scholarly journals Avian Fruit Removal: Effects of Fruit Variation, Crop Size, and Insect Damage

Ecology ◽  
1987 ◽  
Vol 68 (6) ◽  
pp. 1711-1723 ◽  
Author(s):  
Pedro Jordano
Keyword(s):  
Insect Damage ◽  
Fruit Removal ◽  
Crop Size

THE RELATIONSHIPS BETWEEN FRUIT RIPENESS, WASP SEED PREDATION, AND AVIAN FRUIT REMOVAL IN PISTACIA PALAESTINA

1998 ◽  
Vol 46 (4) ◽  
pp. 273-278 ◽  
Author(s):  
Ido Izhaki
Keyword(s):  
Seed Predation ◽  
Individual Variation ◽  
Tree Height ◽  
Reproductive Parameters ◽  
Substantial Variation ◽  
Fruit Removal ◽  
Crop Size ◽  
Fruit Abortion ◽  
Pistacia Terebinthus ◽  
Unripe Fruits

Substantial variation in fruit removal between individual Pistacia palaestina plants was observed in northern Israel. To elucidate the causes of this variation, I examined several proximal sources of between-individual variation in fruit removal and dispersal efficiency. Crop size, tree height, and diameter explained some between- individual variation in fruit removal. Dispersal efficiency was mainly influenced by the proportion of the unripe fruits (including aborted and parthenocarpic fruits). Comparison of several reproductive parameters of P. palaestina with another Pistacia species (P. terebinthus) in Spain, revealed that P. palaestina produces larger fruit crop, faces higher seed prédation by infesting wasps, and has lower proportions of parthenocarpy and fruit abortion than Pistacia terebinthus. Fruit removal and dispersal efficiency of the former is much higher than the latter.

Effects of Fruit Crop Size on Intensity of Fruit Removal in Viburnum prunifolium (Caprifoliaceae)

Oikos ◽  
1994 ◽  
Vol 69 (2) ◽  
pp. 199 ◽  
Author(s):  
Mark S. Laska ◽  
Edmund W. Stiles
Keyword(s):  
Fruit Removal ◽  
Crop Size ◽  
Fruit Crop ◽  
Fruit Crop Size

RELATIONSHIP BETWEEN CONE CROP SIZE AND CONE DAMAGE BY INSECTS IN RED PINE SEED-PRODUCTION AREAS

1971 ◽  
Vol 103 (4) ◽  
pp. 617-621 ◽  
Author(s):  
William J. Mattson
Keyword(s):  
Seed Production ◽  
Red Pine ◽  
Insect Damage ◽  
Crop Size ◽  
Pine Cone ◽  
Pine Cones ◽  
Production Areas ◽  
Cone Damage

AbstractAnnual cone abundance and insect damage to cones are highly variable in red pine seed-production areas. Cone crop size fluctuates almost unpredictably from year to year, but the number of insect-attacked cones tends to increase annually unless limited by cone abundance. Sixty-six per cent of the variation in cone damage can be associated with variations in cone abundance. This information, coupled with the fact that red pine cone insects are almost entirely dependent on red pine cones for food, implies that crop size is highly important in regulating populations of cone insects. Insects will be most devastating in areas where crop size varies little from year to year.

Fruit removal efficiency and success: influence of crop size in a neotropical treelet

Plant Ecology ◽  
2006 ◽  
Vol 189 (1) ◽  
pp. 147-154 ◽  
Author(s):  
Raúl Ortiz-Pulido ◽  
Yuri V. Albores-Barajas ◽  
S. Anaid Díaz
Keyword(s):  
Removal Efficiency ◽  
Fruit Removal ◽  
Crop Size

Crop size, plant aggregation, and microhabitat type affect fruit removal by birds from individual melastome plants in the Upper Amazon

Oecologia ◽  
2008 ◽  
Vol 158 (2) ◽  
pp. 273-283 ◽  
Author(s):  
Pedro G. Blendinger ◽  
Bette A. Loiselle ◽  
John G. Blake
Keyword(s):  
Fruit Removal ◽  
Crop Size

Fruit removal rates from aggregated and isolated bushes of the red elderberry, Sambucus pubens

1987 ◽  
Vol 65 (6) ◽  
pp. 1229-1235 ◽  
Author(s):  
Julie Sloan Denslow
Keyword(s):  
Fruit Quality ◽  
Sugar Content ◽  
Fruit Size ◽  
Fruit Removal ◽  
Removal Rates ◽  
Differential Probability ◽  
Local Competition ◽  
Crop Size ◽  
First Reproduction ◽  
Dispersal Success

