Vulture Ecology and Conservation

This part looks at the relations between New and Old World Vultures and people; through the lens of vulture ecology and human culture, politics, history and varied scientific outlooks. The first important issue concerns vulture presence in human landscapes in urban settings, and how this new interaction affects vultures and people. Other cultures created by agricultural activities are also important. These have altered both the landscapes and the vulture human relationship. One current example of these new or transformed engagements has the been the diclofenac disaster that has greatly reduced vulture populations. These issues have been hinted in the preceding chapters.

Before delving into the details of these topics, there are important topics to be tackled in this introduction. These concern; rates of urbanisation and the meaning of urbanisation for avian foragers and the impacts of agricultural intensification and technological advancements not only on scavengers, but also on the predators and herbivores that provide them with food. The political structures that underpin actions to save vultures are also important. The future of vultures may be assessed in relation to these dynamics.

Urbanisation refers to both the increased number of people living in urban areas and the development of the infrastructure of settlement and commerce, such as roads, parking lots, buildings, railways, parks, rubbish dumps and commercial centers. Urbanization is increasing throughout the range of the New and Old World vultures. Avian, mostly scavenger colonization of urban areas has emerged as a vital field of enquiry, especially as heterogeneous urban landscapes attract varied species, urban waste provides for avian foraging and links are perceived between avian ecology, sanitation and human quality of life (Campbell 2006, 2007; Gbogbo and Awotwe-Pratt 2008).

Central business districts, industrial zones, parks, gardens, urban riverine areas and (mostly in developing tropical countries) open sewers, rubbish dumps and open abattoirs, are important avian foraging areas (Marzluff et al. 2001; Schochat et al. 2006). This habitat status is derived from the land cover configuration, general human behavior (recreational food stands, garbage disposal sites, food markets and abattoirs), individual human perception and reactions to birds in that particular context, and how these may vary in different levels of population density, food and cover availability, land cover heterogeneity and socio-cultural understanding (Campbell 2006, 2007).

An important issue concerns the changes in the human-vulture relationship in different land uses within the urban areas (Philo and Wilbert 2000). In particular, people's attitudes and reactions to birds and human socio-cultural relations, combine with land cover factors as factors for species presence. Few studies have examined the spatial variations in avian-human relations (especially those with large scavengers), avian adaptation, local attitudes to wildlife and socio-cultural relations in both urban and rural areas (Brooks and Thompson 2001).

Avian species numbers and density are much higher in the tropics than in temperate countries (Marzluff et al. 2001). Tropical cities in developing countries are often characterised by open food markets, large garbage disposal areas and in some cases poor sanitation that may facilitate avian colonisation (Mundy et al. 1992). Large, tropical avian scavengers are relatively understudied (Borrow and Demey 2001; Marzluff et al. 2001; Schochat et al. 2006). Due to 'the expected increase in human populations and urbanization in the tropics and the rich biodiversity that characterizes this region', 'more studies are desperately needed to inform public policy so that the negative consequences of human development are mitigated' (Marzluff et al. 2001: 1; also Schochat et al. 2006).

In tropical cities, vultures and corvids are dominant foraging guilds (Borrow and Demey 2001). Factors for this include their aerial mobility, attraction to refuse, large size and tolerance by people (Gbogbo and Awotwe-Pratt 2008). Human perceptions of large avian scavengers may be practical, based on their cleaning role, aggressive behavior, defecation and/ or food stealing (Soewu 2008). These perceptions may also be spiritual, the birds being associated with witchcraft, demons, spirits or bad luck omens (Adeola 1992; Soewu 2008). Perceptions of avian scavengers are important, as they influence human responses to avian presence in increasingly dense urban settings and have implications for conservation (Marzluff et al. 2001).

As noted in Chapter 3, Black Vultures in the United States have been identified as affecting human quality of life in urban areas. Human quality of life is a broad concept, related on multiculturalism, historical changes and environmental dynamics (Campbell 1998; Schalock et al. 2002). Definitions vary among scholars and lists of QOL indicators have been attempted (Felce and Perry 1995, 1996; Hughes and Hwang 1996; Cummins, 1997a, 1997b; Schalock 1997, 2000). Frequently cited aspects are: (a) emotional well-being, (b) interpersonal relationships, (c) material well-being, (d) personal development, (e) physical well-being, (f) self-determination, (g) social inclusion, and (h) rights (Schalock et al. 2002). These vary according to other social variables such as age, culture and social outlook (Elorriaga et al. 2000). Implicit in these definitions is idea that animals may both enhance and degrade QOL (Campbell 2007; 2008a,b; Schaltegger and Bestandig 2011). The relevant environmental variables in this case are shared physical spaces in urban areas (green spaces, car parks, river banks, beaches, airports, recreational facilities) and the biological actors (in this case scavengers).

