Bird conservation strategy for region 5: Northern Pacific rainforest, chapter 8
Section 3: Additional Issues
Some well known conservation issues may not be identified in the literature as significant threats to populations of an individual priority species and therefore may not be captured in the threat assessment. However, these issues, while they may or may not be limiting factors for any individual species or population, contribute to avian mortality or decreases in reproductive success across many species and thus warrant conservation attention. Usually these issues transcend habitat types and are considered “widespread”. Examples of these issues include:
- Collisions with man-made structures (buildings, cars, utility/telecommunications towers and lines, etc.)
- Predation by domestic cats
- Pollution/pesticides/oil spills
- Climate change
Because the widespread issues do not fit into the standard presentation format used in the BCR strategies, they are presented separately here. The mortality estimates included here are largely based on draft reports that were available within Environment and Climate Change Canada when this strategy was produced; the numbers may change as the final scientific papers are peer-reviewed and published. Human-related avian mortality across all sectors was standardized and compared in Calvert et al. 2013.
Collisions with glass windows or reflective panels on buildings, is believed to be a significant source of bird mortality in Canada. Estimates of mortality from collisions with houses in Canada (including birds using feeders) range from approximately 15.8-30.5 million birds per year (Machtans et al. 2013). Mortality from collisions with buildings of fewer than 12 storeys is estimated at approximately 0.3-11.4 million birds/year, and for all cities in Canada with tall buildings in an urban core the estimate is 13,000-256,000 birds/year (Machtans et al. 2013). The total estimate of mortality from collisions with buildings in Canada is therefore between 16.1-42.2 million birds/year (Table 26; Machtans et al. 2013).
Data from Canada and the northeastern United States reveal that 163 species of birds of 32 families are known to have been killed by buildings. Some families and species of birds are disproportionately affected by collisions with buildings. Parulidae (warblers), Fringillidae (sparrows and allies), and Regulidae (kinglets) account for 70% of all bird deaths; the species most frequently killed are White-throated Sparrows (13.5% of all reported deaths), Golden-crowned Kinglets (10.2%), Dark-eyed Juncos (6.1%), Ovenbirds (5.3%) and Ruby-crowned Kinglets (5.3%). The population-level effects of bird mortality from building strikes are unknown. See Table 26 for conservation objectives and actions.
The 2,955 wind turbines in Canada in 2011 have drawn considerable attention for their potential to cause mortality to birds and other species (notably bats). Two sources of mortality are typically associated with wind turbines: collisions with the turbines themselves, and the destruction of nests by turbine construction activities during the breeding season. On average, 5.9 birds are killed per turbine per year. Scaling up to a national level, an estimated 16,700 birds (range 13,300 - 21,600) die from collisions with wind turbines each year (Table 26; Zimmerling et al. 2013).
Some species are particularly vulnerable to collisions with wind turbines, for example, raptors flying along a land/water interface. For smaller, more common passerine species (warblers, thrushes, kinglets, etc.), the relatively small number of birds affected does not appear to pose a population level threat. However, the anticipated proliferation of wind turbines means we should continue to ensure that turbines are sited to avoid important bird habitats and migration corridors. In BCR 5, there is great potential for future wind development in coastal and offshore habitats. While no offshore wind developments have yet been built, developments have been proposed and it is likely that at least some of these will proceed in the future. Seabirds tend to have long lifespans with low annual productivity, and these life-history traits increase the likelihood that increases in adult mortality will result in population-level impacts (Drewitt and Langston 2006). However, species susceptibility to collisions is highly variable, depending on, among other factors, flight altitude, maneuverability, and avoidance behaviours (Garthe and Hüppop 2004; Desholm and Kahlert 2005).
In addition to collision mortality, wind turbines construction and installation can result in the loss of habitat for birds. At the 43 terrestrial wind farms in Canada for which data are available, on average, total habitat loss per turbine is approximately 1.23 ha on average. Based on this average, the predicted total habitat loss for wind farms nationwide is 3,635 ha. Using published estimates of nest densities, the total number of affected nests, not accounting for construction that might occur outside the breeding season, is approximately 5,700 (Zimmerling et al. 2013). For sensitive species, effective loss of habitat to wind turbines can far exceed the actual installation footprint of the turbine, and for offshore wind development, loss of habitat due to avoidance of wind farms could have as much or larger impact on birds than collision mortality. Avoidance behaviours have been observed in Europe, where several species of waterbirds have been observed to avoid offshore wind farms and the surrounding area. In contrast, other species (e.g., gulls, terns) were apparently attracted to the wind farm. In addition, offshore wind developments have been shown to present potential migration barriers, with migrating birds preferring to fly around wind farms rather than between individual turbines. If not carefully designed and located, large complexes of offshore wind farms could present significant barriers (Drewitt and Langston 2006). See Table 26 for conservation objectives and actions.
