Predator control improves nesting success in Waikato forest fragments

Predation at nests contributes importantly to current declines of New Zealand forest birds. We monitored the survival of natural and artificial arboreal nests in small forest remnants south-west of Hamilton, where ship rat (Rattus rattus) and possum (Trichosurus vulpecula) abundances were also being...

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Main Authors: Innes, John G., King, Carolyn M., Bartlam, Scott, Forrester, Guy, Howitt, Robyn
Format: Article in Journal/Newspaper
Language:English
Published: New Zealand Ecological Society 2015
Subjects:
DNA
Online Access:https://hdl.handle.net/10289/9463
id ftunivwaikato:oai:researchcommons.waikato.ac.nz:10289/9463
record_format openpolar
spelling ftunivwaikato:oai:researchcommons.waikato.ac.nz:10289/9463 2023-09-05T13:22:47+02:00 Predator control improves nesting success in Waikato forest fragments Innes, John G. King, Carolyn M. Bartlam, Scott Forrester, Guy Howitt, Robyn 2015 application/pdf https://hdl.handle.net/10289/9463 en eng New Zealand Ecological Society http://newzealandecology.org/nzje/ New Zealand Journal of Ecology Innes, J. G., King, C. M., Bartlam, S., Forrester, G., & Howitt, R. (2015). Predator control improves nesting success in Waikato forest fragments. New Zealand Journal of Ecology, 39(2), 245–253. 1177-7788 https://hdl.handle.net/10289/9463 © 2015 New Zealand Ecological Society. Used with permission. artificial nests bird nest success brushtail possum DNA harrier pest control predator identification ship rat Journal Article 2015 ftunivwaikato 2023-08-22T17:22:54Z Predation at nests contributes importantly to current declines of New Zealand forest birds. We monitored the survival of natural and artificial arboreal nests in small forest remnants south-west of Hamilton, where ship rat (Rattus rattus) and possum (Trichosurus vulpecula) abundances were also being measured in Summer 2008/09. Artificial cup nests (N = 77) were placed in replicated blocks with and without pest control, in both December and January. Natural nests (N = 11, five bird species) were observed from 13 October to 23 December 2008 in a forest with no pest control. Digital video cameras identified ship rats, brushtail possums and harrier hawks (Circus approximans) as predators of eggs and chicks. There was no difference between artificial and natural nests in daily survival rates monitored in December in a block with no pest control, suggesting that artificial nests are reasonable surrogates for natural nests. Bite marks on clay eggs, other diagnostic sign, and DNA swabbed from real and clay eggs confirmed ship rats and possums were the major introduced predators at artificial nests. Bite marks also confirmed that harriers contribute to nest failure. Removal of ship rats and possums in December improved the 14-day probability of survival of artificial nests, from P = 0.63 (95% CI 0.45–0.77) in the non-treatment block to P = 0.88 (0.74–0.95) in the treatment blocks. In January, the 14-day probability of survival in all three blocks was intermediate at 0.80 (0.69–0.87), and the variation between them could not be explained by including pest control in the model. The abundance of ship rats apparently declined even in the non-treatment block over this time, for unknown reasons. Our data from tawa (Beilschmiedia tawa) forest remnants confirm that control of ship rats and possums alone is sufficient to improve nesting success of small arboreal birds in North Island forests. Article in Journal/Newspaper Rattus rattus The University of Waikato: Research Commons New Zealand
institution Open Polar
collection The University of Waikato: Research Commons
op_collection_id ftunivwaikato
language English
topic artificial nests
bird nest success
brushtail possum
DNA
harrier
pest control
predator identification
ship rat
spellingShingle artificial nests
bird nest success
brushtail possum
DNA
harrier
pest control
predator identification
ship rat
Innes, John G.
King, Carolyn M.
Bartlam, Scott
Forrester, Guy
Howitt, Robyn
Predator control improves nesting success in Waikato forest fragments
topic_facet artificial nests
bird nest success
brushtail possum
DNA
harrier
pest control
predator identification
ship rat
description Predation at nests contributes importantly to current declines of New Zealand forest birds. We monitored the survival of natural and artificial arboreal nests in small forest remnants south-west of Hamilton, where ship rat (Rattus rattus) and possum (Trichosurus vulpecula) abundances were also being measured in Summer 2008/09. Artificial cup nests (N = 77) were placed in replicated blocks with and without pest control, in both December and January. Natural nests (N = 11, five bird species) were observed from 13 October to 23 December 2008 in a forest with no pest control. Digital video cameras identified ship rats, brushtail possums and harrier hawks (Circus approximans) as predators of eggs and chicks. There was no difference between artificial and natural nests in daily survival rates monitored in December in a block with no pest control, suggesting that artificial nests are reasonable surrogates for natural nests. Bite marks on clay eggs, other diagnostic sign, and DNA swabbed from real and clay eggs confirmed ship rats and possums were the major introduced predators at artificial nests. Bite marks also confirmed that harriers contribute to nest failure. Removal of ship rats and possums in December improved the 14-day probability of survival of artificial nests, from P = 0.63 (95% CI 0.45–0.77) in the non-treatment block to P = 0.88 (0.74–0.95) in the treatment blocks. In January, the 14-day probability of survival in all three blocks was intermediate at 0.80 (0.69–0.87), and the variation between them could not be explained by including pest control in the model. The abundance of ship rats apparently declined even in the non-treatment block over this time, for unknown reasons. Our data from tawa (Beilschmiedia tawa) forest remnants confirm that control of ship rats and possums alone is sufficient to improve nesting success of small arboreal birds in North Island forests.
format Article in Journal/Newspaper
author Innes, John G.
King, Carolyn M.
Bartlam, Scott
Forrester, Guy
Howitt, Robyn
author_facet Innes, John G.
King, Carolyn M.
Bartlam, Scott
Forrester, Guy
Howitt, Robyn
author_sort Innes, John G.
title Predator control improves nesting success in Waikato forest fragments
title_short Predator control improves nesting success in Waikato forest fragments
title_full Predator control improves nesting success in Waikato forest fragments
title_fullStr Predator control improves nesting success in Waikato forest fragments
title_full_unstemmed Predator control improves nesting success in Waikato forest fragments
title_sort predator control improves nesting success in waikato forest fragments
publisher New Zealand Ecological Society
publishDate 2015
url https://hdl.handle.net/10289/9463
geographic New Zealand
geographic_facet New Zealand
genre Rattus rattus
genre_facet Rattus rattus
op_relation http://newzealandecology.org/nzje/
New Zealand Journal of Ecology
Innes, J. G., King, C. M., Bartlam, S., Forrester, G., & Howitt, R. (2015). Predator control improves nesting success in Waikato forest fragments. New Zealand Journal of Ecology, 39(2), 245–253.
1177-7788
https://hdl.handle.net/10289/9463
op_rights © 2015 New Zealand Ecological Society. Used with permission.
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