Data from: A multi-scale test of the forage maturation hypothesis in a partially migratory ungulate population
Data from: A multi-scale test of the forage maturation hypothesis in a partially migratory ungulate population
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Date
2016-01-29
Citation
Hebblewhite M, Merrill E. 2016. Data from: A multi-scale test of the forage maturation hypothesis in a partially migratory ungulate population. Movebank Data Repository. https://doi.org/10.5441/001/1.k8s2g5v7Abstract
The forage maturation hypothesis (FMH) proposes that ungulate migration is driven by selection for high forage quality. Because quality declines with plant maturation, but intake declines at low biomass, ungulates are predicted to select for intermediate forage biomass to maximize energy intake by following phenological gradients during the growing season. We tested the FMH in the Canadian Rocky Mountains by comparing forage availability and selection by both migrant and nonmigratory resident elk (Cervus elaphus) during three growing seasons from 2002–2004. First, we confirmed that the expected trade-off between forage quality and quantity occurred across vegetation communities. Next, we modeled forage biomass and phenology during the growing season by combining ground and remote-sensing approaches. The growing season started 2.2 days earlier every 1 km east of the continental divide, was delayed by 50 days for every 1000-m increase in elevation, and occurred 8 days earlier on south aspects. Migrant and resident selection for forage biomass was then compared across three spatial scales (across the study area, within summer home ranges, and along movement paths) using VHF and GPS telemetry locations from 119 female elk. Migrant home ranges occurred closer to the continental divide in areas of higher topographical diversity, resulting in migrants consistently selecting for intermediate biomass at the two largest scales, but not at the finest scale along movement paths. In contrast, residents selected maximum forage biomass across all spatial scales. To evaluate the consequences of selection, we compared exposure at telemetry locations of migrant and resident elk to expected forage biomass and digestibility. The expected digestibility for migrant elk in summer was 6.5% higher than for residents, which was corroborated with higher fecal nitrogen levels for migrants. The observed differences in digestibility should increase migrant elk body mass, pregnancy rates, and adult and calf survival rates. Whether bottom-up effects of improved forage quality are realized will ultimately depend on trade-offs between forage and predation. Nevertheless, this study provides comprehensive evidence that montane ungulate migration leads to greater access to higher-quality forage relative to nonmigratory congeners, as predicted by the forage maturation hypothesis, resulting primarily from large-scale selection patterns.
Keywords
Cervus elaphus,animal tracking,Banff National Park,behavioral plasticity,behavioral syndrome,Cervus elaphus,elk,forage selection,partial migration,phenology,radio telemetry,Rocky Mountains,ungulates,Yellowstone National Park
BibTex
@misc{001/1_k8s2g5v7,
title = {Data from: A multi-scale test of the forage maturation hypothesis in a partially migratory ungulate population},
author = {Hebblewhite, M and Merrill, E},
year = {2016},
URL = {http://dx.doi.org/10.5441/001/1.k8s2g5v7},
doi = {doi:10.5441/001/1.k8s2g5v7},
publisher = {Movebank data repository}
}RIS
TY - DATA ID - doi:10.5441/001/1.k8s2g5v7 T1 - Data from: A multi-scale test of the forage maturation hypothesis in a partially migratory ungulate population AU - Hebblewhite, Mark AU - Merrill, Evelyn Y1 - 2016/01/29 KW - Cervus elaphus KW - animal migration KW - animal tracking KW - Banff National Park KW - behavioral plasticity KW - behavioral syndrome KW - Cervus elaphus KW - elk KW - forage selection KW - partial migration KW - phenology KW - radio telemetry KW - Rocky Mountains KW - ungulates KW - Yellowstone National Park KW - Cervus elaphus PB - Movebank data repository UR - http://dx.doi.org/10.5441/001/1.k8s2g5v7 DO - doi:10.5441/001/1.k8s2g5v7 ER -