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Frugivore guild analyses and analyses of fruit trap contents (78x1m² traps under 29 tree species) (Bollen and Van Elsacker 2002a, Chapter3a; Bollen et al., Chapter 2). For Pteropus rufus faecal droppings were collected weekly under the roost site year-round. Dietary data on the rodents resulted mainly from identifying gnawing marks on seed remains collected at feeding sites. Since Eulemur fulvus collaris was studied intensively in parallel to the present study (Baldi 2002; Donati 2002; Morelli 2002), fruits eaten by this species may be more thoroughly sampled than other species. The con-generic species Cheirogaleus medius and C. major could not always be distinguished during observations and are treated as Cheirogaleus spp. in the analyses. The same applies to rodent species, Eliurus webbi and Rattus rattus (introduced), as not all gnawing marks could be attributed to a single species. Details of the diets of the various species are given in Appendix I. For the frugivorous bird species, diets are treated separately, but for feeding selection Alectroenas madagascariensis, Treron australis, and Hypsipetes madagascariensis were combined, as they are the only seed dispersing birds at our site. Dietary overlap was calculated among pairs of frugivores using Sørensen’s similarity index (Krebs 1989). This index generates a value ranging from 0 to 1, with 0 representing no overlap and 1 representing complete overlap. The dataset comprises accounts of fruit species consumed by different frugivore consumers along with the impact they have on the seeds. Based on this, frugivores can be classified into the following categories: seed dispersers or fruit consumers (D), neutral or pulp consumers (N) and seed predators (P) according to Gauthier-Hion et al. (1985) and Debussche and Isenmann (1992). The first group disperses intact seeds by endozoochory through droppings or synzoochory through regurgitation, while the second group eats fruit pulp but drops the seeds under the parent plant. The last group eats and destroys the seeds. It is difficult to assign a certain frugivore to one category only, as one species may have different impacts on the same and on different plant species. The stage of ripeness of the consumed fruits was scored as well. To differentiate between unripe and ripe fruits changes in size, colour and consistency were looked at. Data analyses Most of the variables measured have highly skewed distributions so the median value is given instead of the mean. For the same reason non-parametric statistics were used. Chisquare analyses were conducted to compare discrete fruit traits in the diet with those in the overall dataset, whereas Mann Whitney U tests were carried out to control for feeding preferences when comparing continuous traits between food and non-food items. Afterwards sequential Bonferroni corrections were performed on the significance levels (Rice 1989). To understand which factors influence the diet of the different frugivores separately a logistic generalised model was applied in which morphological and biochemical variables were included as fixed factors. Dietary data were used as binomial response variables (0=non-food, 1=food item) in a generalised mixed linear model with logit link (glimmix procedure in SAS 8.1.) with forward procedure retaining significant variables. As Cheirogaleus spp. and Microcebus rufus go into torpor in austral winter, comparison of their diet and total dataset available were restricted to the fruits that were present during their active period. Statistical significance was accepted for α≤0.05 for all tests. All statistical tests were carried out according to Siegel (1956) with the statistical software SAS for Windows. 63
Chapter 3 64 Body 1,2 Body lenght (cm) 1 Table 1. List of frugivorous vertebrate species at Sainte Luce, with indication of their diet (F: frugivorous, G: granivorous, O: omnivorous), their activity budget (D: diurnal, N: nocturnal, C: cathemeral), feeding height (A: arboreal, T: terrestrial), body mass and length. ND: no data available. Family Scientific name English name Diet Activity Feeding Group size height (N individuals) mass (g) 32 28 28 24 35 50 215 ND 190 45 218 ND 3-8 3-12 1-2 5-15 3-15 3-15 A A T A A A D D D D D D F F G F G G Malagasy Green Pigeon Malagasy Blue Pigeon Madagascar Turtle Dove Madagascar Bulbull Lesser Vasa Parrot Greater Vasa Parrot Treron australis L. Alectroenas madagascariensis L. Streptopelia picturata Temminck Hypsipetes madagascariensis Müller Coracopsis nigra L. Coracopsis vasa Shaw AVES Columbidae Pycnonotidae Psittacidae 15-23 10-16 100 88 1-2 1-2 AT AT N N O G Black Rat Webb's Tuft-Tailed Rat Rattus rattus L. Eliurus webbi Ellerman MAMMALIA RODENTIA Muridae Nesomyinae 23-27 500-750 250-300 A N F Madagascar Flying Fox Pteropus rufus Tiedemann CHIROPTERA Pteropodidae PRIMATES Lemuridae Eulemur fulvus collaris E. Geoffroy Collared Brown Lemur F C A 3-10 2000-2300 40-47 Cheirogaleidae Microcebus rufus E. Geoffroy Brown Mouse Lemur O N A 1 42 12,5 Cheirogaleus major E. Geoffroy Greater Dwarf Lemur O N A 1-3 443 25 Cheirogaleus medius E. Geoffroy Fat-tailed Dwarf Lemur O N A 1-3 119-282 20 1 Data from Langrand (1990), Fietz and Ganzhorn (1999), Goodman et al. (1997b), Goodman et al. (in press), Ganzhorn et al. (1999a), Donati (pers. comm. 2002). 2 Body length is total length for birds and bats but head/body length for lemurs and rodents.
