Song learning in the wood thrush

A typical wood thrush (Hylocichla mustelina) song has three phrases. The first (A) is a series of low pitched sounds, the second (B) consists of loud flutelike notes, and the third (C) is usually a trill. Males have repertoires of two to eight different B phrases, which they use in different songs. In a previous study, males reared in isolation of adult song developed songs that were normal except for the structure of the B phrases. We tutored young males (at age 20–80 days) with recorded B phrases. The phrases were of four previously defined structural types, with four variants of each type, giving a total of 16 phrases. The variants of each type differed only in frequency (Hz). The objectives of the experiment were to determine (i) if wood thrushes copy the structure of B phrases that they hear as juveniles, and (ii) if they copy selectively in such a way as to develop repertoires of highly contrasting phrases. Results were obtained for five males. The B phrase repertoires developed by four subjects consisted entirely of phrases (N = 17) copied from the tutor tape. The repertoire of the fifth subject was of phrases (N = 4) that appeared not to be copied. The males that copied from the tutor tape showed no tendency to develop repertoires of highly contrasting B phrases. Three of the four males developed multiple versions of one or more phrase types, while ignoring other types, and in some cases these versions were very similar in frequency and other details of structure.

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Wood Thrush Movements and Habitat Use: Effects of Forest Management for Red-Cockaded Woodpeckers

The Auk ◽

10.1093/auk/119.1.109 ◽

2002 ◽

Vol 119 (1) ◽

pp. 109-124 ◽

Cited By ~ 9

Author(s):

Jason D. Lang ◽

Larkin A. Powell ◽

David G. Krementz ◽

Michael J. Conroy

Keyword(s):

Habitat Use ◽

Pinus Taeda ◽

Loblolly Pine ◽

Small Scale ◽

Picoides Borealis ◽

Adult Males ◽

Hylocichla Mustelina ◽

Wood Thrush ◽

Dispersal Distances ◽

Wood Thrushes

Abstract We monitored adult and juvenile breeding-season movements and habitat use of radio-tagged Wood Thrushes (Hylocichla mustelina) at the Piedmont National Wildlife Refuge, central Georgia, USA. We investigated the effects that management for Red-cockaded Woodpeckers (Picoides borealis), thinning and burning >30 year old loblolly pine (Pinus taeda) habitat, had on Wood Thrushes, a ground-foraging and midstory-nesting species. Adult Wood Thrush pairs regularly moved long distances between nesting attempts (range 1 to 17,388 m). The only experimental effect we found on adult movements was a decrease in weekly emigration rates (Ψ) from thinned and burned compartments after silvicultural management. Adult males preferred riparian hardwoods with sparse to moderate cover and those preferences increased following management. Juveniles remained near their nest site (x̄ = 177 m, SE = 113) for an average 24 days (SE = 6.3), and then dispersed a mean 2,189 m (SE = 342). Before dispersal, juveniles preferred upland hardwood–pine mixed habitat (P < 0.05) with moderate overstory cover (P < 0.05). We found no management effects on dispersal distances or predispersal habitat use. However, juveniles from thinned and burned compartments dispersed to hardwood habitats with dense cover, whereas birds from control compartments dispersed to pine-dominated habitats with sparse cover. All juveniles dispersed to areas with habitat similar to what they used before dispersal. Small-scale thinning and burning for Red-cockaded Woodpeckers may have had little effect on Wood Thrush habitat use and movements because typical movements were often larger than the scale (stand or compartment) targeted for management.

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A Productivity Model for Parasitized, Multibrooded Songbirds

The Condor ◽

10.1093/condor/108.2.292 ◽

2006 ◽

Vol 108 (2) ◽

pp. 292-300 ◽

Cited By ~ 1

Author(s):

Larkin A. Powell ◽

Melinda G. Knutson

Keyword(s):

Simulation Model ◽

Field Studies ◽

Hylocichla Mustelina ◽

Wood Thrush ◽

Driftless Area ◽

Annual Productivity ◽

American Redstarts ◽

Complex Life History ◽

Species Specific ◽

Wood Thrushes

Abstract We present an enhancement of a simulation model to predict annual productivity for Wood Thrushes (Hylocichla mustelina) and American Redstarts (Setophaga ruticilla); the model includes effects of Brown-headed Cowbird (Molothrus ater) parasitism. We used species-specific data from the Driftless Area Ecoregion of Wisconsin, Minnesota, and Iowa to parameterize the model as a case study. The simulation model predicted annual productivity of 2.03 ± 1.60 SD for Wood Thrushes and 1.56 ± 1.31 SD for American Redstarts. Our sensitivity analysis showed that high parasitism lowered Wood Thrush annual productivity more than American Redstart productivity, even though parasitism affected individual nests of redstarts more severely. Annual productivity predictions are valuable for habitat managers, but productivity is not easily obtained from field studies. Our model provides a useful means of integrating complex life history parameters to predict productivity for songbirds that experience nest parasitism.

