This study determined the influence of nutritional fruit content on their consumption by chimpanzees in Kalinzu forest. Fruits consumption frequencies were obtained from analysis of chimpanzee faecal samples picked ov...This study determined the influence of nutritional fruit content on their consumption by chimpanzees in Kalinzu forest. Fruits consumption frequencies were obtained from analysis of chimpanzee faecal samples picked over a period of two years. Fruit content was analyzed using freeze dried fresh samples using standard techniques. Musanga leo-errerae (76.14%), Ficus spp (66.05%) and (18.68%) were the most commonly eaten fruits of all faecal samples (N = 2683). Generally, fruit consumption increased for fruits with total phenols and tannins below 1% per gram except for Musanga leo-errerae, Uvariopsis congoensis and Aframomum angustifolium. Multiple regression revealed that of the 15 nutrient parameters investigated, only calcium, tannins, crude fat, protein and energy content of the fruits that constitute the major food components for basic animal body needs and functioning of energy, body building and a healthy skeleton significantly predicted 76.86% of consumption (R2 = 76.86%;P = 0.019). However, the fact that some of the most eaten fruits like Aframomum angustifolium and Musanga leo-errerae were recorded to have the highest amounts in tannins shows that there must be additional factors into play. Other than fruit availability, consideration of effect of fruit size and handling within the existing models of chimpanzees’ diet could hence enhance further the understanding of fruit consumption.展开更多
One hundred and eighteen (118) tree species were identified, among which 58 species produced fruit within the two-year study. Fruit of only 26.3% of the latter is eaten by chimpanzees. The consumption of each of these...One hundred and eighteen (118) tree species were identified, among which 58 species produced fruit within the two-year study. Fruit of only 26.3% of the latter is eaten by chimpanzees. The consumption of each of these fruits was generally low, with only two species constituting more than 25% consumption. Only about 1.7% of woody biomass is relied upon by chimpanzees in Kalinzu for food. The major tree species in chimpanzee diet monitored showed that fruit production varies monthly and seasonally. Apart from Musanga leo-errerae and Ficus spp. whose fruiting was consistent throughout the year, general fruit phenology was positively correlated with rainfall. Only three species namely: Craterispermum laurinum, Aframomum angustifolium and Beilschmiedia ugandensis produced fruit in the dry seasons. Correlation between fruit availability and consumption was significantly positive for only one species, Landlophia dawei. This indicated that frugivory of chimpanzees in Kalinzu was not opportunistic;they search for what they like to eat. Chimpanzees would have to range furthest in periods of scarcity and asynchronous fruiting hence a lot of energy expenditure in the food search alone. Therefore, diversity in fruit phenology is important for chimpanzees’ energy conservation, health and survival. Selective logging and other selective human activities that involve cutting down trees that are palatable would in future affect the food diversity and consequently the health of frugivores if not done sustainably. Since patterns of fruit phenology are also linked to patterns of rainfall, changes in the former can assist in predicting the influence of climate change on food availability for big frugivores like chimpanzees.展开更多
Sedimentary TOC （total organic carbon）, TN （total nitrogen） and C/N （carbon/nitrogen） at selected sites of Lake Victoria basin have provided evidence of phytoplankton productivity, input of nitrates and allochth...Sedimentary TOC （total organic carbon）, TN （total nitrogen） and C/N （carbon/nitrogen） at selected sites of Lake Victoria basin have provided evidence of phytoplankton productivity, input of nitrates and allochthonous （land） plant materials/catchment destruction in the basin during the late Holocene period （last 4,000 years to present）. TOC and TN in the sediment cores were determined using EuroEA3000 Series Elemental Analyser and radiocarbon dating done using AMS （accelerator mass spectrometry） standard method. Results showed that TOC （13.45%-20.78%） and TN （1.07%-1.92%） values were higher at Napoleon Gulf from about 4,186 years before present （ca. 4,186 yr. BP） to present than at inlet of river Kagera （TOC： 3.27%-6.32% and TN： 0.30%-0.59%） from about 190 years before present （ca. 190 yr. BP） to present. Generally TOC and TN had a negative correlation （r = -0.37, p = 0.04, n = 32） at Napoleon Gulf in the last 4,186 years to present signifying that C/N ratios were governed mostly by phytoplankton productivity which markedly increased during some periods in the last 370 years to present possibly as a result of increased input of nitrates. However, the periods from about 4,186 years to 1,684 years before present （ca. 4,186 yr. BP to 1,684 yr. BP） and some periods between the last 370 years to present indicated increased input of allochthonous plant materials/catchment destruction. On overall, there was a positive correlation between C/N and TOC at inlet of river Kagera （r = 0.57, p = 0.01, n = 20） in the last 190 years to present possibly signifying that C/N ratios were governed mainly by input of allochthonous plant materials hence increased catchment destruction. Input of land plant materials （catchment destruction） along Kagera basin declined during some period after 1950 AD. However the most recent years have shown increased input of land plant materials （catchment destruction） in Kagera basin.展开更多
