Tag: prey

Pied-billed Grebe Feeding Behaviors

Pied-billed Grebes are fascinating little birds with a chip on their shoulders.  They are pugnacious, full of personality and quite small.  They don’t seem to get a lot of attention from bird photographers, possibly because of their generally drab colors and because they’re so common.  I really enjoy watching and photographing their behaviors. I’ve stated here before that “behavior” is a major focus of this blog and if I have images of interesting behaviors that are less than perfect technically I will still post them if they illustrate the behavior well.  There are several in that category in this post.    Grebe with young carp Carp are the primary food for these birds in many of the ponds I frequent.  Even young fish can make a huge mouthful for these very small grebes.       Swallowing a carp I’ve seen it take several minutes for a grebe to finally work one of these huge (for them) fish down their throats.  And I’ve yet to see one give up on the meal because it’s too big.     A slippery meal Fish are slimy and slippery and sometimes get away from the grebe temporarily, though they always seem to be recaptured.      A potential thief in the background  These birds are very social so there’s nearly always other grebes close by when one catches a meal and some of them will invariably try to steal the prize from its rightful owner.  This can make for some very interesting but challenging encounters for the photographer because the action is usually so…

Continue reading

The Challenges of Photographing Birds in Flight in Low Light

Photographing birds in flight in relatively low light (dusk, dawn, cloudy conditions etc) isn’t easy.  In addition to the expected challenge of locking focus onto a fast and often erratically moving target, in low light you have the problem of getting enough shutter speed to get a moving subject sharp.   A potential solution to the problem is “opening up” – increasing the size of the aperture, which is the same as reducing the f-number – say as in changing your setting from f/7.1 to f/5.6.   This lets more light into the camera in the same amount of time, allowing for an increase in shutter speed to freeze the motion of the bird.  Opening up however has another effect – reducing depth of field, so less of your subject is likely to be tack sharp.  Another potential solution is to increase ISO.  Increasing ISO in digital cameras has the effect of seeming to increase the sensitivity of the camera’s sensor to light so that faster shutter speeds can be used but the downside to increasing ISO is that it can increase digital noise in the image. Sometimes in bird photography fantastic opportunities with birds in flight present themselves in less than ideal light.  Your best chance at an acceptable image under those conditions is to understand the interplay between your camera settings – how changing aperture affects shutter speed and depth of field and how changing ISO affects shutter speed and the production of digital noise.      Male Northern Harrier, 1/1250 @ f/11, ISO 800 It’s not often I get a…

Continue reading

American Kestrel – The Killing Bite

I have watched American Kestrels consume their prey up close many times.  Usually that prey has been a vole but occasionally it’s been a small bird or mouse.  But until this day the prey had always been already dead when I arrived on the scene.  It was cold and snowy when I spotted this male kestrel with a mouse (I was surprised it wasn’t a vole) that was still very much alive.   As a side note I want to add here that this kestrel was not baited.  Many photographs are taken of raptors when they’ve been baited by mice (they can be bought at pet stores) that have been provided as an enticement by the photographer.  That was not the case here – I do not bait.       Male kestrel with live mouse It was obvious that the mouse was alive because it was struggling slightly, its tail was twitching and its eyes were open.  In my experience these birds often prefer a more stable perch than this while they eat their meal – something like a fencepost or pole that provides some kind of platform from which to eat.  So I didn’t think he would eat the mouse here and I was right.  He gave me time for a few quick shots and then flew off to another perch.     Kestrel on second perch He didn’t go far however and I was able to approach him again.  This next perch was also precarious to eat from because the wind was blowing and both perch and bird were swaying in the breeze. …

Continue reading

Northern Harriers Fight to Survive Harsh Winters

  Typically life is good for the hundreds of Northern Harriers who spend fall and winter in the marshes and prairies surrounding the Great Salt Lake after spending breeding season up north.  Here their diet consists almost exclusively of microtine voles (small rodents resembling mice).  These voles are incredibly abundant and relatively easy prey.  It’s quite unusual to see a harrier even attempt to catch a songbird or anything else for that matter.    Harrier hunting voles near the Great Salt Lake   However the easy life takes a major turn for the worse during unusually harsh winters with intense cold and deep snow packs.  During these times the voles spend most of their time underground eating roots and dried vegetation which means the primary source of food for harriers is suddenly unavailable just when they most need nourishment for warmth.  And since most songbirds (their fall-back food source) have either migrated south or have already succumbed to the many American Kestrels in the region, simple survival for the harriers is suddenly very precarious.  Now, out of desperation,  harriers begin to go for larger prey – ducks and coots for example.     Harrier on a duck kill frozen into the ice They aren’t able to take these prey often and when they do they can’t eat them quickly like they can a vole.  The result is intense aggression – fighting fiercely over food.  Typically I see very little true aggression(other than territorial squabbles) between harriers but all that changes when food becomes scarce.  A relatively large prey item will provide multiple…

Continue reading

Loggerhead Shrike Impaling Prey, revisited

  Recently on this blog I posted images of a juvenile Loggerhead Shrike impaling a dragonfly on thorns and said I hoped to get more documentation of the behavior but it would likely have to wait until next years nesting season.  I was wrong.  I witnessed and photographed this behavior again just three days ago.  This time the shrike was also a juvenile but the prey was a large spider.    Juvenile shrike with spider What happened after the capture was interesting for me.  The bird didn’t simply impale the prey and leave it (as a cache or food store)  as might be expected of an adult.  Instead, it attempted to impale the spider on different thorns multiple times, like it was practicing – learning how to do it (keep in mind, the bird is a juvenile).  In fact, at one point the shrike even seemed to be “studying” its work, as you will see (I’m sure that’s anthropomorphic of me).  Sometimes they don’t actually impale the prey, instead they wedge it into crevices or between forked branches/twigs.  This shrike tried to do both with the spider.  After what I believe was four attempts at impaling/wedging the spider on some thorny branches someone had placed in a campground fire pit, the bird had apparently had enough practice and simply ate the prey in several pieces.   Some of the  images below aren’t of the best quality but I think they do document what I saw.  As far as I could tell, the spider was dead through this whole process.    Attempting to impale…

Continue reading