeding areas but they are also aggressive toward a variety of other species and are suspected of stabbing them with their bill from under water.  BNA reports Mallards and Red-necked Grebes found dead from stab wounds to the abdomen that were probably administered by Western Grebes. I’ve found photographing them as they dash across the water to be very challenging because of their speed and the unpredictable nature of the behavior – it usually comes with little or no warning and direction is difficult to anticipate.    1/1250, f/6.3, ISO 640, 500 f/4 Though these birds appear slim while sitting on the water, in reality they are fairly chunky and at the end of one of these “runs” their wide body throws up quite a wide wake as they begin to slow down and settle back into the water – much like a speedboat after the engine has been cut.     1/1000, f/6.3, ISO 500, 500 f/4, 1.4 tc  This grebe is early in the acceleration stage with its “bow” still raised high.      1/1000, f/6.3, ISO 500, 500 f/4, 1.4 tc  And then another wake as it begins to settle into the water.      1/1600, f/6.3, ISO 500,…

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Can’t We Go Any Faster Dad?

I’ll preface this post with an apology for the cutesy title.  I usually avoid them at all costs but in this case I just couldn’t help myself…  (I’m making the assumption that the adult bird here is the male because of its straight bill but it’s a subtle distinction and I could be wrong). For the last few days we’ve been having a great time with Clark’s and Western Grebes and their chicks.  Both sexes of both species brood their chicks on their backs (back brooding) from almost the moment they hatch until they are quite large.  I’ve seen up to three chicks of about this size on the back of a single adult, although by the time they get this size the other parent often shares the burden.    1/1600, f/8, ISO 400, 500 f/4, 1.4 tc When I first saw this image of a Clark’s Grebe and its chick on my screen I assumed it was simply another case of the youngster having just jumped onto the back of the adult (as evidenced by the position of the feet and the direction of the water splash).  But now I’m quite convinced that the adult was actually allowing the youngster to act as an outboard motor of sorts as the chick seems to be providing the propulsion as the parent relaxes.  If so, and I think it is, in all the time I’ve spent watching these birds this is the first time I’ve noticed such interesting behavior.     I offer this image as further evidence of my theory…

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