scholarly journals Nut Selection by Captive Blue Jays: Importance of Availability and Implications for Seed Dispersal

The Condor ◽  
2006 ◽  
Vol 108 (2) ◽  
pp. 377-388 ◽  
Author(s):  
Jeffrey E. Moore ◽  
Robert K. Swihart

Abstract We assessed dietary preference of 14 captive Blue Jays (Cyanocitta cristata) for different food types under different conditions of availability. In four separate feeding trials, we provisioned jays with the following: Trial 1, two nuts each of white oak (Quercus alba), pin oak (Q. palustris), black oak (Q. velutina), northern red oak (Q. rubra), and shagbark hickory (Carya ovata); Trial 2, two small and two large red oak acorns; Trial 3, two germinating and two nongerminating white oak acorns; and Trial 4, one large red oak acorn, one large white oak acorn, and one shagbark hickory nut. We used discrete choice models to describe selection under conditions of changing choice sets. Blue Jays displayed a clear preference for pin oak and strong avoidance of red oak acorns when alternative foods were available. White oak and black oak acorns were selected intermediately. Shagbark hickory nuts were never used. Correlation coefficients suggested that preference was inversely related to seed size and the proportion of seed consisting of hard seed coat. In the absence of alternative food items, small red oak acorns were readily taken, whereas large red oak acorns were mostly avoided but still used by some birds. These results highlight the importance of considering food availability when making conclusions about preference, and lend support to the hypothesis that Blue Jays can be important dispersers of even less-preferred oak species. We discuss the potential as well as the limitations for Blue Jays to act as seed dispersers, with respect to postglacial range expansion of fagaceous tree species, and in the context of present-day dispersal in regions where forests are highly fragmented.

1978 ◽  
Vol 110 (3) ◽  
pp. 241-244 ◽  
Author(s):  
G. A. Surgeoner ◽  
W. E. Wallner

AbstractTotal foliage consumption per larva of Heterocampa manteo (Doubleday) was 334 ± 49.3 cm2 of leaf area. Approximately 85% of the consumption occurred during the fifth larval stadium. There was no significant difference in consumption by H. manteo when fed northern red oak, Quercus rubra L., or white oak, Quercus alba L. Foliage consumption at 27 °C, 24 °C, and 21 °C did not differ significantly; but larvae reared at 15.5 °C consumed 42.6% less foliage. Larvae parasitized by Diradops bethunei (Cresson) consumed 61.3% less foliage than non-parasitized larvae reared at the same temperature. Two methods of predicting defoliation are discussed based upon larval foliage consumption data.


2011 ◽  
Vol 41 (10) ◽  
pp. 1936-1947 ◽  
Author(s):  
David C. LeBlanc ◽  
Mark A. Terrell

The objective of this study was to evaluate growth–climate associations for northern red oak ( Quercus rubra L.) across much of its geographic range in eastern North America and to compare these associations with those of white oak ( Quercus alba L.). Tree-ring and climate data were obtained for a total of 82 sites, including 51 sites where both oak species were sampled. Northern red oak radial growth was most strongly and spatially consistently correlated with site water balance variables for the early growing season (May through July). Correlations with prior year autumn and winter precipitation were also identified at a smaller number of sites. The phenology of growth–climate correlations was virtually identical between northern red oak and white oak, although there was modest evidence that correlations were stronger for white oak. These results support the hypothesis that species with similar wood anatomy, geographic distribution, and habitat preferences may have similar growth–climate relationships. This suggests that functional groups of tree species may be defined a priori based on existing knowledge of their wood anatomy and ecology.


HortScience ◽  
2010 ◽  
Vol 45 (4) ◽  
pp. 696-700 ◽  
Author(s):  
Jayesh B. Samtani ◽  
John B. Masiunas ◽  
James E. Appleby