There are currently almost 8,000 communication towers in Canada > 60 m high (Longcore et al. 2012), each of which can pose a hazard to birds during migration. Birds are attracted to the lights of communication towers and are killed when they collide with the structures and guy wires. Mortality increases exponentially with tower height, in part because the use of guy wires also increases with tower height. Poor weather also plays a significant role in increasing migrant fatality; foggy and cloudy conditions increase the lit area around towers and block celestial clues used by migrating birds. The result is that birds circle to exhaustion in the halo of artificial light, or collide with each other, the tower, or its guy wires (American Bird Conservancy 2012).
Avian mortality at towers is unequally distributed among species and regions, but estimates suggest that over 220,000 birds are killed in Canada each year (Table 26; Longcore et al. 2012). However, BCR 5 is estimated to contribute relatively little to the total avian collision mortality in Canada (Longcore et al. 2010).
Neotropical migrants in the families Parulidae (wood-warblers) and Vireonidae (vireos) are the species most commonly killed by communication towers. These families include threatened species and many that are of conservation concern in Canada and/or the United States. When considered in concert with mortality at towers in the United States (which is 20 times higher due to the larger number and greater height of towers in the United States), and the mortality from other stationary structures, mortality from collisions with communications towers may negatively affect the population trends of some birds. See Table 26 for conservation objectives and actions.
Birds may be killed by colliding with power lines, or they may be electrocuted. Species with high wing-loading and thus low maneuverability, such as waterfowl, appear particularly at risk for collisions (Bevanger 1998). Electrocutions are most likely for large birds such as raptors and herons, whose bodies are large enough to span the distances between wires and create a short circuit. Raptors’ habit of using power poles as perches further increases their risk. However, estimates of total mortality due to collisions and electrocutions can vary widely (Manville 2005) and population-level impacts are difficult to determine. Canadian estimates are that 161,000 - 802,000 birds are killed annually by electrocution and another 5.3 - 20.6 million birds are killed each year by colliding with electrical transmission lines (Calvert et al. 2013). See Table 26 for conservation objectives and actions.
There are over 1.4 million km of roads and hundreds of airports in Canada (World Bank Indicators 2012) that are often bordered by fences and vegetation that provide convenient places for birds to perch, forage, and nest. The paved surfaces can attract birds through the heat they emit, the puddles that form beside roads, and the salt and grit used for de-icing. Current estimates for one- and two-lane paved roads outside of major urban centres in Canada are that between 4.65 and 13.8 million birds are killed annually (Bishop and Brogan 2013).
Bird collisions with cars are influenced by the location of the road, proximity of vegetation, and vehicle speed. Raptors and owls that hunt and forage near roads are particularly vulnerable, but many species forage for grit and road salt or are otherwise attracted to roads have a high likelihood of being hit by vehicles. The population level effects of this source of mortality are not known. See Table 26 for conservation objectives and actions.
Predation by Domestic Cats
Based on the number of pet cats in Canada and published kill rates by cats elsewhere, roughly 204 million birds (range 105-348 million) are killed by domestic and feral cats in Canada each year (Blancher 2013). The broad range on this estimate reflects imprecise information on the average number of bird kills per cat, especially for rural and feral cats, and a lack of information on the number of feral cats (versus owned or pet cats) in Canada.
The birds most susceptible to cat predation are those that nest or forage on or near the ground or spend substantial time in human-dominated landscapes (both rural and urban) where cats are abundant. The proportion of Canada’s birds killed by cats would be higher if additional cat predation when migrating through, or wintering in, the U.S. is factored in.
Without detailed study of the individual species affected, it is difficult to assess whether mortality caused by cat predation impacts population trends of birds in Canada. Nevertheless, it is likely that many species of birds are potentially vulnerable to population effects at the local scale in southern Canada. See Table 26 for conservation objectives and actions.
Pollution caused by industrial chemicals, pesticides and heavy metals can have both direct and indirect effects on survival and reproduction in birds. Sometimes the effects of exposure to pollutants are unexpected and do not result in immediate, measurable impacts on bird populations (Eeva and Lehikoinen 2000, Franceschini et al. 2008, North American Bird Conservation Initiative, U.S. Committee 2009, Mineau 2010). However, persistent exposure can result in sharp declines in bird populations as happened with Peregrine Falcons in eastern Canada prior to the ban of DDT.
The most recent estimate suggests that 0.96-4.4 million birds are killed by pesticides annually in Canada (Mineau 2010). Provinces such as Saskatchewan, which have a large agricultural land base, account for the majority of the estimated kill, and pesticides are thought to be an important contributor to the decline in grassland bird species in Canada (Mineau 2010). Pesticides can kill birds rapidly following contact or may have sub-lethal impacts such as suppressed immune function and reduced stress response. There may also be indirect effects of pesticides such as reduction in prey and changes in vegetation that reduce habitat quality. While the use of the many toxic pesticides has been eliminated in Canada, migratory birds are still exposed while on wintering grounds in countries where their use is still permitted (Mineau 2010). See Table 26 for conservation objectives and actions.