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Fruit-frugivore interactions in a M
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Cover photographs: Front: Back: -
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Table of contents III. General conc
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Acknowledgements A special word of
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PREFACE Preface This work brings to
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General introduction Finally, seed
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General introduction high as 98% fo
Page 19 and 20: ’Hazo tokana tsy mba ala’ One t
Page 21 and 22: Chapter 1 changes in resource avail
Page 23 and 24: Chapter 1 For analyses we narrowed
Page 25 and 26: Chapter 1 Fig. 2. Seasonal variatio
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Page 29 and 30: Chapter 1 Fig 4. Comparison of data
Page 31 and 32: Chapter 1 Table 4. Data on phenolog
Page 33 and 34: Chapter 1 Relation with abiotic fac
Page 35 and 36: Chapter 1 Malagasy rainforests disp
Page 37 and 38: Chapter 1 Appendix I Continued Fami
Page 39 and 40: Chapter 1 Appendix I Continued Fami
Page 41 and 42: Malagasy proverb Drawing © Giusepp
Page 43 and 44: Chapter 2 the successful establishm
Page 45 and 46: Chapter 2 40 Table 1. The frugivore
Page 47 and 48: Chapter 2 Statistical analyses To v
Page 49 and 50: Chapter 2 Overall fruit trap data d
Page 51 and 52: Chapter 2 Table 3. Morphological an
Page 53 and 54: Chapter 2 depressed seeds (Fig. 3a)
Page 55 and 56: Chapter 2 Fig. 3. Ordination plot o
Page 57 and 58: Chapter 2 On a community level the
Page 59 and 60: Chapter 2 Appendix II. Plant-animal
Page 63 and 64: Malagasy proverb Lemur drawing © S
Page 65 and 66: Chapter 3 different consumer specie
Page 67: Chapter 3 Bollen et al. in press, C
Page 71 and 72: Chapter 3 dominant plant families s
Page 73 and 74: Chapter 3 Table 4. Morphological an
Page 75 and 76: Chapter 3 Table 4 Continued Paramet
Page 77 and 78: Chapter 3 Besides testing feeding s
Page 79 and 80: Chapter 3 and do not consume the fi
Page 81 and 82: Chapter 3 (1997) already pointed ou
Page 83 and 84: Chapter 3 1989; Galetti 1993; Saini
Page 85 and 86: Chapter 3 Appendix I. All plant spe
Page 87 and 88: Chapter 3 Other SD Hss Rats Rr Ew 8
Page 90 and 91: Pteropus rufus Feeding ecology of P
Page 92 and 93: Pteropus rufus number per species a
Page 94 and 95: Pteropus rufus Table 1 Continued Fr
Page 96 and 97: Pteropus rufus larger number of spe
Page 98 and 99: Table 2 Continued Number of seeds/d
Page 100 and 101: Pteropus rufus Food selection: expl
Page 102 and 103: Pteropus rufus presence. On the oth
Page 104 and 105: Pteropus rufus Marshall (1983). Occ
Page 106 and 107: Coracopsis nigra The feeding ecolog
Page 108 and 109: Coracopsis nigra fruit pulp (70%) b
Page 110 and 111: Coracopsis nigra Table 1 Continued
Page 112 and 113: Coracopsis nigra Table 2. Morpholog
Page 115 and 116: Malagasy proverb Drawing of fruits
Page 117 and 118: Chapter 4 Most seed dispersal studi
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Chapter 4 Mean temperature is aroun
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Chapter 4 Number of seeds: 1-2, 3-1
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Chapter 4 Fig. 2. Monthly fruit ava
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Chapter 4 120 Table 3. Soil charact
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Chapter 4 Table 4. Morphological ch
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Chapter 4 Table 5. Biochemical char
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Chapter 4 Chemistry At both sites,
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Chapter 4 considering species numbe
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’Ny valala tsy indroa mandry eo a
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Chapter 5 environmental degradation
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Chapter 5 at a very low density in
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Chapter 5 Table 1. A list of plant
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Chapter 5 (Ganzhorn et al. 1999a).
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Chapter 5 Animals The degree of vul
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Chapter 5 comm.). Mixed species pla
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Chapter 5 data are needed we believ
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General conclusion as in other site
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General conclusion selection pressu
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General conclusion are consumed by
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Samenvatting omstandigheden zijn bo
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Samenvatting vruchtkenmerken. Beide
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Samenvatting zaadverspreiding moete
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Résumé température et précipita
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Résumé (Sud-est de Madagascar) et
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Résumé des frugivores sur l’év
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References Bollen A, Van Elsacker L
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References Dowsett JR (2000) Le sta
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References Godfrey LR, Junger WL, R
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References Janson CH, Chapman CA (1
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References Marshall AG (1983) Bats,
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References Rabevohitra R, Lowry PP,
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References Tattersall I (1982) The
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family Loganiaceae scientific name
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