Hen harrier management

insights from demographic models fitted to population data

Leslie F. New, Stephen T. Buckland, Stephen Redpath, Jason Matthiopoulos

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

1. The impact of hen harriers Circus cyaneus on red grouse Lagopus lagopus scoticus populations has received much attention. However, little has been done to model the population dynamics of the hen harrier alone. Such a model is needed to help inform the differing aims of conserving harriers and managing grouse moors, which serves as a reflection of human-wildlife conflicts around the globe.

2. On Langholm estate in Scotland, intensive studies have resulted in harrier numbers being known without error. We fit a Bayesian population model to these data, using a super-population model to permit inference in the presence of demographic and environmental stochasticity and in the absence of observation error.

3. Hen harriers have a straightforward life history. After fledging, juveniles show little natal site fidelity, often dispersing long distances into breeding areas rich in their preferred prey, the field vole Microtus agrestis and meadow pipit Anthus pratensis. Therefore, any increase in a local population is largely because of recruitment into the area as opposed to fledging success. Once birds have settled in an area, harriers are generally site faithful, with year-to-year survival depending, in part, on the density of meadow pipits.

4. Our model suggests that temporal patterns in harrier numbers on managed grouse moors, in the absence of illegal persecution, are influenced by vole numbers, whereas meadow pipit density appears to have a limited effect.

5. Synthesis and applications. Our modelling approach is a useful way to infer population processes, and the effects of the environment on these processes, for populations censused without error. When used to predict future harrier numbers under alternate management scenarios, our model indicates that harrier numbers on Langholm estate, Scotland, could be reduced without any direct human intervention if the estate can be managed in a way that reduces vole populations. In contrast, there appears little to gain from managing meadow pipit densities. If these conclusions apply to other harrier populations, then management to reduce vole numbers, while maintaining grouse densities, may help alleviate the conflict between conservationists and managers of grouse moors.

Original languageEnglish
Pages (from-to)1187-1194
Number of pages8
JournalJournal of Applied Ecology
Volume48
Issue number5
Early online date31 May 2011
DOIs
Publication statusPublished - Oct 2011

Keywords

  • Bayesian model
  • field voles
  • meadow pipits
  • population dynamics
  • red grouse
  • super-population model
  • wildlife management
  • microtus-agrestis abundance
  • human-wildlife conflict
  • circus-cyaneus
  • dynamics
  • conservation
  • prey
  • productivity
  • passerines
  • predation

Cite this

Hen harrier management : insights from demographic models fitted to population data. / New, Leslie F.; Buckland, Stephen T.; Redpath, Stephen; Matthiopoulos, Jason.

In: Journal of Applied Ecology, Vol. 48, No. 5, 10.2011, p. 1187-1194.

Research output: Contribution to journalArticle

New, Leslie F. ; Buckland, Stephen T. ; Redpath, Stephen ; Matthiopoulos, Jason. / Hen harrier management : insights from demographic models fitted to population data. In: Journal of Applied Ecology. 2011 ; Vol. 48, No. 5. pp. 1187-1194.
@article{70c6f926a4334b87a0cd18d7a8562b10,
title = "Hen harrier management: insights from demographic models fitted to population data",
abstract = "1. The impact of hen harriers Circus cyaneus on red grouse Lagopus lagopus scoticus populations has received much attention. However, little has been done to model the population dynamics of the hen harrier alone. Such a model is needed to help inform the differing aims of conserving harriers and managing grouse moors, which serves as a reflection of human-wildlife conflicts around the globe.2. On Langholm estate in Scotland, intensive studies have resulted in harrier numbers being known without error. We fit a Bayesian population model to these data, using a super-population model to permit inference in the presence of demographic and environmental stochasticity and in the absence of observation error.3. Hen harriers have a straightforward life history. After fledging, juveniles show little natal site fidelity, often dispersing long distances into breeding areas rich in their preferred prey, the field vole Microtus agrestis and meadow pipit Anthus pratensis. Therefore, any increase in a local population is largely because of recruitment into the area as opposed to fledging success. Once birds have settled in an area, harriers are generally site faithful, with year-to-year survival depending, in part, on the density of meadow pipits.4. Our model suggests that temporal patterns in harrier numbers on managed grouse moors, in the absence of illegal persecution, are influenced by vole numbers, whereas meadow pipit density appears to have a limited effect.5. Synthesis and applications. Our modelling approach is a useful way to infer population processes, and the effects of the environment on these processes, for populations censused without error. When used to predict future harrier numbers under alternate management scenarios, our model indicates that harrier numbers on Langholm estate, Scotland, could be reduced without any direct human intervention if the estate can be managed in a way that reduces vole populations. In contrast, there appears little to gain from managing meadow pipit densities. If these conclusions apply to other harrier populations, then management to reduce vole numbers, while maintaining grouse densities, may help alleviate the conflict between conservationists and managers of grouse moors.",
keywords = "Bayesian model, field voles, meadow pipits, population dynamics, red grouse, super-population model, wildlife management, microtus-agrestis abundance, human-wildlife conflict, circus-cyaneus, dynamics, conservation, prey, productivity, passerines, predation",
author = "New, {Leslie F.} and Buckland, {Stephen T.} and Stephen Redpath and Jason Matthiopoulos",
year = "2011",
month = "10",
doi = "10.1111/j.1365-2664.2011.02013.x",
language = "English",
volume = "48",
pages = "1187--1194",
journal = "Journal of Applied Ecology",
issn = "0021-8901",
publisher = "Wiley",
number = "5",

}

TY - JOUR

T1 - Hen harrier management

T2 - insights from demographic models fitted to population data

AU - New, Leslie F.