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Quantifying Male Wood Thrush Nest-Attendance and its Relationship to Nest Success

The Condor ◽

10.1093/condor/107.1.138 ◽

2005 ◽

Vol 107 (1) ◽

pp. 138-144 ◽

Cited By ~ 2

Author(s):

Kenneth A. Schmidt ◽

Christopher J. Whelan

Keyword(s):

New York ◽

Nest Success ◽

Nest Attendance ◽

Success Rates ◽

Hylocichla Mustelina ◽

Wood Thrush ◽

Cyanocitta Cristata ◽

Significant Difference ◽

Accipiter Striatus ◽

Wood Thrushes

Abstract Male Wood Thrushes (Hylocichla mustelina) attend their nests by perching near its rim, a behavior common to many species and presumed to be for the purpose of guarding eggs or young in the nest. We classified nests into two groups based on whether or not we observed an attending male during any nest inspection. We found that nests attended by male Wood Thrushes had higher success rates (i.e., lower predation rates) than unattended nests in Illinois where Blue Jays were a dominant nest predator. In contrast, there was no significant difference in nest success between attended and unattended nests in New York where rodents (mice and chipmunks) and raptors, such as the Sharp-shinned Hawk, were important predators on nests and adults, respectively. Despite differences in risk to adults and nests between the two sites, the frequency of observing attendant males did not differ between sites. In contrast to studies in the literature, the frequency of nest-attendance in the New York population was negatively related to year-to-year variation in chipmunk density, an independent measure of the risk of nest predation. Cuantificación de la Presencia del Macho de Hylocichla mustelina en el Nido y su Relación con el Éxito del Nido Resumen. Los machos de Hylocichla mustelina se posan cerca del borde sus nidos aparentemente con el propósito de vigilar sus huevos o sus crías, lo que representa un comportamiento común en muchas especies. Clasificamos los nidos en dos grupos basados en la presencia o ausencia de un macho durante las inspecciones de los nidos. Encontramos que los nidos que presentaron machos de H. mustelina tuvieron mayores tasas de éxito (i.e., menores tasas de depredación) que los nidos sin machos en Illinois, donde Cyanocitta cristata fue el depredador de nidos dominante. En contraste, no hubo una diferencia significativa en el éxito de los nidos entre los que contaron o no con la presencia de machos en Nueva York, donde los roedores (ratones y ardillas listadas) y las rapaces (como Accipiter striatus) fueron importantes depredadores tanto de nidos como de adultos. A pesar de las diferencias en el riesgo al que están sujetos los adultos y los nidos entre los dos sitios, la frecuencia de observación de presencia de machos no difirió entre los sitios. En contraste con los estudios publicados, la frecuencia de la presencia de machos en los nidos en la población de Nueva York se relacionó negativamente con la variación interanual en la densidad de ardillas listadas, lo que representa una medida independiente del riesgo de depredación de los nidos.

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Impacts of Housing Developments on Wood Thrush Nesting Success in Hardwood Forest Fragments

The Condor ◽

10.1093/condor/107.1.97 ◽

2005 ◽

Vol 107 (1) ◽

pp. 97-106 ◽

Cited By ~ 2

Author(s):

Judith Phillips ◽

Erica Nol ◽

Dawn Burke ◽

Wendy Dunford

Keyword(s):