Toxic Chemicals and Heavy Metals
Toxic organic chemicals and heavy metals released into the environment can also negatively impact bird populations. While some industrial chemicals such as PCBs are regulated, there is concern about new chemicals such as flame retardants (PBDE) that are used in computers, car parts and upholstery and whose effects on wildlife are largely unknown (Great Lakes Fact Sheet 2003). Scavengers experience toxic effects when they ingest lead shotgun pellets or bullet fragments embedded in carcasses of game animals, and loons and other waterbirds are exposed to lead from shotgun pellets, sinkers and jigs that they ingest either while collecting grit for their gizzards or by eating bait fish with line and sinker still attached (Scheuhammer and Norris 1996, Scheuhammer et al. 2003). In some areas lead poisoning from sinkers and jigs can account for approximately half of the mortality of adult Common Loons on their breeding grounds (Scheuhammer and Norris 1996). Birds are also susceptible to bioaccumulation of other toxic metals such as methylmercury, selenium, and others when they consume prey that has been exposed to these substances. See Table 26 for conservation objectives and actions.
Oil may enter the environment either accidentally, through deliberate dumping, or in contained tailings ponds. It may be a single large event, as occurred in the Gulf of Mexico in 2010, or numerous smaller events. Annual estimates are that between 217,800 and 458,600 birds are killed by ship-source oil spills annually (Calvert et al. 2013). Typically, diving birds are most at risk of oiling; however any birds that come into contact with oil are vulnerable. Oil can impact birds through direct effects such as hypothermia (resulting from lost water-proofing of feathers following oil contamination), toxicity (from ingesting oil as they preen or by inhaling volatile organic compounds), and indirect effects, such as reduced prey availability and decreased quality of habitat. While techniques exist to clean and rehabilitate oiled birds, many birds die before, during and after rescue attempts (Brown and Lock 2003). See Table 26 for summary and objectives and actions.
Table 26. Conservation objectives and actions associated with bird mortality from collisions, cats and contaminants. Accessible Version of Table 26.
The effects of climate change are already measureable in many bird habitats and have resulted in range shifts and changes in the timing of migration and breeding in some species (National Audubon Society 2009, North American Bird Conservation Initiative, U.S. Committee 2009). Birds in all habitats will be affected by climate change. The most vulnerable are predicted to be those that are dependent on oceanic ecosystems and those found in coastal, island, grassland, arctic and alpine habitats (North American Bird Conservation Initiative, U.S. Committee 2010). Changing climate may also facilitate the spread of disease, the introduction of new predators and the invasion of non-native species which alter habitat structure and community composition (North American Bird Conservation Initiative, U.S. Committee 2009, Faaborg et al. 2010). See Tables 27 and 28 for a summary of impacts of climate change and conservation objectives.
A recent exercise used bioclimatic modeling to predict changes in bird species ranges based on anticipated climate change for different time periods and under different emissions scenarios (Lawler et al. 2010). Bioclimatic models use statistical associations between the current range of a species and a suite of climate variables to predict future ranges under new climate conditions. The study focused on bird species currently found within Bird Conservation Regions in Canada. The results suggest that bird species turnover in Canada will be highest in northern Bird Conservation Regions as species ranges continue to shift northward in the coming decades. In BCR 5 Pacific and Yukon, the model predicts a gain of 16 species, a loss of 11 species for a total turnover (species gains + species losses) of 13% by the period of 2071-2100.
In BCR 5, the effects of changing climate are apparent. Over the last 50 years, temperatures have increased, and more precipitation is falling as rain rather than as snow. These changes have resulted in shorter winters and a longer growing season. Sea surface temperatures have increased all along the coast, and relative sea level has also risen in many areas, increasing vulnerability of low-lying areas to flooding under extreme weather conditions.
As these trends continue, British Columbia can expect warmer temperatures year-round, along with wetter winters and drier summers. Extreme weather events are expected to become more common, and increased windthrow disturbance is expected to occur in coastal forests. Geographical shifts in vegetation are expected for many species as climatic envelopes shift markedly upslope and northward, and will result in the redistribution of ecosystems on the landscape. Rates of individual species movement will vary widely, however. Many species (e.g., trees) are likely to take decades or centuries to shift accordingly, while some birds within British Columbia have already shifted northwards and/or show increased density in the northern portions of their ranges. There is potential for expansion northwards and upslope for dry forest types such as Douglas-fir and Garry Oak parklands, and upslope movement of moist conifer at the expense of subalpine forest types is expected. There is also great potential for the loss of alpine habitats to upslope forest encroachment (B.C. Ministry of Environment 2006, Pojar 2010).
Sea-level rise is also expected to have significant impacts in the coming years. Projections indicate that relative sea level will probably rise on the order of 0.2 to 0.5 m by 2100, and possibly as much as 1.2 m in some locations (Bornhold 2008). While most of British Columbia’s coastline is steep and rocky, increases in sea level will have strong negative impacts on mudflats, sandflats, beaches, salt marshes and estuaries. The Fraser River delta and the east coast of Graham Island (Haida Gwaii) have been identified as particularly at risk (Bornhold 2008; Thomson et al. 2008). In some areas, low-lying coastal habitats may be able to migrate inland to some degree as sea level rises; however extremely valuable tidal habitat in developed areas (such as Robert’s Bank and Boundary Bay in the Fraser River delta) will be squeezed between the rising waters and coastal dykes and significant amounts of habitat will inevitably be lost. Continued increases in sea surface temperatures are also expected to impact marine ecosystems, altering the timing and availability of prey for breeding seabirds and affecting their reproductive success (Gjerdrum et al. 2003).
