Thursday, October 12, 2017

Autumn's Arrival

It's finally fall! It's officially been fall for a couple weeks now, but for me the season doesn't really start until I start seeing migrating birds in my yard.

Today I glanced out my front door and was overjoyed to see a plump White-throated Sparrow scarfing up sunflower seeds. Yay! This is only the first of several, I am sure. I've been trying to log some birds on eBird every day this year, so I look forward to spotting many more of these winter birds and their cohorts.

My first White-throated Sparrow of 2017.

The weather couldn't feel more autumnal today, either. Last night was full of moody rain, which I love to listen to as I fall asleep. Today the rain has mostly stopped, but the clouds are still full and gloomy. I love the cool, dim light, it makes me want to cuddle up inside with a good book, some cider, and a fire in the fireplace. This kind of weather usually makes my cats more cuddly, too!

I hope you are enjoying the season's change wherever you are. Are new birds arriving in your yard too? Let me know in the comments what you're seeing.

Thursday, May 4, 2017

Butterfly Update-- Eggs and Eclosures!

My garden's first Black Swallowtail egg of 2017

As I mentioned several months ago, I had a LOT of Black Swallowtail caterpillars at the end of the summer. I think I ended up with 26 (!) chrysalises to babysit over the winter. Sadly, three of them eclosed too soon. The first one was when the sun's seasonal shift sent a beam of light into their cage and warmed one chrysalis up way too early: in January/February. I handfed the butterfly (sugar water, in a 4:1 water to sugar ratio) from a cottonball for several days, and eventually set it free during one of the weird early thaws we had this winter. I knew it was unlikely the butterfly would live very long, let alone find many flowers for food, but I wanted a more natural life for the butterfly than constant captivity. Since that butterfly eclosed during a snowstorm, we named it Snowflake.

Then while we were away from the house for about a week a second butterfly eclosed. Unfortunately since it never got any food it died before we returned. Sorry, little one.

The last early eclosure happened during the storm Stella, in mid March. It was a male but I couldn't resist naming the butterfly after a blizzard, so Stella he was. Again I fed him by hand. Something interesting about both of these butterflies: they didn't seem to recognize when I put them on the moistened puff that it was food. I had to gently unroll the proboscis with a straightened paper clip and place the tip on the surface of the cotton ball to get both of them to eat. But as soon as they tasted the sugar water they were happy to suck it up. The second butterfly we also set free a few weeks after eclosure. It was still pretty early but I know Stella survived for at least 24 hours because I saw him soar back through my yard the next afternoon.

A few weeks later, once temperatures at night were reliably in the 40s, I put the cage of remaining chrysalises outside to start their natural end of diapause. Last week several butterflies eclosed: three females. Then two males this weekend, and finally another female two days ago. Today while bringing my tomato and basil seedlings outside for some sunshine I spotted a female Black Swallowtail in my garden laying eggs in my carrot greens. I followed her around and managed to find two eggs. I'm pretty sure she laid more than that, but they're really hard to spot.

So the cycle begins again! I hope I get more eggs soon, I have plenty of carrots and dill sprouting in the garden.
The second egg this year. I'm so excited for little tiny caterpillars to hatch!

Sunday, April 2, 2017

How to raise caterpillars from eggs to butterflies

So you want to raise caterpillars. Congratulations! Maybe you want to help support the Monarch butterfly migration, or you want to share a biological investigation with your children, or you think it looks like fun. Whatever your reasons, I'm happy to help.

For the purposes of this post, I'm not going to go into how to get butterflies into your yard, that's another post. I'll assume at this point that you have a caterpillar or eggs in hand.

Please don't buy caterpillars online-- they may be sickly and you are very likely to find caterpillars in your own yard or garden, or in that of someone you may know. Many gardeners, if you ask them, would be overjoyed for you to remove caterpillars from their plants!

A Black Swallowtail caterpillar about to devour carrot greens.

Finding and Feeding caterpillars
Different types of butterflies need different hostplants for their caterpillars to eat. In my area the most common kind of butterfly is the Cabbage White (Pieris rapae). They aren't native to the U.S., but I think they're fine for your first try. It's easy to find a plant they'll eat: anything in the cabbage family -- radishes are probably the easiest and quickest to grow, and they're happy in a flowerpot if you don't have an in-ground garden. If you spot a radish whose leaves look pretty chewed up, that's a good clue you might find Cabbage White caterpillars on it.

Other caterpillars that are popular to raise include Black Swallowtails, which eat anything in the carrot family; and Monarchs, which eat any species of milkweed. My posts about raising caterpillars are collected here. Always make sure to identify caterpillars you find so you can provide the right hostplant. When I was a little girl I tried to raise caterpillars every summer by feeding them grass, because I didn't know they wouldn't eat just any plant. Of course, they all died. But you can do better!

