Since 1990, timber harvesting in the Pyrenees has resulted in around 25 regenerating 10- to 20-ha sites of various ages surrounded by unharvested forest. Three alternative analyses demonstrated negative frequency dependence in many cases, a result generally consistent with a mixed feeding strategy. This was achieved for forbs by harvesting all plant material within a number (5–20, depending on local forb density) of 10-cm2 × 1.5-m-high subplots established along a 10-m transect. Consequently, the forb and tree models were rerun using traditional multiple regression after excluding the relative availability of trees and forbs, respectively. The effect-size index A showed that the observed difference in diet selection was about 4 times smaller than the difference in diet composition. Data across seasons incorporating selection, availability, and information about forage quality (e.g., Forsyth et al. Regardless of the habitat, forbs constituted the major portion of the wallabies' diets, with moderate amounts of shrubs and grass also consumed. Usually, swamp wallabies do not behave aggressively towards each other, except when males fight over a female for mating rights. During the wet season, they eat a variety of native grasses, shrubs and bushes, leaves, and fruits. Compositional analysis (Aebischer et al. However, mixed diets are expected if consumption is constrained by nutrient availability (partial preference hypothesis—Pulliam 1975; Westoby 1974), or if eating a range of foods reduces the negative effect of plant toxins (detoxification limitation hypothesis—Freeland and Janzen 1974; Marsh et al. Swamp wallabies, like other species of rock wallabies and scrub wallabies, eat Australian native grasses, herbs, and ferns. For consistency with the diet analysis procedure (see below), cover values for grass and sedges were combined into a single monocotyledon category. Forbs were defined as nonwoody plants, whereas shrubs were defined as all woody plants except for Eucalyptus, which were categorized as a tree. However, patterns of selection do not stay constant in space or time, and may be influenced by factors such as concentrations of toxins and nutrients (Lawler et al. Thanks to G. Hepworth for statistical advice and M. Flett for facilitating field work. 1a and 1b) are exemplified by the comparison of shrubs versus forbs, and all comparisons containing ferns. During the dry season, these wallabies feed on moisture-rich roots, stems, and discard the leaves. Major differences between the unharvested-forest and 5-year-old sites (Figs. Collection of stomach samples.—Twenty-two wallabies from 14 spatially independent sites were shot to obtain stomach samples. Forage quality.—For each plant group, the plots described above were used to collect healthy foliage growing below wallaby foraging height (1.5 m). Unharvested-forest and 5-year-old sites were more similar in terms of overall selection, although the P-value was still small (Fig. At each plot the abundance of 6 plant functional groups (ferns, forbs, grass, sedges, shrubs, and trees) was recorded as the percent projected cover in three 1-m2 × 1.5-m-high subplots positioned 3 m apart along a linear transect. The group of 4 lower on axis 2 selected shrubs to a greater extent and forbs to a lesser extent than their counterparts. How much food should a German shepherd eat daily? The plant fragment closest to each grid intersection (defined by crosshairs) was identified on the basis of microhistological features (e.g., Storr 1961) as either forb, grass, sedge, shrub, fern, tree, or unknown, using a previously established reference collection of plants from the study site. Because of the high correlation between the relative availability of forbs and trees (r = −0.71) these 2 models were rerun using traditional multiple regression after excluding the highly correlated predictor. Coefficients (β) have been standardized and 95% LCL and 95% UCL are the 95% lower and upper confidence limits, respectively, of β. Swamp Wallabies live in thick understorey vegetation; They browse on shrubs and coarse vegetation; Swamp Wallabies are generally solitary animals; The Swamp Wallaby joey is born 33-38 days after conception; The Swamp Wallaby joey stays in its mother's pouch for approximately 8-9 months. This 20,000-ha forest is underlain by stony red duplex soils and dominated by a single range running approximately east–west and rising to 750 m above sea level. Trees and ferns were eaten less at unharvested sites, and more at 5-year-old sites. In zoos, swamp wallabies are usually kept in small groups