Habitat use by white-winged and surf scoters in the Mackenzie Delta Region, Northwest Territories
Apparent long-term declines of white-winged and surf scoter (Melanitta fusca and M. perspicillata) populations in the northern boreal forest have raised concern for these sea duck species. Reasons for population declines are not well understood but some evidence suggests that factors associated with...
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ftusaskatchewan:oai:harvest.usask.ca:10388/etd-11292004-152440 2023-05-15T17:09:31+02:00 Habitat use by white-winged and surf scoters in the Mackenzie Delta Region, Northwest Territories Haszard, Shannon Clark, Robert G. Hobson, Keith A. Alisauskas, Ray T. August 2004 http://hdl.handle.net/10388/etd-11292004-152440 en_US eng University of Saskatchewan http://hdl.handle.net/10388/etd-11292004-152440 TC-SSU-11292004152440 land cover classification forest fire wetland productivity habitat associations amphipod water chemistry text Thesis 2004 ftusaskatchewan 2022-01-17T11:53:48Z Apparent long-term declines of white-winged and surf scoter (Melanitta fusca and M. perspicillata) populations in the northern boreal forest have raised concern for these sea duck species. Reasons for population declines are not well understood but some evidence suggests that factors associated with events on the breeding grounds may be responsible. Breeding ground changes could adversely affect abiotic or biotic characteristics of upland or wetland habitats or key food sources for breeding females or ducklings, which in turn may lower productivity or recruitment. Like most boreal-nesting ducks, virtually nothing is known about wetland habitat preferences of scoters. Determining habitat features that scoters need to breed successfully, and how habitat changes in the boreal forest affect scoters, is an important step in understanding their ecology and developing conservation initiatives. Thus, my overall goal was to look for evidence of habitat selection in scoters at two spatial scales by characterizing biotic and abiotic features of areas used by scoter pairs and broods, and comparing these features with those of areas not used by scoters. Habitat characteristics and scoter use of wetlands in recently burned forest was also contrasted with unburned forest to determine whether habitat change caused by fire could affect patterns of habitat use by scoters. I used remote sensing data as a tool to delineate coarse-scale patterns of habitat use by scoter pairs and broods. Results indicate that although scoters may not settle on wetlands in areas dominated by burned vegetation two years following the fire, three years after the fire I found no difference in scoter pair or brood use between wetlands in burned and unburned upland. I found that surf and white-winged scoter pairs often co-occurred on wetlands. I was unable to find any evidence to support the prediction that scoters prefer wetlands with irregular shorelines that might enhance pair isolation and offer greater protection to ducklings from severe winds and wave action. Based on fine-scale wetland habitat characteristics, scoter pairs and broods used wetlands with more abundant food, a finding that is consistent with many other waterfowl studies. However, unlike some previous waterfowl studies, I did not find a consistent correlation between total phosphorus levels and amphipod abundance or wetland use by scoters. Very high total nitrogen to total phosphorus ratios in sampled wetlands lead me to speculate that wetlands in my study area may be phosphorus limited. I did not detect a difference in fine-scale features of wetlands surrounded by burned versus unburned vegetation. This study of scoters in the northern boreal forest was among the first to determine why scoters use specific wetlands or areas and not others. Thesis Mackenzie Delta Melanitta fusca Northwest Territories University of Saskatchewan: eCommons@USASK Mackenzie Delta ENVELOPE(-136.672,-136.672,68.833,68.833) Northwest Territories |
institution |
Open Polar |
collection |
University of Saskatchewan: eCommons@USASK |
op_collection_id |
ftusaskatchewan |
language |
English |
topic |
land cover classification forest fire wetland productivity habitat associations amphipod water chemistry |
spellingShingle |
land cover classification forest fire wetland productivity habitat associations amphipod water chemistry Haszard, Shannon Habitat use by white-winged and surf scoters in the Mackenzie Delta Region, Northwest Territories |