In July in northern Wisconsin, the red elderberry (Sambucus pubens (Michx.) synchronously ripens large panicles of bright red, small, watery, sweet drupes. During 1982 and 1983, I monitored bushes aggregated along an old logging track or isolated in tree-fall clearings to investigate the effects of isolation, crop size, and fruit quality on fruit removal by birds. All three factors significantly affected rates of fruit removal, although fruit removal rates were primarily a function of crop size. More fruits per bush per day were removed from large crops of both aggregated and isolated plants. Fruits were not removed disproportionately faster from plants with large than with small crops in either habitat. These results do not support the hypothesis that differential probability of dispersal success is an important selective factor in the evolution of delayed first reproduction or supraannual fruiting periodicities. However, removal rates from aggregated plants were lower than from isolated bushes in tree-fall clearings, probably an effect of local competition for frugivores. Sugar content of the pulp (but not fruit size) also significantly affected rates of fruit removal.

The relationship between crop size and fruit removal and its implication for the evolution of dioecy

1992 ◽  
Vol 70 (9) ◽  
pp. 1784-1789 ◽  
Author(s):  
David E. Carr
Keyword(s):  
Empirical Studies ◽  
Stable State ◽  
Relative Fitness ◽  
Female Fitness ◽  
Fruit Removal ◽  
Crop Size ◽  
Fruit Crop ◽  
The Stability ◽  
Evolution Of Dioecy ◽  
The Relationship

The number of fruits removed by birds from individual Ilex opaca (Aquifoliaceae) was found to increase as a function of crop size in both 1986 and 1987. The proportion of the fruit crop removed, however, was not significantly affected by crop size in either year. In 1986 the increase in relative female fitness as a function of crop size rapidly became asymptotic. In 1987 relative female fitness increased more linearly over the range of fruit crop sizes. Differences between years were attributed to differences in disperser abundance. The change in relative fitness with increasing crop size was not sufficient to explain the evolutionary stability of dioecy under conditions such as those in 1986 (i.e., asymptotic fitness gains). Under conditions of more proportional increases in relative fitness (as seen in 1987), circumstances became more favorable for the stability of dioecy, though still not sufficient. This and other empirical studies of the response of avian dispersers to variation in fruit crop size suggest that selection for increased crop size is not likely, by itself, to be strong enough to allow dioecy to exist in a stable state. I suggest that the combined effects of sexual selection (especially through male–male competition) and inbreeding depression will be more important than the effect of differential dispersal success for the evolution and maintenance of dioecy in plants. Key words: dioecy, dispersal, frugivore, holly, Ilex.

Ethephon for American Ginseng (Panax quiquefolium L.) Inflorescence Removal

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 481b-481
Author(s):  
A.E. Fiebig ◽  
J.T.A. Proctor ◽  
D. Murr ◽  
R. Releeder
Keyword(s):  
Additive Concentration ◽  
Root Mass ◽  
Panax Quinquefolium ◽  
Fruit Removal ◽  
Plant Damage ◽  
Low Concentrations ◽  
Production Practice ◽  
Whole Plants ◽  
Mass Increase ◽  
Standard Production

Varying concentrations (500-4000 mg·L–1) of ethephon, an ethylene-releasing compound, were applied to 3-year-old ginseng (Panax quinquefolium L.) plants in fields of southern Ontario. The effects of this chemical on fruit removal, plant damage, infructescence morphology, and root mass were studied and compared to the normal practice of manual inflorescence removal. The highest concentrations had the highest rates of removal but also caused the greatest amount of damage to the whole plants when compared to the mid-range concentrations. The lowest concentrations showed less foliar damage but did not provide sufficient fruit removal to mimic hand removal. When individual inflorescences of the ethephon treatments were studied, the seed heads had fewer ripe berries and more unpollinated florets than the untreated controls. When root masses were compared, high and low concentrations showed lower masses than those of the standard production practice of hand removal. However, mid range concentrations showed similar root mass increase to manual removal. When all parameters were considered, the concentration range giving the best results was 1000-1500 mg·L–1. Multiple applications of ethephon, at weekly intervals, had an additive effect on flower removal and plant damage. Treatments having an additive concentration of over 2000 mg·L–1 had detrimental effects on all parameters. Those within the 1000–1500 mg·L–1 range showed the highest similarity to the hand removal benefits.

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