For some of the wildlife of Belfast, particularly the red fox and hedgehog, it was difficult to compare the number of sightings recorded as a whole with current wildlife population trends of Northern Ireland. According to Burns (2013) conservationists know the least about the species trends of Northern Ireland than the rest of the UK. However Burns (2013) has stated that UK trends of certain species would be similar to that of Northern Ireland but deviations are still possible as it’s a separate island from the rest of the UK.
Focusing now on wildlife sightings recorded along the urban-rural gradient of Belfast. Integrating this ‘gradient paradigm’ allowed for spatial effects of urbanisation to be identified and analysed. Landuse change over space can dictate ‘structure and function of ecological systems’ including populations and the distribution of them (Donnell & Pickett, 1990). For some of the urban locations on the edges of the city, species abundance of red foxes and grey squirrels was higher than suburban locations situated near open or bare habitat. (Tables 3.2 and 3.3). According to Hermy and Claessens (2011) this type of distribution of wildlife is expected with more species found on the edges of the cities rather than in cultivated landscapes of the rural area. However this point did not hold true for the number bird species regarded as common. The surveyed rural areas had the highest number of bird species that are commonly sighted in either front or back gardens. (Tables 7.25-7.27). Other factors such as garden size influenced this kind of distribution. This is discussed below in Section 4.3.
This trend however does not apply to hedgehogs as the highest number of sightings were recorded in Millars Forge near cultivated land (Table 3.4 and Fig. 7.13 ). A national census for hedgehog population numbers in the UK has never been carried out and the reasons for their extensive decline since the 1950’s is relatively unknown. However, on-going surveys from 1996 have indicated a decrease in hedgehog abundance by several percent every year. The most probable reasons for their decline according to Wembridge (2011) include:
i) Impermeable boundaries of smaller and tidier gardens.
ii) Reduced connectivity between habitats therefore hedgehogs become isolated.
iii Development of buildings and roads that reduce the extent of urban habitats making hedgehogs more vulnerable to local extinction.
iv) Local extinction can be driven by heavy road traffic that kills thousands of hedgehogs every year.
v) Predation from badgers when coverage and foraging opportunities are limited in a shared habitat.
vi) The intensification of farming and removal of hedgerows in rural areas.
Residents of Sharman Park stated that badgers were sighted in their gardens or in the vicinity of the residential area in the last two and five years. This corresponded with the lack of hedgehog sightings in these areas with only one sighted in the last five years.
There is evidence of this trend stated by Hermy and Claessens (2011) in red fox and grey squirrel sightings in a number of survey locations on the outskirts of the city, that can be compared to locations that are situated closer to the rural area on the rural-urban fringe. The number of red foxes and grey squirrels sighted in Old Coach Avenue, Old Coach Road, Belvoir Dive, Kilwarlin Walk and Kilwarlin Crescent contrasted heavily with the sightings recorded from Laurelgrove Park (3.8 miles from Belfast city centre) and Millars Forge and the Comber Road (5.5 miles from Belfast city centre) (Tables 3.2 and 3.3). The cultivated land around these areas of large open fields with very little tree and hedge cover would influence this kind of species abundance. In Northern Ireland since the 1970’s the intensification of farming has dominated land use with 44% of land cover now characterised by enclosed farming with 70% of as improved grassland (Burns, 2013). The loss of diversity in Northern Ireland has been accelerated by this change in land use and the transition to intense monoculture.
Laurelgrove Park, Millars Forge and Comber Road are also adjacent main roads that could be a hindrance on the connectivity of wildlife to move between habitats. Old Coach Avenue/Road, Belvoir Dive and Kilwarlin Walk/Crescent are adjacent heavily forested areas (Figs. 7.7-7.13). This increased coverage of trees and hedges would be ideal shelter for wildlife while also providing an abundant food source of birds and insects for red foxes.
These areas are not situated adjacent main roads therefore connectivity is increased for the movement of wildlife with fewer implications.
