Thursday 31 October 2013

Halloween Spiders

When I was little my dad would keep us home from school on Halloween, he felt it should be a holiday. We'd go get dry ice, decorate the front hall with coffins that opened, witches that stirred bubbling cauldrons and my dad would drag his sound equipment upstairs, hide and scare the crap out of the neighbourhood kids. There were permanent pulleys on the ceiling in the hall, our house was famous. Then afterwards we would all play with the leftover dry ice in the kitchen while eating candy. So I have a special place in my heart for Halloween and all it's ghosts, bats and spiders. 

Me being spooky a long time ago

So, in honour of this, the most spooky of holidays, I give to you as a gift an assortment of facts about spiders, our eight-legged arachnid friends.
  • Spiders are not insects. Insects (Insecta) have three body parts - head, thorax, abdomen. Spiders are in Arachnida with ticks, mites and scorpions which have two main body parts - abdomen and cephalothorax (head/thorax combo).
Spider Anatomy
http://www.cirrusimage.com/spider.htm

  • Most spiders have eight eyes, some have none and some have 12. There are usually two main eyes with high resolution and secondary eyes that detect the difference between light and dark.
Jumping Spider
By Lukas Jonaitis from Vilnius, Lithuania (Eyes of Jumping spider - Marpissa radiata)
[CC-BY-2.0 (http://creativecommons.org/licenses/by/2.0)],
via Wikimedia Commons
Hogna Wolf Spider
By Thomas Shahan from USA (Eye Arrangement of a Hogna Wolf Spider)
[CC-BY-2.0 (http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons

  • There are 35-40,000 known spiders in the world. 3,000 in North America. But there are probably just as many out there we don't know about.
Theraphosa blondi © G Beccaloni
http://www.nhm.ac.uk/nature-online/species-of-the-day/biodiversity/loss-of-habitat/theraphosa-blondi/

  • The smallest known spider is Patu digua at  roughly 0.37 mm in size
  • The Giant Huntsman Spider has the largest legspan at 30cm
By Petra & Wilfried (Flickr)
[CC-BY-2.0 (http://creativecommons.org/licenses/by/2.0)],
via Wikimedia Commons

  • On average, spiders live for a year. Some spiders can live 3 to 4 years, and some tarantulas live for 25 years or longer.
  • Spider silk is a protein. It leaves the glands as a liquid and squeezed out. It hardens to become strong. There are several types of silk from specialized glands called spinnerets. Each gland produces a specific silk such as prey wrapping, support, sticky, and egg sac wrapping. 
  • Spiders can't fly but their spiderlings balloon! They spin silk until they are caught by the wind and float upwards. Some have been seen at altitudes of 10,000 feet!
Spiderlings!
By Brocken Inaglory (Own work)
[GFDL (http://www.gnu.org/copyleft/fdl.html) or CC-BY-SA-3.0-2.5-2.0-1.0
(http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons

  • Fear of spiders is arachnophobia, if you have this don't read the next bullet point (or look at the pictures above, although I suppose you don't have it if you made it this far).
  • Studies show that you are never more than ten feet away from a spider. One estimate puts that distance at three feet. To be "spider-free" you'd have to go into space or Antarctica.
Beans and I getting closer than 3 feet to a tarantula
at Science North a few years ago

  • Hummingbirds use spider silk to help weave their nests.
  • In the South Pacific people make fishing nets from a spider's silk. Nephila spiders build webs between two bamboo stakes which can then be used to fish. They also eat the same spiders - apparently they are nutty and sticky like peanut butter.
Yum?
By J.M.Garg (Own work) [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC-BY-SA-3.0-2.5-2.0-1.0
(http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons

HAPPY HALLOWEEN!

 

For more Halloween creatures see our post on BATS!

Spider facts from:
http://animal.discovery.com/arachnids/spider-facts.htm
http://www.explorit.org/science/spider.html
http://news.nationalgeographic.com/news/2004/06/0623_040623_spiderfacts.html
spider clip art from: http://www.halloweenclipart.com/

Friday 25 October 2013

Autumn Fever

This time of year is deer season. Not just for shooting them - it's a big seasonal time for them to be out and about, stocking up some fat stores for the winter and, well, mating. I have seen quite a few on my morning drives lately and Beans and Bunny are always jealous when I tell them it was a deer day (or turkey day - everyone loves turkeys!). So it was very timely that I have a question from my cousin requesting an explanation on the rutting season in deer and some of the strange behaviour that goes with it - and specifically - why do they keep scraping up her lovely newly planted front yard?

You've heard of spring fever? Well in deer it's "autumn fever".


