Hairy Woodpecker Research Articles

Foraging Behavior of Dendrocopos villosus and D. pubescens in Eastern New York State

Studies on differential foraging behavior have usually pertained to the interspecific level (Lack 1947; MacArthur 1958; Dixon 1961; Brewer 1963; Koplin 1969; Koplin and Baldwin 1970). Some recent emphasis, however, has been placed on intraspecific differences (Kilham 1965, 1970; Storer 1966; Selander 1966; Koplin 1967; Ligon 1968; Jackson 1970; Willson 1970). Kilham (1965) noted that female Hairy Woodpeckers (Dendrocopos villosus) feed on elms dying of the Dutch elm disease more frequently than males, and he stated that this differential feeding is adaptive by making more effective use of the environment. Concurrent studies by Jackson (1970), Kilham (1970), and Willson (1970) have shown intersexual partitioning of the foraging niche in the Downy Woodpecker (D. pubescens). Selander and Giller (1963) found that the degree of sexual dimorphism in culmen length of Centurus woodpeckers is greater than any other morphological measurement compared. Their proposal that this disproportionate degree of sexual dimorphism in trophic structure is adaptive and serves to alleviate intersexual competition for food was later confirmed by Selander (1966). In support of this postulate, Koplin (1967) found that the intersexual difference in culmen length of the Northern Three-toed Woodpecker (Picoides tridactylus) correlated with spatial, temporal, and dietary differences in the feeding ecology of the sexes. However, he found no significant differences in foraging behavior of either the Hairy or Downy Woodpeckers, probably because the spruce-fir forest is a marginal habitat for both species. As both the Hairy and Downy Woodpeckers are common residents of the maple-beechhemlock forests of New York, I undertook this study to determine whether there are spatial or temporal differences in their foraging behavior in this location, which correlate with interspecific and intersexual differences in culmen length. METHODS

Woodpecker Preclation on Red Oak Borer1 in Black, Scarlet, and Northern Red Oak2

Woodpeckers rank high among the natural agents that help to control the red oak borer, Enaphalodcs rufulus (Haldeman), which infests living oak trees in Ohio. The hairy woodpecker, Dendrocopus villosus , and the downy woodpecker, D. pubescens , commonly peck on borerinfested trees. The red-headed woodpecker, Melanerpes erythrocephalus , and the red-bellied woodpecker, Centurus carolinus, do this only occasionally, although Solomon (1969) reported that these species prey upon red oak borers in oaks of less than 6 in. diameter in Mississippi and Arkansas.

Hairy and Downy Woodpecker Attacks on Cocoons of Urban Hyalophora cecropia and Other Saturniids (Lepidoptera)1

Observations in the field and experiments with a caged bird show that both the downy and hairy woodpeckers prey upon cecropia pupae, Hyalophora cecropia (L.), leaving an injury which is indistinguishable from that found on cocoons collected in Champaign and Urbana, Illinois. Cocoons of H. promethea (Drury) and Antheraea polyphemus (Cramer) may show similar injuries.

Geographic Size Variation in Birds and Its Relationship to Climate

There is a high degree of concordance among the patterns of geographic size variation in birds in the eastern and central United States. This is demonstrated for 12 species by assuming that wing length measurements are an indicator of body size on the intraspecific level, and by arranging the data in the form of a grid of means of wing lengths for sample areas. Maps giving isophenetic lines for wing length indicate gradually increasing size clines northward and westward from Florida in the Hairy Woodpecker (Dendrocopos villosus), Dowy Woodpecker (Dendrocopos pubescens), Blue Jay (Cyanocitta cristata), Carolina Chickadee (Parus carolinensis), White—breasted Nuthatch (Sitta carolinensis), and Eastern Meadowlark (Sturnella Magna). In each case there is a trend for larger (or longer—winged) birds to extend southward in the Appalachian Mountains and for smaller (or shorter—winged) birds to extend northward in the Mississippi River valley. Maps made by a computer and automatic plotter using contour intervals of 0.5 mm of mean wing length for the Downy Woodpecker, for male White—breasted Nuthatches, and for female Blue Jays show that, in addition to the patter just mentioned, relatively longer—winged birds extend southward in the interior highlands of Arkansas, and relatively shorter—winged birds extend northward up other river valleys. These subtle relationships between intraspecific size variation and topographic features suggest that the link between the two phenomena may be precise adaptations to even minor climatic gradients. The relationship between these findings and the subspecies concept is discussed. Correlation coefficients for the patter of variation in the Downy Woodpecker with seasonal and annual wet—bulb temperature, vapor pressure, and absolute humidity were all either equal to or higher than correlations with dry—bulb temperature. Since these variables reflect the combined effects of temperature and humidity, the obvious indication is that size variation is more closely related to this combination than to temperature alone. Additional correlations using the mean wing length data for seven other species confirmed that wet—bulb temperature patterms are more closely related to bird size than either dry—bulb temperature patters or latitude. These relationship can be expressed numerically as regressions of mean wing length on either annual wet—bulb temperature or mean annual total heat per pound of air. Since increased evaporation at high altitudes and in arid areas accentuates the depression of a wet—bulb thermometer, my hypothesis may partially account for several cases of size variation in birds cited by others as disturbing exceptions to Bergmann's ecogeographic rule. Sections of a translation of Bergmann's paper published in 1847 are given. The biological mechanisms by which these relationships are maintainted are unknown, and the wide range of tolerance by birds to diurnal and seasonal temperature variations tends to mask them. If the well—established inverse relationship between weight and metabolic rate per gram of homeotherms is operative on the intraspecific level, the relationships can be discussed in terms of avenues of heat loss and of energy budget equations.