If we are to maintain healthy bird populations in the face of a changing climate, conservation must be carefully planned and must be implemented so as to buffer birds from the negative impacts of climate change wherever possible (Faaborg et al. 2010).
|Climate change risk||Threat category||Example priority species affected|
|Direct bird mortality due to temperature extremes and severe weather.||11.3 Temperature extremes
11.4 Storms and flooding
|Barn Swallow, Belted Kingfisher, Common Nighthawk, Olive-sided Flycatcher, Purple Martin, Violet-green Swallow|
|Reductions in food availability (e.g., nectar, invertebrates) and/or mismatches in the timing of breeding and peak food abundance due to phenological shifts, droughts, or temperature extremes.||11.1 Habitat shifting and alteration
11.3 Temperature extremes
|Barn Swallow, Common Nighthawk, Olive-sided Flycatcher, Purple Martin, Rufous Hummingbird, Violet-green Swallow|
|Changes in marine productivity, food webs, and foraging conditions.||11.1 Habitat shifting and alteration
11.4 Storms and flooding
|Ancient Murrelet, Black-footed Albatross, Buller’s Shearwater, Cassin’s Auklet, Common Murre, Flesh-footed Shearwater, Horned Puffin, Laysan Albatross, Leach’s Storm Petrel, Manx Shearwater, Northern Fulmar, Pigeon Guillemot, Pink-footed Shearwater, Short-tailed Albatross, Thick-billed Murre, Tufted Puffin, Western Grebe|
|Loss or degradation of habitat due to climate change (e.g., loss of mudflats, sandflats, beaches, and tidal marshes with increased storm severity, sea level rise and coastal flooding; loss of alpine and subalpine).||11.1 Habitat shifting and alteration
11.4 Storms and flooding
American Golden-Plover, American Wigeon, Belted Kingfisher, Black-bellied Plover, Brant (Black), Brant (Western High Arctic), Dunlin, Great Blue Heron (fannini), Green-winged Teal, Lesser Snow Goose, Long-billed Curlew, Marbled Godwit, Northern Pintail, Purple Martin, Red Knot, Sanderling, Short-billed Dowitcher, Trumpeter Swan, Western Sandpiper, Whimbrel, Wilson’s Phalarope
Alpine and subalpine:
Sooty Grouse, White-tailed Ptarmigan (saxitallis)
|Threats addressed||Threat category||Objective||Objective category||Recommended Actions||Action category||Priority species affected|
|Climate change impacts habitat and negatively affects survival and productivity of birds||11.1 Habitat shifting and alteration||Reduce greenhouse gas emissions
Mitigate the effects of climate change on bird habitat
|6.1 Support efforts to reduce greenhouse gas emissions
6.2 Manage for habitat resilience as climate changes
|Support efforts to reduce greenhouse gas emissions.
Manage for habitat resilience to allow ecosystems to adapt despite disturbances and changing conditions. Minimize anthropogenic stressors (such as development or pollution) to help maintain resilience.
Manage buffer areas and the matrix between protected areas to enhance movement of species across the landscape.
Manage ecosystems to maximize carbon storage and sequestration while simultaneously enhancing bird habitat.
Incorporate predicted shifts in habitat into landscape level plans (e.g., when establishing protected areas ensure the maintenance of north-south corridors to facilitate northward range shifts of bird species).
|5.2 Policies and regulations
1.1 Site/area protection
2.1 Site/area management
5.2 Policies and regulations
|Population-level effects of climate change are unknown||12.1 Information lacking||Improve understanding of climate change on birds and their habitats||7.5 Improve understanding of potential effects of climate change||Evaluate which species are most vulnerable to climate change.
Investigate the cumulative effects of climate change.
Investigate behavioural responses to climate change (such as range shifts, changes in demographic rates, and changes in timing of breeding and migration) through long-term studies.
Continue to monitor bird populations so changes in numbers and distributions can be identified.
Undertake monitoring to evaluate the effectiveness of mitigation activities.
Research and Population Monitoring Needs
An estimate of population trend for each species is necessary for the development of elements 1 and 3 (Species Assessment and Population Objectives). However, there are many species for which we are currently unable to estimate a population trend (PT) score. These species were typically assigned a population objective of “assess/maintain.” The inability to estimate a PT score may be the result of a lack of monitoring data for the BCR as a whole or may be because certain species are not well captured by common monitoring techniques (such as the Breeding Bird Survey [BBS]). To be able to effectively evaluate species believed to be of conservation concern, and to track those not yet of concern for future changes in status, we require more comprehensive monitoring that enables us to generate population trends for all species of birds in Canada. However, it is important to note that for some species, population trends are better understood at scales larger or smaller than the BCR unit, and lack of BCR-scale population trend data should not preclude acting to conserve these species.