This spot is OK, but the grass is greener over there in Jane's yard...

Here in North America the rut for white-tailed deer (Odocoileus virginianus) is about 1-3 months long and is triggered by the shortening days, like so many fall wildlife activities. The daylight period shortening is a dependable sign that winter is on its way, although the snow today is also a good sign. The specific timing is based on species gestation period - they time mating to coincide with a spring birth, so that temperatures and resources are available. In tropical areas, where deer don't have to think about things like snow and food availability, the rut can last a lot longer. 


During the days leading up to the rut males will do some sparring, like boxers getting ready for the big fight. They also rub their antlers on the tree to lose the velvet (tree rubs) and make scrapes on the ground with their hooves (like Jane's front lawn). These last two activities are ways to mark their territory, advertise to the does and let the other bucks know just how awesome and powerful they are and who rules here. Later on they may do some actual fighting and sometimes they get stuck together and then they both die, so there's another reason that fighting is never the solution - they should use their words.

Deer don't live in big groups, they tend to form small female-led groups (matriarchal) and the bucks hang out with buddies. Because of this deer don't often come across each other and they use pheromones and signs to communicate - territories, locations and mood - which is particularly important in mating season when the future of the species depends on finding each other. The actual time a female is fertile can be very short - a day or two, so there's not a lot of time to waste wandering about looking for an acceptable buck. To shorten the time they wander around in random patches of cedar (I've wandered in a lot of cedar, it's hard to find stuff) they have created an intricate communication system of scrapes, branch licking, rubs and urine using pheromones from tarsal, forehead and pre-orbital glands.



SCENT GLANDS IN WHITE-TAILED DEER
White-tailed deer have a number of external scent glands that are used
primarily for communication with other deer. Gland secretions can describe
a deer’s social status, breeding condition, health and warn other deer
of potential danger.
http://www.mnr.gov.on.ca/en/Business/FW/2ColumnSubPage/STDPROD_097096.html

When a buck makes a scrape by pawing the ground he will then urinate on the tarsal gland (about halfway up the back leg) while pressing their legs together to create their own distinctive musky signature. Yes - they pee on their own legs, which when I pee in the woods I try to avoid at all costs. But then again I'm not trying to alert others to the fact I've peed there. When other deer come along they sniff this calling card and it provides an identity to the holder of the territory as well as health and dominance. If a doe likes what she smells she'll stick around for him to come back. If she's really into him then she pees on his pee as an enticing gesture. While I find this fascinating, I'm really glad it's not a part of the human mating system (for the average person at least). If another buck comes along he gets the same info and can then decide whether he wants to stick around and challenge for does or whether he should just move along and find his own spot. The younger, subordinate bucks do most of their scraping after the dominate males are done. Scrapes are usually accompanied by a "licking branch" - chewing and rubbing the forehead and preorbital (eye) glands on overhanging branches above the scrape. 

Sorry to tell you Jane, the peak of the rut is usually the last few weeks of November, so there's still some lawn scraping to do yet.  

Sorry about your lawn Jane!

More about those wacky deer:
http://outdoorcanada.ca/6633/hunting/big-game/decoding-deer-scrapes
http://www.fieldandstream.com/articles/rut-report/2010/10/buck-scrapes-turn-hot-10-days-prior-peak-rut
http://bowsite.com/bowsite/features/armchair_biologist/deerscrapes/deerscrapes.html
http://www.hww.ca/en/species/mammals/white-tailed-deer.html
http://www.mnr.gov.on.ca/en/Business/FW/2ColumnSubPage/STDPROD_097096.html

Tuesday 15 October 2013

Thanksgiving

OK, so I actually wrote this before the weekend and I planned to add some pictures and  post it on actual Thanksgiving. But then the internet didn't work and I couldn't get anything to load right from my phone so yeah, this is a smidgen late. But then again, my homework always was too.

There are far too many things I am thankful for to ever dream about trying to list them all here. So to sum many of them up in one fell swoop (and to keep with the topic of this blog) - we are thankful for outside. The way it feels and smells (except maybe some wetlands for smell) and sunshine on your face and rain on your nose and leaves under your feet. All of it wrapped up in to one big ball of awesome.


We encourage you, even if you don't get to eat turkey and pie this weekend, to take a step back, observe and appreciate the amazing natural world that we are each a small cog in. And pie. Also appreciate pie.

Every year on Thanksgiving we take a family hike and we'd like to share a bit of that with you and what we saw, talked about and looked at (and if you were here I'd share pie. Maybe.)