The implications of a busy road on the movement of wildlife were significant in this study as recorded sightings corresponded to its proximity to surveyed locations. Bladon Park and Deramore Drive are adjacent an open field that is 198 x 77 m smaller than the field adjacent Laurelgrove Park and 300 x 80 m smaller than the fields adjacent Millars Forge/Comber Road. The field adjacent Bladon Drive and Deramore Drive is also subject to higher level of disturbances of sporting activities. Despite this, this area had 170 more fox sightings and 666 more grey squirrel sightings than Laurelgrove Park and 173 more fox sightings and 561 more grey squirrel sightings than Millars Forge and Comber Road. Bladon Drive and Deramore are not adjacent a main road therefore these results may reflect that connectivity is more efficient here. Jaarsma and Willems (2002) described the decreased landscape connectivity from the presence of roads as the ‘barrier effect’. Due to the implications of roads dividing habitats wildlife at times are prevented crossing roads, therefore these barriers are causing habitat fragmentation and separating populations.
Adams (1994) stated that ‘small bodied herbivores’ species are best adapted to the urban environment. In Belfast the distribution of grey squirrels was extensive with high densities adapted to residential areas where they are seen on a daily basis, more so in urban areas than rural areas. Evidently the red fox is also one of the most successful urban colonisers in Belfast and many other UK cities, with back gardens becoming an increasingly favourable habitat. The endless availability of food provided by humans in urban areas is the main driver for the high densities of red foxes and the movement of them from surrounding rural areas into cities (Unknown, 2015).
Species richness of surveyed areas of Belfast was generally higher in the urban locations than the surrounding countryside. In a previous study by Evans et al., (2011) that investigated the effects of urbanisation on species richness, found that where population density increased so did that of species richness. From an ecological perspective built up areas tend to be more ecologically significant than rural environments (Evans et al., 2011).
4.3) Wildlife sightings and garden boundary permeability.
As expected the rural area had the highest frequency of permeable boundaries with more than 70% of the boundaries here being of an permeable nature (Fig. 7.3). Fence type #127 was the most common here. It contained the largest gaps between the panels allowing for a higher rate of connectivity, particularly in the gardens of the Mealough Road and Ballycoan Road where most residents have recorded red fox or grey squirrel sightings. In relation to the proportion of surveyed properties, the rural area had the highest percentage of hedges as garden boundaries. The proportion of hedges to the number of surveyed properties increases with increasing distance from the city centre, from a built up environment to farmland. The primary reason for hedges in many rural areas is for the identification and separation of land between owners into manageable sized fields for farming (DOENI, 2016). These interconnected hedgerows provide corridors for the movement of wildlife between habitats enhancing connectivity, however they can have detrimental effects on species diversity. According to Betts (2015) limited hedgerows are often shared by predator and prey species, this can result in the decline of hedge/ground dwelling prey species if both species are occupying the same corridor for movement. These encounters may be one of the reasons for the continuing decline of the UK’s hedgehog population. 14% of surveyed rural properties recorded seeing a hedgehog in their garden in the last two and five years while 67% recorded seeing red foxes. There is high chance that these species are occupying the same hedgerows in this area of farmland were corridors are limited. As mentioned in section 1.5 the need for varying corridors for different target species is vital for their conservation.
Presented in Section 3.2 is the evidence for the positive correlations between boundary permeability, connectivity and wildlife sightings on a number of occasions. Laurelgrove Park had the least number of wildlife sightings out of all survey locations. This area has a higher percentage of impermeable boundaries with fence #111 being the most common type (Fig 7.2). However Sharman Park and Sharman Drive contained the highest percentage of impermeable boundaries of the suburban area but recorded more wildlife sightings than Laurelgrove Park. Factors contributing to these results is that wildlife do not need to cross a main road to get to the gardens of Sharman Park and Sharman Drive and adjacent these locations is the heavily vegetated Lagan Towpath. Figure 4.1 is an example of one of the gardens of Sharman Park which has a completely open boundary onto the Lagan Towpath.
The largest gardens of the urban area were within Adelaide Park and Wilmont Park (Figs. 4.2 and 4.3) and were the only locations with a higher percentage of permeable boundaries than any other urban survey location. This relationship positively correlated with all surveyed properties in these two locations recording both red fox and grey squirrel sightings in their gardens, something no other surveyed property of the urban area had experienced. Windsor Park had a higher percentage of impermeable boundaries than Adelaide Park shown in (Fig. 7.1) and the significant difference in the number of red fox sightings between these area correlated with this (Table 3.2).