For example, the PIF species assessment database (Rocky Mountain Bird Observatory 2005) and local re-analysis of BBS data yields a PT of 3 for many priority waterfowl (25 of 26 species) in BCR 5. However, many of these species primarily winter in BCR 5, and are subject to widespread and intense monitoring on their breeding grounds. Population trends for waterfowl are typically well-understood at the flyway scale. It is for this reason we set population objectives for waterfowl from the Pacific Coast Joint Venture’s Strategic Plan and Biological Foundation (Martell 2005), rather than directly from local PT scores.
Similarly, the Partners in Flight (PIF) species assessment database and local re-analysis of Breeding Bird Survey (BBS) data yielded PT scores of 3 for all priority shorebirds (18 species) and most waterbirds (37 of 38 waterbird species). Both shorebirds and waterbirds are poorly sampled by the BBS. However, for many of these species (13 of 18 shorebirds, and 24 of 38 waterbirds), population trends are better understood at a national scale (see Table 1 for PT scores from national assessments in Wings Over Water: Canada’s Waterbird Conservation Plan (Milko et al. 2003) and the Canadian Shorebird Conservation Plan (Donaldson et al. 2000)). In addition, many colonial waterbirds (e.g., Ancient Murrelet, Cassin’s Auklet, Double-crested Cormorant, Horned Puffin) are best monitored via colony counts, though this information does not always scale up to the entire BCR.
BBS data yields much better information for landbirds, though population trends remain uncertain at the BCR scale for some landbird species. Our inability to more accurately assess population trends for these species is due, at least in part, to the rugged, remote, and inaccessible nature of much of BCR 5, which means that many areas have poor or non-existent coverage by volunteer-based survey efforts like the BBS. In addition, coastal and pelagic habitats present their own unique monitoring challenges. However, volunteer-based surveys such as the BBS, Christmas Bird Count, British Columbia Breeding Bird Atlas and the British Columbia Coastal Waterbirds Survey provide much of the population trend data that exists, and maintaining these programs is critical. Supporting the expansion of these programs into under-sampled habitats and remote areas--possibly by use of paid observers--will also improve their utility in the future.
Key areas and habitats lacking monitoring effort in BCR 5 include the central and north coasts of British Columbia, particularly outside estuaries. Data on the abundance and distribution of pelagic seabirds is sparse and both opportunistic and planned surveys should continue. Remote forests and high-elevation habitats are also deserving of attention. Specific recommendations for some groups of priority species with unknown or uncertain population trends are presented in Table 29.
A recent Environment and Climate Change Canada review (Avian Monitoring Review Steering Committee 2012) of avian monitoring programs in Canada made the following recommendations for each of the four main species groups:
- develop options for on-the-ground monitoring across boreal Canada;
- evaluate the ability of migration monitoring and checklist surveys to contribute to Environment and Climate Change Canada‘s monitoring needs; and
- evaluate the feasibility and cost-effectiveness of improving demographic monitoring to help understand causes of population change.
- complete a first round of Arctic PRISM breeding shorebird surveys to obtain reliable population estimates and baseline distribution information across the Arctic;
- develop more reliable sampling methods for counting shorebirds in migration to address concerns about bias; and
- increase Latin American involvement in monitoring shorebirds on the wintering grounds, including Red Knot.
- evaluate alternative strategies for filling gaps in coverage for both colonial waterbirds and marsh birds;
- consider both costs and potential reduction in risks; and
- carry out any necessary pilot work to evaluate options.
- develop strategies to reduce expenditures on the prairie and eastern waterfowl breeding surveys, while retaining acceptable precision in population estimates;
- review the information needs and expenditures for arctic goose and duck banding programs;
- reduce the number of Greater Snow Goose survey components;
- redesign the Trumpeter Swan surveys; and
- realign resources for eider and scoter monitoring to a more efficient suite of surveys.
|Category||Example priority species||Possible monitoring approaches|
|Aerial insectivores||Black Swift, Common Nighthawk, Purple Martin, Vaux's Swift, Violet-green Swallow||Conduct regular colony counts where applicable (e.g., Purple Martin, Violet-green Swallow; Vaux's Swift roost sites). Initial surveys may be required to locate breeding areas, colonies, and/or communal roosts.
Implement or expand focused crepuscular surveys for Common Nighthawk. These surveys could be modeled after the United States Nightjar Survey Network.
|Diurnal raptors||Bald Eagle, Gyrfalcon, Northern Goshawk (laingi), Northern Harrier, Peregrine Falcon (anatum), Peregrine Falcon (pealei), Rough-legged Hawk, Short-eared Owl||Support and expand Christmas Bird Counts to capture wintering raptors such as Bald Eagle, Gyrfalcon, Northern Harrier, Rough-legged Hawk, and Short-eared Owl. Support increased observer training in raptor identification.
