Field Fun Friday

DSC01876A grizzly bear feeding in the Elk Valley, British Columbia.  Grizzly bears need big spaces to roam, and the southern Rockies of BC provide ideal habitat for this species.  This bear may be one of the 604 bears detected by Clayton Lamb and his colleagues in BC’s Ministry of Natural Resources since the start of the South Rockies Grizzly Bear Project in 2006. Post by Clayton Lamb.

 

The use of citizen science to identify the factors affecting bird-window collisions at residential houses

Here’s the second post looking at the results of the Birds and Windows project! Here’s a link if you missed the first one. Today I’m focusing on the factors affecting collisions at residential houses.

In the past there have only been four studies looking at why one house has more collisions than another and each of these studies have focused on different aspects of window collision risk. These studies did not look at the impacts of multiple factors, including window type and yard attributes at the same time.

We propose the factors influencing bird-window collisions at houses be categorized based on scale into four levels: neighbourhood type, yard conditions, house attributes, and window types. Understanding the level that has the greatest impact on bird-window collision rates has implications for prioritizing mitigation options

The Birds and Windows citizen science project was developed to gain a better understanding of the factors affecting collisions at residential houses at all four levels with our main objective to focus on understanding the relative importance of variables at each of our four levels.

Birds and Windows 1

Since the launch of the Birds and Windows project there have been 34114 observations entered from homeowners in Alberta. Of these there were 930 collisions and 102 fatalities.

Of the collisions in Alberta, 497 could be identified to species or family. There were collisions from 53 different species. Birds that frequent feeders accounted for 295 of the identified collisions and 202 collisions were by those birds that do not visit feeders.

The most common species were Black-capped chickadees (n=50), American robins (n=40), Dark-eyed juncos (n=31), Bohemian waxwings (n=30), Cedar waxwings (n=24), and Black-billed magpies (n=22). There were a number of birds categorized as sparrows, chickadees, or waxwings which could not be identified further and as a result the numbers for Black-capped chickadees, House sparrows and both waxwing species are likely higher than reported above.

Birds and Windows 2

The factors identified at the yard level were the best explanation for the number of collisions. Those at the neighbourhood level were a close second.

Overall, the 3 factors identified as having the largest effect on bird-window collisions was whether the house was in an urban or rural location, the height of vegetation in the front yard of a house and whether or not there was a bird feeder present within 10 m of the house. There was additionally a large effect of seasonality on collision risk.

At the neighbourhood level there was a strong effect of both urban/rural location and season. Rural homes during the fall had a daily collision risk 10.84 times greater than urban houses in the winter. Those houses more likely to have a collisions where rural homes during spring and fall migration.

At the yard level the presence of a bird feeder, the height of vegetation in the front yard, whether the yard was considered developed or undeveloped and season had the largest effect on collision risk. Houses with a feeder in the fall had 5.96 times more collisions than a house without a feeder in the winter. Those houses more likely to have a collision were homes with a bird feeder, during spring and fall migration, houses with vegetation in the front yard 2 storeys or higher and houses in an undeveloped landscape.

At the house level the number of windows, the year the house was build, the building type and season had the strongest effect on collision risk. Those houses more likely to have a collision include houses with more than 10 windows, houses built before 1970, single-attached houses and during spring and fall migration.

At the window level whether or not vegetation was reflected in the window, the side of the house the window was on, the direction the window faced and the type of glass of the window were the best predictors of a collision. Those windows more likely to be a collision window include windows that reflect vegetation, windows on the front of a house, windows facing south and Low-E and UV glass windows. Birds and Windows 3In looking at differences between those birds that visit feeders and those birds that do not, the presence of a bird feeder increased collision risk 6.13 times for feeder birds and 2.96 times for non-feeder birds. This suggests that similar factors are affecting both groups. As well, those homes with bird feeders are more likely to have urban gardens and have created bird-friendly regions at their homes which are attracting non-feeder birds.

These results are generally consistent with other studies which have focused on a handful of the factors we have outlined. Factors associated with vegetation and increasing bird abundance have the largest effect on collision risk. Reductions to vegetation cover and abundance might reduce collisions however homeowners are not likely wanting to reduce the vegetation and number of birds in their yard. Instead we suggest we shift our focus towards developing the most effective window deterrents.

