Muskrat shopping

Posted on August 8, 2014 by Alistair

 

A muskrat heads out to do the morning’s shopping,

and returns with salad for lunch.

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Damselfly mating

Posted on August 7, 2014 by Alistair

 

Damselflies are mating again.

Courtship is simple: The male looks for a good egg-laying site and then shows it off to a potential mate. Usually the site is an aquatic weed near the water’s surface, but this particular damselfly male has ineptly chosen a muskrat. Lots of luck with this one, buddy.  

Once a male (blue) finds a female (brown), he grabs the back of her neck with his cerci and seeks a landing spot. Mating takes place in the wheel position.

Female damselflies seem happy to mate with many males and use the fertilization principle: last in, first out—that is, the last sperm deposited is used to fertilize the eggs. So to protect his investment, a male maintains his grip on her neck and accompanies her to an egg-laying spot. Here, she is depositing eggs on an aquatic weed. 

Normally, that is that. However, on a few occasions I have seen him force her head below the water’s surface while she lays. Such a sight is a tad jarring: Is he now drowning her? Actually, no. An insect breathes through openings (spiracles) in its abdomen rather than nostrils on its face. Holding her head underwater presents no more of a breathing problem than it would be for a human with a hand in the water. Note the two potential suiters on the left just awaiting the opportunity to take over.

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Derek’s bats

Posted on August 2, 2014 by Alistair

 

In a recent posting, I told of an evening’s visit to the lakeshore with Derek Kite to watch bats feast on mayflies.

Derek has persisted in his attempts to record bats feasting and his pictures have progressively improved as he became more familiar with their behaviour. I have combined his best shots of last evening into two composites. 

Alas, we yet don’t know which bat species this is.

This two-shot composite of a single bat fits his description of how “they go up about 6 feet, stall, drop and continue in the opposite direction, sometimes… [while eating] a mayfly.” The bat on the right is ascending towards the mayfly (the speck above it); a moment later this same bat is eating that mayfly as it descends on the left.

This eight-shot composite of various bats fits his description of hunting as they “turn staying at the same level, 6″ to 18″ above the water.” The specks are mayflies.

Derek Kite’s pictures are used with permission.

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Toadpoles

Posted on July 30, 2014 by Alistair

 

Ok, I admit it: biology does not recognize the term, toadpole, and instead speaks of a toad’s tadpole. However, not only is toadpole a delightful portmanteau, it is the original form, the tad merely being a corruption of toad. 

These tadpoles were observed on a pond, not far from where an adult Western Toad was seen this spring. Following that there was a posting about a passion of toads. It seems that once again this year we may see toadlets aplenty. Three pictures follow.

 

Posted in herptiles | 3 Comments

Wolf

Posted on July 29, 2014 by Alistair

 

I have not seen a wolf, but Doug Thorburn has—or at least his trail camera has. High in the Selkirk Mountains just south of Nelson, it captured a number of images of a foraging Grey Wolf. 

I had wondered whether the camera might have recorded a feral dog. After all, the Grey Wolf does resemble a largish German Shepard. But no, experts confirm that Doug’s picture does show a wolf.


Doug Thorburn’s picture is used with permission.

Posted in mammals | 4 Comments

Thunk

Posted on July 28, 2014 by Alistair

 

It seems that you are never too young to start a career of colliding with windows. Following a resounding thunk, this juvenile robin sat motionless on a porch roof below the offending window. After about ten minutes, it flew off. 

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Fawn not seen

Posted on July 27, 2014 by Alistair

 

A doe in my yard is clearly eating for both herself and another. I have yet to see the fawn.

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Lizard’s tail

Posted on July 26, 2014 by Alistair

 

When I was a small child, I chased a lizard across a scree slope. I caught it by the tail, which promptly disconnected and was left wiggling in my hand. The lizard made its escape; it had autotomized.

Autotomy (Gr: auto- “self-” and tome “severing”) or self amputation is the behaviour whereby an animal sheds an appendage, usually as a defence against a predator’s grasp. The lizard has a zone of weakness in its tail allowing it to break cleanly. A new tail is then grown.

When spotted yesterday, the Western Alligator Lizard had already shed its tail in response to who knows what. 

Initial views of the head of the lizard revealed nothing unusual.

A full view shows the lizard to be truncated. The coppery coloured back reveals that the lizard is young.

As the lizard walked, three sinews (tendons?) extending from the break whipped about as if still controlling a tail.

Posted in herptiles | 3 Comments

Local Nature Tasting

Posted on July 24, 2014 by Alistair

 

This posting is shamelessly promotional.

At 7:30 p.m. on Tuesday, August 5th, I shall give a presentation at the Visitors’ Centre of Kokanee Creek Park (BC Parks’ map, Google’s map). Part of a weekly series, Science in the Park, my offering is entitled

Local Nature Tasting

It will be a naturalist’s version of a wine tasting. 

Often for a wine tasting, a theme is chosen and participants are invited to make new distinctions among subtly different varieties. As my tastes run to observing local nature, I have chosen themes from among my own pictures. Some themes feature colourful bears, dancing devils, perplexing bows, and, ta-da, local ogopogoes. Within each theme, assorted images encourage savoury distinctions; following each theme, a palate cleanser clears the way for the next. The local constraint is easy as most of my pictures were taken within or near the Park.

The title slide shows Trumpeter Swans at Kokanee Creek Park.

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Bat feast

Posted on July 22, 2014 by Alistair

 

It was an amazing experience to sit amidst a horde of hunting bats.

Derek Kite alerted me to the shoreline feast. For an short intense period in the late evening, the air above a tiny stretch of beach became filled with swift, silent bats feasting on hundreds of mating mayflies. Abruptly it all ended, only to be replayed the next evening.

Derek and I adopted different photographic strategies. He tried to record bats as they approached and left the feeding area; I tried to capture the action just offshore. Each approach had a remarkably low yield. We were, after all, attempting to photograph small, dark, swift flyers in unknown positions at night. His percentage of somewhat acceptable shots was about 1%; mine was even lower.

But, what fun.

In Derek’s first two pictures, the bats seem to follow a line of rocks as they leave the feeding grounds.

I managed one head-on shot over the water.

And while the bat (and its reflection) is soft, it does show one hunting amidst the crowd of mayflies.

Derek Kite’s pictures are used with permission.

Posted in mammals | 8 Comments