Sparsely distributed raptors that are not well represented by regular survey efforts such as the Breeding Bird Survey require targeted, species-specific inventory efforts, particularly on the coast and Haida Gwaii (e.g., Peregrine Falcon [anatum], Peregrine Falcon [pealei], Northern Goshawk [laingi]).
|Nocturnal raptors||Barn Owl, Northern Saw-whet Owl (acadicus), Northern Pygmy-Owl, Northern Saw-whet Owl (brooksi), Spotted Owl, Western Screech-Owl (kennicottii)||Support and expand Nocturnal Owl Surveys.
Species-specific surveys may be required for species that are not well sampled by typical survey methods (e.g., Northern Pygmy-Owl), rare species (e.g., Spotted Owl) and endemic subspecies (e.g., Northern Saw-whet Owl [brooksi]).
|Hummingbirds||Rufous Hummingbird||Coordinate with the Western Hummingbird Partnership and the Hummingbird Monitoring Network to design and implement an effective hummingbird monitoring program that will build upon existing programs.|
|Colonial waterbirds||Ancient Murrelet, Cassin's Auklet, Common Murre, Brandt's Cormorant, Horned Puffin, Leach's Storm-Petrel, Pelagic Cormorant, Pigeon Guillemot, Rhinoceros Auklet, Thick-billed Murre, Tufted Puffin||Support and expand continued annual surveys of principal colonies across the BCR.|
|Pelagic waterbirds||Black-footed Albatross, Buller's Shearwater, Flesh-footed Shearwater, Laysan Albatross, Northern Fulmar, Manx Shearwater, Pink-footed Shearwater, Short-tailed Albatross, Xantus's Murrelet||Support and expand both opportunistic and planned pelagic surveys of seabird distribution and abundance.|
|Coastal species||Barrow's Goldeneye, Black Oystercatcher, Black Scoter, Black Turnstone, Brandt's Cormorant, Bufflehead, Caspian Tern, Common Loon, Harlequin Duck, Heermann's Gull, Horned Grebe, Pelagic Cormorant, Rock Sandpiper, Ruddy Turnstone, Sanderling, Surf Scoter, Surfbird, Western Grebe, White-winged Scoter, Yellow-billed Loon||Support initiatives such as the B.C. Coastal Waterbirds Survey. Increase coverage on western Vancouver Island and expand surveys into the central and north coasts of B.C. and Haida Gwaii.|
|Estuary-associated species||Barrow's Goldeneye, Black Scoter, Blue-winged Teal, Brant (Black), Brant (Western High Arctic), Bufflehead, Cackling Goose, Canada Goose (Dusky), Canvasback, Common Goldeneye, Great Blue Heron (fannini), Greater Scaup, Lesser Scaup, Trumpeter Swan, Tundra Swan||Support and expand regular estuary surveys throughout the coast. Conduct surveys in winter as well to capture wintering species.|
|Wetland-associated species||American Bittern, Black-crowned Night-Heron, Blue-winged Teal, Cinnamon Teal, Great Blue Heron (fannini), Greater White-fronted Goose, Green Heron, Lesser Scaup, Northern Pintail, Northern Shoveler, Rusty Blackbird||Implement, support and expand Marsh Monitoring Programs similar to those in the Great Lakes Basin. Conduct surveys in winter as well to capture wintering species.|
|Easily mis-identified species||Cackling Goose, Canada Goose (Dusky), Short-billed Dowitcher||Implement increased observer training to increase accurate identification of easily confused species where they co-occur (e.g., identification of Cackling Goose vs. Dusky Canada Goose vs. Pacific Canada Goose; Short-billed Dowitcher vs. Long-billed Dowitcher).|
|Migrating/wintering shorebirds||Black-bellied Plover, Dunlin, Short-billed Dowitcher, Western Sandpiper||Continue seasonal migration and wintering counts of shorebirds at key stopover and wintering sites (e.g., Tofino Mudflats, the Fraser River delta, Sydney Spit).
Support and expand Arctic PRISM surveys to determine population trends for arctic-breeding shorebirds.
|Species inhabiting poorly-sampled habitat||Belted Kingfisher, Common Loon, Harlequin Duck, Rusty Blackbird, White-tailed Ptarmigan (saxatilis)||Increase Breeding Bird Survey coverage of remote or poorly-sampled habitats, such as alpine and subalpine areas (White-tailed Ptarmigan), forested wetlands (Rusty Blackbird) and aquatic habitats such as lakes and rivers (Belted Kingfisher, Common Loon, Harlequin Duck). Modified or separate methodology may be required in some habitats.|
|Other species captured by Breeding Bird Survey, but currently lacking enough data for trend analysis in the BCR.||Black-throated Gray Warbler, Chestnut-backed Chickadee, Hairy Woodpecker, Pacific Wren, Pacific-slope Flycatcher, Pine Grosbeak (carlottae), Spotted Towhee, Steller’s Jay, Townsend’s Warbler, Varied Thrush||Increase Breeding Bird Survey coverage in all habitats (both density of routes and geographic coverage) to increase data and improve trend information on undersampled species.|
The focus of this section is to outline the main areas where a lack of information hindered our ability to understand conservation needs and make conservation recommendations. Research objectives presented here are bigger picture questions, and not necessarily a schedule of studies, that are needed to determine the needs of individual species (Table 30). Undertaking research will allow us to improve future iterations of BCR strategies and to focus future implementation, and will also enable the development of new tools for conservation.
|Objective||Example priority species affected|
|For all priority bird species exhibiting declines in BCR 5, or those that are known to be declining nationally or continentally:
Determine the primary drivers of population decline (e.g., productivity, juvenile survival, adult breeding season survival, overwinter survival) to identify when and where species are being limited.