Conservation Genetics of American Pikas

Photo by Jessica Haines

Pika caching plants, photo by Jessica Haines.

Clayton Lamb and colleagues at the University of British Columbia-Okanagan published a paper on the conservation genetics of American pika in the Columbia River Gorge, Oregon, USA. American pika have low thermal tolerances and as a result models of climate-mediated extinction predict that pikas may be lost from as much as 80% of their current range by the end of the century. Here we used novel non-invasive hair collection techniques and genetic approaches to document the existence of American pika outside its biogeoclimatic envelope, and to identify genetic signatures of reduced dispersal and population size. The conservation value of populations from this region is high as they may be a significant component of intraspecific biodiversity and a source of adaptive potential and persistence in the face of climate change.

Public Seminar: The use of citizen science to identify the factors affecting bird-window collisions at residential houses

On Tuesday, December 8, Justine Kummer will be presenting a public seminar for her MSc defence. Come hear about her research in the University of Alberta Biological Sciences Building room CW 313 at 1pm.

Bird Feeders 2

Talk Summary

Every year a large number of birds die when they collide with windows. The actual number however is difficult to ascertain. Previous attempts to estimate bird-window collision rates in Canada relied heavily on a citizen science study that used memory-based surveys which may have potential biases. Building upon this study and their recommendations for future research the Birds and Windows citizen science project was designed to have homeowners actively search for collision evidence at their houses and apartments for an extended period. The first objective of the Birds and Windows project was to see how a more standardized approach to citizen science data collection influenced bird-window collision estimates and to see if the same patterns observed by memory-based surveys were observed using different data collection methods. Comparing the results from the Birds and Windows standardized searches and memory-based surveys revealed differences in absolute values of collisions but similar relative rankings between residence types. This suggests that memory-based surveys may be a useful tool for understanding the relative importance of different risk factors causing bird-window collisions.

The second objective from the Birds and Windows project was to gain a better understanding of the factors affecting collisions at residential houses. It currently remains poorly understood which types of buildings and windows are most problematic. Understanding whether neighbourhood type, yard conditions, house attributes, or window types have the largest effect on collision rates is crucial for identifying which mitigation options might be most effective. Factors at the yard level had the best model fit for predicting bird-window collisions at residential houses. Conservation efforts should target variables at this level and those factors that attract birds to an individual yard. As few homeowners are likely to take an approach that reduces the number of birds in their yards, focus should instead be given to bird-friendly urban design and developing the most effective window deterrents.

Finally, the effects of bird feeder presence and placement on bird-window collisions at residential homes was determined through a manipulative experiment. During the study there were 1.84 times more collisions when the bird feeder was present. However, there were no collisions at half of the study windows. High variance was observed in the number of collisions at different houses, indicating that effects of bird feeders are context dependent. Changing the occurrence, timing, and placement of feeders can alter collision rates but is only one of many factors that influence whether a residential house is likely to have a bird-window collision or not.

In conclusion, I provide recommendations for conducting future survey-based citizen science projects and outline the next steps for bird-window collision research in working towards stopping avian mortality from collisions with windows. I have thoroughly outlined a number of factors affecting bird-window collisions and the focus of future research should now shift towards reducing the problem. The Birds and Windows project saw a number of successes as a citizen science project and citizen science remains the best method for collecting large scale data in real-world scenarios and should continue to be used in similar experiments.

Bird Feeders 3

Field Fun Friday

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Mid-spring and late fall shots of the upper reaches of the Elk River, north of Elkford, British Columbia, looking east into Elk Lakes Provincial Park. This is a remote region of the Kootenays only accessible by a single, dirt road. The area supports abundant populations of grizzly bears, elk, moose, mountain goats, sheep, wolverines, and cougars. We are working hard to maintain the spatial integrity of this landscape so that these areas continue to support wild creatures and wilderness experiences for those who venture into them.

