With our organization Taxon Expeditions, for example, Iva Njunjić and I take eco-tourists on expeditions into the unspoiled rainforest of Borneo, where we discover and name entirely new species of wildlife. But most people will never go into the jungle. All they will see of nature for most of their lives will be that neighborhood park, or those few plants and insects in their back garden. That’s why it is so important not to dismiss these bits of urban ecosystem as dreary and uninteresting. That’s why an awareness of the exciting evolutionary processes going on in cities is so crucial for the quality of urban life.
I hope that, by reading this book, your eyes have been opened to the wonders of HIREC, Human-Induced Rapid Evolutionary Change. One of my aims is that the urban organisms you see on your daily wanderings of the city streets will now become more special, more interesting, worthy of more than a casual glance. So when you see a flock of pigeons, you’ll look out for the ones with dark feathers and think to yourself, “Hey, those are the ones that can deal better with the zinc flaking off that lantern post over yonder.” That, when you see insects circling the fluorescent tube at a vending machine, you’ll imagine that it’s actually the ones genetically predisposed not to be drawn to that light that are the chosen ones for future urban insect life. That, when a blackbird crosses your path, you will realize that this species is your city’s answer to the Galápagos finch. And I hope that, over the years to come, there will be citizen science projects for you to observe evolution in action where you live. Or, better still, that you’ll start one of your own.
What will the future bring? At least in the short run, cities and urban populations will grow even further and we’ll claim an even bigger role in the world’s food web. Sometime in the twenty-first century, probably half of the energy that the ecosystems on earth produce will, directly or indirectly, pass through us. In ecology, a species with such a central role is termed a keystone species. Humans are a keystone species of unprecedented magnitude: we are a hyperkeystone, ecosystem-engineering supertramp species.
As you may remember from the ants and their myrmecophiles at the beginning of this book, powerful ecosystem engineers are like a magnet to other species. With such concentrations of food and resources, other species evolve to cohabit with them—for shelter and protection, to steal and pilfer from their hosts, or to trick them into giving them their scraps. Many go unnoticed, some are tolerated or even valued, and some prosecuted, but all evolve, adapt to a life shared with their willing or unwilling benefactors. Humans have been in this position for a much shorter duration than ants, and our anthropophiles are still only starting to evolve. But evolve they do, and further adapt they will.
Especially if we give them a helping hand. By observing, monitoring, and understanding urban evolution, we can design our urban environments in such a way that we may harness and steer this process. We can engineer our own ecosystem engineering. And we should do so in a constructive way, by applying Darwinian rules to urban greening—not in a destructive way by weeding out those species that actually hold the best cards for evolving into anthropophiles. Like the house crow.
Once again, I contact Sabine Rietkerk of the Save the House Crow committee. It has been nearly a year since I last was in touch with her, and things are not well in Hoek van Holland, she tells me in rapid, staccato Facebook messages. The hunters have returned and, in early spring, have managed to kill the last remaining birds. And that includes the one I saw sauntering across the street in the shopping center. “He lasted the longest,” Sabine writes. “He was always the one who was most alert, always calling, always warning the others of danger.” It is almost as if he threw in the towel when there was nobody left to warn.
So, the potential urban evolution of a North European version of the tropical Corvus splendens has been nipped in the bud. “Well … There’s still that rumor,” she writes. Which rumor? “That somewhere in the neighborhood, a few crows have gone into hiding in somebody’s home.” Is that true? I ask her. “That’s the neighborhood’s best kept secret,” she writes back.
And then, after a few seconds, Facebook messenger pings one more time: “;-).”
NOTES
CITY PORTAL
The descriptions of nature in inner city London was based on a visit to London June 21–24, 2016. The story of the London Underground mosquito was based on Shute (1951), Byrne & Nichols (1999), Fonseca et al. (2004) and Silver (2016), and on the presentation by Katharine Byrne at the European Society for Evolutionary Biology congress in 1995 in Edinburgh. The data on the history of urbanization are from Merritt & Newson (1978), Seto et al. (2012), Newitz (2013) and Reumer (2014). The recent study showing the increasing distance to the nearest forest is Yang & Mountrakis (2017). The amount of primary productivity that humans appropriate is from Imhoff et al. (2004) and Haberl et al. (2007), and the amount of freshwater consumed is from Postel et al. (1996). The opinion paper I mention is Huisman & Schilthuizen (2010). The area where I spent much of my childhood naturalist days in the late 1970s and early 1980s were the fields and swamps north and northwest of the village of Kethel, part of the municipality of Schiedam. Much of that area was converted to residential areas in the 1990s and the early twenty-first century.
