Bald Bird

It is that time of year when some Northern Cardinals (Cardinalis cardinalis) exhibit featherless heads. Two years ago I noticed a few of our backyard cardinals in various states of baldness in late August. After googling "bald cardinal" I came up with over 700,000 websites with that term, so I knew I was not the only one witnessing this odd molting pattern.

Most birds molt twice a year, in fall and then again in spring. In early fall most birds go through what is called a pre-basic molt. This is where the birds gradually lose their worn breeding feathers (plumage) and grow in their fall plumage, which is often not as bright and showy as their breeding plumage. Having duller feather colors in the fall and winter assist the birds in camouflaging themselves from predators. In the spring they molt into fresher brighter colors that assist them in attracting mates.

So is the case of the balding cardinals just pre-basic molting? Maybe. Or it could be feather mites. Or it could be both molting and feather mites. Scientists who study birds are now just starting to look at this condition. Either way, it does not seem to have a negaitive affect on the bird. Other than looking scary for a little while (some refer to the cardinals in this state as "mini red vultures"), they still behave the same way, and soon the feathers grow back in.

By the way, this temporary baldness has also been reported in Blue Jays and Grackles!

Insects, Bugs, and Bogs

Saturday we went to the Atlanta Botanical Garden to see David Rogers' Big Bugs & Killer Plants exhibit. It was a lot of fun! David Rogers created these huge wooden sculptures of insects and had them cleverly placed throughout the garden. They were also showcasing “killer plants” such as pitcher plants and venus flytraps. Some of the carnivorous plants they had are actually native to the southeast such as Spoonleaf Sundew (Drosera intermedia) and Whiteleaf Pitcher Plants (Sarracenia leucophylla).

To learn more about the exhibit and related programs see the Atlanta Botanical Garden website: http://www.atlantabotanicalgarden.org

Or go check out the exhibit for yourself!

Grizzly Cam

So there are no grizzly bears in Georgia, but this website based Alaska is too good to not mention. The Alaska Fish & Game and National Geographic currently have a live web cam operating at McNeil River State Game Sanctuary. This is a place where grizzlies congregate to feed on migrating salmon. The footage is just amazing!

The cam is live from 7am to 10 pm AST and other times it runs past footage.

Check it out!
http://magma.nationalgeographic.com/ngm/wildcamgrizzlies/

You can also learn more about grizzlies here:
http://magma.nationalgeographic.com/ngm/wildcamgrizzlies/about_bears.html

Hummingbird Moth

Yesterday afternoon while inspecting the butterfly bush (Buddleia) in our backyard for butterflies I was caught off guard by the Hummingbird Clearwing Moth (Hemaris thysbe). At first glance I thought it was an actual hummingbird, but after a second look knew it was a hummingbird moth.It is not difficult to see why many people would mistake this moth for a small hummingbird, they have similarities in size, foraging behavior, and feeding structures. This moth is most often seen during the day, hovering over flowers and sipping the nectar through a long feeding tube (proboscis). The moth hovers briefly, sipping for only a few seconds before darting off to a new flower, just like a hummingbird.

The Hummingbird Clearwing Moth is native to Georgia and can be found throughout the eastern half of the U.S. and Canada. Its host plants include honeysuckle, hawthorns, viburnum, and black cherry. Their caterpillars are often referred to as “horn worms” due to having a horn-like tail. They are in the family Sphingidae, a group also known as Sphinx Moths or Hawk Moths. This family includes the notorious the tomato hornworm as well an estimated 850 other species worldwide.

To see a bit of the amazing hummingbird/sphinx/hawk moth diversity see this site: http://www.whatsthatbug.com/sphinx_moth_2.html

To see a previous post on the tomato hornworm see:
http://katalystdesigns.blogspot.com/2007/06/hornworm.html

golden orb weaver

Yesterday I caught the golden orb weaver spider (Argiope aurantia) that lives on our deck wrapping up its latest victim. She had spun silk around it so fast I did not get to see what it was; I did notice it was about fly or small bee size.
Like all spiders, the orb weaver is carnivorous. They spin a typical spider shaped web to capture small flying insects such as aphids, flies, grasshoppers, and bees. A female can take prey up 200% of her own size!

The web can be up to two feet across and in the center of the web, the spider will hang, head down, waiting for prey. Often, she holds her legs together in pairs so that it looks like an X. They typical take down their web and rebuild it each night.

To learn about orb weaver spiders see:
http://animaldiversity.ummz.umich.edu/site/accounts/information/Argiope_aurantia.html

To read a previous post about orb weaver reproduction see:
http://katalystdesigns.blogspot.com/2007/03/waiting-patiently.html

Heat Wave

During heat waves like this current week’s, birds can suffer from heat illness just like humans. To deal with the heat, birds have a few behaviors they can use to avoid over heating. They will seek shade, pant (also called gular fluttering), hold their wings out away from their body, and bathe.

You can help the birds around your home deal with the heat by providing a bird bath that can be a source of drinking water as well a place to bathe.


Here are some tips:

• Empty and refresh the water daily to keep it clean and free of mosquito larvae.
• If possible, try to place your birdbath where shade will be during the hottest part of the day.
• Remember that smaller birds prefer shallow water. A few stones placed in the middle of the bird bath will provide smaller birds a place to perch.

Also:

• Clean hummingbird feeders and refresh their sugar water regularly. Very warm conditions can lead to the growth of dangerous bacteria and fungi. We have been changing and cleaning our hummer feeder every 1.5 days.
• Keep any seed feeders clean of refuse where germs could breed and spread.

More Monarchs!

We have a new batch of monarch caterpillars taking over our milkweeds. They just hatched two days ago and have already more than tripled in size!

To read past posts about monarchs see: http://katalystdesigns.blogspot.com/2007/06/monarch-caterpillars.html
http://katalystdesigns.blogspot.com/2007/04/first-of-season.html

Milkweed Bugs

If you have milkweed plants, not only are you likely to attract monarch butterflies, but also milkweed bugs! The milkweed plants in our backyard currently have several milkweed bugs (Oncopeltus fasciatus) congregated on them. They are a “true bug” found in the order Hemiptera.

They feed on milkweed and other related plants. Using their long proboscis, they pierce the milkweed seeds and inject a salivary enzyme which digests their food, then they suck it up.

Milkweed bugs are native to this region and can be found most places east of the Rocky Mountains. They are reddish-orange in color (much like the monarch butterfly) and have black markings. You can easily distinguish males from females by looking at their ventral (under) side: males will have two black bar markings and females will have dots.Milkweed bugs are one of a small group of insects that have the ability to tolerate the toxic compounds found in the milkweed plant. They are important in regulating populations of this plant. They have few predators due to absorbing the bad tasting compounds found in the sap of milkweed plants they eat. And just like the monarch, they use their bright colors to advertise their bad taste. Inexperienced birds that taste their first milkweed bug are unlikely to try to eat another orange and black insect.

References:
Bugs of the World
Discover Entomology