Sunday, September 16, 2012

The only bird here that does a good job of smelling

Turkey Vulture
Almost all birds have a very weak or no sense of smell. The one exception in north Texas is the Turkey Vulture. Through evolution it developed a good sense of smell in order to survive.

Turkey Vulture
The Turkey Vulture's purpose in life is to get rid of carcasses (roadkill, dead animals etc.)    It locates them by smell. Turkey Vultures are so good it that they can locate leaks in natural gas lines (The chemical mercaptan, added to gas, smells similar to rotting flesh). By the way, no kind of vulture has ever been known to attack or kill a healthy animal.


Another evolutionary modification helps it pick apart dead animals. It developed its featherless, macabre-looking, head and neck so it could probe into rotting carcasses without picking up bits of flesh and blood.


 Birds here talk Texan.   In a 'birdy' way.   Identical kinds of birds often sing differently, depending on where they were raised.  For instance a Blue Jay here in north Texas sounds a bit different from one (for instance) from Connecticut.

Wednesday, September 12, 2012

Luckily we have Cardinals almost everywhere now

Northern Cardinals (female, male)
Several decades ago Cardinals were very, very rare in north Texas. In the 1800s the Northern Cardinal (its full name) lived in North America only as far north as southern New York, and west only to wooded portions of the Great Plains.

Times change!!   In the 21st Century, the Cardinal is almost everywhere in this country (except chunks west of the Rocky Mountains). This is largely due to their adaptability, and the large number of people who feed birds and provide habitat (you're probably one), so Cardinals can survive hot summers and freezing winters. Today their range extends into southern Canada, and from the Rockies east to the Atlantic coast. And north Texas!

Cardinals live naturally only in forest edges. However, as man cleared millions of small areas for homesites, more and more 'forest edge' was created. We even grew and stored lots of Cardinal-food such as corn and wheat.

Cardinals are easy to attract to your yard. All you'll need are well-stocked feeders and the appropriate habitat - some dense vegetation including trees. Adult Cardinals will escort their fledglings to the vicinity of a birdfeeder. Then the parents will bring seeds to the fledglings from the feeder. The fledglings soon catch on, and will visit the feeders themselves. This "teaching  by example" often happens at backyard birdbaths too - throughout the year.

Black oil sunflower seeds are their favorite, but they'll often eat other seeds. They actually like suet too, especially if it contains sunflower seeds.


 

Saturday, September 8, 2012

This is "goodbye" month for hummingbirds

Costa's Hummingbird
It's as if the birds and the plants planned it this way!     In a way, they did. The hummingbirds will be here in north Texas only 'til the end of this month.  Just when hummingbirds need a lot of extra nectar for the upcoming migration, nectar-laden plants (such as Lantana and Turks-cap) burst into spectacular bloom. Coincidence?

All during the month, thousands and thousands of north Texas' hummingbirds (including the ones born this year) are trying to pack on extra weight and stockpile extra energy for the long, draining migration flight to Central America. They know instinctively that they'll need all their energy for the trip. So you'll see them crowding around nectar feeders and blooming flowers.

Ruby-throated Hummingbird
Birds couldn't do much without help from north Texas' native plants.  Over the ages they've coordinated their needs and production; it's mutually beneficial. If you want to plant the right "birdscape" plants, you're in luck. Beginning with the start of Ocober (not spring like up north) is the very best time to plant things to attract next year's hummingbirds. If they like what you've planted, they'll probably return to your yard the following year.

This year, make sure the nectar in your feeder(s) is clean, clear and plentiful, up until the start of October.


The accidental release of radiation at the Japanese Fukushima nuclear plants in 2011 has damaged the genetic makeup of local wildlife. Butterflies are the first to be studied (due to their short life cycle) but others may come later.

Researchers from the University of Ryukyus, as reported in "The Week" magazine, found that 12 percent of the pale grass blue butterfly larvae collected from Fukushima developed mutations as adults. Mutations include damaged wings, eyes, legs etc. Then, 18 percent of their offspring also had mutations, even though they had never been exposed to radiation themselves.

Wednesday, September 5, 2012

Cattle Egrets are here to stay

Cattle Egret
Cattle Egrets came to this country through totally natural means, but it took an incredibly long time - possibly beginning in the 1500s.

The large, white bird is a species of Heron, and originally came from Africa.  Nobody knows for sure, but a combination of strong winds and adventurous flying brought a few of them to northeastern South America - modernday Brazil. Very gradually they expanded their range, fitting in well with the wide distribution of large herbivores and the warming climate.

The first documented Cattle Egret in North America was 1952.  In 1959 a few had reached Texas. Now they're a common sight around here, feeding in insects in very efficient groups called 'stampedes'.







 

Saturday, September 1, 2012

How do birds deal with hurricanes?

Major storms like hurricane Isaac are unquestionably harmful in many ways. They've been occuring for ages;  and will certainly occur again.  As of this writing, Isaac has done its worst, and is slowly fading away. But more hurricanes WILL occur. So I will not stray from the core purpose of this blog.  Hurricanes are interesting, recurring events with regard to birds and migration.