In northern countries such as Canada, and northern Europe, Larus gulls and corvids are rare or the dominant urban avian scavengers, as vultures are absent. Some have considered these birds as affecting human quality of life, because of their large populations and invasive scavenging in densely populated urban areas (Campbell 2007, 2008, 2010; Ma et al. 2008). The principal foraging areas for these birds are green spaces, car parks, roads, waterfronts, riverbanks, beaches, eating places, transport spaces and suburban farms. These areas are used by people for recreation, feeding, transport, and social interaction, and by birds for feeding and sometimes nesting. Invasive behavior, including roof colonisation, nuisance scavenging, human life space intrusion, defecation, colonisation and obstruction of human communications and transport by birds are common problems (Campbell 2007; Camphuysen et al. 2011).

For Larus gulls, there are arguments for both increased bird presence (bird conservation and even more extreme preservation) and bird eradication. Waterbird conservation has pros and cons; visual biodiversity and wetland and coastal conservation are seen as beneficial for human emotional, physical and material well-being, and ecosystem health (Deluca et al. 2008; Jones and Kress 2012). Simultaneously, there is increasing recognition of the pest status of some waterbirds, especially gulls, which have serious impacts on human safety and well-being (Cooper 2002; Rock 2002; DeLuca et al. 2008; Douglas et al. 2010; Camphuysen et al. 2011).

Airline collisions are common; research on Bird-Aircraft Strike Hazard (BASH), is an extremely important aspect of avian and applied social studies (Mackinnon 1999; Gard et al. 2007; Campbell 2008, 2010; Camphuysen et al. 2011). The U.S. Federal Aviation Administration recorded 57,702 bird- aircraft collision reports within the United States between 1990 and 2004, with over $600 million damage (Gard et al. 2007). 'Large flocking birds and birds of large body size' are described as particularly susceptible to such collisions (United States Department of Agriculture 2003). Factors include bird migration patterns and bird attraction to the prey sources in the grassed areas near the airports (Gard et al. 2007).

Gulls have also been implicated in roof nesting, harassing maintenance personnel, and defecating on vehicles, blocking roof drain systems with feathers and excreta and causing chemical and structural damage to buildings (Belant 1997). They also contribute to human diseases through defecation and subsequent microbial colonization of the feces by bacteria (e.g., Bacillus, Clostridium, Campylobacter, Escherichia coli, Listeria and Salomonella bacteria), and general nuisance through noise and human harassment, food stealing, fouling of tables and park benches and frightening pedestrians (Belant 1997; Campbell 2010).

For vultures, there are similar problems. However, they are less researched, possibly because they are absent from most of the northern cities except those of the United States and to a lesser extent southern Canada (Borrow and Demey 2001; Marzluff et al. 2001; Schochat et al. 2006; Campbell 2009). In tropical cities, vultures and corvids are dominant foraging guilds (Borrow and Demey 2001; Gbogbo and Awotwe-Pratt 2008). The avian density in the tropics is much higher than in temperate countries (Marzluff et al. 2001). Tropical cities have more to offer bird scavengers; open food markets, large garbage disposal areas, poorer sanitation and faster rates of decomposition of organic discards (Mundy et al. 1992).

Due to 'the expected increase in human populations and urbanization in the tropics and the rich biodiversity that characterizes this region', 'more studies are desperately needed to inform public policy so that the negative consequences of human development are mitigated' (Marzluff et al. 2001: 1; also Schochat et al. 2006). People perceive vultures as cleaners, and also aggressive polluters or food thieves (Soewu 2008). There are also spiritual perceptions, connected to witchcraft, demons, spirits or bad luck omens (Adeola 1992; Soewu 2008). These perceptions have implications for conservation (Marzluff et al. 2001).

In rural areas, agriculture creates advantages and problems for vultures. It is a major factor for deforestation, savannisation and desertification, this enabling vulture foraging. As recorded in the earlier chapters, although some vultures are predominantly forest foragers (e.g., the Greater Yellowheaded Vulture) most vultures forage in open areas. Also, fires for land clearance may kill small wild animals for vulture consumption. Therefore, the savannaisation prevalent in many forested areas may not necessarily be negative for vultures (Mundy et al. 1992; Campbell 2009). Agriculture is negative for vultures if their predominant food source, large ungulates killed by predators, decline. In many cases, livestock rearing is good for vultures, especially if the vultures are permitted to eat the carcasses of dead domestic livestock.

Vulture relations with agricultural activities are particularly important, due to the recent catastrophic decline in vulture numbers in Asia and Africa. The drug Diclofenac, which kills vultures, has thrust vultures into the league of endangered animals and made vulture research a hot topic globally. The interactions between vultures and humans, as enabling or constraining vulture numbers or ecology is a socio-economic, political and ecological issue. This part of the book will address these issues in successive chapters. The final chapter will speculate on the future of vultures.