Creating a wildlife haven one plant at a time

Saturday, February 23, 2013

A Deeper Level of Communication

The cherry trees are our earliest blooming trees beautifying the garden every February. Well, until the temperatures plummet and put a damper on the pink party.


Both the bees and blooms respond to the first warm, sunny day. It is fascinating to watch these fuzzy pollinators as they amble from bloom to bloom.


These busy bees are filling their pollen sacs with up to a million grains of pollen. Just look at the size of that yummy pollen.



How do they do it so efficiently?
We know that plants have formed associations with pollinators over millions of years to ensure pollination and survival. Plants provide many clues to pollinators using bright colors, patterns and scents to encourage visits.

Vision is very important to bees. Flowers look differently to them. If anything they are even more beautiful! They see things at the blue end of our visual spectrum, hence they don't see the color red. But they do see ultra-violet light patterns that we can not detect. Many flowers have a very distinct UV color pattern that are incredibly eye-catching to bees. You can see an impressive collection of flowers photographed in ultra-violet light (available here). This is how the blooms in your garden look to a bee. 


But scientists have discovered a deeper level of communication between flowers and bees.

New study
A new study has just been published where scientists from the University of Bristol discovered that plants are able to communicate using electric fields.

"Plants are known to emit weak negatively charged electric fields and bees acquire a positive charge of up to 200 volts as they fly through the air. As a charged bee approaches a flower, the difference in electrical potential is not enough to produce sparks but can be felt by the insect."

Amazingly the bees could distinguish between different floral fields as if they were petal colors. The scientists are not sure how the bees detect the electric fields but one theory is that the electrostatic force makes their hair bristle. The plant's electrical potential changed when a bee visited the flower and remained that way for a few minutes. The thinking is that it may be the way the plant lets other bees know that it is temporarily closed for business and to come back in a little while.


Whether it is electrical fields, color, pattern or scent, the bees love these blossoms, even when they've fallen on the ground.


I'll wrestle you for some pollen!

Monday, February 18, 2013

Whose there eating the cherry blooms?

Winter is a hard season for birds for many reasons and feeding them is an important activity that can help our feathered friends conserve energy when they need it most. Donna over at Garden Walk Garden Talk has an excellent post on how beneficial it is to feed birds during our cold months. Do go take a look (here).

Many avid birders decidedly don't feed birds during warmer months with feeders opting to provide food in in the form of plants. After all, birds and blooms are a natural team. They need one another to survive. Birds consume fruits, berries, nuts and seeds that flowers produce and in return the birds pollinate and spread seeds.

Spring comes early to our garden; beginning in February when the ornamental cherry trees burst into bloom  followed by the plum and pear trees. This puts a skip in this gardeners step but did you know that the blooms are also beneficial to some of the birds?


Have you ever witnessed a bird eating the buds or blossoms from your flowering trees? Plant favorites of bud and blossom eating birds are pear, apple, peach, plum, crabapple, cherry, red maple and forsythia. So, the bees and our overwintering rufous hummingbirds are not the only ones visiting our cherry blossoms on a sunny February day.


The trees are also filled with finches who are eagerly eating the blossoms. Some have even nested in these trees making their next meal just a hop away. But why are these birds eating the buds and blossoms? Well, it turns out they are highly nutritious. According to the Georgia DNR some experts believe that the flowers have even more food value than buds. This gives the flower eating birds an advantage in late winter and early spring when food is often scarce.


If you are one to get upset when you find your first signs of spring being eaten, not to worry, this natural pruning of excess blooms actually aides the plant. In fact purple finches are credited with helping fruit trees produce larger fruit.

Cedar waxwings, which still elude my lens, seem to eat blossoms in spring during their spring migration. In fact, spring is the most common time for blossoms to be eaten by birds. Other birds that share this habit are northern cardinals, house and purple finches, northern mockingbirds, blue jays, evening grosbeaks, and American goldfinches. 

So, if you see birds eating your early spring buds and flowers, I hope you don't mind sacrificing a few blooms for your feathered friends.

Wednesday, February 13, 2013

OE & Monarch Conservation

This winter I have attended several talks on the conservation of the monarch butterfly which has opened my eyes further to the importance of gardening with native plants and creating native habitat to help conserve these iconic insects.


If you garden for butterflies you probably have milkweed to attract monarchs and a variety of other butterfly species. Recent studies have shown that planting non-native milkweed is detrimental to the Monarch butterflies. Why you ask? Well, there is evidence that the non-native milkweed species are changing the migration timing of Monarchs. The tropical milkweeds have longer bloom periods and encourage Monarchs to stick around instead of continuing on their epic migration. By lingering they are put at risk of the deadly OE parasite and also at risk of dying in our winter.