Assess threats identified for these species (both within and outside Canada for migratory species) to determine the degree to which they are driving population trends.
|Species exhibiting declining trends in BCR 5:
Band-tailed Pigeon, Barn Swallow, Black Tern, Black Swift, Bullock's Oriole, Cassin’s Auklet, Cassin's Vireo, Common Murre, Cooper's Hawk, Golden-crowned Kinglet, MacGillivray's Warbler, Olive-sided Flycatcher, Orange-crowned Warbler, Pine Siskin, Purple Finch, Red Crossbill, Red-breasted Sapsucker, Rock Sandpiper, Rufous Hummingbird, Sooty Grouse, Western Bluebird, Western Meadowlark, Western Wood-Pewee, Willow Flycatcher
Additional species exhibiting declines nationally or continentally:
American Bittern, American Golden-plover, Ancient Murrelet, Black Scoter, Black-bellied Plover, Black-footed Albatross, Brandt’s Cormorant, Common Tern, Dunlin, Green Heron, Horned Grebe, Laysan Albatross, Leach’s Storm-Petrel, Lesser Scaup, Long-billed Curlew, Manx Shearwater, Marbled Godwit, Marbled Murrelet, Northern Pintail, Pelagic Cormorant, Pigeon Guillemot, Pink-footed Shearwater, Red Knot, Red-necked Phalarope, Ruddy Turnstone, Sanderling, Short-billed Dowitcher, Short-tailed Albatross, Surf Scoter, Surfbird, Tufted Puffin, White-winged Scoter, Whimbrel, Wilson’s Phalarope, Xantus’s Murrelet
|Map land cover changes that have occurred across the BCR between the baseline time periods established in BCR plans and the current day in order to correlate habitat loss with species declines and assess the main types of habitat transitions that have occurred (e.g., wetland to urban development, old growth to managed forest, tidal flats and flood plains to agriculture, etc.).||All species for which habitat-related declines have occurred or are suspected.|
|Combine up-to-date land cover information, additional data on bird densities, and detailed bird-habitat relationships for all priority species to allow for the calculation of quantitative habitat targets and to directly link conservation and population objectives.||All priority species.|
|Identify priority areas for implementation of recommendations in BCR plans.||All priority species.|
|Determine specific population connectivity and migration routes between breeding and wintering areas, using techniques such as genetic analysis, stable isotopes and geolocators.||All non-resident species.|
|Where they do not already exist, conduct research to develop sector-specific beneficial management practices documents, with an emphasis on bird and biodiversity conservation. Monitor adherence to these BMPs and assess their effectiveness at preserving and/or increasing priority bird populations.||All priority species.|
|Determine the population-level significance of bird mortality from collisions with anthropogenic structures of all types and predation by domestic cats. Identify particularly vulnerable species.||All priority species.|
|Continue to engage in and support climate change research with respect to:
-links between climate, forage species (e.g., fish, plankton), and priority seabirds; and model potential responses to changes in climatic conditions.
-alteration and loss of coastal habitat with predicted sea-level rise, particularly estuaries, saltmarsh, beach/dunes and mud/sand flats; and effects on priority species.
-alteration and loss of terrestrial habitats, particularly shifting forest types and loss of alpine habitats.
-range expansion or contraction of priority bird species.
-identification of vulnerable species.
|All priority species.|
|Conduct research to determine the effects of disturbances such as boat traffic on birds at sea and assess the resiliency of birds to disturbance, both during and outside the breeding season. Increase survey efforts to accurately map the seasonal distribution and abundance of seaducks, coastal seabirds and pelagic seabirds to identify potential areas of high conflict.||All seabirds and seaducks.|
|Monitor compliance and assess the effectiveness of current bycatch mitigation measures in commercial longline fisheries. Monitor bycatch in commercial net fisheries, and develop, implement, and assess effectiveness of bycatch mitigation measures for gillnet fisheries. Identify particularly vulnerable species to gillnet and longline bycatch.||All seabirds and seaducks.|
|Assess and quantify direct and indirect impacts of commercial fisheries on priority seabirds (e.g., commercial harvest of forage fish, fishery-induced changes in marine food webs).||All seabirds.|
|Assess the potential effects of coastal and offshore wind developments on birds, including both direct (collision mortality) and indirect (habitat loss due to avoidance of turbine installations) effects. Identify particularly vulnerable species.||All birds found in coastal and offshore areas, including migrating individuals/flocks.|
|Investigate the potential effects of finfish aquaculture on priority bird species. Quantify and assess the population-level significance of direct mortality (e.g., shooting, net entanglement) and habitat loss/degradation (e.g., installation footprint, algal blooms due to nutrient input, etc.).||All waterbirds and seaducks that use nearshore habitats.|
|Engage in interdisciplinary research to identify additive and interactive effects of multiple invasive species on ecosystem structure and function, in both terrestrial (e.g., introduced Sitka black-tailed deer, rabbits, raccoons, cats and rats; European Starling, House Sparrow, Scotch broom, etc.), freshwater (e.g., purple loostrife, yellow flag iris, etc.) and marine habitats (e.g., Spartina spp., green crab, etc.). Identify impacts to priority bird species.||All priority species.|
Threats Outside Canada
Many bird species found in Canada spend a large portion of their lifecycle outside of the country (Fig. 28). These species face threats while they are outside Canada; in fact, threats to some migratory species may be most severe outside of the breeding season (Calvert et al. 2009). Of the 139 priority species in BCR 5, 113 (81%) are migratory and spend part of their annual cycle--up to half the year or more--outside Canada.