Previous research by the authors found simulated acetochlor (with atrazine) and s-metolachlor drift to white oak at the leaf unfolding stage caused loss of interveinal tissues (leaf tatters). Reports of leaf tatters in the landscape and nursery settings are more common on white oak (Quercus alba L.) than on northern red oak (Quercus rubra L.). Our objectives were to determine if white and northern red oak differed in susceptibility to chloroacetanilide herbicides, if injury varied between chloroacetanilide herbicides, and if adding atrazine increased leaf injury. Two-year-old seedlings at the leaf unfolding stage were treated with acetochlor, s-metolachlor, and dimethenamid-P alone or combined with atrazine at 1%, 10%, and 25% of the standard field use rate. Within 6 days, all chloroacetanilides at 10% and 25% field use rates, alone or combined with atrazine, caused leaf tatter injury in both species. Acetochlor, s-metolachlor, and dimethenamid-P caused a similar type of leaf injury. Atrazine did not cause loss of leaf tissues or increase injury from chloroacetanilides. At 1% field use rate, only acetochlor, acetochlor + atrazine, and dimethenamid-P caused leaf injury to northern red oaks. The white oaks were not injured by all of the chloroacetanilide treatments at 1% field use rate. The northern red oaks were slightly more susceptible to chloroacetanilides compared with the white oaks. A second study found acetochlor only injured northern red oak when applied at the leaf unfolding stage and only at 25% of field use rate. Acetochlor at 1% field use rate did not injure red oak. Research is needed to explain the greater frequency of leaf tatters on white oaks than on northern red oaks in the landscape and to develop strategies to avoid tree injury.


2010 ◽  
Vol 27 (3) ◽  
pp. 110-116 ◽  
Author(s):  
Martin-Michel Gauthier ◽  
Douglass F. Jacobs

Abstract We established a study to investigate short-term morphological responses of northern red oak (Quercus rubra L.), white oak (Quercus alba L.), and black walnut (Juglans nigra L.) to a 43% basal area reduction in a mixed planting. Although the effect was not statistically confirmed, thinned northern red oak showed a 23% gain in relative diameter growth and a 25% gain in relative crown surface area expansion compared with nonthinned trees; white oak showed gains of 15 and 10%, respectively. Similar trends were found in percentage of basal area increase for northern red oak (45%) and white oak (37%). Black walnut did not appear to respond to thinning and may have been under less competition from first-tier neighbors than the oaks were. Both northern red oak and white oak were in intermediate and suppressed crown classes, whereas black walnut was in a codominant position. Trends from this study suggest that northern red oak and white oak may respond favorably to thinning when found in lower crown classes where the amount of competition from neighboring trees is high.


2007 ◽  
Vol 31 (1) ◽  
pp. 17-22 ◽  
Author(s):  
Eric Heitzman ◽  
Adrian Grell ◽  
Martin Spetich ◽  
Dale Starkey

Abstract Four mature northern red oak (Quercus rubra L.)–white oak (Quercus alba L.) stands in the Boston Mountains of northern Arkansas were studied to describe the vegetation dynamics of forests heavily impacted by oak decline. Northern red oak was the species most susceptible to decline. Across the four stands, 51–75% of red oak density (trees/ha) was dead or dying, as was 40–70% of the red oak basal area. Red oak damage occurred across a range of tree sizes. Healthy red oak had low populations of red oak borer (Enaphalodes rufulus Haldeman), and dead/dying red oak supported large numbers of borers. Impacts on white oak were less severe and generally limited to smaller trees. Decline had changed what once were red oak-dominated stands to more mixed forests of white oak, hickory (Carya spp.), red oak, blackgum (Nyssa sylvatica Marsh.), and red maple (Acer rubrum L.). Understory trees and seedlings were predominantly blackgum, red maple, hickory, black cherry (Prunus serotina Ehrh), flowering dogwood (Cornus florida L.), and sassafras (Sassafras albidum [Nutt.] Nees). However, well-developed red and white oak advance regeneration was present in all stands. It is unclear if the death of overstory trees will favor the regeneration of nonoaks, or whether oak regeneration will successfully recruit within canopy gaps created by this disturbance.


