How Changes in the Landbase Affect Individual Bird Species
In this section we evaluate how landbase changes (e.g. new forestry footprint, fire) from 2010-2018 in Norbord's operating areas are predicted to affect individual birds species.
Predicted net change in relative abundance as a result of changes in the landbase (2010-2018):
Bay-breasted Warbler
North: -2.5% | South: -1.9%

Brown Creeper
North: -0.4% | South: +3.0%
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Ovenbird
North: -2.1% | South: -4.6%
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Northern Flicker
North: +9.2% | South: +5.9%

Introduction
In this section we provide summaries of the overall predicted change in a species due to different types of change on the landbase, including changes as a result of forestry (new and old), non-forestry footprint (new and old), fire, and aging of undisturbed stands. Results are presented for three bird species associated with mid-age to old forest habitat: Bay-breasted Warbler, Brown Creeper, and Ovenbird. Results are also presented for the Northern Flicker, a cavity-nesting bird which is abundant in young naturally disturbed and harvested stands. Details for calculating attribution can be found in the Methods.

Brown Creeper (Certhia americana)
Results
Effects of Landbase Change on Individual Bird Species
We use “vector diagrams” to show the effects of each type of landbase change on four example bird species in the three operating areas: Bay-breasted Warbler, Brown Creeper, Ovenbird, and Northern Flicker. To interpret the vector diagrams, follow the arrows from the top of the figure, starting at 0% change, to the bottom to see the predicted effects on the species of:
- new forestry, then
- the additional effect of old regenerating harvest areas, then
- new non-forestry human footprint, then
- changes or disappearance of old non-forestry human footprint, then
- fires, and finally
- aging of undisturbed native forest.
The endpoint is the net change predicted in that species from 2010 to 2018.
Click on a bird species to see the effects of landbase change
Northern Operating Area
- New forestry was predicted to have reduced the abundance of the Bay-breasted Warbler by -4.8% between 2010 and 2018.
- Regenerating older harvest areas added 0.8% of that back.
- Other human footprint is rarer in the area and had little effect.
- Fires reduced the predicted abundance a further 2.5%, while aging of undisturbed stands increased the population by 3.9%.
- The net effect was a -2.8% change in the predicted abundance of the Bay-breasted Warbler due to landbase changes from 2010 to 2018 in the Northern Operating Area.
Southern Operating Area
- In the Southern Operating Area, new forestry had a similar predicted reduction of -5.2% in the Bay-breasted Warbler, compared to the Northern Operating Area.
- With a longer history of older forestry, there was a greater positive contribution from regenerating old harvest areas (+1.5%) than in the Northern Operating Area.
- More new non-forestry human footprint reduced the species in the Southern Operating Area a further -1.1%.
- Fires were largely absent in this area, and therefore had no effect on relative abundance.
- Aging of undisturbed stands increased the population by 3.0%.
- The net change of -1.9% in the Southern Operating Areas was less change than in the Northern Operating Area. This was due to lack of fires in the south as well as greater regeneration of old harvest areas.