AU - Buckland, Stephen T.

AU - Redpath, Stephen

AU - Matthiopoulos, Jason

PY - 2011/10

Y1 - 2011/10

N2 - 1. The impact of hen harriers Circus cyaneus on red grouse Lagopus lagopus scoticus populations has received much attention. However, little has been done to model the population dynamics of the hen harrier alone. Such a model is needed to help inform the differing aims of conserving harriers and managing grouse moors, which serves as a reflection of human-wildlife conflicts around the globe.2. On Langholm estate in Scotland, intensive studies have resulted in harrier numbers being known without error. We fit a Bayesian population model to these data, using a super-population model to permit inference in the presence of demographic and environmental stochasticity and in the absence of observation error.3. Hen harriers have a straightforward life history. After fledging, juveniles show little natal site fidelity, often dispersing long distances into breeding areas rich in their preferred prey, the field vole Microtus agrestis and meadow pipit Anthus pratensis. Therefore, any increase in a local population is largely because of recruitment into the area as opposed to fledging success. Once birds have settled in an area, harriers are generally site faithful, with year-to-year survival depending, in part, on the density of meadow pipits.4. Our model suggests that temporal patterns in harrier numbers on managed grouse moors, in the absence of illegal persecution, are influenced by vole numbers, whereas meadow pipit density appears to have a limited effect.5. Synthesis and applications. Our modelling approach is a useful way to infer population processes, and the effects of the environment on these processes, for populations censused without error. When used to predict future harrier numbers under alternate management scenarios, our model indicates that harrier numbers on Langholm estate, Scotland, could be reduced without any direct human intervention if the estate can be managed in a way that reduces vole populations. In contrast, there appears little to gain from managing meadow pipit densities. If these conclusions apply to other harrier populations, then management to reduce vole numbers, while maintaining grouse densities, may help alleviate the conflict between conservationists and managers of grouse moors.

AB - 1. The impact of hen harriers Circus cyaneus on red grouse Lagopus lagopus scoticus populations has received much attention. However, little has been done to model the population dynamics of the hen harrier alone. Such a model is needed to help inform the differing aims of conserving harriers and managing grouse moors, which serves as a reflection of human-wildlife conflicts around the globe.2. On Langholm estate in Scotland, intensive studies have resulted in harrier numbers being known without error. We fit a Bayesian population model to these data, using a super-population model to permit inference in the presence of demographic and environmental stochasticity and in the absence of observation error.3. Hen harriers have a straightforward life history. After fledging, juveniles show little natal site fidelity, often dispersing long distances into breeding areas rich in their preferred prey, the field vole Microtus agrestis and meadow pipit Anthus pratensis. Therefore, any increase in a local population is largely because of recruitment into the area as opposed to fledging success. Once birds have settled in an area, harriers are generally site faithful, with year-to-year survival depending, in part, on the density of meadow pipits.4. Our model suggests that temporal patterns in harrier numbers on managed grouse moors, in the absence of illegal persecution, are influenced by vole numbers, whereas meadow pipit density appears to have a limited effect.5. Synthesis and applications. Our modelling approach is a useful way to infer population processes, and the effects of the environment on these processes, for populations censused without error. When used to predict future harrier numbers under alternate management scenarios, our model indicates that harrier numbers on Langholm estate, Scotland, could be reduced without any direct human intervention if the estate can be managed in a way that reduces vole populations. In contrast, there appears little to gain from managing meadow pipit densities. If these conclusions apply to other harrier populations, then management to reduce vole numbers, while maintaining grouse densities, may help alleviate the conflict between conservationists and managers of grouse moors.

KW - Bayesian model

KW - field voles

KW - meadow pipits

KW - population dynamics

KW - red grouse

KW - super-population model

KW - wildlife management

KW - microtus-agrestis abundance

KW - human-wildlife conflict

KW - circus-cyaneus

KW - dynamics

KW - conservation

KW - prey

KW - productivity

KW - passerines

KW - predation

U2 - 10.1111/j.1365-2664.2011.02013.x

DO - 10.1111/j.1365-2664.2011.02013.x

M3 - Article

VL - 48

SP - 1187

EP - 1194

JO - Journal of Applied Ecology

JF - Journal of Applied Ecology

SN - 0021-8901

IS - 5

ER -