Plant constituents affecting food selection by sika deer

Abstract

We directly observed the feeding behaviors of Yaku sika deer (Cervus nippon yakushimae), the smallest subspecies of Japanese sika deer, by following 6 wild, habituated, and individually identifiable animals in a natural warm‐temperate forest on the island of Yakushima, southern Japan, 2005–2006. Deer fed on various plant species and parts but predominantly on the fallen leaves, fruits, seeds, and flowers of woody plants (∼82% of food items) at 59 natural feeding plots. We analyzed 8 key plant constituents of eaten and uneaten items at the feeding plots, and examined the effects of each constituent on food selection by multivariate and univariate generalized linear mixed models. The multivariate analysis, which evaluated the effect of each plant constituent on food selection by controlling influences of the other constituents in the food items, showed that deer selected food items with higher contents of crude fat, crude protein, and total phenolics but with lower contents of lignin and condensed tannin from the available items at the feeding plots. Neither soluble nor structural carbohydrate, nor ash content affected selection of food items. It may be advantageous for these small ungulates with shorter gastrointestinal tracts to select foods that are relatively rich in fat because of the higher energy content of fat compared with carbohydrates. Furthermore, it appears that non‐tannin phenolics may have beneficial functions in this species. The univariate analyses showed different effects of crude protein and structural carbohydrate on food selection compared to those derived from the multivariate analysis. We demonstrate that accounting for influences of other plant constituents by using multivariate analyses is important to ensure that any effects of individual plant constituents are not overlooked or overstated. © 2018 The Wildlife Society.

Dynamics of rumen microbiome in sika deer (Cervus nippon yakushimae) from unique subtropical ecosystem in Yakushima Island, Japan

“…5 ). This result also supports the previous observation that Yaku sika from high density areas consume tannin-rich unpalatable plants, fallen leaves 27 , 54 , and woody materials more frequently than those from low density areas to meet their nutritional needs 28 , 34 . Similar to previously reported herbivores capable of expanding the niche range of their diet by harboring PSC-degrading bacteria in their digestive systems 50 , 60 , Yaku sika may also have adapted to utilize tannin-rich plants under high population pressure by harboring tannin-degrading bacteria in their RBM.…”

“…In low deer density areas, the availability of the small plants is higher and more species-rich understory vegetation is found, thus the dependence of Yaku sika on food derived from tall trees is lower in those areas 27 . The deer in high density areas have expanded their feed to include tannin-rich unpalatable plants, fallen leaves 27 , 54 , and woody material to meet their nutritional needs 28 , 34 . Thus, the higher diversity of RBM in Yaku sika under high population density may enable deer to scavenge a wider variety of plants and tolerate plant toxins, thus maintain nutritional status even under high density conditions 29 , 55 .…”

Geographical and seasonal variation of plant taxa detected in faces of Cervus nippon yakushimae based on plant DNA analysis in Yakushima Island

“…According to Agetsuma et al (2011), 1.7–10.9% of the seasonal diet of C. nippon yakushimae were droppings supplied by M. fuscata yakui . However, feeding on F. subpisocarpa in W was recorded only once among the 59 observations of Agetsuma et al (2019) on the feeding behavior of C. nippon yakushimae . This discrepancy may be due to observations made at different locations in different years.…”

“…This discrepancy may be due to observations made at different locations in different years. Alternatively, the direct observation of feeding events by Agetsuma et al (2019) may have underestimated feeding on F. subpisocarpa. In any case, the results of this survey suggest that the high availability of F. subpisocarpa may be one of the factors that maintains high deer density in W where the population has not been managed.…”

Vigor and Health of Urban Green Resources under Elevated O3in Far East Asia

“…Another indirect biotic factor is the increased population of sika deer (Cervus nippon), which eat up ground vegetation and destroys related community balance. Sika deer is not fond of eating plants containing high levels of C-based defense chemicals (such as phenolics and lignin) [92]. Therefore, individuals whose defense levels have decreased due to O 3 are grazed.…”