Nest Predation ◽

Molothrus Ater ◽

Forest Edge ◽

Forest Fragments ◽

Hylocichla Mustelina ◽

Wood Thrush ◽

Housing Developments ◽

Las Casas ◽

Wood Thrushes ◽

Small Forest

Abstract We studied the impacts of low density, exurban housing developments on Wood Thrushes (Hylocichla mustelina) breeding in small forest fragments in two regions of rural southern Ontario. In both regions, Wood Thrushes breeding in woodlots with embedded houses (housing penetrating the forest border) experienced significantly higher rates of parasitism by Brown-headed Cowbirds (Molothrus ater) than Wood Thrushes breeding in woodlots with adjacent houses (houses within 100 m of the forest edge), or undeveloped woodlots (no houses within 100 m of the forest edge). Wood Thrushes breeding in Peterborough area woodlots with embedded or adjacent houses experienced significantly increased rates of nest predation compared to Wood Thrushes breeding in undeveloped woodlots. This increased nest predation resulted in significant reductions in seasonal productivity in developed woodlots. No increase in nest predation was experienced by Wood Thrushes nesting in developed woodlots in the Ottawa region. The effects of housing developments appear to be region-specific and may depend on other factors influencing the overall abundance of cowbirds. Impactos de la Construcción de Viviendas en el Éxito de Nidificación de Hylocichla mustelina en Fragmentos de Bosque Resumen. Estudiamos los impactos de la construcción en baja densidad de viviendas peri-urbanas sobre individuos de Hylocichla mustelina que se encontraron criando en fragmentos pequeños de bosque en dos regiones rurales del sur de Ontario. En ambas regiones, los individuos de H. mustelina que se reprodujeron en bosques donde había casas inmersas (que penetraban el borde del bosque) experimentaron tasas de parasitismo por Molothrus ater significativamente mayores que los individuos criando en bosques con casas adyacentes (dispuestas a menos de 100 m del borde del bosque), o en bosques no alterados por la presencia de casas (a más de 100 m del borde del bosque). Los individuos de H. mustelina que se encontraron criando en áreas boscosas de Peterborough, donde las casas estaban adentro o adyacentes al bosque, experimentaron incrementos significativos en las tasas de depredación de nidos comparados con individuos que criaron en bosques no alterados. Este incremento en la depredación de nidos llevó a reducciones significativas en la productividad estacional en los bosques con viviendas. No registramos un incremento en la depredación de nidos de H. mustelina en bosques con viviendas en la región de Ottawa. Los efectos de la construcción de viviendas parecen estar relacionados de modo específico con la región y podrían depender de otros factores que influencian la abundancia de M. ater.

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Are Traditional Methods of Determining Nest Predators and Nest Fates Reliable? An Experiment with Wood Thrushes (Hylocichla mustelina) Using Miniature Video Cameras

The Auk ◽

10.1093/auk/119.4.1126 ◽

2002 ◽

Vol 119 (4) ◽

pp. 1126-1132 ◽

Cited By ~ 7

Author(s):

Gary E. Williams ◽

Petra Bohall Wood

Keyword(s):

Hylocichla Mustelina ◽

Wood Thrush ◽

Traditional Methods ◽

Glaucomys Volans ◽

Predator Species ◽

Video Cameras ◽

Video Footage ◽

Infrared Video ◽

Wood Thrushes ◽

Nest Predators

AbstractWe used miniature infrared video cameras to monitor Wood Thrush (Hylocichla mustelina) nests during 1998–2000. We documented nest predators and examined whether evidence at nests can be used to predict predator identities and nest fates. Fifty-six nests were monitored; 26 failed, with 3 abandoned and 23 depredated. We predicted predator class (avian, mammalian, snake) prior to review of video footage and were incorrect 57% of the time. Birds and mammals were underrepresented whereas snakes were over-represented in our predictions. We documented ≥9 nest-predator species, with the southern flying squirrel (Glaucomys volans) taking the most nests (n = 8). During 2000, we predicted fate (fledge or fail) of 27 nests; 23 were classified correctly. Traditional methods of monitoring nests appear to be effective for classifying success or failure of nests, but ineffective at classifying nest predators.

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Wood Thrush (Hylocichla Mustelina) Nesting Ecology in Relation to Prescribed Burning of Mixed-Oak Forest in Ohio

The Auk ◽

10.1093/auk/120.3.874 ◽

2003 ◽

Vol 120 (3) ◽

pp. 874-882

Author(s):

Vanessa L. Artman ◽

Jerry F. Downhower

Keyword(s):

Reproductive Success ◽

Prescribed Burning ◽

Conservation Status ◽

Local Population ◽

Fire Intensity ◽

Hylocichla Mustelina ◽

Wood Thrush ◽

Nesting Ecology ◽

Burned Areas ◽

Wood Thrushes

Abstract Prescribed burning is increasingly being used to restore and maintain oak-dominated (Quercus spp.) forests in the eastern United States. We assessed effects of prescribed burning on the nesting ecology of the Wood Thrush (Hylocichla mustelina). Recent declines in Wood Thrush populations have prompted concern about their conservation status. Low-intensity surface fires in mixed-oak forests resulted in reductions in midstory vegetation, a documented habitat requirement for Wood Thrushes, but local population levels of Wood Thrushes did not differ between burned and unburned areas. Wood Thrushes inhabiting recently burned areas selected nest sites where leaf litter cover, fern cover, densities of shrubs and saplings, and moisture levels were higher and where fire intensity was lower in comparison to random sites. Wood Thrushes also placed their nests higher off the ground, and in taller and larger-diameter trees and shrubs, in burned than in unburned areas. Reproductive success did not differ between burned and unburned areas. However, successful nests were placed higher off the ground and in areas with lower densities of shrubs and saplings than unsuccessful nests in both burned and unburned areas. Prescribed burning appeared to have minimal effects on nesting ecology of Wood Thrushes, given their flexibility in nest placement, with no adverse consequences in terms of reproductive success. Local variation in fire intensity and moisture levels also maintained availability of suitable nesting habitat within burned areas. Continued monitoring would be appropriate to further assess the response of Wood Thrushes to prescribed burning, particularly in consideration of their conservation status and the uncertainty associated with potential long-term effects of habitat change.

