Eastern towhee

The eastern towhee was described by the Swedish naturalist Carl Linnaeus in 1758 in the tenth edition of his Systema Naturae and given the binomial name Fringilla erythrophthalma. This species is now placed in the genus Pipilo that was introduced by the French ornithologist Louis Pierre Vieillot in 1816. The specific name erythrophthalmus/erythrophthalma combines the Ancient Greek words ' "red" and ' "eye". Four subspecies are recognised: • P. e. erythrophalmus (Linnaeus, 1758), found south-central and southeast Canada to the eastern United States • P. e. canaster (Howell, AH, 1913), found in the interior southeast United States • P. e. rileyi (Koelz, 1939), found in the coastal southeast United States except for central and southern Florida • P. e. alleni (Coues, 1871) found in south and central Florida ==Description==

The eastern towhee is a large and striking species of sparrow. The total length ranges from and the wingspan is . The body of mass of this species ranges from , with an average of . Adults have rufous sides, a white belly, and a long dark tail with white edges. The eyes are red for most populations, though populations in the southeastern U.S. have yellow eyes – often referred to as the "white-eye morph." Males have a black head, upper body, and tail; these parts are brown in the female. Juveniles are brown overall. Eastern towhees of all ages and both sexes generally are unmistakable. In the Great Plains, eastern towhees will occasionally overlap in range with their sister species, the spotted towhee, which has resulted in rare hybrids between the two species. ==Distribution==

The eastern towhee occurs throughout the eastern United States and southeast Canada. Occurrences from southern Saskatchewan, southwest Ontario and Quebec south to Florida, and west to eastern Texas are noted in a literature review. Populations north of southern New England through northern Indiana and Illinois to southern Iowa primarily are summer residents. The range of P. e. rileyi extends from northern Florida through southern Georgia and coastal South Carolina to east-central North Carolina. Pipilo e. alleni occurs in peninsular Florida. For example, in Maryland, eastern towhee territories along a power line right-of-way corresponded with shrubby areas containing species such as Allegheny blackberry (Rubus allegheniensis) and blueberry (Vaccinium spp.). Other species included hawthorn (Crataegus spp.), red maple (Acer rubrum), black cherry, and black locust (Robinia pseudoacacia). ==Timing of major life events==

Arrival and departure of eastern towhees into summer breeding grounds varies with location. According to a literature review, eastern towhees typically arrive in New York in early April and leave by the middle of November. A review of eastern towhees in New Hampshire describes arrival in late April to May with the majority departing in September. Breeding begins in spring and continues to late summer. Reports of eastern towhees nesting as early as late March in Florida and Georgia, in mid- to late April in some midwestern states, and as late as mid-May in northern New England were summarized in a literature review. A wide range of eastern towhee nest success values have been reported. On Sanibel Island, one of the five eastern towhee nests observed was successful. In Louisiana, average daily nest success rate was 95.3% on a bottomland hardwood forest site. The same study found a 92.6% average daily nest success rate in a six-year-old managed cottonwood (Populus spp.) plantation in Alabama. Average eastern towhee nest success across mixed bigtooth (P. grandidentata) and quaking aspen (P. tremuloides) stands of varying ages in Pennsylvania was 48.1%. In South Carolina, only 1 of 10 nests was successful, and the mean daily nest survival rate was 62.9%. This low value was explained by high levels of predation. Due to lower nest success rates of Bachman's sparrow (Aimophila aestivalis) than the previous year, it is suggested that eastern towhee nest success may have been measured during a comparatively poor year. Compared to nests, adult towhee survival rates are high. Average weekly adult survival rate of eastern towhees in a South Carolina study area was 99.3%. This rate was obtained from radio-marked eastern towhees and represented the pooled survival of both sexes and from two South Carolina sites, young and mature stands of loblolly and longleaf pine. Between 1962 and 1967 in Pennsylvania, annual survival of breeding eastern towhees calculated from mist netting recaptures was 58%. According to a literature review, both males and females become reproductively mature in their second year. Eastern towhees of over 12 years old have been reported in the wild. ==Preferred habitat==

