Many tropical animals inhabit mosaic landscapes including human-modified habitat. In such landscapes, animals commonly adjust feeding behavior, and may incorporate non-natural foods. These behavioral shifts can influence consumers’ nutritional states, with implications for population persistence. However, few studies have addressed the nutritional role of non-natural food. We examined nutritional ecology of wild blue monkeys to understand how dietary habits related to non-natural foods might support population persistence in a mosaic landscape. We documented prevalence and nutritional composition of non-natural foods in monkey diets to assess how habitat use influenced their consumption and their contribution to nutritional strategies. While most energy and macronutrients came from natural foods, subjects focused non-natural feeding activity on five exotic plants and averaged about a third of daily calories from non-natural foods. Most non-natural food calories came from non-structural carbohydrates and least from protein. Consumption of non-natural foods related to time in human-modified habitats, which two groups used non-randomly. Non-natural and natural foods were similar in nutrients, and the amount of non-natural food consumed drove variation in nutritional strategy. When more daily calories came from non-natural foods, females consumed a higher ratio of non-protein energy to protein (NPE:P). Females also prioritized protein while allowing NPE:P to vary, increasing NPE while capitalizing on non-natural foods. Overall, these tropical mammals achieved a similar nutrient balance regardless of their intake of non-natural foods. Forest and forest-adjacent areas with non-natural vegetation may provide adequate nutrient access for consumers, and thus contribute to wildlife conservation in mosaic tropical landscapes.

The accompanying data file summarizes individual all-day focal follows of 24 wild adult female blue monkeys in the Kakamega Forest, Kenya, characterizing their daily nutrient intake based on observations of feeding behaviour combined with laboratory analysis of their foods, as described in:

Takahashi, MQ, Rothman, JM, Cords, M. 2022. The role of non-natural foods in the nutritional strategies of monkeys in a human-modified landscape mosaic. Biotropica (see both main text and supplementary material).

Please also refer to the above paper for a list of blue monkey foods categorized as natural and non-natural foods.

Additional information on the methods used in this study can be found in

Takahashi, MQ. 2018. The Nutritional Ecology of Adult Female Blue Monkeys, Cercopithecus mitis, in the Kakamega Forest, Kenya. PhD Thesis. Columbia University. https://doi.org/10.7916/D86M4PV3.

Variables (columns in data set) are described below, in an order corresponding to the order of columns in the data set, left to right.

