Thursday, August 21, 2014

Peccary

Peccaries (also known as Javalinas) look a bit like pigs, but are classified in a family of their own. They are found from the Southwestern United States through much of South America. Curiously, this Peccary, in the Big Bend National Park, is the first I have ever seen.

Apparently Peccaries usually travel in groups of up to a dozen—and even a herd of 50 has been reported. Single individuals are often old or sick. The animals are most active in the morning and evening, and tolerate high temperatures only poorly. They eat roots, fruits, cactus, insects, worms, and reptiles.

Peccaries are not dangerous, but should be respected. The whole herd can attack if one of the group is wounded. They can drive off dogs, coyotes, and bobcats. If fed, they can lose their fear of humans and can become a nuisance at campgrounds and are even becoming an “urban menace” (Desertusa.com).

Wednesday, August 20, 2014

Carmen Mountains White-tailed Deer

The deer in the Chisos Mountains of the Big Bend National Park are a small race named the Carmen Mountains White-tailed Deer. The Chisos Mountains and adjacent Mexican ranges are the only places to find these animals. Because hunting and livestock grazing are prohibited in the national park, the deer in the park are not endangered—they are common above 4500 feet.  Krausman and Ables (1981) conclude, "Big Bend is probably the only area remaining where the Carmen deer may continue to maintain a healthy, reproducing population in a natural state.”

Tuesday, August 19, 2014

Mexican Jay

Erika and I first visited Big Bend National Park 40 years ago when we were heading towards graduate school.As poor students, all we could afford was to spend the night tenting in an overflow campground next to airstream vans running their air conditioners. In February, we stayed at the park lodge in the Chisos Basin. Signs warned not to feed the wildlife, but we were delighted that this Mexican Jay flew up to see if we would break this commandment. Clearly other visitors ignored the sign.
I have previously discussed the amazing social organization of Mexican Jays. The species forms three populations, one in the eastern Sierra Madre Oriental (and ranging north just past the Texas border), one in the western Sierra Madre Occidental (ranging into Arizona and New Mexico), and a third in central Mexico. Recent molecular studies suggest that these populations should be split into two or three distinct species. Arizona and New Mexico birds would be called Mexican Jays, while those in Texas would be Couch’s Jays. The populations are slightly differently plumaged—Texas birds are slightly more blue on the chest—and the two “species” have slightly different vocalizations. Finally, the birds of central Mexico may be a third species, but the data for that split is more ambiguous—these birds might remain as a race of the Couch’s Jay (McCormack and Brown 2008).

Monday, August 18, 2014

Cooper’s Hawk 2

On Saturday, 16 Aug 2014, Erika and I heard a loud, strident, mewing high in the trees at the University of Minnesota Landscape Arboretum in Carver County, just west of Minneapolis. This large hawk was actually difficult to see among the branches. Note how much shorter the hawk’s outer tail feathers are than the central ones—a good field mark of the Cooper’s Hawk.  Other hawks have their tail feathers of about equal length.

Undoubtedly a first-year female—females are about one-third larger than males. The species shows the greatest reverse size dimorphism of any hawk (Curtis et al. 2006). This disparity makes life kind of tough for the males, who are submissive to the females. The males are about the right size to be a meal. Females make reassuring calls when they are willing to be approached males. Males do the nest building and provide almost all the food to the female and young (Allaboutbirds.org).

Cooper’s Hawk numbers appear to be increasing. Surveys indicate increases of 10% in Michigan and 12.3% in Wisconsin. Moreover, Cooper’s Hawks have become common in urban and suburban areas. Allaboutbirds.org writes that Rock Pigeons and Mourning Doves are often consumed. Some Arizona birds suffer from parasites acquired by eating doves (Allaboutbirds.org). In any event, the Cooper’s Hawks in our neighborhood seem to have consumed many of our local birds.

Saturday, August 16, 2014

Blister Beetle

This Blister Beetle is feeding on Narrow-leaved Goldenrod. Scott King pointed it out to me on 12 August 2014, south of Northfield, Minnesota. Blister Beetles are in the family Meloidae, and are known to secrete a substance that causes skin to blister. Although this species is black, others of the 7500 species of Blister Beetles are aposematically colored, warning of their toxicity. Scott and I did not disturb this beetle.

Blister Beetle larvae are insectivorous, attacking bees and grasshoppers. Adults feed on a variety of flowers and leaves, including goldenrods.

Crushed Meloidid beetles are the principle irritant in folk medicine used as a male aphrodisiac. Not a good idea, since the arthropods have also been used to poison people. Some species are toxic to horses. A few beetles ingested with alfalfa hay can be lethal. Alfalfa should be carefully dried and treated (Wikipedia).