in New York , Lenox, MA Eastern towhees range from near sea level to as high as along the border of Tennessee and North Carolina during the summer. A literature review reports eastern towhees up to in New Hampshire. Nests higher off the ground in mixed aspen stands of varying ages in Pennsylvania had significantly (p0.05) differences in habitat surrounding successful and unsuccessful nests. Large snags (≥9 inches diameter at breast height (≥22.9 cm)) did not have an effect on nesting success. Nesting success was not significantly (p>0.05) affected by stand age or distance to edge in even-aged mixed-aspen stands in Pennsylvania. Eastern towhees nest in a variety of species including grape and blueberry (Vaccinium spp.). The majority of nests observed in South Carolina loblolly and longleaf pine forests and clearcuts were located in grape, tree sparkleberry (V. arboreum), and oak (Quercus spp.). On an oak-hickory site in West Virginia, 27% of 41 eastern towhee nests were found in grape, 17% in blackberry (Rubus spp.), 12% in greenbrier (Smilax spp.), and 12% in mountain-laurel (Kalmia latifolia). Nests also occurred in Virginia creeper (Parthenocissus quinquefolia), spice bush (Lindera benzoin), and azalea (Rhododendron spp.). In a power line right-of-way in Pennsylvania, the 6 eastern towhee nests observed occurred in Allegheny blackberry, witch-hazel (Hamamelis virginiana), blueberry (Vaccinium spp.), white oak (Q. alba), eastern hayscented fern (Dennstaedtia punctilobula) and sweetfern (Comptonia peregrina) combined, and on ground level. According to literature reviews, eastern towhee nests located on the ground are embedded in litter in dry areas and typically occur at the base of grasses, forbs, low shrubs, or small trees. Foraging habitat: Selection of foraging habitat by eastern towhees has been investigated in Massachusetts and New Jersey. When gleaning in a southeastern Massachusetts pitch pine barren, eastern towhees preferred species such as pitch pine, bear oak (Q. ilicifolia), and other deciduous trees, mainly oaks. Ericaceous species were avoided. Use differed significantly (p<0.001) from availability. On 2 New Jersey sites, eastern towhee foraging preference switched over the course of the breeding season. On a site dominated by oaks, primarily black oak (Q. velutina), eastern towhees used oaks in May, as would be expected due to their density. However, in June and July, as relative arthropod biomass declined in oaks, use of oaks was less than would be expected. On a pitch pine-dominated site, use of oaks (primarily bear oak and blackjack oak, Q. marilandica) was greater than would be expected in May, but was proportionate to availability in June and July. These negative correlations between date and oak use were significant (p<0.025) for both sites. Use of the oak-dominated site also decreased significantly (p<0.05) through the summer. Effects of spatial area: Eastern towhees appear to prefer edge habitats in many areas. For instance, the mean abundance of eastern towhees in a baldcypress (Taxodium distichum) in northern Florida was 18, while eastern towhees did not occur in either the baldcypress forest or the clearcut. At the interface of the baldcypress stand and a 13-year-old planted slash pine stand, mean abundance of eastern towhees was 22 breeding birds, while in the planted slash pine stand the average abundance was 15 breeding birds. Density of eastern towhees was found to decline with distance from the edge of a power line right-of-way and an oak-hickory forest in eastern Tennessee. At the edge, eastern towhees occurred at a density of just over 10 pairs/40 ha, while from the edge eastern towhee density had dropped to 1 pair/40 ha. In addition, in experimentally clearcut Pennsylvanian forests composed of white oak, northern red oak (Q. rubra), chestnut oak (Q. prinus), scarlet oak (Q. coccinea), red maple, quaking aspen, bigtooth aspen, and pitch pine, male towhees were detected significantly (p<0.05) more often than expected in the areas where the spatial arrangement of clearcuts was most patchy. Several studies have addressed the effect of the size of habitat patches on eastern towhees. In mixed-oak forest in New Jersey, eastern towhee frequency generally increased with patch size, although eastern towhees were detected in all plot sizes () except 0.02–acre (0.01 ha) plots. On a site in South Carolina, eastern towhee frequency of occurrence increased as clearcut size increased from < to clearcut sizes from 21 to about 32 acres (8.5–12.8 ha). On another site eastern towhee frequency declined as clearcut size increased from . Eastern towhees bred in only those riparian vegetation patches in Iowa that were at least wide. In southern and eastern Pennsylvania eastern towhee nest success was not significantly (p≥0.10) different on sites with gradual edges and those with more distinct edges between "wildlife habitat openings" and oak-hickory forest. ==Food habits==

Eastern towhees primarily eat on the ground, although they also glean from vegetation. In a southeastern Massachusetts pitch pine barren, 73.5% of male and 80.4% of female foraging observations were on the ground. In a laboratory study four eastern towhees used this method to successfully obtain seed buried almost deep. When foraging above ground the majority of time is spent gleaning foliage. Plants that comprise at least 5% of the eastern towhee diet include ragweed (Ambrosia spp.), oak, smartweed (Polygonum spp.), and corn (Zea mays) in the Northeast and blackberry, oak, panicgrass (Panicum spp.), ragweed, and wax-myrtle (Morella cerifera) in the Southeast. ==Predators==

Many animals prey on eastern towhees and their eggs, including reptiles, mammals, and birds. A literature review summarizes several reports demonstrating that predators are a major cause of nest failure. At least some mammals also feed on adult eastern towhees. In Maryland, an eastern towhee was found in the stomach contents of a red fox (Vulpes vulpes). In a study of nest parasitism on Sanibel Island, none of five eastern towhee nests found were parasitized. ==References==