Garden Allies

This winter, whenever the Fahrenheit scale tops 50 degrees, I try to spend some time in the garden.  What could I possibly have to do at this time of year?  Well, it allows the chickens to get outside of their 32 square foot pen while I am around to watch for Mr. or Mrs. Hawk, and it allows me to work on expanding the garden. I am planning for a grand affair this summer – with my garden – so I am adding garden beds, expanding my growing space from 128 square feet to 620 square feet (so far).

Last Saturday, even though it only got to 41°F, it was sunny, and I decided to get some garden preparations done.  I was turning over some soil in order to level an uneven path that has annoyed me for years.  Of course, the chickens came over to investigate and quickly discovered the juicy worms that were being disturbed.  So, we had to dig together.  Or rather, I had to dig very slowly to avoid accidently pinching a chicken foot!  It was charming though.  I was in no rush, and I wondered how quickly those worms would transform into healthy omega-3 fats in my eggs.

Whenever I see an earthworm, I am reminded of a National Geographic article (see below) on earthworms and how they are not native to the North American continent. This news surprised me when I first read it years ago.  Many ecologists scorn non-native species, or at least invasive species, and so I had to grapple with my feelings about this information.  My earliest memory of earthworms is collecting them in the third grade playground for our science class’ terrarium.  I was the only girl who would pick up the earthworms, a feat that made me suddenly – if only temporarily – the cool kid, instead of the quiet, shy kid that I was.  Since then, I’ve come to not only like worms, but to value their ability to break up my clay soils and to help transform the materials I add to my lasagna-style garden beds into soil.  Am I to now doubt their “right” to be here?  Are they causing ecological chaos?

My earthworm knowledge is limited.  I know they are hermaphrodites, yet two individuals are needed to transfer sperm.  I know they have several hearts.  I know they are sensitive to light.  I know that you can buy earthworms to have an indoor compost bin, or worm castings to augment your soil.  Recently, I’ve seen catalogs that sell worm cocoons – earthworms lay cocoons after mating, from which one to five small worms emerge.  These cocoons are on my “To Observe” list now.  I shall have to look purposefully because they are smaller than a grain of rice.

What about being non-native?  I reread the National Geographic article I mentioned above.  I also found it online if you’re interested:  http://ngm.nationalgeographic.com/2007/05/jamestown/charles-mann-text/1

It is long, but quite good.  My memory was wrong in the extent of this invasive status of earthworms.  Earthworms were non-existent before, or wiped out by, the last ice age, over 10,000 years ago.  This means any areas north of the southern boundary of the ice sheet evolved since the last ice age without the help or impact of earthworms.  That is until the Europeans introduced them.  It is hypothesized that worms were in the ballast of ships arriving to the New World to load up on tobacco and other colonial exports, and have very slowly made their way to the northeastern United States and into Canada.  Since Virginia is south of the last ice age boundary, we have native earthworms, along with the introduced earthworms.

What harm could these little garden allies do?  We can think of the forest ecosystem as a unit, much like any one individual is a system of parts. The leaf litter, which should be several inches thick, is akin to an organ, a skin barrier that holds in moisture, prevents soil erosion, and supplies nutrients, among other functions.  Earthworms introduced from Europe break down this leaf litter layer too quickly, and change the forest floor ecosystem.  Ecologists have been studying the effects of the earthworm’s actions.  Observed changes include alterations in the nitrogen cycle, conversions of soils from acidic to more neutral pH (most healthy forests thrive in soils with a pH between 4 and 6), and disruption to native wildflower roots.  With a reduced herbaceous layer, there is a resultant reduction in insect pollinators.  It appears the little fellows are quite industrious and can accomplish quite a lot, showing how an introduced species can quickly alter ecological systems that evolved over long time periods.

I would love to have a northern forest ecosystem in which to wander.  They are lovely spaces.  Instead, I have Halcyon and my garden, spaces I love dearly.  I want any help I can get with my soil, which has been compacted by years of dairy farming.  All earthworms are welcome.  I know I am changing the land with my actions, just as the colonists did and the Native Americans before them.  Hopefully, I will do so kindly.

