We tend to think of animals as “set in their ways”, following the pattern of their species and not varying in their behaviour or ecology on an individual basis. In fact, every species is made up of individuals. And once you start to think about it, of course this is the case.
People are often surprised to hear of diet variation, when wild animals feed upon substances that seem to go against their “pattern”. Crocodiles and Alligators will consume fruit, and could even act as seed dispersal agents (Grigg and Kirshner, 2015). White-tailed deer will eat nestling birds if they happen upon them. Chickadees will feed on dead mammals.
A recent observation reported in The Canadian Field Naturalist journal represents another of these striking behaviours that stands out because it is atypical for the species as a whole. The species concerned is one that many people are very familiar with: the Eastern Grey Squirrel (Sciurus carolinensis). There are already accounts of various Squirrel species hunting and feeding on other vertebrate animals, including birds and even other Grey Squirrels (ie. Cannibalism) (Squirrels as Predators, Callahan 1993). Perhaps more surprising is the recent report of hunting an animal that is outside of its normal environment: namely, a fish. In Guelph, Ontario, a Squirrel was seen to dive from a branch headfirst into a shallow portion of a river. After being underwater for a few seconds “the squirrel swam back to the snag with a fish 3-5 cm long in its mouth” (Sutton et. al. 2020). After feeding on the fish briefly, the Squirrel moved out of view into the woods.
There is so much out there to explore, in your own backyard or neighborhood. Animals are individuals, doing individual things. They are not programmed automatons following rigid beahavioural patterns. Even an animal as familiar and commonplace as the Eastern Grey Squirrelcan surprise us if we take the time to pay attention.
Callahan, J. R. Squirrels as Predators. The Great Basin Naturalist, vol. 53, no. 2, 1993, pp. 137–144.
Sutton, A. O., M. Fuirst, and K. Bill. 2020. Into the drink: observation of a novel hunting technique employed by an Eastern Grey Squirrel (Sciurus carolinensis). Canadian Field-Naturalist 134(1): 42-44.
Grigg, Gordon and Kirshner, David. Biology and Evolution of Crocodylians, 2015.
Inspired by one of my favourite blogs on the internet, Tetrapod Zoology, or TetZoo (http://tetzoo.com/), I’d like to create a birthday article every year- not for the day I was born, but for the anniversary of my blog’s creation. In this post, I’ll summarize the past year of my blog, as well as the story of Norfolk Naturalist leading up to the blog’s creation. So here we go…
NorfolkNaturalist Version 1
I’ve tried to start creating blog content many times over the years, but it would usually fall to the wayside of my routine. A few years ago, I created a Tumblr blog in which I wanted to post articles about my own nature observations: norfolknaturalist.tumblr.com. My first post was about Cryptic Caterpillars, and I went on to explore various nature topics through the creatures I had observed myself (usually attempting to do so within a timely manner). Sometimes they were focused on a specific aspect of nature, or a specific animal or plant, and other times they were set up as a slideshow of my trip to a Provincial Park (such as MacGregor Point or Algonquin), giving brief comments about the creatures I observed on my trips. My first tumblr post, Cryptic Caterpillars, was published in March 2018, and it was only a month later that I would acquire my most exciting new tool for nature exploration: a Macro Lens. Up to that point, my nature photos were taken with a telephoto lens, and for insects that meant standing far away and cropping the picture later. Sometimes these pictures hold up, especially for insects like Dragonflies and Butterflies, but my dreams became reality when I was able to photograph Springtails dwarfed by the head of a screw. I had also become a member of iNaturalist at the beginning of 2018. So the ability to photograph the smaller creatures I was so fascinated with, combined with the support and community identification of the amazing iNaturalist website, expanded my horizons as an amateur naturalist.
One of my greatest passions has been learning about the animals and plants and fungi in my own surroundings, and these tools allowed me to do so. My tumblr allowed me to share this passion and interest with others of like mind, and I was excited to be sharing my wonder at the nature that is everywhere.
After a year of posting once or twice a month, I stopped for a while, until in November 2019 I began this current blog as a new platform for sharing my interests and observations. Before we look at Norfolk Naturalist in its current form, let’s take a little detour to Instagram.