• Column Title: Group  
  • Data type= Category
  • Description: Identifies in which of three study groups (named TWS, GSC, GN) subject lived.
• Column Title: Month
  • Data type= Category/Date
  • Description: Formatted as numerical month. Indicates month in which date the data were collected.
• Column Title: Day
  • Data type= Category/Date
  • Description: Formatted as numerical day. Indicates day on which date the data were collected.
• Column Title: ID
  • Data type= Category  
  • Description: Unique identifier for each subject. Subjects are 24 adult female blue monkeys, Cercopithecus mitis stuhlmanni, from a single population inhabiting a ca. 2 km² area of the Kakamega Forest, western Kenya, located near the Kakamega Forest Station (0o 19’ N, 34o 52’ E), a site of long-term study of the species.
• Column Title: Count.village
  • Data type: Quantitative         
  • Description: Number of records during daily observation period that a subject was observed in the habitat type village forest. We recorded subject’s location at 30 min intervals, on the hour and half hour. 
• Column Title: Count.forest
  • Data type: Quantitative         
  • Description: Number of records during daily observation period that a subject was observed in the habitat type near-natural forest. We recorded subject’s location at 30 min intervals, on the hour and half hour.
• Column Title: Count.plantation
  • Data type: Quantitative         
  • Description: Number of records during daily observation period that a subject was observed in the habitat type farm/plantation forest. We recorded subject’s location at 30 min intervals, on the hour and half hour.
• Column Title: Nat.total.energy.kcal
  • Data type: Quantitative         
  • Description: Sum of protein, lipid, NDF and TNC (units: kcal) of natural foods observed to be eaten by focal subject. 
• Column Title: Nat.lipid.kcal
  • Data Type: Quantitative
  • Description: Daily intake of crude lipid on a dry matter basis (units: kcal) of natural foods observed to be eaten by focal subject. We assessed crude lipid with a combination of wet chemistry techniques (ether extraction) and near-infrared spectroscopy. Macronutrient intake (grams) of lipid was converted to energetic values (kcal) using the conversion of 9 kcal/gram (Conklin-Brittain et al. 2006).
• Column Title: Nat.NDF.kcal
  • Data type: Quantitative         
  • Description: NDF=Neutral Detergent Fiber (units: kcal). Daily intake of structural carbohydrates as measured by NDF on a dry matter basis (and accounting for fiber fermentation, and thus digestibility) of natural foods observed to be eaten by focal subject. We assessed NDF using wet chemistry techniques (Conklin-Brittain et al. 2006; Rothman et al. 2008). We converted the intake (grams) of fiber to energetic values (kcal) using the conversion of 3 kcal/gram (Conklin-Brittain et al. 2006). The caloric value was adjusted by multiplication with a group-specific fiber digestibility coefficient: GN group: 0.37, TWS group: 0.39, GSC group: 0.22.
• Column Title: Nat.protein.kcal
  • Data type: Quantitative         
  • Description: Daily intake of available protein on a dry matter basis (units: kcal) of natural foods observed to be eaten by focal subject. We assessed available protein with a combination of wet chemistry techniques (subtracting acid detergent insoluble protein from crude protein amount from combustion) and near-infrared spectroscopy. Macronutrient intake (grams) of available protein was converted to energetic values (kcal) using the conversion of 4 kcal/gram (Conklin-Brittain et al. 2006).
• Column Title: Nat.TNC.kcal
  • Data type: Quantitative         
  • Description: Daily intake of TNC (total non-structural carbohydrates) on a dry matter basis (units: kcal) of natural foods observed to be eaten by focal subject. We computed TNC by subtracting from one the sum of the daily proportions of NDF, protein, lipid, and ash (in terms of grams), then converting the mass intake to caloric intake (with conversion of 4 kcal/g; Conklin-Brittain et al. 2006).
• Column Title: Nat.NPE.kcal   
  • Data type: Quantitative         
  • Description: Non-protein energy (NPE). Sum of lipid, NDF and TNC (units: kcal) of natural foods observed to be eaten by focal subject.
• Column Title: Nat.NDF.g
  • Data type: Quantitative         
  • Description: NDF=Neutral Detergent Fiber (units: grams) of natural foods observed to be eaten by focal subject. Daily intake of structural carbohydrates as measured by NDF on a dry matter basis based on wet chemistry techniques.
• Column Title: Nat.ADF.g
  • Data type: Quantitative         
  • Description: ADF=Acid Detergent Fiber (units: grams) of natural foods observed to be eaten by focal subject. ADF was measured on a dry matter basis based on wet chemistry techniques.
• Column Title: Nat.ADL.g
  • Data type: Quantitative         