Woodpecker Predation on an Endemic Population of Engelmann Spruce Beetles

Northern three-toed and hairy woodpeckers consumed 2 to 26% of the brood of an population of the Engelmann spruce beetle, Dendroctonus obesus. Predation was restricted to the second-year brood and decreased the survival of this age-class by 13 to 25%. Factors to account for the disproportionate losses of firstand second-year brood in the population and for differential losses of brood from the and populations to woodpecker predation are suggested and discussed. INTRODUCTION Knowledge of interactions between woodpeckers and bark beetles is restricted to high-level or epidemic populations of bark beetles (Van Tyne, 1926; Hutchison, 1951; Massey and Wygant, 1954; Blackford, 1955; Yeager, 1955; Baldwin, 1960, 1968; Amman and Baldwin, 1960; Knight, 1958, 1960; Otvos, 1965). To obtain information on interactions between woodpeckers and low-level or endemic populations of bark beetles, studies in a subalpine forest supporting an population of Engelmann spruce beetles, Dendroctonus obesus (Mann.) (=D. engelmanni Hopk.), were initiated in 1961 near Deadman Lookout in Roosevelt National Forest, Larimer Co., Colorado. The objectives of this paper are twofold: to present infornation on beetle mortality caused by woodpeckers in this forest, and to speculate on factors to account for differential mortality by predation from woodpeckers of brood in and populations of the spruce beetle. METHODS Broods of populations of the spruce beetle normally develop in the bark of wind-thrown spruce trees and logging slash (Massey and Wygant, 1954; Nagel et al., 1957). Therefore, 22 and 21 spruce trees, to serve as brood trees, were felled with a chain saw during the autumn of 1961 and 1962, respectively. Abundance was estimated by counting insects in samples of bark 6 inches (15.2 cm) square a total of 3 times throughout brood life: first, when 3Y2 to 4 months old; next when approximately 1 year old, and finally, prior to emergence as adults, when approximately 2 years old. Larvae younger than 3 /2 to 4 months of age were too small to count easily; delaying the first census did not appreciably bias measurements of mortality caused by woodpeckers because woodpeckers in the 1 This study was supported by cooperative aid grants from the Rocky Mtn. Forest and Range Expt. Sta. of the U. S. Forest Service and National Science Foundation grant GB-753. 2 Present address: Division of Natural Resources, Humboldt State College, Arcata, California 95521.

An Apparently Melanic Hairy Woodpecker from New Mexico

An Apparently Melanic Hairy Woodpecker from New Mexico

Hairy Woodpeckers Feeding on Pine Seeds

Hairy Woodpeckers Feeding on Pine Seeds

Spatio‐Temporal Relationships of Nuthatches and Woodpeckers in Ponderosa Pine Forests of Colorado