Releasing one of my successful Black Swallowtails a few years ago.

Caterpillar Cages 
You'll need a container of some sort to keep your caterpillars in, that's closed to keep them safe. A jar  is fine with a paper towel or pantyhose fastened over the top. Your caterpillars will poop (a lot!), so to make cleanup easier, line the container with a piece of paper towel or even a coffee filter. Newly-hatched caterpillars are tiny, and their poops are barely bigger than dust, but soon the larvae will grow and so will the size of their frass (the actual name for caterpillar droppings). Leaving frass in the bottom of the container provides a great medium for nasty bacteria to grow, not a good idea.

My first set-up, with floral vial and paper towel.

When you are ready to move up in commitment (or your caterpillars get too big for their first container), you could use an old fish tank, even one that's no longer watertight. You can also buy professional caterpillar cages made of mesh. I have several of these cages-- one purchased at the thrift store, and four of different sizes that I bought online. You can see one above, where I'm releasing a butterfly. The benefit of the professional cages is that they let plenty of air through. They're collapsible too, so you can easily store them in the off-season.

Some DIY instructions are available here; a good discussion of different ways to set up a cage is here. The latter link is to Raising Butterflies' web site; their store also has good and relatively affordable cages. I can't remember where I originally bought my cages, but they look like the ones on Raising Butterflies.

This very hungry caterpillar is about to devour my carrot greens!

Feeding caterpillars, part 2
When raising caterpillars, you need to provide pesticide-free food for it. Ideally you'll have grown the plants yourself, but I realize not everybody has the space or time to do so. You may get permission from your neighbors, or even be lucky enough to find a vacant lot with the right hostplant.

If you don't have enough hostplants and neither do folks you know, another way to find food is to ask people you DON'T know. Join the Facebook group Raising Butterflies and Moths for Conservation; you'll find lots of helpful information there as well as like-minded folks. A simple post asking folks who live near you for help finding caterpillar food may solve all of your problems, as the friendly members tell you where you can find safe plants or offer you some from their own yards. Don't buy plants at the grocery store, even if they're organic. Organic farmers may treat their crops with Bacillus thuringiensis (or Bt), a bacterium that's deadly to caterpillars but harmless to people.

You don't need to put an entire plant in your caterpillar cage, cuttings are fine. Keep them fresh by placing stems in a cup of water, and make sure you protect the top of the cup so caterpillars can't fall in and drown. I use floral vials I get from buying roses; these are available online or at craft shops.

I prop my floral vials in a small glass inside the cage to keep them from falling.

Pupating
Your caterpillar will go through several instars, or stages, and molt each time between instars. Some species look different in different instars, like the Black Swallowtails I raise.The final molt will be into chrysalis.

Early instars of Black Swallowtails, like this little guy, are black and white; later they get green stripes as well.

When your caterpillar is close to that last molt, it will start wandering around. This is when it's essential to have your cage securely closed. My Black Swallowtail caterpillars walk a really long way, it seems, although I've never measured it. They're looking for just the right spot to make their chrysalis. At this point you should add a few twigs to the cage leaning against the walls at roughly a 45 degree angle.  If you can find twigs that have a few branches, that will give your caterpillars plenty of choice.

This little guy nearly escaped when I took the cage lid off for photographs.

One sign that your caterpillar is almost ready will be a final poop-- this will be very liquidy, not the compact frass you're used to. The caterpillar needs to get rid of any waste before spending days or even months in the closed case of its chrysalis.

Waste voided, this caterpillar is nearly ready to pupate.

Next the caterpillar will attach itself to a twig or the wall of the cage. It will spin a small button of silk and attach its abdominal end (cremaster) to that. Monarchs will then hang down vertically, eventually curling into a "J" shape. Swallowtails will spin themselves a sort of safety belt to support their front end and hang parallel to the wall or twig.

You can see the white silk belt the caterpillar spun to hold itself to the twig.

It takes a few days before the caterpillar actually molts. If you watch it closely you may see it occasionally twitching, like someone dreaming. I'm not sure what's going on here, but perhaps it's separating inside from the old caterpillar skin. When they molt, the chrysalis shell has already formed underneath the skin.

Halfway through shedding its caterpillar skin, you can see the chrysalis already emerging.

Depending on the species and generation, you may have to wait a couple weeks to several months for the butterfly to emerge, or eclose, from the chrysalis. I'll talk about that another time, plus what to do if a chrysalis falls.

Have fun! Let me know how your caterpillars fare.