  • Description: ADL=Acid Detergent Lignin (units: grams) of natural foods observed to be eaten by focal subject. ADL was measured on a dry matter basis based on wet chemistry techniques.
• Column Title: Nat.food.g
  • Data type: Quantitative         
  • Description: Daily intake of food (sum of protein, lipid, NDF, TNC and ash) on a dry matter basis (units: grams) of natural foods observed to be eaten by focal subject.
• Column Title: Non.Nat.total.energy.kcal
  • Data type: Quantitative         
  • Description: Sum of protein, lipid, NDF and TNC (units: kcal) of non-natural foods observed to be eaten by focal subject. 
• Column Title: Non.Nat.lipid.kcal
  • Data Type: Quantitative
  • Description: Daily intake of crude lipid on a dry matter basis (units: kcal) of non-natural foods observed to be eaten by focal subject. We assessed crude lipid with a combination of wet chemistry techniques (ether extraction) and near-infrared spectroscopy. Macronutrient intake (grams) of lipid was converted to energetic values (kcal) using the conversion of 9 kcal/gram (Conklin-Brittain et al. 2006).
• Column Title: Non.Nat.NDF.kcal
  • Data type: Quantitative         
  • Description: NDF=Neutral Detergent Fiber (units: kcal). Daily intake of structural carbohydrates as measured by NDF on a dry matter basis (and accounting for fiber fermentation, and thus digestibility) of non-natural foods observed to be eaten by focal subject. We assessed NDF using wet chemistry techniques (Conklin-Brittain et al. 2006; Rothman et al. 2008). We converted the intake (grams) of fiber to energetic values (kcal) using the conversion of 3 kcal/gram (Conklin-Brittain et al. 2006). The caloric value was adjusted by multiplication with a group-specific fiber digestibility coefficient: GN group: 0.37, TWS group: 0.39, GSC group: 0.22.
• Column Title: Non.Nat.protein.kcal
  • Data type: Quantitative         
  • Description: Daily intake of available protein on a dry matter basis (units: kcal) of non-natural foods observed to be eaten by focal subject. We assessed available protein with a combination of wet chemistry techniques (subtracting acid detergent insoluble protein from crude protein amount from combustion) and near-infrared spectroscopy. Macronutrient intake (grams) of available protein was converted to energetic values (kcal) using the conversion of 4 kcal/gram (Conklin-Brittain et al. 2006).
• Column Title: Non.Nat.TNC.kcal
  • Data type: Quantitative         
  • Description: Daily intake of TNC (total non-structural carbohydrates) on a dry matter basis (units: kcal) of non-natural foods observed to be eaten by focal subject. We computed TNC by subtracting from one the sum of the daily proportions of NDF, protein, lipid, and ash (in terms of grams), then converting the mass intake to caloric intake (with conversion of 4 kcal/g; Conklin-Brittain et al. 2006).
• Column Title: Non.Nat.NPE.kcal
  • Data type: Quantitative         
  • Description: Non-protein energy (NPE). Sum of lipid, NDF and TNC (units: kcal) of non-natural foods observed to be eaten by focal subject.
• Column Title: Non.Nat.NDF.g
  • Data type: Quantitative         
  • Description: NDF=Neutral Detergent Fiber (units: grams) of non-natural foods observed to be eaten by focal subject. Daily intake of structural carbohydrates as measured by NDF on a dry matter basis based on wet chemistry techniques.
• Column Title: Non.Nat.ADF.g
  • Data type: Quantitative         
  • Description: ADF=Acid Detergent Fiber (units: grams) of non-natural foods observed to be eaten by focal subject. ADF was measured on a dry matter basis based on wet chemistry techniques.
• Column Title: Non.Nat.ADL.g
  • Data type: Quantitative         
  • Description: ADL=Acid Detergent Lignin (units: grams) of non-natural foods observed to be eaten by focal subject. ADL was measured on a dry matter basis based on wet chemistry techniques.
• Column Title: Non.Nat.food.g
  • Data type: Quantitative         
  • Description: Daily intake of food (sum of protein, lipid, NDF, TNC and ash) on a dry matter basis (units: grams) of non-natural foods observed to be eaten by focal subject.
• Column Title: natfdgday
  • Data type: Categorical
  • Description: Classification of whether the day’s caloric intake was majority from non-natural foods (coded as 0) or majority from natural foods (coded as 1).

References:

• Conklin-Brittain NL, Knott CD, Wrangham RW. 2006. Energy intake by wild chimpanzees and orangutans: Methodological considerations and a preliminary comparison. In: Hohmann G, Robbins MM, Boesch C, editors. Cambridge Studies in Biological and Evolutionary Anthropology. Vol. 48. Cambridge: Cambridge University Press. p. 445–472.
• Rothman JM, Chapman CA, Pell AN. 2008. Fiber-bound nitrogen in gorilla diets: Implications for estimating dietary protein intake of primates. Am J Primatol. 70(7):690–694.

Any software that can open a csv file.