Interspecific segregation of foraging activities of nuthatches and woodpeckers was investigated from June 1964 to June 1966 in a stand of ponderosa pine. The composition and density of populations were assessed throughout the year. Location of foraging activities was quantified by measuring the length of time each species occurred in specified zones of the environment. Interspecific differences of zonation were statistically analyzed for the reproductive and non—reproductive seasons separately. White—breasted and Pigmy Nuthatches and Hairy Woodpeckers nested in the area and were sympatric throughout the year. Red—shafted Flickers and Williamson's Sapsuckers nested in the area but were sympatric with the 2 nuthatches and Hairy Woodpecker only during the reproductive season. Red—breasted Nuthatches nested at higher elevations and were sympatric with the Hairy Woodpecker and other nuthatches only during the non—reproductive season. Pigmy Nuthatches foraged most extensively in the foilage of live pine in both seasons. White—breasted Nuthatches concentrated their foraging activities on the trunks and large branches of pine. Zones used most extensively by all nuthatches were mutually exclusive in both seasons. Zones of Hairy Woodpeckers and Williamson's Sapsuckers overlapped considerably in the reproductive season. Hairy Woodpeckers foraged for arthropods on the surface of trunks and branches of living trees but more extensively for subcortical arthropods of dead trees, stumps and logs. Williamson's Sapsuckers foraged almost exclusively for ants on trunks of living pines. In the non—reproductive season, Hairy Woodpeckers foraged most extensively for seeds of pine cones. Williamson's Sapsuckers foraged almost exclusively on phloem of trunks of living pines. Foraging activities of Red—shafted Flickers were confined to the ground and thus segregated from the major foraging zones of all other birds. Nuthatches and woodpeckers were shown to be segregated by spatial and behavioral differences of foraging activities and by temporal differences of their residential status. It is concluded that climate, available space and competition for food were important in the evolutionary development of these interspecific differences.

The Auditory Range of a Hairy Woodpecker

Journal Article The Auditory Range of a Hairy Woodpecker Get access Warren K. Ramp Warren K. Ramp Department of Zoology, Colorado State University, Fort Collins, Colorado Search for other works by this author on: Oxford Academic Google Scholar The Condor, Volume 67, Issue 2, 1 March 1965, Pages 183–185, https://doi.org/10.2307/1365260 Published: 01 March 1965

Deformed Hairy Woodpecker

Deformed Hairy Woodpecker

Toxoplasma from the woodpecker, a new natural host

Toxoplasmosis was found in three hairy woodpeckers Dryobates himalayensis himalayensis and one specimen of D. auriceps. These findings added another two species to those known to be naturally infected with Toxoplasma. The incidence of natural infection seemed to be rather high (perhaps in the order of 25 per cent.) The WPH strain of Toxoplasma produced no sickness in mice and was detected only in the 3rd mouse passage. It had been possible to compare the WPH strain with standard RH strain of human origin. Morphologically, they resembled each other, but biologically differed in that the former killed only 90 per cent. of animals and took longer to do it. Serologically, the Toxoplasma of woodpecker origin appeared to be similar to but not identical with the human RH strain. Interestingly, no antibodies could be detected either in the sera of the four infected woodpeckers or 12 other healthy specimens that have been tested so far. The sources and mode of infection as well as the epizootic significance of the findings were discussed.

Courtship and Territorial Behavior of Hairy Woodpeckers

Courtship and Territorial Behavior of Hairy Woodpeckers

Drumming by Female Hairy Woodpeckers

Drumming by Female Hairy Woodpeckers

Hairy Woodpeckers

Hairy Woodpeckers

From Field and Study

Competition between Mountain Bluebirds and Hairy Woodpeckers Get access J. A. Munro J. A. Munro Okanagan Landing, British Columbia Search for other works by this author on: Oxford Academic Google Scholar The Condor, Volume 45, Issue 2, 1 March 1943, Page 74, https://doi.org/10.2307/1364381 Published: 01 March 1943

The Eastern Hairy Woodpecker (Dryobates v. villosus) as a Migrant

The Eastern Hairy Woodpecker (Dryobates v. villosus) as a Migrant

Red Squirrel Eating Young Hairy Woodpecker

Red Squirrel Eating Young Hairy Woodpecker

The Whistled Call of the Hairy Woodpecker

The Whistled Call of the Hairy Woodpecker

Economic Ornithology in Recent Entomological Publications Birds Undoubtedly Play an Important Part in Reducing the Number of Adults Each Year It Is Undoubtedly True That This Species Is Eaten to Some Extent by Birds, and the Hairy Woodpecker Has Been Charged with Destroying It on Several Occasions. The Crow Has Been Observed to Feed on the Beetles and Also to

Economic Ornithology in Recent Entomological Publications Birds Undoubtedly Play an Important Part in Reducing the Number of Adults Each Year It Is Undoubtedly True That This Species Is Eaten to Some Extent by Birds, and the Hairy Woodpecker Has Been Charged with Destroying It on Several Occasions. The Crow Has Been Observed to Feed on the Beetles and Also to

Swarth on a New Hairy Woodpecker from Southeastern Alaska Description of a New Hairy Woodpecker from Southeastern Alaska H. S. Swarth

Swarth on a New Hairy Woodpecker from Southeastern Alaska Description of a New Hairy Woodpecker from Southeastern Alaska H. S. Swarth