Monday, January 16, 2017

How To Make Suet Cakes For Birds

A perky little Carolina Wren on my homemade suet
 
Ingredients
Animal fat (such as raw beef fat, raw pork fat, bacon drippings, or collected drippings from browning unspiced meats)
Peanut butter (either creamy or chunky)
Cornmeal
Oats
Birdseed (mixed seed and/or sunflower seed)
Bits of dried fruit (optional) 
Cracked corn (optional)

Equipment
A pot large enough to hold all the fat with extra room for the other ingredients
Spoon or rubber spatula
Freezer
Stove
Knife to cut cakes apart
Pan to hold suet mix while it chills
Plastic container, large plastic zip-close bag, or individual plastic zip-close bags to store suet cakes
Waxed paper to keep individual cakes from sticking to each other during storage

I signed up for Project Feederwatch again this winter. To keep lots of interesting birds coming to my yard, I have three seed feeders and two suet feeders. But since money is a little tight right now, I decided to see if making my own suet cakes would be any cheaper than buying them pre-made.

First off, you need animal fat. I’d been saving beef and pork trimmings for months, thinking I might make homemade stock.  I also added the drippings from cooking a pound of bacon, and the grease poured off from browning some ground beef earlier this week. If you haven’t been saving fat scraps for months like I did, you can sometimes buy chunks of raw beef fat (suet) from the butcher’s counter at your grocery store for fairly cheap. Of course, you could also just cook up a few pounds of bacon in order to make suet, yum! The birds get suet and you get bacon. Not a bad trade, if you ask me.

Chunks of fat starting to melt in my pan


Put all the fat in a pan over medium heat to render it. If you use fresh trimmings like I did, you’ll have chunks of meat and gristle to spoon out periodically as the fat melts off them. These  could probably be used later to make stock or broth, or as treats for very good pups or kitties. :-)

Eventually, the fat will all be melted, or rendered. While the fat is still warm, add peanut butter (about half the amount of the animal fat) and stir it in til it’s all melted. As I mentioned in the ingredients list, you can use either creamy or chunky peanut butter, whatever you have on hand already.

Gobs of peanut butter starting to melt into the fat


When the peanut butter is melted in, turn off the heat and add your dry ingredients. I had about 2 cups animal fat and 1 cup peanut butter, so to that I added 1 cup each of cornmeal, oats, mixed birdseed and sunflower seed.  You could use more or less of the seeds, or you could add other seeds you might have on hand that are safe for birds to eat. Just don’t use anything that would be invasive, and don’t use seeds that were sold for gardening as they may have been treated with fungicide or something else that’s not good to eat. You can also use dried fruit cut into little bits. This is a great use for hard, ancient raisins or dried apples that might have been forgotten at the back of your pantry! Some people like to add cracked corn to their suet cakes too.


Mix everything in the pan fairly quickly, as you don’t want it to solidify there. Pour the thick mixture into a pan to set. Most suet cages allow for a block about one inch thick, so keep that in mind when selecting your pan. You could also use smaller individual molds if you like. In that case I would recommend using molds that are flexible: either thin plastic containers, or super-cheap metal pans that are flimsy enough to be twisted a little. This will help you pop the cakes out later.

Set your pan(s) in the freezer to solidify. I left the house for a few hours so don’t know exactly how long mine took, but I would guess after an hour it should be solid enough. When the suet has hardened, cut it apart into cakes that will fit your suet cage or pop the cakes out of the individual molds. 

Basically energy bars for birds!


If you’re storing the cakes in one big container, layer them with waxed paper so it will be easier to get a single cake out when you want it. You could also put each cake in its own box or bag if that’s easier for you. Store the cakes in the fridge or freezer.

Fat is very high energy, so it’s great for feeding wild birds in the cold wintertime. I wouldn’t use this recipe to feed birds in the summertime, though, for two reasons. For one thing, summer heat means the fat will go rancid fairly quickly. Also, if nesting birds get the warm fat on their belly feathers, they could transfer it onto their eggs, smothering the chicks developing inside. Frigid wintertime is perfect for suet cakes though!

Such a fuzzy belly! I don't mind squirrels eating from my feeders, their antics are so amusing.


My suet was super popular with the birds and squirrels in my yard. The whole batch lasted only one week. I also made a mini batch again after the first batch was gone, using trimmings from just one chuck roast plus peanut butter & the dry ingredients. Keeping the proportions of two parts animal fat, one part peanut butter, one part cornmeal, one part oats, and one to two parts seeds/dried fruit/cracked corn, you can make as big or small a batch as you like. Using scraps you'd otherwise discard plus ingredients you probably already have on hand means these cakes are way cheaper than buying the pre-made ones from the store. It’s actually a lot of fun too, and feels really good to see the birds enjoying my handiwork.

Do you put suet out for your backyard birds? Let me know what birds you see at your suet, in the comments below. Have fun! 
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