of no more than ten individuals. At the 5-year-old site where 5 wallabies were shot, home-range overlap ranged from 5.9% to 90.1%. Half (10/20) of the overlaps were < 20%, whereas the mean overlap was 32.4%. All wallabies are herbivorous. Copyright © 2021 Multiply Media, LLC. When did organ music become associated with baseball? Wallaby Deterrents. The detoxification limitation hypothesis: where did it come from and where is it going? When wallabies used >1 habitat type, a minimum of 10 plots were established in each. We collected data on diets in a native Eucalyptus forest where the relative availability of food types (defined as 5 plant functional groups: ferns, forbs, monocots, shrubs, and trees) had been altered by timber harvesting. Finally, the results of this study relate to the consumption of broad plant groups in autumn within areas defined by home-range boundaries and should not be extended to other times or spatial scales. 1976) was used to investigate overall (multivariate) differences in both consumption and selection between wallabies at unharvested and 5-year-old sites. But Clifton Hill doesn't follow this pattern. 2002). JDS was supported by an Australian Postgraduate Award. By removing seedlings and leaf litter, wallabies reduce food sources such as worms and insects for these birds. Confidence intervals around the selection index are in parentheses, and were derived using a bootstrapping procedure to account for asymmetry in some of the data sets. The latter effect was primarily driven by changed selection for forbs, shrubs, trees, and ferns, and the selection ranking of trees and ferns changed substantially between sites. Comparisons of selection between different food types (Fig. Wallabies are herbivores whose diet consists of a wide range of grasses, vegetables, leaves and other foliage. 2002; Sprent and McArthur 2002; Tixier et al. (2006) argue that contrasting amounts of grass in the diets of 2 groups of African elephants (Loxodonta africana) was directly related to the availability of alternative forage species. Also, I include in one. In general, our findings were similar to the only other study of diet selection for this species (Wood 2002), in which shrubs and forbs also were identified as important dietary components. Swamp wallabies, like other Due to recent urbanization, many wallabies now feed in rural and urban areas. These and other factors (e.g., Illius et al. Records from the nearest weather station show the mean annual rainfall to be 540 mm, and the mean winter (July) minimum and summer (January) maximum temperatures to be 3°C and 29°C, respectively (Bureau of Meteorology 2006). 1. Swamp wallabies forage widely, eating a variety of ferns, heath and shrubs. M and F refer to male and female, respectively. During spring, wallaby can be seen coming out of the forest to feed on new grass and shrub growth. What was the weather in Pretoria on 14 February 2013? Swamp wallabies eat a wide range of grasses, forbs, sedges, shrubs, trees, vines and fungi, but although their diet is broad, they are selective about what they eat. Because of the low abundance of sedges, cover values of the monocot category were almost totally attributable to grass. On one hand, a positive relationship between selection and relative availability (positive frequency dependence) at the scale of an animal's home range is consistent with diet specialization as predicted by simple optimal foraging models, at least for preferred food types (Hubbard et al. Diet analyses (de Munk 1999; Hollis et al. However, the cover of austral bracken remained high. M. Flett and R. Moyle did the shooting, for which we are much obliged. Sampling intensity was set at 1 plot/ha with the exception of home ranges smaller than 10 ha or larger than 30 ha, where 10 and 30 plots were used, respectively. Nevertheless, at both unharvested and 5-year-old sites, wallabies consistently selected forbs and shrubs over monocots and trees, demonstrating that generalist mixed feeders may still exhibit distinctive foraging choices (Tixier et al. 1) are represented as the value of the 1st listed type minus the value of the 2nd listed type, so a positive estimate represents the selection of the 1st over the 2nd. For each model, the response variable is the selection index B and the predictors are the relative availability of each food type (the Ps). 2005). In this study, we used vegetation change resulting from timber harvesting to investigate diet composition and selection in a wild population of swamp wallabies. 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