Mealough Road and Ballycoan Road also ran parallel and were 168 m apart at the closest point and 481 m apart at the further point. The Ballycoan road had a significantly higher percentage of permeable boundaries (Fig. 3.26) and a greater number of squirrel sightings than the Mealough Road, despite the fact that a greater number of surveys were obtained from the Mealough Road (Table 3.4). The presence of more trees and hedges on the Ballycoan Road could have contributed to these figures (Table 7.2).
Hermy and Claessens (2011) also found evidence of a positive correlation between garden size and species diversity in five UK cities. They found that there was a relationship with housing type and garden size with detached houses (Like those of Wilmont Park) occupying the largest plot of land and terraced houses occupying the smallest. They stated that tree cover increased with garden size creating an area of greater habitat diversity. This was observed for Wilmont Park as more than a quarter of the land cover for each surveyed property of consisted of tree and hedge cover. This contrasted with the terraced houses of Belvoir Drive, Kilwarlin Walk and Kilwarlin Crescent where the average tree and hedge cover was only 9% (Table 7.2). These findings correlated with the difference in the number red fox sightings and the ratio of impermeable to permeable boundaries between these areas. Wilmont Park had a higher density of permeable boundaries that allowed for greater habitat connectivity for wildlife (Table 3.2 and Fig. 7.1).
This correlation was evident for the detached houses of the rural area which occupied relatively large gardens. With a garden size larger than most urban and suburban survey locations the highest number of bird species regarded as common visitors were recorded here, as mentioned in Section 4.2.
4.4. Tree and hedge cover, wildlife features and the presence of garden birds.
Sections 3.3 and 3.4 present evidence for the positive correlation between tree and hedge cover and the number of garden birds that are common visitors. In some cases bird features were an additional factor contributing to these results.
Clergeau et al., (2001) concluded that bird populations in urban areas are influenced by the vegetation structure rather than adjacent habitats. However in surveyed locations of Belfast the adjacent habitat was an influencing factor on species distribution. Both habitat size and tree and hedge coverage were significant and had a positive correlation with the number of common garden birds. For the properties of Belvoir Drive with garden boundaries that join onto Belvoir Park Forest, up to 11 out of 15 recorded bird species were common visitors. This contrasted with Laurelgrove Park and Millars Forge adjacent relatively unsheltered fields as only 6 out of 15 birds were common visitors. Habitat size and species diversity are discussed below in Section 4.6.
Bird feeders were the most common wildlife feature in the surveyed gardens of Belfast. Food availability is the main factor influencing the distribution of bird population with supplementary feeding adding to its effect. In urban areas where tree and hedge cover is limited due to development and habitat fragmentation, the presence of food is a primary driver for the structure of bird populations (Galbraith et al., 2015).
Evans et al,. (2011) concluded that local factors within urban areas such as habitat diversity and fragmentation were predominantly more important than factors of a bigger scale for species diversity. Forested areas and supplementary feeding positively correlated with bird populations as exhibited in Belvoir Drive and Adelaide Park of Belfast (Figs. 3.7 and 3.8).
As urbanisation increases many species of birds have been forced to adapt to developed areas and isolated habitats. For most urban locations the same bird species are regarded as common or occasional visitors with the most common being the robin and the magpie (Figs 7.3-7.13). These species have undergone the process of synanthropy whereby they have developed a relationship with humans in order to persist in predominately human environments (Unknown, 2015). Previous studies have found that magpie population numbers actually decrease along the urban-rural gradient (Unknown, 2015). However this was not evident for the city of Belfast as almost every surveyed resident along this gradient recorded magpies as common. Like red foxes magpies are generalist species which have a varied diet. They have successfully adapted to the urban jungle nesting and foraging in the residential gardens of Belfast.
There were some deviations in bird species that were considered rare or have never been seen between the three survey areas (Fig. 3.5). The bullfinch and common swift are currently Northern Ireland priority species therefore are expected to be rare. After an increase in Bullfinch numbers from 2000 to 2010 in Northern Ireland, the population was subject to a steep decline with the swift population declining by nearly 50% in the last 25 years. The main reason suspected for this is the intensification of farming that has reduced nesting habitat and natural food sources. However residential gardens are not listed as the Bullfinches’ preferred habitat therefore the chances of seeing them in private gardens may be low, regardless of current population numbers. Swifts are one of the last migrant visitors to arrive and they depart in late August (Allen & Mellon, 2011). This study was carried out in September after species of bird had migrated or fledged.
The house sparrow is also listed as a Northern Ireland priority species and is red listed due to steep population declines throughout the UK (Allen & Mellon, 2011). However in the surveyed areas of Belfast, a number of residents recorded this species as a common or occasional visitor (Fig. 7.3-7.27). In a garden bird watch survey conducted by The British Trust for Ornithology (BTO) in 2015, recorded the house sparrow as the third most commonly sighted bird in Northern Ireland (BTO, 2015).
In the rural areas of Belfast the Goldfinch and Greenfinch were rarely seen or not at all in September 2015. In the BTO garden bird watch survey they ranked 13th and 16th in the list of commonly sighted birds in Northern Ireland (BTO, 2015). An explanation for the lack of sightings in rural areas is that the preferred habitat for the goldfinch recorded by the BTO (2015) is urban and suburban areas with woodlands being most preferential for greenfinches rather than mixed farmland or pasture.
4.5. Flowering plant cover and the presence of insects.
Flowering plant cover and the presence of insects had relatively little significance with very few positive correlations. The highest number of positive correlations were in the suburban survey locations with each location consisting of every surveyed plant type. For four out of the six urban locations not all surveyed plant types were present. In literature suburban areas on the edges of cities have been described as being more biologically diverse than inner city locations. McKinney (2005) described suburban areas as richly cultivated with a high variety of fauna and flora species. Adapter species such as bees and butterflies that have been forced to inhabit developed areas, are often more abundant in suburban areas. These adapter species need a high abundance of plant species for food and shelter (McKinney, 2005) thus exhibiting why the suburban areas of Belfast were more positively correlated with the number of common insect species. This combined with the lower levels of urbanisation in suburban areas allowed the generalists nature of insects to colonise such areas with researchers stating that butterfly numbers peak in suburban areas (McKinney 2005). Similarly to Belfast a number of US cities contain higher floral diversity in suburban areas than anywhere else along the urban-rural gradient (Kowarik, 1995). A study conducted in Berlin also acquired similar findings with hotspots for diversity located on the edges of the city with suburban areas recognised as refuges for bees (Hermy & Claessens 2011). With large open areas of fields adjacent the suburban survey locations of Belfast, less impermeable surfaces are evident allowing for efficient habitat connectivity for insects to access the floristic diversity of these areas.
4.6 Wildlife sightings and species diversity with increasing distance from an area of habitat and the relationship between species diversity and habitat size.
The relationship between increasing distance from an area of habitat and species diversity is evident in Belfast with a number of positive correlations in urban and suburban areas. The number of mammal sightings, common birds and tree and hedge coverage decreased within increasing distance from an adjacent habitat. Where this was evident, with increasing distance from a habitat human disturbance, roads and impermeable surfaces generally increased. Wildlife in turn responded to these changes that prohibited them crossing roads, or moving to a garden habitat if connectivity was insufficient. Generally this occurred adjacent heavily forested areas where sheltering and foraging opportunities were greater, which lead to a high number of sightings and less movement for food and shelter further afield from the habitat. In Millars Forge hedgehog sightings decreased with increasing distance from the Comber Greenway. Here there is little tree cover but enough to accommodate the scale required by a hedgehog. Despite the increasing distance from fields adjacent Laurelgrove Park and Millars Forge, the number of common birds decreased to an extent before increasing again at surveyed properties situated furthest from these habitats. The influencing factor here is that these gardens contained a higher percentage of tree and hedge cover than gardens closer to the habitat. In other studies richness of bird species has been closely linked to increasing distance from a habitat as landscape features change and urbanisation becomes more apparent. Melles et al., (2003) focusing on 48 species of bird recorded that species richness declined along a gradient of increasing urbanisation. This similar correlation was evident for Bladon Drive and Deramore Drive of Belfast as the number of common garden birds particularly blackbirds, blue tits and great tits declined with increasing distance from Bladon Park (Figs. 7.19-7.21).
A positive correlation between habitat size and species diversity was evident between Belvoir Drive and Laurelgrove Park (Fig. 3.17 and 3.18). Fedele (2002) found that larger habitats (>1000m) followed a pattern of a steady increase in species diversity with little or no decline where as small scale habitats (>50m) experienced firstly an increase in species diversity before declining. Increasing habitat heterogeneity can cause some species to decline with butterflies being particularly susceptible. Tews et al., (2004) found that butterfly numbers actually increased with increased fragmentation and ‘patchiness’ of habitats. The fragmented network of gardens of Windsor park and those in Sharman Drive and Comber Road situated furthest from the large habitat area, recorded butterflies as common or occasional visitors that those situated closer to the habitat. Overall positive correlations between habitat size and heterogeneity of species was observed with evidence of wildlife communities depending on the physical structure habitats, particularly forested areas contrasted with unsheltered fields.
4.7 The number of participants who garden for wildlife, care, knowledge and awareness of wildlife in Northern Ireland and the socioeconomic factors associated with this
With increasing distance from the city centre, a higher percentage of properties in the suburban and rural areas contain wildlife gardens and are more species diverse in terms of vegetation structure (Section 3.6). The suburban area contains the highest number of wildlife friendly gardens, this coincides with the above statements in Section 4.5 of the suburban areas being more biologically diverse.
The reasons for the public deciding to garden for wildlife were diverse as well as the reasons for deciding not to. 15 participants added features to their gardens for sole purpose of attracting wildlife and observing it. According to Lerman and Warren (2011) sharing positive experiences with wildlife friendly gardening can counteract the effects of urbanisation, as the extensive networks of gardens are important for the ecological management of cities. In relation to wildlife resource index of the number of wildlife features present in gardens, Goddard et al., (2012) stated that the number of features increased with the education level and garden size. However, this was not case for the upper middle class and large gardens of Wilmont Park as only one feature was present here with residents stating they had insufficient time on their hands to purchase features or gardens were designed by landscape gardeners. This contrasted with the working class estates Belvoir Drive, Kilwarlin Walk and Kilwarlin Crescent where more wildlife features were present and the residents here in general cared more for the needs of wildlife and the work of wildlife organisations (Section 3.9.2).
On three occasions residents stated that the surveys reminded them of the importance of the needs of wildlife. Two of which admitted they weren’t doing enough for local wildlife and for the next breeding season they will add wildlife features, while another participant felt ‘it was necessary to build animal shelters’. It was evident that these surveys were promoting awareness of the needs of wildlife in Belfast.
A high level of care was exhibited by participants of Belfast but in relation to the number of people who put this level of care into action with wildlife gardening was insignificant. The drivers and barriers for wildlife gardening varied and on some occasions they differed spatially.
On numerous occasions participants stated that they didn’t want to add bird feeders in case they attracted rats, grey squirrels or magpies with one participant having squirrel proof feeders as a control method.
The majority of residents that weren’t adding wildlife features or have removed due to pest species was in the Old Coach Avenue/Road area. Despite red foxes regarded as pests one participant in the suburban area provided food for them. 22 participants added plants for the sole purpose attracting bees and butterflies to their gardens, two of which were bee keepers. Other main reasons for adding wildlife friendly plants were for the appearance and scent with six participants stating that certain vegetation was already there when they moved in.
On 11 occasions when participants stated they lacked caution for wildlife when carrying out activities in their garden, it positively correlated with them also not being aware of the bird breeding season.
One participant in particular raised awareness of the lack of government involvement in the protection of biodiversity on the ground and at a local level with another participant stating that they were unaware of the type of work of wildlife organisations.
”zg”ner and Kendle (2004) evaluated public attitudes towards nature in the town of Sheffield and their study concluded that urban residents are not responsive to natural landscapes but can find them valueless or fearful due to their unfamiliarity. The majority of urban gardens in Belfast are of a conformist nature with preference for scent and appearance for the vegetation structure. This aesthetic reasoning for wildlife gardens whereby appearance is a priority, can also be achieved in conjunction with ecological quality especially when corridors are established with neighbouring habitats to enhance connectivity. (Daniels & Kirkpatrick, 2006).
4.7 Evaluation of Data Collection Methods
Questions of garden surface types and how often bats were seen were not analysed as it was apparent that garden boundaries were more significant in the connectivity of wildlife which is one of the main themes of this study. Due to time constraints incorporating both surface and boundary types proved challenging. As for the omission of the bat results, it was difficult to establish relationships with these and other aspects of the study such as garden design. Lack of information and knowledge on the species and also the extensive amount of other species included in the study, consequently lead to the exclusion of bats, however their rarity was included in the appendix.
Questionnaire surveys were an appropriate method for data collection given the timescale of the project, however if more time was available other methods would have been implemented. Such as interviews with wildlife organisations of Northern Ireland on their efforts to engage with the public and raise awareness of biodiversity issues. This was attempted initially but due to the lack of responses and the already complex nature of the study, it did not follow through.
As for the timing of the surveys they were conducted in September after the bird breeding season when species of birds had already fledged or began migration. If this study were to be developed surveys would be carried out in Spring/Summer when species count would generally be higher.
Along the urban-rural gradient of Belfast there are variations in garden design, vegetation structure, wildlife sightings and connectivity in response to levels of urbanisation. It is evident that there were positive relationships between garden boundary types and the connectivity of wildlife with barrier effects such as roads and human disturbance having implications. On numerous occasions species diversity correlated with adjacent habitats both in proximity and size and the amount of tree and hedge cover.
In the city of Belfast red foxes and grey squirrels can be found at all points of the urban-rural gradient and in some areas in high densities, mainly near heavily forested habitats and large gardens. Boundary permeability and proximity to main roads were major factors in the connectivity of these species particularly the red foxes with the grey squirrels responding to various landscape factors. Very few correlations between landscape factors and garden structure where established with hedgehogs as compared to the other surveyed mammal species, very few sightings of hedgehogs were recorded. A number of common bird species responded to a range of factors from tree coverage, to the presence of features and proximity to a habitat. Insects responded to a range of landscape factors as there were very few specific correlations between sightings and flowering plant cover and their rarity was the same for all points of the urban-rural gradient.
With the continuing occurrence of urbanisation in Belfast the extensive networks of private gardens must be managed collectively as part of conservation efforts. The city council of Belfast recognises private gardens as an important component of an ecological network, that allow citizens to have positive experiences with wildlife. Ultimately this establishes a connection with nature in an environment where there are less interactions with it. With urbanisation encroaching onto rural areas, it is paramount that conservation efforts maintain the importance of the highly diverse suburban areas of Belfast which already are hotspots of biodiversity. It is evident from the results that opinions on the presence of wildlife in gardens varies among members of the public, but understanding the motivational drivers and barriers of wildlife gardening is key for wildlife organisations to implement the measures to enhance biodiversity from the doorsteps of the public. With the motivational drivers established, it is important now for relevant parties to raise awareness of the link between the aesthetic make-up of wildlife gardening as it was apparent that this was a popular driver for the choosing of plants. Many gardens of Belfast are off a conventional nature but promoting the aesthetic quality of wildlife friendly gardening will directly lead to ecological benefits for wildlife. In conjunction with this, the positive effects on human health and well-being through positive experiences with wildlife such as bird watching need to be brought to light, as again this was another popular reason for having features of a wildlife garden. This indirect approach of enhancing biodiversity by promoting the benefits of wildlife gardening for the public, will ultimately lead to benefits for wildlife.
Previous literature has suggested that there are socioeconomic factors influencing garden design such as education level and social class. When these were incorporated into this study, they did not correlate with garden designs or the level of care for the work of wildlife organisations. However, socioeconomic factors positively correlated with species diversity and vegetation structure of large detached houses that occupied a larger plot of land. These large gardens have the potential to inhabit a variety of wildlife and become hotspots for conserving biodiversity if managed correctly. These areas should also be a main focus for wildlife organisations and the council to expand their efforts of raising awareness of promoting biodiversity in private gardens.
5.1 Recommendations for Future Research
This study could be developed further with an emphasis on hedgehogs, as data on their distribution and interactions with the environment was limited. Involvement with community groups such as horticulture and bird watching groups could allow for access to data on species diversity while further raising awareness of the needs of biodiversity in Belfast.
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