Acorn Woodpecker (Melanerpes formicivorus)

2020 ◽  
Author(s):  
Walter D. Koenig ◽  
Eric L. Walters ◽  
Peter B. Stacey ◽  
Mark T. Stanback ◽  
Ronald L. Mumme
Keyword(s):  
Melanerpes Formicivorus

Acorn Woodpecker (Melanerpes formicivorus)

2019 ◽  
Author(s):  
Walter D. Koenig ◽  
Eric L. Walters ◽  
Peter B. Stacey ◽  
Mark T. Stanback ◽  
Ronald L. Mumme
Keyword(s):  
Melanerpes Formicivorus

scholarly journals Late Summer and Fall Nesting in the Acorn Woodpecker and Other North American Terrestrial Birds

The Condor ◽  
2007 ◽  
Vol 109 (2) ◽  
pp. 334-350
Author(s):  
Walter D. Koenig ◽  
Justyn T. Stahl
Keyword(s):  
Global Warming ◽  
North American ◽  
Breeding Success ◽  
Population Studies ◽  
Late Summer ◽  
Substantial Fraction ◽  
Melanerpes Formicivorus ◽  
Summer Temperatures ◽  
Total Productivity ◽  
Acorn Woodpeckers

Abstract Acorn Woodpeckers (Melanerpes formicivorus) at Hastings Reservation in central coastal California exhibit a bimodal peak in annual breeding activity. One peak occurs in spring during which the majority of breeding takes place, while a second is centered in late August as the new acorn crop matures. These latter nests are mostly initiated in late summer but often do not fledge until at least late September and are thus referred to here as ‘fall’ nests. Fall nests occur in about one-third of all years, taking place when the acorn crop is large and summer temperatures are relatively high. Fledglings from fall nests constitute 4.3% of the population's total productivity and survive and recruit to the population at levels comparable to spring fledglings. Fall nesting is less likely in groups in which either the male or female breeding adults have undergone a change from the prior year, but groups are otherwise indistinguishable. Ecologically, fall nesting is closely tied to the acorn crop and thus to breeding success in the following, rather than the prior, spring. Among North American terrestrial birds in general, fall breeding has been reported in 16% of all species and is significantly more common among residents and colonially nesting species, in which the frequency exceeds 25%. Furthermore, fall nesting is likely to have been underreported in the literature. Thus, this phenomenon is at least an irregular part of the breeding biology of a substantial fraction of North American birds and should be considered a possibility in population studies of temperate-zone species. This is especially true given that fall nesting is likely to increase as global warming takes place.

Experimental evidence that acorn woodpeckers recognize relationships among third parties no longer living together

2020 ◽  
Vol 31 (5) ◽  
pp. 1257-1265 ◽  
Author(s):  
Michael A Pardo ◽  
Eric L Walters ◽  
Walter D Koenig
Keyword(s):  
Experimental Evidence ◽  
Social Group ◽  
Third Parties ◽  
Social Species ◽  
Living Together ◽  
Melanerpes Formicivorus ◽  
Group Members ◽  
The Subject ◽  
Acorn Woodpeckers ◽  
Group Relationships

Abstract Triadic awareness, or knowledge of the relationships between others, is essential to navigating many complex social interactions. While some animals maintain relationships with former group members post-dispersal, recognizing cross-group relationships between others may be more cognitively challenging than simply recognizing relationships between members of a single group because there is typically much less opportunity to observe interactions between individuals that do not live together. We presented acorn woodpeckers (Melanerpes formicivorus), a highly social species, with playback stimuli consisting of a simulated chorus between two different individuals, a behavior that only occurs naturally between social affiliates. Subjects were expected to respond less rapidly if they perceived the callers as having an affiliative relationship. Females responded more rapidly to a pair of callers that never co-occurred in the same social group, and responded less rapidly to callers that were members of the same social group at the time of the experiment and to callers that last lived in the same group before the subject had hatched. This suggests that female acorn woodpeckers can infer the existence of relationships between conspecifics that live in separate groups by observing them interact after the conspecifics in question no longer live in the same group as each other. This study provides experimental evidence that nonhuman animals may recognize relationships between third parties that no longer live together and emphasizes the potential importance of social knowledge about distant social affiliates.