As you might imagine, many birds fly rapidly from the area as a hurricane approaches. They’re alerted by the sudden drop in barometric pressure which they instinctively know means “leave fast”. After all, birds have been dealing with storms for ages. A few will choose to stay put if they can find shelter, and ride it out.
 In addition to the drastic pressure change, hurricanes approach from the south. They’re huge storms, with counterclockwise winds, carrying lots of water. This means that ahead of the core of the storm, winds will be blowing essentially from east to west.   
At the same time, our fall-migrating birds are heading from north to south, many down the Central Flyway (which includes north Texas), and will be driven farther west into Texas. This will obviously increase the concentration of migrating birds coming through north Texas, and decrease the number of birds moving through the east side of the storm. As the storm approaches, winds will be strong, and birds would probably not brave headwinds in excess of 100mph just to follow their usual migration route.  The south winds are far more destructive than east-to-west winds. So east Texas should be spared from significant wind damage by a storm that hits Louisiana. 

The non-migrating birds in the path of a hurricane just hunker down in a crack in some rocks, under the eave of a house or in a hole in a large tree. Some, unfortunately, will be killed. Others may get blown far away by a big storm (Katrina blew many birds as far away as Tennessee).

 While watching migrating birds may be good in Texas this week and slow in Florida, another group of birds may visit. These are the water/shore birds (“pelagic” species) that live along coastlines. Many of them get "trapped" in the eye of the hurricane and carried well inland, to places and habitats they haven't a clue about. Naturally, they turn around and head back to the coast as soon as they can. But it’s not out of the question that someone will see, for instance, a Shearwater or Avocet in north Texas as the remnants of a hurricane pass through. Pelagic birds often drop from what’s remaining of the hurricane’s “eye”, into large lakes.

Of course, the biggest threat to all kinds of birds is the loss of habitat. Despite the fact that a hurricane loses strength over land, it can still harm birds. A Cardinal who lived in an Arkansas forest, for example, may have his forest blown down. Or a Meadowlark may suddenly have his meadow underwater. Or a Woodpecker in a Louisiana swamp may have his habitat inundated by salt water from the gulf. This affects both the birds’ homes and their food supply.

 So let’s keep Louisiana and areas north of it on our minds and in our thoughts. It certainly could have been a lot worse. The birds might have an interesting few weeks as well.

 


A U.S. federal court has ordered the Federal Communications Commission (FCC) to protect migrating birds from colliding with commucation towers (cell phone, television, generation etc.). Each year between 5- and 50-million migrating birds (and many bats) are killed by such collissions. Companies now applying for tower permits must comply with existing federal regulations protecting birds.
 

Wednesday, August 29, 2012

The local Monk Parakeets aren't pets anymore

Monk Parakeet
Monk Parakeet nest
If you see one of these Monk Parakeets, you're not seeing an escaped pet. You are, however, seeing the descendant of an escaped pet. In Denton,  several colonies of them live mainly in the northeast quadrant of the city.

Monk Parakeets are native to South America (Uruguay, Paraguay, Bolivia and parts of other countries) and were brought to this country years ago (nobody's sure when) via the pet trade. Inevitably, some escaped. They adapted to the local environments and have established ongoing colonies in many areas.
Monk Parakeets
 It's the only species that builds a large, communal nest - possibly 2 ft. across and 2 ft. high. Often the nests are built in man-made structures, especially in colder climates. The wild bird (just under a foot long) has become the most widespread parakeet in the country. Actually, the only two parrot species native to the U.S. are both extinct.

Sunday, August 26, 2012

Wrens need a good home. Your yard?

Carolina Wren
Bewick's Wren
Whether you see them or not, wrens live in your neighborhood. And now is a good time to attract them to live closer by - now that the rigors of a Texas summer are ebbing.

Wrens are small birds, with a disproportionately loud voice. It's a pleasant sound, so it's a good thing they're easy to attract. In fact wrens NEED human contact and conform well to the way we live. In north Texas, our native wrens are the Carolina Wren and the Bewick's Wren (pronounced similar to the car). The Carolina is browner than the Bewick's, and both are slightly "huskier" than other wrens. Consequently, our wrens probably won't be able to get into a mass-produced, one-size-fits-all wren house, which is sized for a House Wren (which is sometimes here, but isn't very common).

A key to attracting wrens in Texas is a brushpile; a random pile of branches 4-5 feet high, with lots of spaces and voids on the inside. In bad weather it's a comparatively warm place to roost - which attracts all birds. A brushpile also provides safety from animals that would like a wren for dinner.

 The year-'round availability of water is also essential to attracting wrens; not just during the heat of the summer. Even in winter, wrens need to bathe, and will poke around in vegetation near birdbaths in search of overwintering bugs.



You can try to attract owls as twilight fades. Pause in a meadow or a clearing in a wooded area (or your own yard, if it's wooded enough) and squeak like a field mouse. Draw breath in through almost-closed lips so you squeak (the precision of the sound isn't very crucial!). Owls are attracted to the mouse-like sound, but will veer away at the last second.  (Here in north Texas, our common owls are Great-horned, Barn, Eastern Screech and Barred)