Observations of the Day
In late 2018 I began to post “Observation of the Day” pictures on Instagram under the profile “norfolknaturalist” (for my Instagram account go here: https://www.instagram.com/norfolknaturalist/). These pictures very quickly became “Observation of the Week” as I really wasn’t that fast at finding interesting creatures to photograph, taking pictures, editing the pictures and transferring them to Instagram. Especially since a lot of my identifications were awaiting confirmation on iNaturalist. These first few pictures (which were titled with their species name and location observed) were then superseded by pictures from my archive of nature photos taken over the years. These photos were posted with a fact about the organisms involved, which grew into my new formula for Instagram: picture of a creature, and a paragraph of interesting information about them. It was really at the beginning of 2020 that I started to post regularly on Instagram, and it was exciting to be doing so. I had accumulated over the years a variety of photos of interesting creatures from local trails in Simcoe, Ontario, as well as various Provincial Parks during camping trips. Reviewing these photos and learning more about the creatures portrayed within them, then sharing that information was quite fun, and I’m really glad I started doing this, and I’m thankful for all the support and interest I’ve received.
The Current Blog (norfolknaturalist.ca)
I created and posted my first page on this blog, norfolknaturalist.ca, on November 30, 2019. (Welcome to my New Nature Blog) The first post was simply a quick overview of my interests, ideas, and goals with the website: namely, sharing my passion and interest in the amazing animals and plants that provide me with neverending fascination.
And that brings us to the sum total of 7 posts in a whole year. Not very prolific at all. But there’s one very good reason for that.
In April of this year, my son was born. I haven’t been writing as regularly as I might be otherwise, distracted in the best possible way.
My goal for next year’s Birthday Article is that I’ll be able to summarize more than 7 posts, because I hope to write on my blog a little more regularly.
I hope you enjoyed my small tour through Norfolk Naturalist history and I hope you can return soon for some new content! I’ve got a few things in the works: Savvy Squirrels, Sand Wasps, and maybe even Salamanders!
Sawflies are a group of insects that many people haven’t even heard of. Part of the reason is because, in appearance and behaviour, they are like a hybrid between two major groups: their larval stages look like caterpillars (larvae of Butterflies and Moths ie. Lepidoptera), and their adult stages look like bees or wasps (Order Hymenoptera). Despite appearances and lifestyle, it is the latter category that they actually fall under: Hymenoptera which also includes the Bees, Wasps, and Ants. The major features that set sawflies apart from their relatives is that they eat plants, and they don’t have the constricted “wasp waist”. You might find this a little confusing, as Bees certainly don’t have an obviously thin waist, but they actually do have a constriction between their thorax and abdomen, it’s just more difficult to see than in many wasp species.
Like many insect Orders, the name Hymenoptera refers to a distinct aspect of the members’ wings (‘ptera’ is derived from the Greek for wing). Hymenoptera doesn’t have an easy translation though, like say Diptera for the True Flies (di = two, ptera = wings). The beginning part of the word is either from the word “hymen” which means membranous, or from the word “hymeno” which refers to the Greek God of Marriage. Hymenopteran wings are membranous, but they also have tiny hooks that link their fore- and hind-wings, meaning that they could be said to be “married” wings as well (Grissell, 2010). Whatever the case, the group is one that includes thousands of species of wasps, bees, ants, and of course, sawflies.
The common name “sawfly” is describing the way the female sawfly lays her eggs. Instead of a stinger or stinger-like ovipositor (egg-layer) at the end of her abdomen (like most of the other Hymenopterans), the female sawfly has a saw-like ovipositor, a cutting tool that she uses to open up plant tissue, and then inserts her eggs within.
This is what the Introduced Pine Sawfly (Diprion similis) does to pine needles. D. similis prefers White Pine (Pinus strobus) as its host plant (in North America), but will lay eggs and successfully grow to maturity on several other pine species. The female lays about 10 tiny eggs inside a pine needle (Cranshaw, 2004). After inserting the eggs, the female seals them in with a secretion that hardens for protection (Wagner and Raffa, 1993). The larvae that hatch from the eggs begin to feed on the pine needles. For the first part of their life, they will remain together but begin to disperse as they grow older. These larvae prefer to feed on needles that are at least 1 year old, probably because the younger needles are full of more toxins (Wagner and Raffa, 1993). As they consume needles, they grow, from 2.5 mm long upon first hatching to almost 3 cm before the larva is said to be “mature”. They don’t grow continuously, but rather have to molt and enter a new size class each time they’ve gained enough nutrients. For female larvae, they have six growth stages between molts and the males have five (CABI, 2020).