2000 ◽  
Vol 17 (2) ◽  
pp. 45-50 ◽  
Author(s):  
Felix Ponder

Abstract Survival and height of four hardwood species—black walnut (Juglans nigra L.), northern red oak (Quercus rubra L.), white oak (Q. alba L.), and black oak (Q. velutina Lam.)—were evaluated 4 yr after the trees were outplanted in a recently harvested hardwood site. The study evaluated the influence of numbers of first-order lateral roots (FOLR); preplanting-root treatments (RT) that included both separate and combination treatments of a biostimulant, Roots®, a moisture loss retardant, SuperSorb-F® (SS), and a water control; and tree shelters (TS) on seedling performance.Except for black walnut, 4 yr survival was significantly (P ≤ 0.05) higher with tree shelters than without them. However, survival was not affected by FOLR or RT. The number of FOLR significantly affected the 4 yr height growth of northern red oak and black oak, but they did not affect the height growth of black walnut and white oak. Four-year height growth for black walnut and northern red oak was greater for unsheltered trees than for sheltered trees; the reverse was true for white oak and black oak. First-order lateral roots, root collar diameter (RCD), and TS were significantly correlated with first-year height and/or 4 yr height growth. Root treatments did not affect height growth. The overall good survival and limited treatment effect indicate that the number of FOLR was of limited importance on this site for these tree species. However, treatment effects may have been different on a more stressful site. North. J. Appl. For. 17(2):45-50.


1990 ◽  
Vol 7 (2) ◽  
pp. 79-81 ◽  
Author(s):  
Paul S. Johnson ◽  
Dale R. Weigel

Abstract Nonlinear regression estimates of DBH based on stump diameter outside bark 6 in. above ground are presented for northern red oak, and the white oak-scarlet oak and black oak-chestnut oak species groups in southern Indiana. Model estimates were compared to those from models developed for other regions. DBH estimates obtained from the new models and some previously reported models can be used to recontruct preharvest volume, value, and structure of harvested oak stands in southern Indiana. North. J. Appl. For. 7:79-81, June 1990.


2006 ◽  
Vol 30 (3) ◽  
pp. 117-122
Author(s):  
Eric Heitzman ◽  
Adrian Grell

Abstract Two upland sites in Arkansas were studied to test the performance of 1-0 northern red oak (Quercus rubra L.) and white oak (Quercus alba L.) seedlings planted in group selection openings. Both red and white oak seedlings were planted at one location in the Ozark Mountains,and only red oak seedlings were planted at a second site along Crowleys Ridge. Holes were dug with power augers and seedlings were planted by hand. At the time of planting, the mean height of red oak and white oak seedlings at the Ozark site were 3.4 and 1.9 ft, respectively. Red oak seedlingsat Crowleys Ridge averaged 3.0 ft tall when planted. After 4 years at the Ozark site, 77% of red oak and 86% of white oak were alive. After 3 years at Crowleys Ridge, red oak survival was 80%. Seedlings at both sites grew slowly. Mean 4-year height increment at the Ozarksite was 2.1 ft for red oak and 2.5 ft for white oak, and mean 3-year height increment for red oak at Crowleys Ridge was 1.6 ft. Three years after planting in the Ozark Mountains and 2 years after planting at Crowleys Ridge, naturally regenerating competition had suppressed over one-thirdof the red oak and about one-half of the white oak. This necessitated a release treatment around planted seedlings at both sites. Oaks that decreased in total height over a given growing season were common. Most seedlings that decreased in height had been pulled over or crushed by other vegetationor exhibited top dieback. South. J. Appl.For. 30(3):142–146.


2011 ◽  
Vol 41 (11) ◽  
pp. 2219-2230 ◽  
Author(s):  
Joanne Rebbeck ◽  
Kurt Gottschalk ◽  
Amy Scherzer

Northern red oak ( Quercus rubra L.) seedling growth has been extensively studied. White oak ( Quercus alba L.) and chestnut oak ( Quercus prinus L.), however, are far less investigated despite their importance among upland oak species in eastern North American forests. We characterized white and chestnut oak seedling response to light and available soil nutrients while using northern red oak as a benchmark. Germinants were grown within one of three shade treatments (25%, 18%, and 6% of full sun) in one of two native forest soil mixes over two growing seasons. Leaf area, shoot mass, and root mass of all three species showed positive growth responses to increasing light. Growth and biomass were higher for all species grown in the more nutrient-rich forest soil, but chestnut oak displayed the greatest positive responses to the higher nutrient levels. White oak seedlings were the slowest growers and demonstrated the most root-centered growth, with root to shoot ratios almost twice that of either chestnut or northern red oak seedlings. The oak species evaluated here responded differently to changes in resource availability. Our study demonstrates the differential response of upland oaks to low light and nutrients. These differences need consideration when developing oak management prescriptions for specific oaks.


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