GARDENS, BY DEFINITION, DEPEND ON people; they are an extension of our homes and our personalities, shaped by opportunities and social conventions. The extent to which we use them to engage with birds and other forms of wildlife will also be determined by these factors and this, in turn, will determine their wildlife value and the roles that gardens play in the lives of other creatures. In this, the final cross-species section of the book, we will look at the role that gardens and their birds play in our own lives. We will explore why we value some bird species over others and we will seek to understand the contributions that we, as individuals, can make to the conservation of garden birds, either through how we choose to manage our gardens or through active participation in citizen science projects, like the BTO Garden BirdWatch survey.
GARDENS AND PEOPLE
Office for National Statistics figures, published in 2017, reveal that there are some 27.2 million households in Britain. Roughly three-quarters of these are associated with a private garden, a figure that places Britain relatively highly when compared to other European countries. Access to a private garden may actually be somewhat greater than this when viewed at the level of the individual, with figures from commercial studies suggesting that nearly 90 per cent of adults have access to either a private or shared communal garden. As we saw in Chapter 1, a study by Davies et al. (2009), using data from a number of different datasets, put the proportion of households with an associated garden at 87 per cent. Of course, access to a garden does not necessarily mean access to, and engagement with, nature, since gardens may be used in different ways by different individuals (Bhatti & Church, 2004). A survey carried out in 1999 by the London-based research company MINTEL defined garden use according to five consumer sub-groups. The largest three of these were leisure gardeners (35 per cent) – people who enjoyed their garden but lacked the time and/or skills to do more with it; investors (35 per cent) – people who viewed their garden as adding financial value to their property; and horticultural hobbyists (23 per cent) – people who propagated plants from seed and were highly skilled and knowledgeable. It has been suggested that only horticultural hobbyists are likely to seek an understanding of nature, but there is a strong case to be made for including many leisure gardeners in with those who seek engagement with nature through their gardens.
FIG 105. While individual gardens may represent only a very small space, they provide a unique opportunity for us to engage with the natural world. (Mike Toms)
Gardens themselves are just as varied as the people who own and manage them but there are some common patterns to garden use, and identifiable relationships linked to the class, gender, age and income of their owners. Over time there has, for example, been a shift within gardens away from the growing of fruit and vegetables towards the garden as an outdoor room, dominated by activities that are centred on sitting, looking and playing, and away from activities associated with cultivation. In part, this reflects changing social behaviour but it is also strongly influenced by changes in garden size. Pressures on land, and the almost total dominance of the private sector in the construction of new homes, has seen a significant fall in the size of the average garden plot. This is an ongoing pattern, with the density of new dwellings increasing by 72 per cent between 2001 (25 dwellings per h) and 2011 (43 dwellings per h).
The extent to which individuals engage with nature through their gardens is also shaped by other leisure uses and social issues: for example, certain wildlife-friendly gardening practices – such as the construction of a wildlife pond – may be considered unsafe by householders whose garden is used as a leisure space by young children. Individuals may also respond to the fashion of the day, be it the use of decking, prairie planting or, more recently, wildlife-friendly gardening. In many cases, however, the garden is viewed as being ‘nature under control’, which leaves many gardeners facing considerable ecological dilemmas in terms of how they balance competing garden uses and engagement with the plants and animals that are present (Bhatti & Church, 2001). In many ways, the garden and its biodiversity provide an opportunity for individuals to think about the balance that exists between ‘human control on the one hand and wild nature on the other’ (Francis & Hestor, 1990). It presents a stage on which individuals can experience nature and ecological processes – such as predation and competition – and, in so doing, gain a better understanding of wider ecological communities and systems. In addition, we also need to understand that gardens are, like the home, a semi-private space and that they have a role in the construction of a domestic sense of place (Tuan, 1990).
FIG 106. Gardens are very personal spaces and their structure and function represents the balance that exists between ‘human control on the one hand and wild nature on the other’. (Mike Toms)
As we saw in Chapter 1, private gardens differ from other forms of urban (and rural) green space in many functional aspects; this has consequences for the types of bird species that use them and for the ways in which particular ecological processes play out. They also differ because of the real and imagined connections to home and place that we have just touched on at the start of this chapter. In addition to influencing the bird communities present, and the ways in which individual gardens are used, the nature of garden ownership can also shape our ability to study and monitor the birds – and wider biodiversity – associated with them. If we want to study bird populations and behaviour within the garden environment, then we need to seek the help and support of garden owners. In some cases, this may just require seeking permission to access study gardens, but in other cases there may be a need to actively engage garden owners in the collection of ecological data. This latter point is something that we will explore later in this chapter when we look at citizen science schemes, such as the BTO Garden BirdWatch and Garden Wildlife Health.
ECOSYSTEM SERVICES
There is a growing body of evidence that interactions with birds and other forms of wildlife can provide people with feelings of being connected with nature. Such connections have been shown to have positive effects on human well-being and may be of particular importance within urbanised landscapes, where access to nature is often limited. Access to the natural environment can lead to faster recovery times following surgery (Ulrich, 1984) and to improved mental health and well-being (Kaplan & Kaplan, 1989; Hartig et al., 1991).
Private gardens may offer some of the best opportunities for such connections with the natural world to be established and maintained. The ‘services’ that the natural world provides to its human inhabitants are increasingly referred to as ‘ecosystem services’, some of which are more tangible than others. Tangible services include the pollination of crops and flood alleviation; less tangible services – such as the well-being benefits that come from seeing or hearing species that you like – are known as ‘cultural services’. The ecosystem services approach is centred around identifying and accounting for the contributions that the natural world make to human health and well-being, the ultimately goal being to support better decision-making processes for the benefit of both people and the environment.
FIG 107. Gardens are one form of urban green space, contributing ecosystem services to the built environment and to the humans who live there. (Mike Toms)
Not all interactions between birds and people are necessarily positive; birds are sometimes responsible for the contamination of water sources, for causing unwelcome noise and smells, or for disease transmission; these are referred to as ‘cultural disservices’. Interestingly, the ecological traits of the bird species providing services and disservices tend to be quite different; those associated with cultural services tend to be insectivorous or granivorous and aesthetically pleasing, being interesting to watch, often colourful and small in body size (most garden birds), while those associated with cultural disservices tend to be larger and omnivorous (geese, pigeons and gulls). How the abundance and distribution of birds from these two groups varies across our urbanised landscapes might influence how different human communities experience birds and how this then shapes their wider appreciation of the natural world.
There is substantial variation in the ‘likeability’ of different bird species and most of the people watching garden birds will admit to favouring some species over others – large numbers seem to dislike Magpies, for example. Likeability has been tested here in the UK (Cox & Gaston, 2016), revealing both that people prefer to see greater variation in the species to which they are exposed, rather than a greater number of individuals of the same species, and that those who engage more regularly with wild birds through garden feeding show greater species likeability. Cox and Gaston found a strong correlation between the number of species that a person could identify and how connected to nature they felt when they watched garden birds.
Our understanding of likeability and the different groups of service and disservice birds has benefited from recent work, centred on the towns of Milton Keynes, Luton and Bedford (Cox et al., 2018). By carrying out extensive surveys of the bird communities in these towns, the researchers were able to measure the abundance and species richness of birds within both the cultural services (35 species) and disservices (9 species) groups. They then examined these findings alongside data on the human population, derived from the 2011 National Census and measures of socioeconomic status from the Office of National Statistics. Since, as we have already seen, bird diversity in urban areas is strongly associated with the structure and availability of urban green space, the team also had to take this into account. The results of this work demonstrate that the abundance of service and disservice birds varies with human population density, but each has its own distinctly different patterns. Service species are most abundant in areas of medium housing density (notably the suburbs), while disservice birds are most abundant in areas of dense housing (notably around urban centres). These patterns, which almost certainly result from differences in the pattern of urban green space and resource availability, underline that people living in different parts of the urban environment are likely to have differing relationships with wild birds. People living within the socially deprived parts of towns and cities (often located around urban centres) are exposed to bird species associated with more negative behaviours than wealthier communities, who tend to see more cultural service species.
Of course, we also need to understand how people perceive the bird species with which they share their gardens and the wider environment. Several pieces of research work provide insight here, documenting such perceptions and how they change with location, background and the bird communities to which people are exposed. Working in Rennes, France, Clergeau et al. (2001) found that the perception of birds varied depending upon where in the city people lived, something that was indeed linked to the species to which they were most commonly exposed. While bird diversity was highest within the suburbs, and lowest in the most urban area, the density of birds was actually greatest in the urban centre; this was due to the abundance of particular species, most notably Feral Pigeon and Swift.
FIG 108. Colourful species with attractive songs, like Goldfinch, are well liked by people living in towns and cities; they are one of the ‘cultural service’ species recognised by researchers working on ecosystem services. (John Harding)
Elsewhere, Amy Belaire and colleagues have looked at the aspects of local bird communities that residents of Cook County, Illinois (US), most value, before going on to test residents’ perceptions of the benefits and annoyances of local birds in relation to the characteristics of the species themselves (Belaire et al., 2015). Residents of Cook County were found to value many aspects of their neighbourhood birds, especially those related to aesthetics and to the position that birds occupied within the local ecosystem. They did, however, note several key negative behaviours, most notably the presence of droppings and nests built on personal property. A small number of bird species, including House Sparrow, Blue Jay and Starling, were most commonly associated with the annoyances raised by residents, and it seems that these species are more likely to be noticed for their negative rather than positive qualities.
One of the most interesting things to emerge from the work carried out by Belaire et al. was the lack of a significant relationship between residents’ perceptions of local bird richness and the actual (surveyed) richness of birds near their homes. Other studies, this time carried out in Europe, also underline that urban residents are largely unaware of the biodiversity around them (Dallimer et al., 2012; Schwartz et al., 2014). Two consequences arise from this inability of residents to correctly assess the levels of biodiversity or avian species richness that occur locally: first, individuals are more likely to link the cultural services delivered by birds with their own perceptions of local biodiversity, rather than with actual biodiversity. Second, if residents cannot identify the levels of biodiversity or richness around them, then there is greater likelihood that their experience of nature will be diminished. This latter point is linked to the ‘extinction of experience’ hypothesis, which concerns a theorised cycle of increasing separation between humans and nature over time (Miller, 2005).
FIG 109. Starling is a species that many householders describe in negative terms, and it seems that this species is more likely to be noticed for its negative rather than positive qualities. (John Harding)
‘Extinction of experience’ has been put forward as one of the factors behind the increasing levels of stress, anxiety and depression seen within society. The scale of the economic costs associated with such well-being problems can be seen from the €187 billion figure that is thought to be the annual cost of dealing with anxiety and depression across Europe (Olesen et al., 2012). Viewed alongside evidence that access to nature can reduce stress and anxiety (Maas et al., 2009) and improve mood (Roe & Aspinall, 2011), this adds weight to the argument that interactions with birds, both within the garden and more widely, might be worth encouraging (White et al., 2013). Several studies have already revealed that both watching birds (Fuller et al., 2007b; Brock et al., 2015; Cox & Gaston, 2016) and listening to them (Ratcliffe et al., 2013) can be good for human well-being. Through the use of a questionnaire on urban lifestyle, shared with 1,023 adults living in the Milton Keynes, Luton and Bedford area, Daniel Cox was able to tease out links between particular landscape features (vegetation cover and bird abundance) and the prevalence of depression, anxiety and stress. Perhaps most interestingly, it was afternoon bird abundance, rather than early morning bird abundance, that was positively related with these measures of well-being. This underlines that researchers need to consider the timing of when human study subjects interact with wild birds, rather than using standard measures of bird abundance, which are invariably measured very early in the morning. By using dose response modelling, Daniel Cox and his colleagues were also able to determine the threshold exposure to vegetation cover above which the prevalence of these well-being issues was significantly lowered (typically 20–30 per cent).
The work of Cox et al. (2016), and others, increases our understanding of how humans and birds interact, and identifies opportunities to develop management and planning approaches that counter unfavourable relationships and nurture more beneficial ones. There are also opportunities to deliver beneficial relationships at the householder level, through practices such as wildlife-friendly gardening. These approaches are thought to be of particular importance, not least because of the wider benefits that can be delivered by a small number of people within a community adopting wildlife-friendly gardening approaches. The birds and wildlife using their gardens will also utilise neighbouring gardens, increasing opportunities for the broader community.
WILDLIFE-FRIENDLY GARDENING
We have already seen how the interaction between people and garden birds operates in both directions, with the provision of supplementary food and nest boxes regarded as generally positive for wild birds, and with human health and well-being benefiting from interactions with birds and other garden wildlife. Over recent decades, we have seen a growing interest in adopting approaches to garden management that more directly benefit wildlife. This approach is known as wildlife-friendly gardening (sometimes ‘wildlife gardening’) and it has been defined as ‘any actions conducted in private or domestic gardens to increase their suitability for wildlife’ (Davies et al., 2009).
FIG 110. Wildlife-friendly gardening is becoming increasingly popular, providing the opportunity for householders to encourage birds and other wildlife into their own private spaces. (Mike Toms)
The motivations for participation in wildlife-friendly gardening are similar to those behind the provision of food for wild birds, which is in itself a component of wildlife-friendly gardening. The Biodiversity in Urban Gardens in Sheffield project found, for example, that the prevalence of bird feeding and time spent gardening were both positively related to the proportion of cover by gardens and average garden size but independent of household density (Gaston et al., 2007). However, most wildlife-friendly gardening practices require additional effort on the part of householders and so a higher level of motivation may be required. Work in Leeds also demonstrates that wildlife-friendly gardening is influenced by a combination of factors, some of which relate to the characteristics of the garden and landscape context, and some of which relate to the householders themselves (Goddard et al., 2013). Respondents to a series of interviews and questionnaires highlighted personal well-being and a moral responsibility to nature as the key drivers. However, there were also barriers, such as the feeling of duty to maintain neighbourhood standards – which might run counter to certain wildlife-friendly gardening practices.
More widely, work in the US has sought to understand how wildlife-friendly gardening practices, particularly those aimed at birds, vary between different landscapes. Christopher Lepczyk and colleagues, working along a rural-to-urban landscape gradient, found that urban landowners planted or maintained vegetation in the lowest frequency but had the highest densities of bird feeders. In contrast, rural landowners provided more nest boxes but applied herbicides and pesticides more often (Lepczyk et al., 2004a).
Wildlife-friendly gardening practices vary in the extent to which they are based on scientific evidence, with those directed towards wild birds seemingly better supported than those aimed at many other taxa groups (Gaston et al., 2005b). In Chapters 2 and 3, we saw how gardening practices can influence the feeding and nesting opportunities available within gardens for wild birds. The extent to which the findings of scientific studies reach a wider public audience has depended to a large part on the efforts of organisations like the RSPB, BTO, the Wildlife Trusts, RHS and the Wildlife Gardening Forum. Popular publications, such as those by Toms et al. (2008), Baines (2016), Thomas (2017) and Bradbury (2017), have supported those with a growing interest in helping wildlife. However, a look at garden centre shelves or online will reveal the continued presence of materials, particularly nest boxes, that have clearly been designed with people rather than birds in mind. Just as there is work to be done in supporting individuals in their choices, efforts are also needed to steer wild bird care companies towards evidence-based products of benefit to birds. Doing the science is the starting point for this process and one that has both advantages and difficulties that result from working within privately owned gardens.
FIG 111. It is not just birds that benefit from wildlife-friendly gardening practices; many other species, including this Common Toad Bufo bufo, do well where consideration is given to their needs. (Mike Toms)
SCIENCE AND GARDEN BIRDS
As recent academic books and special journal issues demonstrate (Niemelä, 2011; Murgui & Hedblom, 2017; Isaksson et al., 2018), there has been a step-change in the effort directed towards the study of the urban environment and its biodiversity. One of the most interesting aspects of recent work on the study of urban birds is the finding that urbanisation not only affects the bird communities but also how researchers study them: the more urban a species, the more frequently it is studied (Ibáñez-Álamo et al., 2017).
Despite this, working within the built environment can be challenging, particularly where that work has to take place within a multitude of privately owned gardens. Two of the biggest challenges for the researcher are securing access and controlling how resources – such as food provision – are managed, both within the garden and in the surrounding area. A few studies have, however, been able to secure access and control resources sufficiently to provide an insight into the ecology of the garden habitat – the Sheffield BUGS project is perhaps the best example of this (Gaston et al., 2004). Fortunately, gardens are amenable to surveying and monitoring by the householders who own them (Cannon, 1999), something that has supported a suite of long-running projects studying garden birds, their behaviour, population dynamics and ecology.
Coordinated participation in garden-based experiments, monitoring and surveillance schemes has led to some of the largest and most successful examples of citizen science and mass-participation anywhere in the world. In addition to generating significant datasets and tackling important research questions, such schemes also facilitate public engagement with science, birds and bird conservation. There is, however, one caveat that requires mention: while participation levels in the schemes listed below reinforce the willingness to engage, this engagement is not equal across society. Instead, it tends to be associated with those who have the time and/or financial resources to participate. As we have seen already, gardens and their bird communities have been shown to vary in relation to their location within a city and with various socioeconomic factors. Because of this the results from most mass-participation surveys are biased towards certain kinds of garden, with others – typically small inner city gardens – under-represented. We must be careful, therefore, not to generalise about gardens and the birds when talking about the results of such schemes; nevertheless, they provide valuable and much-needed information that can help planners and land managers to make better-informed decisions about future land use and future urban landscapes. The following sections provide details about some of the citizen science schemes targeted at garden birds and operating here in the UK and elsewhere.
FIG 112. Citizen science studies of garden birds have underlined the importance of gardens during periods of poor winter weather. (John Harding)
BIG GARDEN BIRDWATCH
The RSPB’s Big Garden Birdwatch is the UK’s highest-profile project linked to garden birds, receiving substantial media coverage and participation around its annual event. The project began in 1979 as a simple winter activity for junior RSPB members, attracting the attention of the children’s programme Blue Peter and leading to in excess of 34,000 submissions. The project, focussed on children, was relaunched in 2001 as an activity for the wider family and it has grown substantially since then, raising awareness and funds for the RSPB and its conservation work. That the project has been able to engage so many people in watching garden birds, and introduce them to the idea of citizen science, is a major achievement.
Big Garden Birdwatch works by asking participants to record the birds that they see visiting their gardens during an hour-long period over one weekend at the end of January. By asking participants to follow a series of simple and standard methods, it is possible to compare what is seen in different parts of the country, and indeed from one year to the next, to create a ‘snapshot’ of bird numbers across the UK. It is just a snapshot, however, the counts made over the weekend not just reflecting the number of birds visiting garden feeding stations more generally but also shaped by the weather conditions experienced over the short recording period.
The data collected through Big Garden Birdwatch are analysed and a set of results published within a few weeks of the survey being completed, enabling comparisons with previous years and across different regions. No peer-reviewed publications have, as yet, emerged from the study, but the data may be of value for broader analyses, looking at landscape scale patterns.
FIG 113. Long-term projects like the BTO’s Garden Bird Feeding Survey have helped to document the changing status of species like Siskin. (John Harding)
BTO GARDEN BIRD FEEDING SURVEY
Launched as a pilot study in the July 1970 edition of BTO News, the BTO Garden Bird Feeding Study (GBFS) was designed to gather information on a national scale concerning ‘which species are currently coming to garden feeding stations in the British Isles and when; what foodstuffs are being presented and which items consumed most readily’. The pilot, which covered the 1970/71 winter, was organised by Norman Pullen, working alongside Chris Mead and David Glue; David Glue was to take over the running of the survey longer term, something that he continued to do up until his death in 2014.
GBFS is restricted to approximately 250 gardens each year, chosen to ensure good geographical coverage across the UK and an approximately equal split between rural and suburban gardens. Each year a few participants drop out and suitable replacement gardens are identified from among the membership of BTO Garden BirdWatch. Participants make observations from October to March, their weekly observations split into two 13-week periods, with the maximum number of each species seen using provided food or water (or observed hunting the birds that are using these resources) recorded on a weekly basis. Additionally, participants are asked to log the foods that they have provided in each week.
FIG 114. The increased use of garden feeding stations by Blackcaps during the winter months in urban areas is evident from BTO Garden Bird Feeding Survey data. Data used with permission from the BTO.
The weekly data provided by participants in the survey are used to calculate ‘peak count indices’, by week, habitat and species, that can reveal changes in the use of garden feeding stations by nearly 40 species, plus Sparrowhawk. Having been running since the 1970/71 winter, the survey provides important information on the broad-scale changes in the garden bird community over a substantial period. Its results reveal the timing and pattern of decline in House Sparrow populations, the increase in Woodpigeons and Goldfinches, and the development of the wintering Blackcap population (see Figure 114). It also reveals some interesting changes in other species, such as Blue Tit and Jackdaw, for example, which can be compared with long-term trends seen in these species within the wider countryside.
Data from the survey have been well used in peer-reviewed research, particularly in relation to work looking at how the size of tree seed crops influences the use of supplementary food (Chapter 2: Chamberlain et al., 2005; 2007a) and in relation to the possible impacts of Sparrowhawks on garden birds (Chapter 4: Chamberlain et al., 2009b; Swallow et al., 2016a; 2016b). They are also being used by Kate Plummer and colleagues to examine how garden bird communities are being shaped by long-term feeding (Plummer et al., in prep.). GBFS data have also been valuable in helping to document and understand the long-term population declines of House Sparrow and Starling (Crick et al., 2002).
BTO GARDEN BIRDWATCH
Although launched in January 1995, BTO Garden BirdWatch (GBW) has its origins in an earlier study carried out by the organisation, namely the BTO/BASF Garden Bird Survey. This launched in June 1987 and ran for three full years, with data collected on a weekly basis using paper forms that could then be put through an Optical Mark Reader (OMR) machine. Some 6,500 people contributed to the study during the period of data collection, providing a valuable insight into what could be achieved by adopting a mass-participation, citizen science approach to the study of garden birds (Muirhead, 1990).
The BTO/BASF Garden Bird Survey approach underlined the very valuable information that could be gained from urban and garden habitats by engaging householders in the collection of scientific data. The challenge, however, was how to fund such a project when core funding from government was being directed towards the bird communities in other habitats. One option would have been to continue to seek commercial sponsorship, but one argument against this was the typically short-term nature of such funding and the likely wish of subsequent funders to want the project to be different from what had been run previously – with long-term monitoring, the goal is to maintain the methods used over time so as not to introduce bias. In the end, the decision was taken by Nigel Clark and Chris Mead, both key individuals driving forward the BTO’s garden-based research agenda, to take the idea to the BTO leadership team of a survey funded by contributions from its participants. What was potentially a risky strategy was softened by the support of Chris Whittles and C. J. Wildlife Ltd, who offered to support the project financially, at least initially, so that it could test the willingness for participants to make a financial contribution. In the event, the decision backed by BTO management was a huge success, and by the end of the first year the scheme had received submissions from roughly 3,000 participants. Since then it has grown into a significant mass-participation survey, delivering weekly records of birds and other garden wildlife throughout the year.
FIG 115. BTO Garden BirdWatch volunteers have made a significant contribution to our understanding of how birds use gardens and how this use has changed over time. (Paul Stancliffe)
During the initial years, Garden BirdWatch was entirely paper-based, with participants submitting records of 42 common bird species on special recording forms. Web pages offering online submission were trialled in 2001 and then launched, enabling greater detail to be collected across a broader range of species. The proportion of participants recording through the online system has increased over time but a substantial number of participants continue to make their submissions on paper. Following requests from participants, the recording of other taxa species was initially trialled, before being launched and becoming fully integrated in 2007.
Like any other mass-participation project, the size of Garden BirdWatch imposes some constraints on the way in which data can be collected and used. The use of OMR forms and data entry web pages minimises the effort required to get the data into a useable format and loaded into the core database tables that hold the vast numbers of observations of birds recorded since 1995. A central component of the recording methodology is that participants should be consistent in the way that they, as individuals, carry out their weekly recording. Participants are asked to make records from the same place (their defined ‘recording area’), which could be their whole garden, at more or less the same time or times each week. Continuity of recording effort is more important than the quantity of recording carried out, since each weekly submission made by an observer provides a relative measure of garden use. Only species actively using the garden are recorded, so birds seen flying over the garden are excluded. Differences in effort between participants can be handled statistically during any subsequent analysis and modelling. Individuals are asked to record the maximum number of individuals of each species seen together at any one point in time during the recording period. Hence, if a participant recorded for an hour each day throughout the week and saw two Blackbirds together on the Monday, one each on the Tuesday and Wednesday, none on Thursday, three on Friday and two each on Saturday and Sunday, the maximum count for the week would be the ‘three’ from the Friday. This approach tackles the problem of double-counting individuals but only provides a minimum count for the number of different individuals using the garden and its resources over the course of the week. We know from bird ringing in gardens that up to 100 different Blue Tits may visit a garden feeding station during a single winter’s day.
Data validation is often problematic for mass-participation surveys, and this is something that has been addressed for the online submissions made by participants but not to the same degree for paper submissions. As each participant enters their count details online, the data entered are checked against some simple validation tables. These warn observers of potential inputting errors by alerting them to unusually high counts, records that appear to fall outside of the known geographic range for a particular species or which are from an unusual time of the year (the latter particularly useful for migrant species). Alerted to a possible error, the observer has the opportunity to make a correction, but may choose not to. Since the paper recording forms rely on participants placing a mark in a box at a particular place on the form, there is the potential to fill in an incorrect box – for example, by ticking Tree Sparrow when you meant Treecreeper. While this is not a problem for the core national analyses of the most common species, where such an error just adds a very tiny amount of background ‘noise’ to an underlying trend, it can be a problem if the data are taken and used for county atlases or local projects. This is where the opportunity to use local volunteers, such as county bird recorders, could be particularly useful. Despite these small criticisms, BTO’s weekly Garden BirdWatch continues to play a central role in helping us to understand how and why birds use gardens and how this use varies with season and location.
FIG 116. Garden BirdWatch records include those of less common visitors, something that can provide useful additional information for bird atlas projects and county bird reports. (John Harding)
BTO Garden BirdWatch data have featured in several dozen peer-reviewed papers and have also been used in Wild Bird Indicators to provide a measure of change in urban bird communities. One of the first papers to emerge from the project was the work by Cannon et al. (2005), which reported on trends and seasonal patterns of garden use for the first time. This paper was important because it demonstrated ecologically important trends for wild bird populations in the UK’s gardens and provided new insights into the seasonal cycles of garden use, additionally underlining the scheme’s potential as a monitoring tool for a habitat that is both important in its own right and not adequately covered by other monitoring schemes. Other papers have since extended the peer-reviewed monitoring outputs of the survey, not just for birds but also for other taxa (Toms & Newson, 2006), or looked at garden use in relation to wider landscape features (Chamberlain et al., 2004a; Mckenzie et al., 2007), behaviour (Ockendon, 2009a; 2009b), disease (Lawson et al., 2010; 2012b; 2018) and demographics (Morrison et al., 2014).
GARDEN WILDLIFE HEALTH
Garden Wildlife Health (GWH) is a collaborative project between the Zoological Society of London, British Trust for Ornithology, Froglife and RSPB, which aims to monitor and identify disease threats to British wildlife, including birds. The scheme is comprised of two components: one that allows the opportunistic reporting of disease through an online system, and one that delivers systematic surveillance of disease by asking participants in the weekly BTO Garden BirdWatch to submit information on the presence or absence of disease in the wildlife being observed in their gardens. Participants in Garden BirdWatch seeing evidence of disease can then submit additional information through Garden Wildlife Health. The system effectively pairs citizen science observers with veterinary scientists, the latter also being able to request carcasses of birds found dead for post-mortem examination. Participants receive feedback from the veterinary scientists on the likely causes of death of any birds that have a post-mortem examination carried out on them. As with many of the other projects mentioned within this section, Garden Wildlife Health reports its findings back through web pages, some of which are interactive. In addition, the findings are shared with UK-wide disease surveillance networks and with government, alerting others to the potential risks of emerging diseases. The use of citizen scientists in this way is a hugely valuable and financially efficient way of securing national disease surveillance that can draw on the strengths of combining opportunistic reporting with systematic observations. The scheme has operated for a number of years, formerly under the name of the Garden Bird Health initiative, and thanks to the generosity of its funders – the organisations themselves, the Universities Federation for Animal Welfare, government, the Esmée Fairbairn Foundation and representatives of the wild bird care industry.
As can be seen from many of the papers mentioned in Chapter 4, the project has delivered a significant amount of new information on the diseases of garden birds, from the emergence and spread of finch trichomonosis and paridae pox through to beak and feather disease in Ring-necked Parakeets and drowning mortality in Starlings (Sa et al., 2014; Lawson et al., 2015b; 2018). In addition, the extensive sample and tissue archive allows current and future researchers to test for and study other disease-related topics going forward.
BTO NEST BOX CHALLENGE
Launched in 2007, Nest Box Challenge is an online survey offering interested nest box owners the opportunity to record simple details about their nest box, its location and use. The survey is essentially a cut-down version of the long-running Nest Record Scheme, collecting information on those demographic parameters relating to garden-breeding attempts. To date, 40,000 nests have been registered from just under 15,000 gardens, the bulk of which relate to species using the familiar small-hole boxes described in Chapter 3, notably Blue Tit, Great Tit and House Sparrow. Participants are asked to monitor the box across the season, noting occupancy and collecting information on the progress of any nest contents.
FIG 117. Nest Box Challenge provides valuable information on garden nesting attempts by species like Spotted Flycatcher. This information feeds into the BTO Nest Record Scheme. (John Harding)
Monitoring visits follow the guidance provided to participants and a code of conduct, based on the premise that locating and observing a nest should not jeopardise its safety. Each observer is asked to exercise a sense of responsibility, always putting the bird’s interests first, something that is important for both ethical and scientific reasons. By following the guidance and the code of conduct, possible disturbance at the nest is minimised. As noted in Chapter 3, it has sometimes been difficult to overcome people’s nervousness about looking into occupied nest boxes, but Nest Box Challenge is helping to address this, as are the materials put out in support of this project and the BTO Nest Record Scheme. Research in the US underlines that citizen scientists involved in the monitoring of nests in their backyards have no negative effect on the nests that they monitor and provide estimates of nest survival comparable to those of professional ecologists (Ryder et al., 2010).
A similar project operates in North America; called the Neighborhood Nestwatch Program, the project is driven by two goals: to collect data on the ecology and population dynamics of eight species along an urban-to-rural gradient in the Washington DC area, and to teach people about bird biology. Operated by researchers at the Smithsonian Conservation Biology Institute, Nestwatch began as a pilot project in 2000 with just 45 participants. The project has since expanded and now averages between 50 and 100 participants annually, across several regional centres, leading to a series of peer-reviewed papers and other publications (Evans et al., 2005; Ryder et al., 2010; Narango et al., 2017).
PROJECT FEEDERWATCH
The North American Project FeederWatch began its life during the winter of 1976/77 as the Ontario Bird Feeder Survey, launched by researchers at the Long Point Bird Observatory with the aim of seeing which species visited garden feeding stations, in what numbers, and which foods they preferred. After a successful 10-year run involving more than 500 participants, the organisers determined that if the survey could be expanded to cover the whole of North America, then it would greatly add to the knowledge being gathered. It was at this point that the Cornell Lab of Ornithology became involved, and Project FeederWatch was launched. Cornell has a history of delivering mass-participation surveys through citizen science. From 1987 to 1988, more than 4,000 people enrolled, since when participation has grown to more than 20,000. Project FeederWatch continues to be a cooperative research project of the Cornell Lab of Ornithology and Bird Studies Canada (formerly the Long Point Bird Observatory).
FIG 118. The spread of the Collared Dove across North America is being charted through Project FeederWatch. (John Harding)
This winter-only project asks participants to keep a simple count of the number of individuals of each species that they see, the counts being made several times throughout the winter. Participants are asked to count a portion of their yard (garden) that is easy to observe, and make counts on two consecutive days – with at least five days between subsequent counts. As with BTO Garden BirdWatch, it is the maximum number of each species visible at any one time during the recording period that is noted, and again the target is birds using the garden and its resources rather than birds seen from the property or flying overhead. The project always starts on the second Saturday of November and runs for 21 weeks.
As is the case with BTO Garden BirdWatch, Project FeederWatch data can inform us of changes in species populations, particularly when used alongside data from other schemes and habitats. For example, Project FeederWatch data from Florida revealed that the winter population of the Painted Bunting Passerina ciris had declined steadily since the 1980s, prompting an examination of complementary data from the US Breeding Bird Survey (which itself suggested a decline of 4 per cent per year) and leading to systematic monitoring of bunting populations and a programme of conservation work. A wider comparison of Project FeederWatch data with those from the US Breeding Bird Survey found significant correlations between the average percentages of garden feeders visited during winter and Breeding Bird Survey indices across 13 US states for nine species (Wells et al., 1998). They have also been instrumental in revealing changes in the range of Northern Cardinal, Evening Grosbeak Coccothraustes vespertinus, Collared Dove and Anna’s Hummingbird (Greig et al., 2017), and for understanding the emergence and spread of mycoplasmal conjunctivitis in House Finch populations (see Chapter 4). Project FeederWatch has also been particularly useful in helping to recognise citizen science projects as a valuable research tool (Bonter & Cooper, 2012).
OTHER INTERNATIONAL GARDEN BIRD SURVEYS
Launched in 2007 and modelled on Big Garden BirdWatch, the New Zealand Garden Bird Survey operated by Manaaki Whenua Landcare Research currently involves c. 3,500 gardens annually, equivalent to 0.19 per cent of all New Zealand households. A one-hour count is made on one day within a week-long period within the New Zealand winter. BirdLife Australia and Birds in Backyards now operate the Aussie Backyard Bird Count, another single-session-based count, that takes place during late October. In this instance, the recording period is limited to a 20-minute session. Within France, a national garden bird survey is run by the Ligue pour la Protection des Oiseaux (LPO) and the Muséum National d’Histoire Naturelle. Participants are directed towards key periods: the last weekend of January (for wintering birds, and matching the UK’s Big Garden Birdwatch weekend) and the last weekend of May (for breeding birds).
SHORT-TERM CITIZEN SCIENCE PROJECTS
In addition to the ongoing schemes already mentioned, there have been a number of large-scale one-off or short-duration projects providing valuable information on garden birds and their ecology. The results from several of these studies have already had a central place in some of the other chapters of this book, most notably the BTO Garden Nesting Survey (Bland et al., 2004), the Shortest Day Survey (Ockendon et al., 2009a; 2009b), the BTO House Sparrow Survey (Shaw et al., 2011; Chamberlain et al., 2007c), the London Bird Project (Chamberlain et al., 2004b) and the Biodiversity in Urban Glasgow study (Humphreys et al., 2013). The networks of volunteers established through such schemes also provide opportunities to ask research questions whose answers may support ongoing pieces of research work. The study of what has driven the increase in wintering Blackcap populations within the UK (Plummer et al., 2015), for example, benefited from being able to go out at short notice and ask for additional information on the food preferences of this warbler. A central theme of all of these projects has been the willingness of garden owners to get involved in citizen science, something that underlines the place that garden birds play in many of our lives.
FIG 119. The BTO’s Garden Nesting Survey underlined that gardens make an important contribution to the breeding populations of species like Robin – here a juvenile. (Jill Pakenham)
CONCUDING REMARKS
The conservation value of gardens
It can be difficult to imagine that a small private space, with its neat borders and lawns, perhaps with a bird table, hanging feeders and nest boxes, has any conservation value. It may be even more difficult for the owner of that space to see how they can deliver conservation benefit through the decisions that they make about how it is managed and used. Yet each of our small private spaces does not exist in isolation; they are part of a wider landscape and – if viewed as a whole – represent an important resource for other creatures. This suggests that despite their ecological limitations, the conservation significance of private gardens is substantially greater than their absolute value in terms of habitat for birds. Gardens provide experiences and opportunities, from those that build connections with other creatures through to those that enable us to recognise and understand processes that shape our planet and its resources. Andrew Cannon captured these opportunities well in an opinion piece delivered through the journal Bird Conservation International, when he saw gardens as providing direct conservation value as habitats and havens, and indirect conservation value through engagement and empowerment (Cannon, 1999).
As we have seen from earlier sections within this book, UK gardens are important for several bird species, from Starlings and House Sparrows through to migrant Spotted Flycatchers and wintering Blackcaps. UK gardens may also provide a refuge for species whose populations have declined markedly within other habitats. In the arable areas of East Anglia, for example, gardens appear to be an important refuge for breeding thrushes; Mason (2000) found that although farmland occupied 67 per cent of his study area, it held significantly fewer Blackbird and Mistle Thrush territories than expected, with many more of the breeding territories of these two species located within urban areas and gardens than predicted. Importantly, Mason failed to find any evidence of Song Thrushes breeding within farmland, only locating breeding Song Thrushes within the urban areas, where they favoured areas of scrubby vegetation.
FIG 120. Gardens and the food resources they provided have almost certainly supported the range expansion seen in Nuthatch. (John Harding)
FIG 121. Rural gardens may well be providing farmland Tree Sparrows with a vital food resource during the difficult late winter period, something that may have helped to reduce the severity of their national decline. (Jill Pakenham)
The food provided at garden feeding stations is a significant resource and has the potential to support populations of birds that may be struggling to find natural foods in other habitats, but this may come at the cost of an increased risk of disease and carry-over effects, both into the breeding season and into subsequent generations. Garden nest boxes may provide alternative nesting opportunities for species whose favoured nesting cavities under roof tiles or behind barge boards have been lost to changing building regulations and the development of new materials for house construction. The birds nesting in these gardens may benefit from these new opportunities but some may struggle to find sufficient invertebrate prey for their chicks, something that might turn gardens into ecological traps. Alternatively, the birds nesting in our gardens may be less dominant individuals, unable to secure a nest site in a nearby piece of suitable wider countryside habitat; for these individuals, a garden nest box may be a choice worth making, perhaps leading to chicks that fledge successfully, perhaps helping them to gain experience that will provide them with better opportunities the following year.
This all suggests that while there is real conservation value in gardens for wild birds, there are also some challenges and it is essential that we should seek to understand what these are and what impact they might have in a wider context. We also need to recognise that lessons learned in one part of the world – or even one part of a city – may not necessarily translate elsewhere because of the variation seen in gardens and because of the complex interactions that exist between gardens and the landscapes within which they sit. Finally, we need to recognise that the European-style garden is very different from other, more common, forms of garden and that it is these latter forms of garden that may be most relevant in the context of urbanisation at a global scale. If gardens are to serve a role for engagement and empowerment, then we need to understand and tease out conservation messages that are relevant and correctly focussed for individual garden owners.
The future of gardens and birds
The world’s population is growing at a rate of nearly 1 per cent per annum and our larger cities are expanding at a rate even higher than population growth, particularly within important biodiversity hotspots (Seto et al., 2012). Such growth, and its associated expansion in urban landscapes, has profound consequences for biodiversity; this makes it all the more important to understand the role that private gardens and wider green space play in the ecology of our towns and cities. Not only will this enable us to understand how avian communities will change as land is converted from other land uses to a built environment, but it will also help us to plan our cities better, so that we can maintain as much avian biodiversity as is possible.
Recognising the role that access to nature and interactions with garden birds plays in human health and well-being is the first step towards building upon this knowledge to tackle the rising levels of anxiety, stress and depression being documented within our increasingly urbanised population. While gardens are private and personal spaces, they also have a wider societal role, often delivering benefits well beyond their boundaries. We must, however, recognise that not all of the interactions between householders and garden birds are necessarily positive. As we saw in Chapter 4, gardens present both risks and opportunities to wild birds, and not all birds respond in the same way to these different risks and opportunities; for example, finch trichomonosis has hit Greenfinch populations but not those of Goldfinch – why is this and what are its implications for the garden bird community? We also need to understand what a changing climate will mean for our garden birds: will we see more summer visitors staying to overwinter; will we see fewer winter visitors; will we receive new and exotic colonists? One thing is certain, we will need people’s love of garden birds to support the research that is needed; some of this support will be financial and some will also involve participation in citizen science schemes. We have been able to do a great deal and learn a significant amount since the feeding of garden birds became a popular pastime here in the UK. We need to ensure that we continue to support this interest through the provision of appropriate, evidence-based advice, using the knowledge that we gain from scientific study to support those who watch garden birds and, of course, the birds themselves.
FIG 122. The appearance of a rare visitor, such as this Wryneck Jynx torquilla, can be the highlight of any garden birdwatcher’s year. (Jill Pakenham)