This earthworm research has left me with more questions.  I will close with one:  Why do earthworms come to the surface when birds drum or create vibrations?  Evolution should select for worms that do not come to the surface, causing this behavior to largely disappear because the earthworms that survive a “vibration episode” would be the cautious ones, and they would produce cautious offspring.  So I speculated that rain must also cause vibrations, and that earthworms were better off risking being a possible meal than drowning.  I am wrong.  Apparently earthworms do not get flooded out of their homes, but emerge on purpose to more easily migrate to new spaces.  So why do they answer the call of the hungry bird?

Daily Visits From the Mob

The red-tailed hawk that lives at or near Halcyon has it rough.  Not only did I interrupt his chance for a nice chicken dinner a few weeks ago (see: http://www.halcyonnature.com/2013/01/06/chicken-matters/), he is constantly bullied.  Not by me mind you, or by the chickens, who might be justified in engaging in such behavior.  No, it is Corvus brachyrhynchos, the American crow.

The following scene has occurred often over the years we’ve been at Halcyon, and no doubt for hundreds of years before, but lately it seems to occur on a daily basis: a group of crows harassing a red-tailed hawk.  Is it the season?  Is it because I am here to notice? Or, quite possibly, is it because I am raising hawk-tempting food?

Red-tail hawk surveying for prey

Red-tail hawk surveying for prey

Sometimes the scene reminds me of an animal world version of an elementary school field trip:  8 excited children being rowdier than they’d dare in the classroom under the care of a patient adult.  The hawk will be perched in a tall dead tree quietly surveying the territory below.  Crows arrive one by one, cawing noisily.  I admire the ability of the hawk to sit seemingly serenely on its perch while the crows fly in, cursing at it, and gathering on nearby tree limbs.  My nerves would be rattled – I do not enjoy chaos.  If I were the hawk, I would have no patience with the noise, and I’d be quite irritated that my presence had now been announced to all potential prey in the vicinity.

Crow harassing a hawk.  Eventually eight other crows joined in.

Crow harassing a hawk. Eventually eight other crows joined in.

Other times the scene seems more violent and I feel anxious for the hawk, or at least anxious for the tension that is created.  During these episodes a group of crows will fly after and sometimes dive bomb a hawk in the air.  This behavior seems very daring and can go on for several minutes.  I always thought crows did this to cause the hawk to drop a recently caught prey, but any time I’ve seen this behavior, the talons of the hawk are empty.

This audacious behavior by the crows is known as mobbing.  I find it a very fitting term.  I can almost imagine long black jackets and sunglasses on the crows as they fly after and bully the hawk.  A flock of crows is sometimes called a murder of crows, another fitting term.  The intensity of the mobbing can make me wonder if someone or something is about to come to a terrible end.  Crows have been known to mob a fellow crow to death and eat the corpse.

Mobbing is an antipredator behavior and the term is used whenever a group of one species harasses a predator.  It is a cooperative behavior to protect young, procure food, or escape or distract a predator.  Mobbing is seen mostly in birds, but can occur in other animals, including, and often disturbingly, in humans.  I tend to avoid large crowds because of an aversion to mobs and the potential for group excitement to lead to disaster.  The last time I found myself in a small mob was when we were trying to buy iPhones at the newly opened Apple store in Barcelona.  I was in line behind a group of men who were quite angry with the security guard, who was making sure no one cut in line.  My heart raced – largely because I had little understanding of what was being said – and I remember thinking of the absurdity of incurring potential harm for a phone.  Now I wonder if the crows that killed that other crow intended harm or just partook in a behavior that got out of control.

Crows exhibit signs of intelligence in their food procurement behavior, in their ability to learn tricks, and to, ostensibly, just have fun as noted in a recent you-tube video of a crow snowboarding down a rooftop with the help of a plastic lid: http://www.youtube.com/watch?v=8kEpxDe6dxo

Some species have learned to make their own tools to obtain food or use our tools to help them.  For example, dropping nuts into the street and then removing the meat once cars have crushed the nuts.  My understanding of ecology would suggest that since the crow is very successful in obtaining food, they then learned to play because of all the “free time on their claws”.

