Last of the Season

These are some photos of the last batch of monarch caterpillars for this season. These caterpillars are getting really big and are almost 2 inches long! They will soon pupate and form into a chrysalis, and will most likely overwinter in that state.


To see a neat time series photography site on the chrysalis formation click this link.

Sounds of Fall

You can tell it is finally fall in Athens, not only by the cooler temperatures, but also by the song of the mockingbird. Starting in mid September the Northern Mockingbird (Mimus polyglottos) begins to sing to setup up their fall territory. They sing in spring too, to attract mates and hold their breeding territory. In summer they do not sing as much and by late summer they are very quiet. Once fall comes about, the adults generally kick their offspring out of their territory, and begin to sing to set up their fall/winter territory. Their fall territory is generally smaller than their breeding territory, and often their offspring will setup up their territories nearby.

The song of the Northern Mockingbird is long and complex. It is a series of varied phrases, with each phrase usually repeated at least 3 times in a row. The phrases are imitations of many other bird songs and calls. One study found that the song repertoire between spring and fall singing only had 1% in common, so mockingbirds effectively may have two vocal repertoires. Other studies have shown that the spring repertoire size (the total number of distinct song types recorded from an individual as determined from analysis of extensive recordings) increases with age.

To learn more about mockingbirds see this link.

To hear the song of the mockingbird, go outside and listen! Or you can hear one online at this link.


References:
Derrickson, K. C. and R. Breitwisch. 1992. Northern Mockingbird. In The Birds of North America, No. 7 (A. Poole, P. Stettenheim, and F. Gill, Eds.). Philadelphia: The Academy of Natural Sciences; Washington, DC.: The American Ornithologists’ Union.

Chimney Swifts

Downtown Athens is home to several large Chimney Swift (Chaetura pelagica) roosts. These are places that have a large enough chimney that can hold large numbers of swifts roosting together. For the past few weeks the swifts have been gathering in large numbers, soon they will migrate to South America.

All of the dark specs in this picture are actually the Chimney Swifts. This picture was taken on Broad Street and Jackson.

During spring and summer the swifts are quite common here in Athens. You can see them flying above and chittering. They have been referred to as “flying cigars” due to their small, cigar shaped body. Swifts are among the most aerial of birds, flying almost continuously except when at the nest or roosting at night.

Chimney Swifts used to nest in caves and hollow trees before European settlement of North America. The swifts greatly benefited by the construction of chimneys and quickly adapted to using them as nesting and roosting sites. Recent changes in chimney design, with covered, narrow flues, have decreased the available nest sites and may be a factor in their declining population numbers.

Good news is they will readily use a Chimney Swift Tower made specifically for nesting swifts. A nature reserve in Texas has experimented with many designs and has published the most successful design plans. To see some of their designs, see this link. To purchase their book see this link.

If you are interested in constructing a chimney swift tower, you have to first make sure you have the right type of habitat. The most successful towers have been in city parks and pastures, and suburban yards. The tower has to have at least a 10 foot radius clearing, so that predators such as cats and raccoons are unable to jump to the top of the tower and gain access to the interior nesting chamber.


To check out the local Chimney Swifts roosts, head to the Bottleworks building on Prince right at dusk. Another good spot to see them is the corner of Broad Street and Jackson.

Birding Basics for Adults

Fall migration is in full swing! Warblers, thrushes, grosbeaks, and the like are making their way through Georgia. Not sure what I am talking about? Then you need to attend the Birding Basics for Adults class I am instructing next Saturday, September 15th, at the Georgia State Botanical Garden.

Blackburnian warbler is one neotropical migrant we might see.

In this class you will learn the fundamentals of bird watching. The program begins with an introduction on how to identify birds by sight and sound and will cover bird watching tools including binoculars, field guides, audio, video, computer guides and websites. We will also discuss how to attract birds to your yard through the use of plants, feeders, and nest boxes. The second part of the class will be spent outside looking for birds. September is the peak of Fall migration, so we are sure to see some outstanding neotropical migrants as well as many local birds. It is highly recommended that you bring your own pair of binoculars.

Tennessee warbler is another neotropical migrant that is passing through Georgia on its way to Central and South America.

Class starts at 9am in classroom A in the visitor center. Space is limited! To sign up call 706-542-6156 or register online at http://www.uga.edu/~botgarden/educationalevents.html

Spider Happenings

The Golden Orb Weaver spider (Argiope aurantia) that inhabits our deck has just laid her first group of eggs. I found this magnificent egg sac in a potted plant next to her web. She will create 1-2 more of these egg cases before she dies this fall.

Each egg sac contains 300 to 1400 eggs. The eggs will hatch in the late fall, but the hatchling spiders become dormant and do not leave the egg sac until the following spring. The over wintering egg case will help protect the newly hatched spiders from predation.

To read related posts see:
http://katalystdesigns.blogspot.com/2007/03/waiting-patiently.html

http://katalystdesigns.blogspot.com/2007/08/golden-orb-weaver.html


In other spider news, I saw a Green Lynx spider that has made its home in one of our basil bushes in the garden in the midst of capturing its prey, a stink bug. The green lynx is a great beneficial insect to have around in the garden. They are voracious predators and assist us in keeping the pest populations low.

To read related posts see:
http://katalystdesigns.blogspot.com/2007/05/green-lynx.html

Mushrooms

After a few days of some good rain that broke that 3 week heat wave, we are finally seeing some mushrooms emerge. One common mushroom seen this time of year is the Oyster Mushroom (Pleurotus ostreatus). The oyster mushroom is a commonly sought after edible wild mushroom due to its tastiness and lack of confusing look-alikes, making it easy to identify. It creates fruiting bodies (the part we call the mushroom) from spring-fall.

In the wild these mushroom are commonly found growing on dead hardwood trees. They also are cultivated commercially and can found in the produce sections of many grocery stores.

To learn more about identifying edible mushrooms see the Mushroom Club of Georgia's website, and for those of you who are interested, they are having a mushroom walk next weekend at Stone Mountain Park.