Melanerpes formicivorus (Acorn Woodpecker)

2015 ◽  
Vol 28 (04) ◽  
pp. 265-268
Author(s):  
Wiet Helmond
Keyword(s):  
Melanerpes Formicivorus

scholarly journals Temporal variability and cooperative breeding: testing the bet-hedging hypothesis in the acorn woodpecker

2015 ◽  
Vol 282 (1816) ◽  
pp. 20151742 ◽  
Author(s):  
Walter D. Koenig ◽  
Eric L. Walters
Keyword(s):  
Reproductive Success ◽  
Cooperative Breeding ◽  
Group Living ◽  
Bet Hedging ◽  
Hedging Strategy ◽  
Ecological Conditions ◽  
Variable Environments ◽  
Melanerpes Formicivorus ◽  
Mean Fitness

Cooperative breeding is generally considered an adaptation to ecological constraints on dispersal and independent breeding, usually due to limited breeding opportunities. Although benefits of cooperative breeding are typically thought of in terms of increased mean reproductive success, it has recently been proposed that this phenomenon may be a bet-hedging strategy that reduces variance in reproductive success (fecundity variance) in populations living in highly variable environments. We tested this hypothesis using long-term data on the polygynandrous acorn woodpecker ( Melanerpes formicivorus ). In general, fecundity variance decreased with increasing sociality, at least when controlling for annual variation in ecological conditions. Nonetheless, decreased fecundity variance was insufficient to compensate for reduced per capita reproductive success of larger, more social groups, which typically suffered lower estimated mean fitness. We did, however, find evidence that sociality in the form of larger group size resulted in increased fitness in years following a small acorn crop due to reduced fecundity variance. Bet-hedging, although not the factor driving sociality in general, may play a role in driving acorn woodpecker group living when acorns are scarce and ecological conditions are poor.

scholarly journals Is the distribution of the Acorn Woodpecker (Melanerpes formicivorus flavigula) associated with oaks and granaries? A local study in an urban area in northern South America

2019 ◽  
Author(s):  
Hana Londoño Oikawa ◽  
Paulo C. Pulgarín-R
Keyword(s):  
South America ◽  
Rural Areas ◽  
Food Storage ◽  
Territory Size ◽  
Local Study ◽  
Resource Requirements ◽  
Melanerpes Formicivorus ◽  
Northern South America ◽  
Acorn Woodpeckers ◽  
Urban And Rural Areas

ABSTRACTAbiotic and biotic factors are known to be key in limiting the geographical distribution of species. However, our understanding on the influence of habitat heterogeneity on ecological interactions and behavior in tropical animals is limited. We studied groups of Acorn Woodpeckers (Melanerpes formicivorus flavigula) in urban and rural areas in northern South America to understand how habitat and resource requirements (food storage structures) influences patterns of distribution across the Aburrá Valley, in the northern area of the Central Andes of Colombia. Using focal observations of 10 different groups over nearly a two-year period, we estimated territory size, habitat use, and described the use and presence of granaries. We found that territory size, tree diversity, and the use of granaries varied among groups. Accordingly, Acorn Woodpeckers use a wide variety of tree species to make cavities, to feed and to build granaries for social interactions. Our study supports the hypothesis that Acorn Woodpeckers do not rely on the Colombian Oak (Quercus humboldtiiBonpl.) for feeding, nesting or foraging in the Aburrá Valley, and that the construction of granaries to store food is present in urban populations, despite the lack of strong seasonal changes in tropical areas. We suggest that the distribution of the Acorn Woodpecker in our study area is strongly associated with one particular species of tree,Albizia carbonariaBritton, and the behavior of granaries construction might be hardwired in this species for the maintenance and cohesion of family groups.

scholarly journals Design Considerations for Examining Trends in Avian Abundance Using Point Counts: Examples From Oak Woodlands