If you’ve ten minutes of your own free time to spare (and thank you for spending some of it reading this post), this TEDTalk on crows: http://www.youtube.com/watch?v=NhmZBMuZ6vE  is a fascinating call for creative mutualism between humans and the very species we often scorn, instead of admire, for their tenacity in the face of human expansion.

So while the call of the crow is quite loud and can disturb a peaceful moment in my garden, I have come to appreciate their vigilante behavior – preferring to think of them as Robin Hoods of the land, rather than gangsters – because their warnings are a constant reminder to me that the hawk would really like some chicken for dinner.

Who me?

Who me?

An Eggstraordinary Week

The first one was magical.  I’d been waiting for five months and suddenly there it was. A little brown, nature-packaged meal of protein, riboflavin, selenium, phosphorus, and Vitamin B12 left in a tenderly prepared nest.  Finally, we’d gotten an egg.  I’m pretty sure that the chickens did not understand my excitement; my husband and son did though.  We scrambled it and divided it three ways and had a taste test comparing it to a store-bought egg.  I’d never had as fresh an egg, and I found its texture creamy, its color a golden yellow, and its flavor exquisite – I can’t quite come up with an egg-equivalent terminology such as is used in oenology, but it had a very satisfying finish.

Prepared chicken nest

Prepared chicken nest

Our first egg arrived on January 20, 2013.  As of this writing, we’ve received 23 eggs, gifts really, from our girls.  I am trying to imagine what it must be like to produce such a masterpiece – a magnum opus as Charlotte called her egg mass in Charlotte’s Web – and then to have it snatched.  Is this akin to a human having a baby snatched after the hard work of labor?  Or is it more akin to “merely” the removal of an egg, one of many, through a process that causes varying degrees of pain or discomfort for each individual human female?  These thoughts make me also wonder if it is painful for a chicken to lay an egg.  We can’t ever really know of course, but my girls do not squawk when laying or seem overly stressed.  In fact, the only time they seem stressed is when I bring them a treat, but do not let them out to roam.

Three eggs in one day!

Three eggs in one day!

So how impressive is a catch of 23 eggs in 19 days?  I was told that production would be erratic at first.  This makes sense; their young bodies are adjusting to producing the correct balance of hormones and nutrients required to create an egg.  Normal production means an egg every 24 to 36 hours.  If I assume that all three girls started laying around the same two-day period – because of their age, not because of any (now disputed) theories of pheromone synchronizing – then each hen laid more than 7 eggs in that 19 day period, or an egg every 2.5 days.  This is not a bad start at all to what is supposed to equilibrate to 5-7 eggs/bird/week.  Egg production looks even more promising if I look more carefully at the trend in the data from the first week through this last week.  It is then that I notice we’ve had an eggstraordinary week!

Here is the data I collected:

  1. During the first seven days, we received five eggs.
  2. During the first 11 days, we received nine eggs total.
  3. On 1/31/13 we had the first day with three eggs!
  4. In the last eight-day period (1/31/13 to 2/7/13) we received 14 eggs.

Based on Australorps’ laying history, each bird should produce 5 to 7 eggs/week during her prime.  Having three birds means we should receive 15-21 eggs/week.  So here is how my girls are trending:

  1. Looking at the whole period all together: 23 eggs in 19 days = 8.5 eggs/week.  But . . .
  2. Looking at the first eleven days: 9 eggs in 11 days = only 5.7 eggs/week.
  3. Looking at the last 8 days since the first day we received three eggs in a day: 14 eggs in 8 days = 12.3 eggs/week!

I did not think the girls would produce so regularly so quickly.  The data shows a trend toward the 15-21 eggs expected for their breed, and I expect to be netting 15-21 eggs/week very soon.  How eggstravagent!

Egg on right is our fresh egg

Egg on right is our fresh egg

Egg on right is fresh.  Notice extra layer of albumin and how yolk is more raised.

Egg on right is fresh. Notice extra layer of albumin and how yolk is more raised.

 

 

 

Little Kings

My field is alive with the sound of birdsong.  It has been every evening for months and I’ve just figured out what bird is creating this wondrous melody.  When I first heard it I was on my way out just as it was getting dark.  The whole field seemed in the middle of a symphony, with notes popping up everywhere, and I was mesmerized for several minutes.  I asked my friend, an expert birder, what species she thought it was.  Based on my pathetic attempts to describe the song (and probably things like the habitat I described and the time of year), she suggested a yellow-rumped warbler or the ruby-crowned kinglet.

I assumed it was a one time show, that the birds were migrating, but soon came to realize that I was hearing it every evening as I closed the chicken coop or was heading out for an evening engagement.  A good naturalist would have gone early to the show and waited patiently to catch a glimpse of the singers.  My excuse is I’m still a practicing naturalist that errors on the side of warmth and comfort perhaps a little too much.  The show always starts during my dinner prep/cocktail hour/might even be in my pajamas already time of day and I just never make it out to investigate.  I could also truthfully argue that I cannot see well at dusk making any attempt to sit in a cold field futile anyway.

Well, I serendipitously caught a glimpse of a kinglet out my window yesterday and now I am convinced that kinglets are the players in my symphony.  Going to Cornell Laboratory’s Ornithology site I can quickly confirm the sound that I hear: http://www.allaboutbirds.org/guide/Golden-crowned_Kinglet/lifehistory

But wait a minute.  My friend suggested the ruby-crowned kinglet, and the little guy I saw outside my window – which I immediately recognized as a kinglet from our days in Houston – was wearing a yellow crown.  And if my memory is correct, the golden crown had no orange tint to it, indicating that the kinglet was a queenlet, well, indicating I saw a female kinglet.

I listened to calls and songs from both species at the Cornell site and on my Peterson bird app.  Since, it is winter and not breeding season, I focused on the calls.  Birdsong is considered more complex and mostly done by males during courtship and mating.  Calls are made for alarm or to keep a flock in contact with its members.  Do they know that many members calling to each other creates a magical music show to the human hear?  I wonder what it sounds like to them.  I am almost convinced the call of the golden-crowned kinglet is the better match than the ruby-crowned kinglet, but I find the distinction between the birds’ sounds not discreet enough to be convinced.

If you read last week’s blog entry you will recall that I am fascinated with animals’ abilities to survive winter temperatures.  How does the kinglet, a mere six grams of flesh and feathers, survive the winter?  They are quite common in the extreme winters of the north.  I dug out and am thoroughly enjoying a book I bought years ago in Maine:  Winter World (2003) by Bernd Heinrich.  In it Heinrich gives an engaging account of how he tried to answer this very question.  Until his research, kinglets were thought to survive mainly on snow fleas in the winter.  Heinrich sampled the stomach content of several kinglets and found no snow fleas, but lots of caterpillars.  He was amazed because the birds had been foraging at the tops of trees in the winter.  How were they finding caterpillars, thought to overwinter in pupa form or underground?

Heinrich next spent several winters collecting insects from treetops in a very sophisticated manner, hitting them with a club and collecting the fallen insects.  He was amazed again; he found caterpillars.  The next part of his story amazes me.  He proceeded to collect and raise these frozen caterpillars in order to identify them.  He did not give up when failure struck: one year a spider ate all the happily growing larva; and another year a lone surviving caterpillar pupated and then drowned in the glass because of condensation that formed on the jar sitting on a sunny windowsill.  He did not quit, and in the third year he managed to raise to emergence a moth known as the one-spotted variant, Hypagyrtis unipunctata.  I am in as much awe in what Heinrich learned as I am in his diligence.  This is the beauty of science and the magic that drives all the men and women working on answering their own questions of wonderment.  You can read about Heinrich’s study here: http://birdnote.org/show/kinglets-winter  and here: http://www.npr.org/templates/story/story.php?storyId=1177500

As a scientist, albeit one with no where near the diligence – or cold tolerance – of Heinrich, I know that seeing one golden-crowned kinglet is not proof that there is a large group of them conducting a symphony every evening.  Unfortunately I will have to don some warm clothes, boots, and binoculars and situate myself out in the field to listen quietly, and hopefully get a glimpse of the players in my show.  I sure hope the show’s playing through March.