Birds are some of the most mobile species on the planet, and some species are true global wanderers. Priority birds from BCR 5 range widely throughout North, Central and South America. Some species merely withdraw from the northernmost parts of their range during winter, such as the Band-tailed Pigeon, which winters from Washington state to California. Many of our waterfowl migrate somewhat further, wintering in the southern parts of the United States and through Mexico. Neotropical migrant songbirds from BCR 5 are particularly reliant on central and western Mexico, with many species, including the Black-throated Gray Warbler, Bullock’s Oriole, MacGillivray’s Warbler, Pacific-Slope Flycatcher, and Townsend’s Warbler wintering in those areas. Other species, such as the Barn Swallow, Common Nighthawk, and Purple Martin migrate further south, wintering throughout South America. In addition, BCR 5’s seabirds venture widely in the Pacific Ocean. Some, such as Tufted Puffin and Horned Puffin breed in BCR 5, but wander throughout the North Pacific in the non-breeding season. Others, such as the Laysan Albatross, Short-tailed Albatross, Flesh-footed Shearwater, and Pink-footed Shearwater breed as far away as Japan, Australia, New Zealand, Hawaii, and Chile, and are only seasonal visitors to Canadian waters.
Outside Canada, key migration, wintering and breeding habitats can be lost or degraded through development, agriculture, forestry, resource extraction or other human activities. Some species have relatively small and concentrated wintering ranges, where any habitat degradation or loss could have major impacts on the species population. Others, such as Dunlin and Western Sandpiper, are particularly vulnerable as large proportions of the species’ population concentrate at just a handful of key migratory stopover sites; degradation or loss of these sites could have devastating impacts. In addition, birds may be incidentally killed as fisheries bycatch or by colliding with man-made structures; lit communications towers and tall buildings can pose a major hazard to night-migrating birds. Birds can be exposed to toxic pollutants, including chemicals which may be banned or tightly regulated in Canada and the United States but are more freely available elsewhere. While the United States and Mexico have passed laws similar to Canada’s Migratory Birds Convention Act, 1994, which provide legal protection to many birds, other countries have not and migratory birds can be threatened by unsustainable or illegal hunting and persecution.
Similar to our assessment of threats facing priority species within Canada, we conducted a literature review to identify threats facing priority species while they are outside Canada (Fig. 29). A lack of data was a pervasive issue for this exercise. For many species, little is known about threats they face during migration or while on their wintering grounds. Indeed, for some species, their wintering ranges and habitat use are only poorly known, if at all. There is also little information linking specific wintering areas to particular breeding populations, making it difficult to connect declines in breeding populations to potential problems on the wintering grounds. In addition, what data exist on wintering migrant species are heavily biased towards work done in the United States and little research is available from Mexico, Central and South America. While many of the threats identified in the United States likely affect species throughout their range, unique issues outside of the United States may have been missed. An absence of threats in a region may reflect that the necessary research has not yet been conducted (or may not be published in English). Because information on bird distributions during the non-breeding season is limited, we were unable to assess the scope and severity of threats to priority species while they are outside of Canada.
Despite the paucity of data regarding migration and wintering migrant birds, actions must be taken to support our migratory species. We need to support conservation initiatives outside of Canada if we are to reach our goals and ensure the future of our migratory birds.
Note: Magnitudes could not be assigned for threats outside Canada due to lack of information on scope and severity. Categories representing ≤1% of all identified threats are omitted for clarity. 5.1 Hunting and trapping terrestrial animals refers primarily to hunting (legal and illegal) and lead poisoning from consumption of spent shot, but also includes accidental mortality of non-target species in pest bird control programs. 5.4 Fishing and harvesting aquatic resources refers primarily to bycatch of birds in fisheries. 8.1 Invasive non-native/alien species includes habitat degradation from invasive plants and introduced herbivores, as well as direct predation by introduced predators (primarily on seabird colonies). 9.2 Industrial and military effluents refers primarily to oil spills, but also includes exposure to heavy metals and other industrial contaminants. 9.3 Agricultural and forestry effluents refers to pesticides. Finally, 9.4 Garbage and solid waste refers to ingestion of plastic debris.
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