What is OE? Ophyryocystis elektroscirrha (that is a mouthful!) is a parasite that infects monarch and queen butterflies. It is a protozoan or single celled organism that must live within a host to grow and multiply. Between infections it lives as a spore and can survive extreme environmental conditions.

OE was first found in the 1960's in Florida and as far as researchers have discovered the monarch and queen butterflies are the only known host. Over the years OE has been discovered in monarch populations world-wide and the research is showing that OE has co-evolved with the monarchs. You can see in the diagram below the life cycle stages of OE in the monarch. You can click on the photo credit below for a larger view.

Photo courtesy of monarchparasites.org

OE only reproduces in the butterfly's body. According to Monarch Watch spores can be transferred from an infected male to a healthy female during mating. Infected females also pass along OE to their offspring. When the female lays her eggs, dormant spores are scattered on the eggs and milkweed leaves. When the caterpillar emerges from the egg the first thing it will eat is its eggshell and then begin munching on the leaves thus ingesting the spore.


Most butterflies with mild infections look and act normally but they are usually smaller than healthy adults, weighing less and with shorter forewings. The only way to know for sure is to test for the parasite. Volunteers can participate in this process by collecting samples from monarch butterflies they see in their garden. (More information on participating is provided at the end of this post)

Heavily infected butterflies often die before emerging from their chrysalis. If they do emerge they are weak and often fall to the ground before they can expand their wings. These butterflies do not survive long.


In North America the populations of monarch butterflies are divided into three groups. The Eastern where the monarchs breed east of the Rocky Mountains and overwinter in the transvolcanic mountains in central Mexico. The Western population which are west of the Rocky Mountains where the butterflies roost along California's coast and finally the Non-migratory which breed year round in southern Florida, coastal Texas, Hawaii and the Caribbean. Of these populations the Eastern population is the least heavily infected at 8%. The Western population is at 30% and the Non-migratory group is the highest with 70% of the population heavily infected with OE.

photo courtesy of Project Monarch Health Watch

So, this begs the question, what implications does the monarch migratory behavior have on the occurrence of OE? Well, new research at the Altizer lab at the University of Georgia has shown that migration allows hosts to escape infected habitats reducing disease levels. Diseased butterflies lost more of their body weight during flight and therefore would not survive the long migration to Mexico thus weeding out the parasites with them. Non-migratory populations retain their weakened butterflies and so the parasites persist. Researchers also found (in a 2010 study) that wild monarchs in the non-migratory populations were smaller. The Eastern population had the largest and most elongated forewings and largest bodies.


So what does all this mean for the average butterfly gardener? To best support healthy monarch populations it is best to bring into cultivation milkweed seeds from local sources. Migrating monarchs have co-evolved with the native milkweed, timing arrivals and departures with bloom periods over many generations. There are 22 milkweed species native to Georgia and for a complete list and plant profiles click here.

If you are so inclined you can participate in the Project Monarch Health which is a citizen-science survey where volunteers sample wild monarch butterflies to help track the spread of the OE parasite in North America. This is great activity for backyard gardeners, school groups, nature centers, senior groups and is done by people of all skill levels and age groups.

Tuesday, February 5, 2013

Textures & Colors of my Winterscape

The predominant colors of the southeastern winter landscape are various shades of gray and brown. I often read articles about how to brighten this drab palette but I find that if you look closely these grays and browns offer a great deal of interest.

Gray is the color of intellect, knowledge and wisdom so it seems to reason that Mother Nature should cloak much of the winter terrain with this color.


I think this stump looks rather brainy, don't you?
 

Moss creeping through this bark creates an interesting abstract and lovely contrast.


Even the female birds stand out against the gray backdrop.


Being the color of earth, brown is associated with the maternal side of life. It is also the color of solidarity and makes a great background color. 

Fallen trees look fantastic in the landscape. Not only are they beneficial to wildlife but they also make great structures to plant around.


The American Beech trees hold their leaves until spring. They look like little scrolls hanging from the branches.


The insects and birds have been busy on this dead tree giving it a second purpose.



The leaf scar lined with tooth-like spines on this Devil's Walking Stick (Aralia spinosa) looks like a vicious bulldog collar.



The monochromatic colors of winter don't have to be boring. If you take a closer look they offer varied textures and patterns that may otherwise go unnoticed at other times of year. What are you finding in your winter garden that is providing you with some inspiration?