"Fairy Tree"
The soil on the shield is so shallow that wind will just tip the trees
right over. Note the piece of rock entangled in the top roots. 


How to mark a trail on the rock

This entire area was logged over a hundred years ago,
so there are very few large trees.

Craterellus cornucopioides 
Black Trumpet Mushroom

Gaultheria procumbens
Wintergreen/Teaberry

A small piece of Georgian Bay

Beans is in an Eastern White Pine (Pinus strobus)
During the logging days these were used as masts for the
British Navy because they grew so straight and tall.



Erethizon dorsatum
PORCUPINE
A large rodent that lives in trees, porcupines have antibiotics
in their skin in case they fall and get stuck with their own quills.

Juniperus communis
Common Juniper
Needle shaped leaves help conserve water compared to a flat leaf,
which helps them to survive the winter. Having zillions increases the
ability to photosynthesize. So it's not just for prickling.


Pause for tree climbing (Beans fell out, she was fine)

Even the aquatic vegetation is looking like fall.

Observation: Groundwater is COLD

Lithobates pipiens
Northern Leopard Frog
Listen to what they sound like here: 
http://www.torontozoo.com/adoptapond/audio/leopardfrog.wav

Taking a closer look at Mr. Frog (and her leaf collection for the dinner table)

No walk with a biologist is complete without poop.
This poop belongs to a White-tailed Deer (Odocoileus virginianus)


Lucky Day! Two kinds of poop!
This one is a Red Fox (Vulpes vulpes)



For me, the highlight of the day (other than pie) was seeing the porcupine just snuffling about on the rocks. Well, and I suppose spending a beautiful day outdoors with my family was alright too.

Happy Thanksgiving!


P.S. pie.

Sunday 6 October 2013

Jelly Jerry

So somewhere mid-summer we were swimming off the dock when we noticed a large jelly-like mass on the ladder. At first we assumed it was eggs, but it didn't look quite right and was more solid then an egg mass usually is. After a bit of research we came up with Bryozoa, which are more commonly known as "moss animals" for their resemblance to coral or moss - although ours is a bit different jelly-like freshwater species and it is indeed ALIVE! There are 4,000 species of these guys identified in the world. We left that one in the water and unfortunately we didn't take any pictures of it as we were swimming and therefore wet, and well, I'm not one to have my phone with me at all times. But generally it looked like this:

By Triclops200

Fast forward a month or two and we were getting the place ready for winter, which included taking the dock ladder in. And wasn't it covered in these jelly guys! So Bunny took it upon herself to "rescue" them from Grandpa's pressure washer and safely stored them in a costco-sized cashew jar for further observation. She named it en masse Jelly Jerry. Beans helped by putting in some small pieces and naming them Veronica (no doubt influenced by the large Archie comic collection stored in the cabin). 


Jelly Jerry in a Jar

So, what the heck are Bryozoa and why is it attached to the dock? 

They are a teensy weensy aquatic critter that lives in colonies. The little guys themselves are microscopic, but they get together in such numbers that the colonies are visible and can actually get quite large! Check out this article of a giant one! The ones we found are a gelatinous species that are native to North America and they do love to hang out on docks or other submerged wood - so we essentially found it in a "natural" habitat. I would assume this would mean originally they like submerged logs and the like, but we have a bunch of boards all together in a large rectangle which it seems to be fond of. They are filter feeders and eat things like algae, bacteria, protozoa and other microscopic things, which make sense as they are also microscopic. And they are helpful little guys in that they improve water quality with their filtering (which is just eating to them). Stuff eats them too and here in Georgian Bay that's snails, insects and fish. In the ocean it would be sea slugs, sea urchins, starfish, crustaceans and fish.

The gelatinous material is secreted by the zooids (fancy name for the little guys individually) and they stick to it. So the "jelly" is like their house. Every summer they release small larvae that swim away and establish new colonies, which may explain why there were SO MANY on the ladder of all different sizes (I'm really kicking myself now for not having my camera). Super cool fact: they don't have a respiratory or circulatory system - they absorb oxygen and eliminate carbon dioxide right through their body.

General anatomy of a bryozoan
 


Bunny is pretty entranced by the whole deal and the fact that these are tiny creatures in there she can't really see. It's kind of like magic creatures to her. So we've put them in a clear jar with some freshwater so she can take Jelly Jerry to school. Hopefully her teacher likes magical jelly lake creatures too.

Jelly Jerry in his new clear water for school

Pleased with her new Jelly "pet"
Photobomb by Beans who cannot eat a cookie
without getting it entirely all over her face.


Where we learned from and LOTS more stuff about Bryozoa: