Dataset Information

Coping with spatial heterogeneity and temporal variability in resources and risks: adaptive movement behaviour by a large grazing herbivore.

ABSTRACT: Movement is a key mean for mobile species to cope with heterogeneous environments. While in herbivorous mammals large-scale migration has been widely investigated, fine-scale movement responses to local variations in resources and predation risk remain much less studied, especially in savannah environments. We developed a novel approach based on complementary movement metrics (residence time, frequency of visits and regularity of visits) to relate movement patterns of a savannah grazer, the blue wildebeest Connochaetes taurinus, to fine-scale variations in food availability, predation risk and water availability in the Kruger National Park, South Africa. Wildebeests spent more time in grazing lawns where the grass is of higher quality but shorter than in seep zones, where the grass is of lower quality but more abundant. Although the daily distances moved were longer during the wet season compared to the dry season, the daily net displacement was lower, and the residence time higher, indicating a more frequent occurrence of area-concentred searching. In contrast, during the late dry season the foraging sessions were more fragmented and wildebeests moved more frequently between foraging areas. Surprisingly, predation risk appeared to be the second factor, after water availability, influencing movement during the dry season, when resources are limiting and thus expected to influence movement more. Our approach, using complementary analyses of different movement metrics, provided an integrated view of changes in individual movement with varying environmental conditions and predation risk. It makes it possible to highlight the adaptive behavioral decisions made by wildebeest to cope with unpredictable environmental variations and provides insights for population conservation.

SUBMITTER: Martin J

PROVIDER: S-EPMC4342283 | biostudies-literature | 2015

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Coping with spatial heterogeneity and temporal variability in resources and risks: adaptive movement behaviour by a large grazing herbivore.

Martin Jodie J Benhamou Simon S Yoganand K K Owen-Smith Norman N

PloS one 20150226 2

Movement is a key mean for mobile species to cope with heterogeneous environments. While in herbivorous mammals large-scale migration has been widely investigated, fine-scale movement responses to local variations in resources and predation risk remain much less studied, especially in savannah environments. We developed a novel approach based on complementary movement metrics (residence time, frequency of visits and regularity of visits) to relate movement patterns of a savannah grazer, the blue ...[more]

PMID: 25719494

Similar Datasets

Project description:Extensively grazed semi-natural grasslands contribute to a wide range of ecosystem services, including the preservation of biodiversity and provision of livestock feed. Depending on the grazing intensity, cattle are set in motion to fulfill their nutritional needs. In this way, they influence the vegetation composition, while at the same time the foraging behavior is affected by the vegetation. A better understanding of the relationship between grazing intensity and animal behavior is an essential component for strategies to improve the value of semi-natural grasslands and for gaining insights for the development of smart farming technologies. The long-term cattle grazing experiment "FORBIOBEN" with its replicated three paddock-scale (1 ha) grazing intensities [moderate (M), lenient (L), very lenient (VL)] was used to investigate the movement behavior of suckler cows during four grazing periods between 2017 and 2020. For this, pregnant suckler cows (Fleckvieh) were equipped with Vectronics GPS Plus (VECTRONIC Aerospace GmbH, Berlin) collars, which recorded the position of the animals at defined time intervals. The main outcomes were that with an increase in the grazing intensity, the herbage on offer declined and, consequently the herbage allowance. However, the spatial heterogeneity of the herbage on offer decreased with increasing grazing intensity (M < VL) which means that the amount of available herbage was lower but more evenly distributed under moderate grazing. Further, there was a tendency that the moderate grazing intensity was associated with the highest effort of walking compared to lenient and very lenient grazing in three out of four grazing periods. We found a strong (p < 0.001) negative correlation among walking distance vs. herbage variability across all treatments × periods. Consequently, the grazing intensity itself was not a good predictor of walking distances which were mainly a result of the available herbage, its distribution or heterogeneity. Future smart farming livestock management systems will, therefore, likely require interfaces with the grassland growth rates and heterogeneity benchmarks if decisions based on livestock movement should be reliable.

Project description:Land-use and land-cover change associated with agriculture is one of the main drivers of biodiversity loss. In heavily modified agricultural landscapes, grazing lands may be the only areas that can provide essential resources for native grassland species. Management decisions, such as choice of livestock species, affect the extent to which grazing lands provide suitable habitat for native species such as pollinators.Our study compared how sheep versus cattle herbivory affected floral resources and butterfly abundance across low-diversity, former Conservation Reserve Program (CRP) pastures managed with patch-burn grazing.Across all years (2017-2019), flowering species richness and abundance were significantly higher in cattle pastures than sheep pastures. On average, we recorded 6.9 flowering species/transect in cattle pastures and 3.8 flowering species/transect in sheep pastures. The average floral abundance per transect was 1278 stems/transect in cattle pastures and 116 stems/transect in pastures grazed by sheep.Similarly, we observed higher butterfly species richness, diversity, and abundance in cattle than in sheep pastures. In cattle pastures, we observed an average of 75 butterflies and 6.75 species per transect, compared with an average of 52 butterflies and 3.37 species per transect in sheep pastures. However, the butterfly community composition did not significantly differ between grazing treatments likely because agricultural-tolerant, habitat generalists comprised the majority of the butterfly community. Five generalist butterflies comprised 92.3% of observations; Colias philodice was the most abundant (61% of observations). Speyeria idalia and Danaus plexippus, two butterflies of conservation concern, comprised less than 0.5% of butterfly observations.Our results, which are among the first attempt quantifying butterfly use of post-CRP fields grazed by livestock, show that increased precipitation and cattle grazing promoted higher forb abundance and richness. However, additional interventions may be needed to enhance floral resources to sustain and improve pollinator diversity in these landscapes.

Project description:Individual stress coping style has profound effects on how animals respond to environmental change, and individuals within a population strikingly differ in how gene expression shifts in response to challenge. This study used a wild type Zebrafish (Danio rerio) population to: 1) identify and screen for individual coping style using a screening protocol for risk taking in groups and 2) do global transcriptomics of brains from proactive, reactive or randomly chosen individuals (n=10/group) under control conditions. Results show that within our population proactive and reactive individual coping styles can be accurately identified and may represent 10-30% of individuals within the population. Microarray data analyses identify fundamental differences between the three different groups where variance in gene expression values are reduced by using coping style as an explanatory variable. Furthermore, significant differences in mRNAs and related biological processes suggest that even under identical environmental conditions the molecular mechanisms that underpin physiological processes are very different between proactive and reactive individuals within a population. Experimental tank was an 18 litre glass aquarium (dimensions (LxWxH): 40 X 25 X 20cm) lined on three sides with white paper; the front wall was not covered to allow the observer to record the behaviour and divided at 1/3 of his length with a black PVC screen with a 3cm diameter hole in the middle. All the tank surfaces around this third area of the tank were covered with dark paper and closed on the upper part with a removable lid to provide a shelter for the animals. The hole was covered with the same PVC plastic material and removed once the screening started to allow the fish enter the novel environment. Food was not supplied the day before to ensure that during the test the fish were hungry and they had to make the decision to leave a safe area in order to forage. Boldness was measured as the time taken by individual fish to leave a group from a safe, darkened area. It hence represents the willingness of a fish to explore a new, potentially dangerous environment, or boldness. Tests were conducted with groups of 9 randomly-selected fish from stocking tanks. Fish were familiar to each other in the sense that they were previously held in the same stocking tank. Test started with a 10 min. habituation period in the sheltered area with the hole closed with a PVC screen and the top of the sheltered area of the tank also covered to provide a complete quiet place. Then the lid covering the hole was gently removed. Either the first 3 fish to exit the shelter or fish with latency times inferior to 10 minutes were considered bold fish and were removed gently with a fish net from the test tank and placed apart in another tank. Latency times of emergency from the sheltered area were recorded individually. Next 3 animals to emerge before 15 minutes were considered intermediate and also removed gently. At the end of this last 15 minutes, animals that still remained inside the sheltered area were considered shy. Intermediates were discarded and fish selected for different coping strategies where placed in different tanks for posterior molecular analysis. Selected animals were killed by an overdose of MS-22 and the brains were sampled. Individual tissue samples were homogenized into 0.3 ml of Tri-Reagent and stored at -80C for further molecular analysis.

Dataset Information

Coping with spatial heterogeneity and temporal variability in resources and risks: adaptive movement behaviour by a large grazing herbivore.

Publications

Coping with spatial heterogeneity and temporal variability in resources and risks: adaptive movement behaviour by a large grazing herbivore.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets