Of sheep and rain: large-scale population dynamics of the red kangaroo
(2005) In Journal of Animal Ecology 74(1). p.22-30- Abstract
- 1. We analysed time-series data from populations of red kangaroos (Macropus rufus, Desmarest) inhabiting four areas in the pastoral zone of South Australia. We formulated a set of a priori models to disentangle the relative effects of the covariates: rainfall, harvesting, intraspecific competition, and domestic herbivores, on kangaroo population-growth rate. 2. The statistical framework allowed for spatial variation in the growth-rate parameters, response to covariates, and environmental variability, as well as spatially correlated error terms due to shared environment. 3. The most parsimonious model included all covariates but no area-specific parameter values, suggesting that kangaroo densities respond in the same way to the covariates... (More)
- 1. We analysed time-series data from populations of red kangaroos (Macropus rufus, Desmarest) inhabiting four areas in the pastoral zone of South Australia. We formulated a set of a priori models to disentangle the relative effects of the covariates: rainfall, harvesting, intraspecific competition, and domestic herbivores, on kangaroo population-growth rate. 2. The statistical framework allowed for spatial variation in the growth-rate parameters, response to covariates, and environmental variability, as well as spatially correlated error terms due to shared environment. 3. The most parsimonious model included all covariates but no area-specific parameter values, suggesting that kangaroo densities respond in the same way to the covariates across the areas. 4. The temporal dynamics were spatially correlated, even after taking into account the potentially synchronizing effect of rainfall, harvesting and domestic herbivores. 5. Counter-intuitively, we found a positive rather than negative effect of domestic herbivore density on the population-growth rate of kangaroos. We hypothesize that this effect is caused by sheep and cattle acting as a surrogate for resource availability beyond rainfall. 6. Even though our system is well studied, we must conclude that approximating resources by surrogates such as rainfall is more difficult than previously thought. This is an important message for studies of consumer-resource systems and highlights the need to be explicit about population processes when analysing population patterns. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/147422
- author
- Jonzén, Niclas LU ; Pople, A R ; Grigg, G C and Possingham, H P
- organization
- publishing date
- 2005
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Journal of Animal Ecology
- volume
- 74
- issue
- 1
- pages
- 22 - 30
- publisher
- Wiley-Blackwell
- external identifiers
-
- wos:000226514300003
- scopus:13844261300
- ISSN
- 1365-2656
- DOI
- 10.1111/j.1365-2656.2005.00915.x
- language
- English
- LU publication?
- yes
- id
- 3e5afe57-ab3e-4f40-8c67-c29cae101842 (old id 147422)
- date added to LUP
- 2016-04-01 12:03:45
- date last changed
- 2022-01-26 22:13:01
@article{3e5afe57-ab3e-4f40-8c67-c29cae101842,
abstract = {{1. We analysed time-series data from populations of red kangaroos (Macropus rufus, Desmarest) inhabiting four areas in the pastoral zone of South Australia. We formulated a set of a priori models to disentangle the relative effects of the covariates: rainfall, harvesting, intraspecific competition, and domestic herbivores, on kangaroo population-growth rate. 2. The statistical framework allowed for spatial variation in the growth-rate parameters, response to covariates, and environmental variability, as well as spatially correlated error terms due to shared environment. 3. The most parsimonious model included all covariates but no area-specific parameter values, suggesting that kangaroo densities respond in the same way to the covariates across the areas. 4. The temporal dynamics were spatially correlated, even after taking into account the potentially synchronizing effect of rainfall, harvesting and domestic herbivores. 5. Counter-intuitively, we found a positive rather than negative effect of domestic herbivore density on the population-growth rate of kangaroos. We hypothesize that this effect is caused by sheep and cattle acting as a surrogate for resource availability beyond rainfall. 6. Even though our system is well studied, we must conclude that approximating resources by surrogates such as rainfall is more difficult than previously thought. This is an important message for studies of consumer-resource systems and highlights the need to be explicit about population processes when analysing population patterns.}},
author = {{Jonzén, Niclas and Pople, A R and Grigg, G C and Possingham, H P}},
issn = {{1365-2656}},
language = {{eng}},
number = {{1}},
pages = {{22--30}},
publisher = {{Wiley-Blackwell}},
series = {{Journal of Animal Ecology}},
title = {{Of sheep and rain: large-scale population dynamics of the red kangaroo}},
url = {{http://dx.doi.org/10.1111/j.1365-2656.2005.00915.x}},
doi = {{10.1111/j.1365-2656.2005.00915.x}},
volume = {{74}},
year = {{2005}},
}