During this time, you would be forgiven for thinking they were caterpillars, because they look very similar. The way to tell caterpillars from sawflies is to count the number of legs. Their first set of legs will be six, and jointed for both groups, but they will also have a number of legs behind these called “prolegs”. If the larva you’re looking at has more than 5 pairs of prolegs, it’s a sawfly. Another giveaway is the distinct single eyes of sawfly larvae, as opposed to tiny ocelli (miniature eyes in clusters) in caterpillars.
Once they’ve reached their final larval stage, they spin a cocoon around themselves with silk, and transform within. Diprion similis larvae prefer to form their cocoons in the pine trees where they feed, rather than on the ground like many other sawflies.
In Europe and most of North America there are two generations per year, which means that what happens next depends on what time of the year it is. If the larvae have grown enough and created their cocoons in the summer, they will develop within in about 2 weeks into adults, but if they have reached this point near the end of fall, they will enter diapause (essentially insect hibernation) for several weeks before emerging in the spring (CABI, 2020). When they emerge, the adult sawflies are entirely different creatures, just as butterflies and moths are very distinct from their caterpillar young. The adults have wings, and with these they search for mates.
Males are attracted to females by pheromones (a chemical signal between members of the same species), as one would guess by the male’s elaborate antennae. The males can be attracted to a female across 61 m of open field, which is a great distance for an insect only a matter of centimeters long (Wagner and Raffa, 1993). Once mated, the female lays eggs in pine needles, and we are back at the beginning of their life history.
One note about mating: it isn’t necessary for the female to mate to be able to lay eggs. She shares with the other Hymenoptera a bizarre (to us) chromosome setup known as haplodiploidy. Females have one set of chromosomes (the mother’s) and males have two (mother and father). What this means in practice is that a female sawfly can lay an egg that will develop into a fully functional male offspring without ever going through the trouble of mating. This has implications for the spread of such organisms, as not all members of the population need to pair up to contribute to the next generation.
Which brings me to my final discussion of this species: they are commonly referred to as the Introduced Pine Sawfly because they were accidentally introduced into North America from Europe, likely in plant nursery stock imported in 1914. They have become well established in North America since then. Thankfully, they only very rarely reach a high enough population density to be considered an “outbreak” invasive species, and though they feed on tree leaves (needles), many predators and parasitoids feed on them (Wagner and Raffa, 1993).
The last time we were camping at Algonquin Provincial Park, I encountered quite a few of their larvae likely because they were in the fairly mobile phase before finding a spot to spin a cocoon (it was the end of September, the beginning of October). They may be an introduced species, and they may feed on White Pines, defoliating some of the branches, but as with any organism, they have a story all their own, and I think it’s worth telling.
Wagner, Michael R. and Raffa, Kenneth F. Sawfly Life History Adaptations to Woody Plants, 1993.
Cranshaw, Whitney. Garden Insects of North America. 2004.
Marshall, Stephen. Insects: Their Natural History and Diversity. 2006.
Pinery Provincial Park is a great place to visit any time of the year, and Winter is the season when you can get closest to a few of the bird species that make their home there.
We always bring along bird-seed to Pinery when we go in the Winter, because there are a number of birds that will come very close when presented with a nutritious food supply. Some (Black-capped chickadees and White-breasted nuthatches) can be induced fairly quickly to landing on your hand and feeding from it. This year, we were a bit early in the season and most of the birds except a few brave chickadees were too wary to feed from our hands. Despite this, we were able to feed many birds by leaving out a pile of seeds on the railing on our site (we were staying in one of the yurts they have there). If you’re planning to do this yourself, remember to not leave the birdseed out overnight. During the day, you will attract small foraging songbirds but at night, you’ll most likely be feeding raccoons, who can devastate snapping turtle populations in the park, if they overpopulate themselves.
The first birds we attracted to our food supply were the bold chickadees, ever-eager to exploit any opportunity available.
Next came the nuthatches, with their impressive ‘talons’ which they use to grip bark as they scale down tree-trunks to pry out insect food.
Tufted titmice were quite abundant as well. I’ve never been able to feed one from my hand, but they were quite content to fling seeds about in the pile, picking out the ones they desired.
The final visitor to our railing was a downy woodpecker. Downys are the smallest woodpeckers in Canada, at approximately 15-17 cm (Backhouse, 2005). Still jabbing as though he were piercing bark, the woodpecker walked awkwardly along the railing. It truly appeared strange to be perched and moving horizontally, as they are so superbly adapted for their vertical orientation on tree trunks.
Although only a few landed on our hands to pick at seeds, we were pleased to see these little birds foraging nearby, bringing cheer to the wintry woods of Pinery Provincial Park.
Backhouse, Frances. Woodpeckers of North America. 2005.
When you’re interested in insects, you’re always going to be running into something new. There is always one more creature that you have never seen before, one more behaviour you haven’t heard of, and that’s because insects are incredibly diverse. Today, I’m going to pick out just one of the many species of insects to zoom in on, and explore it’s story.
The species I’ve chosen is Ocyptamus fascipennis, or the Eastern Band-winged Hover fly. Let’s start from the top: Ocyptamus fascipennis is a “True Fly”, a member of the Order Diptera, which is a division of the Class Insecta. Diptera means “two wings” which gives you the easiest way to identify this group of insects when you encounter them. Almost all insect groups have 4 wings (two pairs) but these pairs of wings have been modified into very different structures in different lineages of insects. For the True Flies, one pair of wings still provides lift and flight, while the other has been reduced into tiny knobs known as halters. These reduced wings act as stabilizers, giving the flies the ability to perform aerobatic feats of agility (as I’m sure we’re all familiar with in House Flies (Musca domestica)). The halters of Diptera are more than just balancing beams, they’re actually sending complicated signals to the fly about its aerial position.
Ocyptamus fascipennis is part of a Family of True Flies called Hover Flies, or Flower Flies (Family Syrphidae). The Syrphids are common insects in gardens where they feed on nectar and pollinate flowers. Because of this habit, many species of Syrphids have taken on the appearance of more conspicuous flower visitors such as bees and wasps, in order to gain some protection from the classic warning colours of black-and-yellow stripes. O. fascipennis in particular seems to mimic solitary wasps or types of parasitoid wasps with its elongated and narrow abdomen.
So far, we’ve been talking about adults of these flies, but all insects go through multiple life stages, some more dramatically varied than others. Diptera undergo holometabolous growth which is a fancy way of saying that they have life stages that look very different from each other and one of those stages is a transformation phase which is mostly immobile. When young hoverflies (larvae) hatch from eggs, they look very different from the adults landing and lifting from flower petals in gardens. Larval O. fascipennis have no wings, and no legs, and are sometimes known by the name that many fly larvae receive: maggots. O. fascipennis larvae don’t consume garbage or dead animals, but instead are active predators, squirming across leaves in search of their prey: aphids.
Stephen Marshall, in his incredible book about Insects describes Syrhpine larvae hunting as this: “at night they move blindly among the aphids, grasping victims using typical maggot mouth hooks, then holding the doomed aphids up off the surface to consume the body contents.” (Marshall, 2006).
It seems then that Flower Flies are very beneficial insects to have in the garden. They provide pollination for flowers, and their larvae consume plant-eaters such as aphids and related scale insects.
While I was unable to find very much information pertaining to Ocyptamus fascipennis specifically, one other member of the genus deserves special mention because of its interesting larval habitat: tank plants (Bromeliaceae). The Central American and South American species of Ocyptamus that inhabit these confined aquatic habitats (pools of water within the plant itself) ambush and consume other aquatic insect larvae that live in the plants alongside them. The larvae are even thought to use a paralyzing venom to subdue their prey (Rotheray et al, 2000).
All in all, Ocyptamus fascipennis and its relatives are fascinating flower flies with intriguing habits. I hope you’ve enjoyed taking a closer look at them today.
If you’re interested in the living things that inhabit this world with us, then you’ve come to the right place. I’ve always found it fascinating that there are so many different kinds of creatures, living out lives in different ways to us humans. In some cases, it’s difficult to believe that we share the same planet, let alone the same backyard. There are countless species that surprise and delight in your own neighbourhood, and there are many more around the world. I’d like to explore this diversity, and try to share my own excitement about these creatures, whether they are insects, fungi, plants, birds, mammals, or any of the other species that crawl, fly, swim, run or grow across the planet.
To do this, I’m planning on producing posts detailing a specific species or group of species to get a taste of what sort of creatures are out there. I will also occasionally post about my own observations (and photos) of species that I’ve encountered in my own travels in Southern Ontario. Another thing I’d like to do is review books that are relevant to learning about nature, as I have a personal library stocked with some great books about the diversity and wonder of life.
I hope that when you visit this blog you learn a little something, gain a greater appreciation for living things, and get inspired to pay a little more attention to the world of nature that’s all around us.