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Enriched feather hydrogen isotope values for Wood Thrushes sampled in Georgia, USA, during the breeding season: implications for quantifying dispersal

Canadian Journal of Zoology ◽

10.1139/z06-114 ◽

2006 ◽

Vol 84 (9) ◽

pp. 1331-1338 ◽

Cited By ~ 26

Author(s):

L.A. Powell ◽

K.A. Hobson

Keyword(s):

Breeding Season ◽

Geographic Location ◽

Information Criterion ◽

Small Scale ◽

Hylocichla Mustelina ◽

Wood Thrush ◽

Future Studies ◽

A Site ◽

Wood Thrushes ◽

Criterion Approach

We used an analysis of deuterium values (δD) of 151 Wood Thrush ( Hylocichla mustelina (J.F. Gmelin, 1789)) feathers collected during the breeding season at the Piedmont National Wildlife Refuge in Georgia, USA, to determine fidelity to the study site. We compared δD values in feathers of birds with known molt locations and birds with unknown molt locations. Mean feather value of δD was –24.8‰ (SD = 10.5‰, range = –48.0‰ to –5.5‰), and we were unable to determine a site-specific signature to assess fidelity of breeders within our sample. We used an information criterion approach to evaluate multiple hypotheses to explain the high variation in δD, and the geographic location of sample sites within the study area was selected as the best model. Feather δD values were higher than expected from mean growing-season rainfall δD values predicted for our study site. We discuss possible explanations for the enriched δD values and postulate that heat stress during molt may have contributed to our results. We suggest that future stable isotope data collection consider the potential for small-scale variation in feather δD values; information on diet gathered simultaneously with feather samples may be valuable for future studies.

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Demographic Variables are Poor Indicators of Wood Thrush Productivity

The Condor ◽

10.1093/condor/104.1.92 ◽

2002 ◽

Vol 104 (1) ◽

pp. 92-102 ◽

Cited By ~ 4

Author(s):

Todd J. Underwood ◽

Roland R. Roth

Keyword(s):

Nest Success ◽

Temporal Trends ◽

Significant Proportion ◽

Demographic Variables ◽

Hylocichla Mustelina ◽

Wood Thrush ◽

Return Rates ◽

Annual Productivity ◽

Productivity Indices ◽

Population Indices

Abstract We tested the ability of 29 indices of productivity to predict and track actual productivity of a Wood Thrush (Hylocichla mustelina) population for 21 years and to detect year-to-year changes in that productivity. Of 29 indices tested, only the productivity of nests initiated in May showed promise. This index reasonably predicted productivity, correctly tracked two out of three temporal trends in productivity, and detected a significant proportion of year-to-year changes in actual productivity. Although they were not useful for predicting annual productivity, other indices based on nest data tracked trends in productivity moderately well, and all, except percent nest success, detected a significant proportion of year-to-year changes in productivity. Productivity indices based on non-reproductive variables, such as abundance of males or females, return rates, and veteran:novice ratios, did not reflect productivity trends or changes. From these results, we recommend that only an intensive measure of actual productivity or a partial measure of it, such as May productivity, be used to make inferences about annual productivity of a population. Indices based on other nest data should be used only for tracking productivity trends. Non-reproductive indices are unreliable for making any inferences about productivity. Las Variables Demográficas son Malas Indicadoras de la Productividad de Hylocichla mustelina Resumen. Pusimos a prueba la capacidad de 29 índices de productividad para predecir y seguir las variaciones anuales en la productividad real de una población de Hylocichla mustelina por un período de 21 años. De los 29 índices probados, sólo el de la productividad de los nidos iniciados en mayo resultó promisorio. Este índice predijo la productividad razonablemente bien y detectó correctamente dos de tres tendencias temporales en la productividad y una proporción significativa de los cambios anuales en la productividad real. Aunque no fueron útiles para predecir la productividad anual, otros índices basados en datos de nidos siguieron las tendencias en la productividad aceptablemente bien. Con excepción del porcentaje de nidos exitosos, todos estos índices detectaron una proporción significativa de las variaciones anuales de la productividad. Por su parte, los índices de productividad basados en variables no reproductivas como la abundancia de machos y hembras, las tasas de regreso y el cociente de aves veteranas: novatas no reflejaron las tendencias o cambios en la productividad real. Con base en estos resultados recomendamos que para hacer inferencias sobre la productividad anual de una población sólo se utilice una medida intensiva de la productividad, o una medida parcial de ésta (i.e., la productividad en mayo). Los índices basados en otros datos de nidos deben ser utilizados únicamente para monitorear las tendencias en la productividad. Los índices no reproductivos son poco confiables para hacer inferencias sobre la productividad.

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