The Condor ◽  
2005 ◽  
Vol 107 (2) ◽  
pp. 305-320 ◽  
Author(s):  
Kathryn L. Purcell ◽  
Sylvia R. Mori ◽  
Mary K. Chase
Keyword(s):  
Keystone Species ◽  
Sampling Period ◽  
Observer Variability ◽  
Point Counts ◽  
Avian Abundance ◽  
Bird Monitoring ◽  
Negative Effect ◽  
Melanerpes Formicivorus ◽  
Para Determinar ◽  
Adequate Power

AbstractWe used data from two oak-woodland sites in California to develop guidelines for the design of bird monitoring programs using point counts. We used power analysis to determine sample size adequacy when varying the number of visits, count stations, and years for examining trends in abundance. We assumed an overdispersed Poisson distribution for count data, with overdispersion attributed to observer variability, and used Poisson regression for analysis of population trends. Overdispersion had a large, negative effect on power. The number of sampling years also had an especially large effect on power. In all cases, 10 years of sampling were insufficient to detect a decline in abundance of 30% over 10 years. Increasing the sampling period to 20 years provided adequate power for 56% of breeding species at one site. The number of count stations needed for detecting trends for a given species depended primarily on observer variability. If observer variability was high, increasing the number of years and visits was a better approach than increasing the number of stations. Increasing the number of stations was most beneficial for species with low abundance or low observer variability. When the number of stations is limited by the size of the area, we recommend multiple visits to stations. For most species, multiple visits per year (six or more) for 15–20 years were needed to detect a 30% decreasing trend in 10 years with adequate power. We suggest potentially useful focal species for monitoring, such as keystone species like the Acorn Woodpecker (Melanerpes formicivorus).Consideraciones de Diseño para Examinar las Tendencias en la Abundancia de Aves Usando Conteos Puntuales: Ejemplos con Datos de Bosques de Encino en CaliforniaResumen. Usamos datos de dos sitios ubicados en bosques de encino en California, con el fin de desarrollar una guía para diseñar programas de monitoreo usando conteos puntuales. Usamos un análisis del poder de la prueba para determinar el tamaño adecuado de la muestra al cambiar el número de visitas, el número de estaciones de conteo y los años de conteo con el fin de examinar las tendencias en la abundancia. Supusimos la distribución de Poisson para el conteo, con sobredispersión atribuida a la variabilidad del observador. La sobredispersión tuvo un efecto fuerte y negativo en el poder de la prueba. El efecto del número de años de muestreo fue especialmente grande sobre el poder. En cada caso, 10 años de muestreo fueron insuficientes para detectar una disminución de la abundancia del 30% en 10 años. Al aumentar el período de muestreo a 20 años, el análisis proporcionó un poder adecuado para 56% de las especies reproductivas en uno de los sitios. El número de estaciones de conteo requeridos para una especie dada dependió principalmente de la variabilidad del observador. Si la variabilidad del observador era alta, aumentar el número de años de observación y visitas fue una estrategia mejor que aumentar el número de estaciones. Aumentar el número de estaciones fue más benéfico para especies poco abundantes o con baja variabilidad del observador. Cuando el número de estaciones es limitado por el tamaño del área, recomendamos visitas múltiples a las estaciones. Para la mayoría de las especies se requieren visitas anuales múltiples (6 o más) durante 15–20 años para detectar una tendencia de decrecimiento a una razón del 30% en 10 años con un poder adecuado. Sugerimos especies focales potencialmente útiles para monitoreo tales como la especie clave Melanerpes formicivorus.

Genetic monogamy in single-male groups of acorn woodpeckers, Melanerpes formicivorus

1995 ◽  
Vol 4 (6) ◽  
pp. 765-770 ◽  
Author(s):  
J. DICKINSON ◽  
J. HAYDOCK ◽  
W. KOENIG ◽  
M. STANBACK ◽  
F. PITELKA
Keyword(s):  
Single Male ◽  
Genetic Monogamy ◽  
Melanerpes Formicivorus ◽  
Acorn Woodpeckers
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