文摘This study determined the influence of nutritional fruit content on their consumption by chimpanzees in Kalinzu forest. Fruits consumption frequencies were obtained from analysis of chimpanzee faecal samples picked over a period of two years. Fruit content was analyzed using freeze dried fresh samples using standard techniques. Musanga leo-errerae (76.14%), Ficus spp (66.05%) and (18.68%) were the most commonly eaten fruits of all faecal samples (N = 2683). Generally, fruit consumption increased for fruits with total phenols and tannins below 1% per gram except for Musanga leo-errerae, Uvariopsis congoensis and Aframomum angustifolium. Multiple regression revealed that of the 15 nutrient parameters investigated, only calcium, tannins, crude fat, protein and energy content of the fruits that constitute the major food components for basic animal body needs and functioning of energy, body building and a healthy skeleton significantly predicted 76.86% of consumption (R2 = 76.86%;P = 0.019). However, the fact that some of the most eaten fruits like Aframomum angustifolium and Musanga leo-errerae were recorded to have the highest amounts in tannins shows that there must be additional factors into play. Other than fruit availability, consideration of effect of fruit size and handling within the existing models of chimpanzees’ diet could hence enhance further the understanding of fruit consumption.
文摘One hundred and eighteen (118) tree species were identified, among which 58 species produced fruit within the two-year study. Fruit of only 26.3% of the latter is eaten by chimpanzees. The consumption of each of these fruits was generally low, with only two species constituting more than 25% consumption. Only about 1.7% of woody biomass is relied upon by chimpanzees in Kalinzu for food. The major tree species in chimpanzee diet monitored showed that fruit production varies monthly and seasonally. Apart from Musanga leo-errerae and Ficus spp. whose fruiting was consistent throughout the year, general fruit phenology was positively correlated with rainfall. Only three species namely: Craterispermum laurinum, Aframomum angustifolium and Beilschmiedia ugandensis produced fruit in the dry seasons. Correlation between fruit availability and consumption was significantly positive for only one species, Landlophia dawei. This indicated that frugivory of chimpanzees in Kalinzu was not opportunistic;they search for what they like to eat. Chimpanzees would have to range furthest in periods of scarcity and asynchronous fruiting hence a lot of energy expenditure in the food search alone. Therefore, diversity in fruit phenology is important for chimpanzees’ energy conservation, health and survival. Selective logging and other selective human activities that involve cutting down trees that are palatable would in future affect the food diversity and consequently the health of frugivores if not done sustainably. Since patterns of fruit phenology are also linked to patterns of rainfall, changes in the former can assist in predicting the influence of climate change on food availability for big frugivores like chimpanzees.
文摘Sedimentary TOC （total organic carbon）, TN （total nitrogen） and C/N （carbon/nitrogen） at selected sites of Lake Victoria basin have provided evidence of phytoplankton productivity, input of nitrates and allochthonous （land） plant materials/catchment destruction in the basin during the late Holocene period （last 4,000 years to present）. TOC and TN in the sediment cores were determined using EuroEA3000 Series Elemental Analyser and radiocarbon dating done using AMS （accelerator mass spectrometry） standard method. Results showed that TOC （13.45%-20.78%） and TN （1.07%-1.92%） values were higher at Napoleon Gulf from about 4,186 years before present （ca. 4,186 yr. BP） to present than at inlet of river Kagera （TOC： 3.27%-6.32% and TN： 0.30%-0.59%） from about 190 years before present （ca. 190 yr. BP） to present. Generally TOC and TN had a negative correlation （r = -0.37, p = 0.04, n = 32） at Napoleon Gulf in the last 4,186 years to present signifying that C/N ratios were governed mostly by phytoplankton productivity which markedly increased during some periods in the last 370 years to present possibly as a result of increased input of nitrates. However, the periods from about 4,186 years to 1,684 years before present （ca. 4,186 yr. BP to 1,684 yr. BP） and some periods between the last 370 years to present indicated increased input of allochthonous plant materials/catchment destruction. On overall, there was a positive correlation between C/N and TOC at inlet of river Kagera （r = 0.57, p = 0.01, n = 20） in the last 190 years to present possibly signifying that C/N ratios were governed mainly by input of allochthonous plant materials hence increased catchment destruction. Input of land plant materials （catchment destruction） along Kagera basin declined during some period after 1950 AD. However the most recent years have shown increased input of land plant materials （catchment destruction） in Kagera basin.