Friday, August 15, 2014

Dragonfly Day

On Tuesday, 12 August 2014, dragonfly expert Scott King and I walked in a restored prairie just south of Northfield. With Scott along, I brushed up on my nascent identification skills. Here is a quick list of some of the odonates we saw. I have linked the species’ names to other posts I have published. We also listed three additional dragonflies, a Wandering Glider,  Black Saddlebags, and Common Whitetail, but which we failed to photograph.
Common Green Darner—These large, migratory dragonflies were just emerging from the pond. The link will take you to a more complete photograph.

Lance-tipped Darner—Scott netted (and released) a few of these dragonflies. In this photo, Scott is holding on to the wings. I was hoping he would net me a Canada Darner, which can be an abundant migrant, but which I have never seen.
Halloween Pennant—We found a couple of these gaudy dragonflies near a larger lake.
Ruby Meadowhawk—This individual is my first gynomorph Ruby Meadowhawk. Recently I posted a  photo of a male, and I have also seen an andromorph female. That some female dragonflies look like males, and others come in dark forms, are part of what makes this sport so difficult. This typical female is identified by the amber bases of her wings and by the black triangles on her sides.
This year has been excellent for White-faced Meadowlarks—always common, this year they have been abundant. Scott (aka, The Dragonfly Whisperer) demonstrated that, unlike most other meadowlarks, if you slowly raise your hand under a White-faced Meadowhawk, sometimes the dragonfly will perch on you. I have unsuccessfully attempted this feat several times since Scott's demonstration.
Eastern Forktails are among are most common damselflies around Northfield. On this male, note the green-striped body, the blue-tipped abdomen and the dark notch on the sides of the abdomen tip.
Most of the day was spent with Scott patiently teaching me how to identify spreadwings. This first damselfly is a Lyre-tipped Spreadwing. Note the large, inward-curved spines at the abdomen tip.
Also flying were Slender Spreadwings. Their best field mark is a tinge of white at their their outer wing edges.
Finally, Scott netted several Spotted Spreadwings. These damselflies have darker top sides than the other two spreadwings. Their best field mark, however, are the spots on their “bellies” (the underside of their thorax). They are also smaller than the others.

Thursday, August 14, 2014

Say’s Phoebe

Back at the parking lot at the Chisos Basin visitor center at Big Bend National Park last February, we found a Say’s Phoebe. This flycatcher is found across western North America, from central Mexico to the Arctic. In the winter, migrants overlap with southern resident birds. They build their nests on rocky ledges and human buildings. In South Dakota, they often nest in abandoned barns and farm houses. Unlike Eastern Phoebes, Say’s Phoebes rarely add mud to their moss and grass nests. These birds are insectivorous, preferring wasps and bees, but also taking a variety of other flying arthropods.

Wednesday, August 13, 2014

Vermillion Flycatcher

At Big Bend National Park’s Panther Junction campground, we discovered several Vermillion Flycatchers. These are among our favorite birds, and not only because of their brilliant plumage. When we were much younger, in 1970, Erika and I studied field ecology in Arizona’s Organ Pipe Cactus National Monument. We camped out for two months near Quitobaquito and William’s Springs. These days you need reservations and an armed guard to visit these border areas.

In the national monument, we watched a pair of Vermillion Flycatchers nest in a large cottonwood at Quitobaquito. The male made high display flights, singing the whole time, while the female incubated. When she left the nest, she was soundly scolded by the male. We were impressed by this domestic behavior, but did not realize it had not been described in the ornithological literature. Someone else wrote about it the next year.

Vermillion Flycatchers are found from the American southwest to Argentina and Peru. In Lima, black morphs exist. The advantage to being all black is uncertain, as is why other populations do not show this dimorphism.

Tuesday, August 12, 2014

American Rubyspot

At Panther Junction in the Big Bend National Park, on 25 Febraury 2014, Erika and I walked to the edge of the Rio Grande. There we found a dozen American Rubyspots, damselflies with which I was well familiar from Northfield. I am surprised that a tiny odonate would enjoy such a wide range. Not only is this species found in the United States from coast to coast, it is also found south to Nicaragua. You might think that local populations of such a wide ranging species might differentiate into distinct species. They are, nevertheless, generally common along clear, running streams, with rubyspots in the western United States also favoring slower, muddy rivers (Paulson 2012).

Monday, August 11, 2014

Vesper Sparrow

This rather handsome Vesper Sparrow watched John Holden and me as we drove up a road in Dakota County, Minnesota, on 30 July 2014. I have seen many Vesper Sparrows, but I can not say that I previously noticed the strong dark line surrounding the cheek (auricular) feathers. My identification book, however, assures me this mark is an identifying feature of this species.

Vesper Sparrows are found in shrub-laced, grassy fields and in cultivation. The scientific name of this species is Pooecetes gramineus, which means “grass-inhabiting lover of grass.” If you look closely, you might see a trace of chestnut on this bird’s shoulder. An older name for the bird is Bay-winged Sparrow.