topic_facet |
land cover classification forest fire wetland productivity habitat associations amphipod water chemistry |
description |
Apparent long-term declines of white-winged and surf scoter (Melanitta fusca and M. perspicillata) populations in the northern boreal forest have raised concern for these sea duck species. Reasons for population declines are not well understood but some evidence suggests that factors associated with events on the breeding grounds may be responsible. Breeding ground changes could adversely affect abiotic or biotic characteristics of upland or wetland habitats or key food sources for breeding females or ducklings, which in turn may lower productivity or recruitment. Like most boreal-nesting ducks, virtually nothing is known about wetland habitat preferences of scoters. Determining habitat features that scoters need to breed successfully, and how habitat changes in the boreal forest affect scoters, is an important step in understanding their ecology and developing conservation initiatives. Thus, my overall goal was to look for evidence of habitat selection in scoters at two spatial scales by characterizing biotic and abiotic features of areas used by scoter pairs and broods, and comparing these features with those of areas not used by scoters. Habitat characteristics and scoter use of wetlands in recently burned forest was also contrasted with unburned forest to determine whether habitat change caused by fire could affect patterns of habitat use by scoters. I used remote sensing data as a tool to delineate coarse-scale patterns of habitat use by scoter pairs and broods. Results indicate that although scoters may not settle on wetlands in areas dominated by burned vegetation two years following the fire, three years after the fire I found no difference in scoter pair or brood use between wetlands in burned and unburned upland. I found that surf and white-winged scoter pairs often co-occurred on wetlands. I was unable to find any evidence to support the prediction that scoters prefer wetlands with irregular shorelines that might enhance pair isolation and offer greater protection to ducklings from severe winds and wave action. Based on fine-scale wetland habitat characteristics, scoter pairs and broods used wetlands with more abundant food, a finding that is consistent with many other waterfowl studies. However, unlike some previous waterfowl studies, I did not find a consistent correlation between total phosphorus levels and amphipod abundance or wetland use by scoters. Very high total nitrogen to total phosphorus ratios in sampled wetlands lead me to speculate that wetlands in my study area may be phosphorus limited. I did not detect a difference in fine-scale features of wetlands surrounded by burned versus unburned vegetation. This study of scoters in the northern boreal forest was among the first to determine why scoters use specific wetlands or areas and not others. |
author2 |
Clark, Robert G. Hobson, Keith A. Alisauskas, Ray T. |
format |
Thesis |
author |
Haszard, Shannon |
author_facet |
Haszard, Shannon |
author_sort |
Haszard, Shannon |
title |
Habitat use by white-winged and surf scoters in the Mackenzie Delta Region, Northwest Territories |
title_short |
Habitat use by white-winged and surf scoters in the Mackenzie Delta Region, Northwest Territories |
title_full |
Habitat use by white-winged and surf scoters in the Mackenzie Delta Region, Northwest Territories |
title_fullStr |
Habitat use by white-winged and surf scoters in the Mackenzie Delta Region, Northwest Territories |
title_full_unstemmed |
Habitat use by white-winged and surf scoters in the Mackenzie Delta Region, Northwest Territories |
title_sort |
habitat use by white-winged and surf scoters in the mackenzie delta region, northwest territories |
publisher |
University of Saskatchewan |
publishDate |
2004 |
url |
http://hdl.handle.net/10388/etd-11292004-152440 |
long_lat |
ENVELOPE(-136.672,-136.672,68.833,68.833) |
geographic |
Mackenzie Delta Northwest Territories |
geographic_facet |
Mackenzie Delta Northwest Territories |
genre |
Mackenzie Delta Melanitta fusca Northwest Territories |
genre_facet |
Mackenzie Delta Melanitta fusca Northwest Territories |
op_relation |
http://hdl.handle.net/10388/etd-11292004-152440 TC-SSU-11292004152440 |
_version_ |
1766065625838387200 |