Post and photos by Clayton Lamb

Comparing different data collection methods in understanding bird-window collisions at residential houses

Here’s the first post discussing the results of my Birds and Windows project. Today I will focus on how the results from this study compare to the previous study conducted at the University of Alberta on bird-window collisions at houses.

dkendall (12-06-14) cedar waxwingEvery year a large number of birds die when they collide with windows. The actual number however is difficult to estimate. Previous attempts to estimate bird-window collision rates in Canada have relied heavily on a study where homeowners were asked to recall whether or not they could remembered a bird colliding with a window of their home in the past year. This was the first bird-window collision study to use citizen science, or members of the general public to conduct their research. However, this study relied entirely on memory and there were a number of potential issues.

We built upon this study and their recommendations for future research by creating a citizen science project where homeowners reported on previous bird-window collisions at their home and then actively searched for collision evidence at houses and apartments for an extended period. The Birds and Windows project was born. Our main objective was to see how standardized approaches to data collection compared to memory recall.

grynoch (28-09-2013)1315 participants registered with the project since September 2013. 93% of homeowners were from Canada but there were also a handful of participants from the United States, the United Kingdom and other various countries. Within Canada, 81% of homeowners were from Alberta.

Based on homeowner searches rural residences with a feeder had a 91.7% probability of a collision occurring, this was greater than rural residences without a feeder (69.2%), urban residences with a feeder (50.5%), urban residences without a feeder (33.9%), and apartments (25.0%). The types of houses with the highest number of collisions were similar between all studies and methods.

machtansc (21-05-14) white-winged crossbill WCR1We compared absolute collision estimates as well as relative differences between residence types and found considerable differences in absolute values of collisions but similar rankings of collision rates between residence types. Collision rates based on memory recall in our study (56.5%) were very similar to the previous Bayne et al. (2012) study where 50.5% of participants remembered a bird colliding with a window at some time in the past. Fatality estimates however were 1.4 times higher in Bayne et al. (2012) than our study based on standardized searches however.

This suggests that memory recall-surveys may be a useful tool for understanding the relative importance of different risk factors causing bird-window collisions which is essential for creating effective mitigation strategies. Citizen scientists were essential in conducting this study and we argue that until there’s a more technological solution, citizen science is the most cost-effective option for achieving the sample sizes required in real-world scenarios. Shifting from estimating the magnitude of the problem to using citizen scientists to help solve the problem of bird-window collisions should become a focus of future research and conservation efforts.

Literature Cited

Bayne, E. M., C. A. Scobie, and M. Rawson-Clark. 2012. Factors influencing the annual risk of bird-window collisions at residential structures in Alberta, Canada. Wildlife Research 39:583-592.

Seminar: Projecting boreal bird responses to climate change: considering uncertainty, refugia, time lags, and barriers

Diana Stralberg will be presenting her thesis defense seminar on Tuesday, November 3 at 1pm in the University of Alberta Biological Sciences Building room CW313. Check out her abstract below.

Photo by Craig Machtans, Environment Canada.

Photo by Craig Machtans, Environment Canada.

Abstract: Often referred to as North America’s bird nursery, the boreal forest biome provides a resource-rich environment for breeding birds, supporting high species diversity and bird numbers. These birds are likely to shift their distributions northward in response to rapid climate change over the next century, resulting in population- and community-level changes. Using a new continental-scale avian dataset, I have developed models to project climate-induced changes in the distribution and relative abundance of 80 boreal-breeding passerine species. For such projections to be useful, however, the magnitude of change must be understood relative to the magnitude of uncertainty in model predictions. In my first chapter, I found that the mean signal-to-noise ratio across species increased over time to 2.87 by the end of the 21st century, with the signal greater than the noise for 88% of species. I also found that, among sources of uncertainty evaluated, the choice of climate model was most important for 66% of species, sampling error for 29% of species, and variable selection for 5% of species. In addition, the range of projected changes and uncertainty characteristics across species differed markedly, suggesting the need for a variety of approaches to climate change adaptation.

Species and ecosystems may be unable to keep pace with rapid climate change projected for the 21st century, however. In my second chapter, I evaluated an underexplored dimension of the mismatch between climate and biota: limitations to forest growth and succession affecting habitat suitability. I found that end-of-century projected changes in songbird distribution were reduced by up to 169% when vegetation lags were considered, indicating that limits to forest growth and succession may result in dramatic reductions in suitable habitat for many species over the next century. I used these results to identify conservative and efficient boreal conservation priorities anchored around climatic macrorefugia that are robust to century-long climate change and complement the current protected areas network.

Vegetation change may also be delayed in the absence of disturbance catalysts. In the western boreal region, a combined increase in wildfires and human activities may aid these transitions, also resulting in a younger forest. In my third chapter, I developed a hybrid modelling approach based on topo-edaphically constrained projections of climate-driven vegetation change potential, coupled with weather- and fuel-based simulations of future wildfires, and projections of large-scale industrial development activities, to better understand factors influencing decadal-scale upland vegetation change. I simulated scenarios of change in forest composition and structure over the next century, conservatively concluding that at least one-third of Alberta’s upland mixedwood and conifer forest is likely to be replaced by deciduous woodland and grassland by 2090, with a disproportionate loss of both young and old forest classes. During this timeframe, the rate of increase in fire probability diminished, suggesting a negative feedback process by which a warmer climate and more extensive near-term fires leads to an increase in deciduous forest that in turn, due to its relatively low flammability, leads to a long-term reduction in area burned.

Finally, boreal species’ projected range shifts could be impeded by the northwestern cordillera, which separates boreal Alaska from the rest of the North American boreal region, and appears to have historically prevented many species from expanding into climatically suitable habitat after the last glacial maximum (LGM). Using paleoclimate simulations for the past 20,000 years, I analyzed the relative importance of migratory and life-history characteristics vs. climatic factors on the distributions of North American boreal-breeding species. I then used this information to predict which species are most likely to shift their distributions from Canada into the Alaskan boreal region in the future. The high relative importance of climatic suitability within the northwestern cordilleran region suggests a capacity for several species to disperse into Alaska once climatic connectivity is achieved in the future, which is supported by recently recorded signs of breeding activity.

A Grizzly Bear Population Inventory in the Threatened Kettle-Granby Grizzly Bear Population Unit

Between June and August of 2015, field crews led by Clayton Lamb conducted a grizzly bear population inventory in the threatened Kettle-Granby Grizzly Bear Population Unit. Crews set 124 bait sites across the ~8,000 km­2 area, which consists of rotten cow blood enclosed by barbed wire to non-invasively collect grizzly bear hair, which is then used to identify individuals through multi-locus genotyping. The bait sites were checked for hair samples at two week intervals, with most sites being checked four times throughout the summer.

A total of 1360 hair samples were collected, and field staff visually identified 29 percent of the samples as grizzly hair. The hair samples are currently at the genetics lab (Wildlife Genetics International) in Nelson, and we expect to have the genetic results back before March 2016. During fiscal year 2016-17, the genetic data will be used to generate population estimates and address questions regarding population size, composition, connectivity and the distribution of grizzly bears within the study area.

The study area for the 2015 Kettle-Granby Grizzly Bear Population Inventory, with the locations of the 124 baited hair snag sites identified by coloured circles. No grizzly bears were detected at the turquoise circles, while grizzly bears were detected during at least one check at the purple circles. While grizzly bears were detected throughout the study area, they were more commonly detected in the area in and around Granby Provincial Park. Note: Hair samples were classified as grizzly samples in the field based solely on visual indicators.

The study area for the 2015 Kettle-Granby Grizzly Bear Population Inventory, with the locations of the 124 baited hair snag sites identified by coloured circles. No grizzly bears were detected at the turquoise circles, while grizzly bears were detected during at least one check at the purple circles. While grizzly bears were detected throughout the study area, they were more commonly detected in the area in and around Granby Provincial Park. Note: Hair samples were classified as grizzly samples in the field based solely on visual indicators.

Post by Clayton Lamb.

Field Fun Friday

Birdandkitty

This week Justine Kummer experienced the first bird-window collision at her house since she started on the Birds and Windows project three years ago, but instead of showing you that poor dead bird, here’s one of her favourite photos sent in by a friend of his cat eyeing up a little feathered friend.