CHAPTER 1: THE ULTIMATE ECOSYSTEM ENGINEER
The beetles I collected in Voorne are now part of the collection of Naturalis Biodiversity Center. The texts I used as the basis for the study of myrmecophily are Hölldobler & Wilson (1990) and Parker (2016). For the behavior of Claviger, I also used Cammaerts (1995, 1999). The great age of the Claviger–ant association and the total number of myrmecophiles are reported in Parker & Grimaldi (2014). The concept of ecosystem engineers is laid out in Jones et al. (1994). I obtained information on beavers as ecosystem engineers from Wright et al. (2002). The information on the Mannahatta Project comes from Reumer (2014), the project’s main website, http://welikia.org, and also from Paumgarten (2007), Miller (2009), Sanderson & Brown (2007), Bean & Sanderson (2008) and Eric Sanderson’s 2009 TED Talk (available via YouTube). Muhheakantuck is the original Lanape name for what today we call Hudson River.
CHAPTER 2: THE ANT(HROPO)-HILL
The trip to Maliau Basin Studies Center took place July 27–30, 2016. For more on this area and our work there, see www.taxonexpeditions.com. For the text about ecosystem engineering in hunter-gatherers, I used Marlowe (2005) and Smith (2007). The human trophic level is discussed in Bonhommeau et al. (2013). For the history of urbanization, I used Gross (2016), Reba et al. (2016), Newitz (2013), Misra (2015, 2016), The Data Team (2015) and Vance Kite’s TED animation at https://ed.ted.com/lessons/. The animation of Reba’s data can be viewed on https://youtu.be/yKJYXujJ7sU.
CHAPTER 3: DOWNTOWN ECOLOGY
The walk through Singapore with Chan Sow-Yan took place on August 2, 2016. I used the following sources. General urban ecology texts: McDonnell & MacGregor-Fors (2016) and Schmid (1978). General Singaporean urban ecology: Ward (1968), Lok & Lee (2009), Davison (2007) and Davison et al. (2008). On relicts of original habitat in Singapore: Brook et al. (2003), Clements et al. (2005) and Lok et al. (2013). On organisms from rocky habitats utilizing buildings and walls: Ward (1968), Sipman (2009) and Tan et al. (2014). On the Singapore urban heat island: Chow & Roth (2006) and Roth & Chow (2012). On pollutants in Singapore: Xu et al. (2011), Sin et al. (2016) and Rothwell & Lee (2010). Use of human food by urban fauna in Singapore: Soh et al. (2002). On the spread of exotic species in Singapore: Tan & Yeo (2009), Chong et al. (2012), Ng & Tan (2010) and Teo et al. (2011). The collapse of Singaporean food webs: Jeevanandam & Corlett (2013). The exotic species in the San Francisco Bay area are mentioned in Cohen & Carlton (1998); see also Schilthuizen (2008). For the theory of island biogeography, and the Bracknell roundabout study, see MacArthur & Wilson (1967), Helden & Leather (2004), and Schilthuizen (2008). The introduced millipede is reported for Singapore in Decker & Tertilt (2012). The entire text about Singapore was checked by Chan Sow-Yan and Tan Siong-Kiat.
CHAPT
ER 4: URBAN NATURALISTS
For the story on the Rotterdam house crows, I used Nyári et al. (2006), De Baerdemaeker & Klaassen (2012), Hendriks (2014) and Dooren (2016). My visits to the live and deceased parts of the Hoek van Holland house crow population took place on August 17, 2016, as did my visit to the permanent exhibition of the Rotterdam Natural History Museum. More on the red squirrels in Rotterdam can be found in Moeliker (2015). Kees Moeliker checked and corrected my text on the Rotterdam museum. The Mannahatta book is Sanderson (2009). Information on Herbert Sukopp is from Reumer (2014). Further notes on the growth of urban ecology as a field are from Schilthuizen (2016b). The growth of citizen science as a means of biodiversity discovery is highlighted in Nielsen (2012). The Malaise trap results from Leicester are in Owen (1978). An introduction to the railway triangle inventories by the KNNV in Rotterdam is in Werf (1982). BioBlitzes are treated in detail in Baker et al. (2014). More about the City Nature Challenge 2017 can be found at http://www.calacademy.org/citizen-science/city-nature-challenge, and on Belles de Bitume at https://www.frederique-soulard-contes.com/belles-de-bitume. The BioBlitz in Wellington that resulted in a new diatom is in Harper et al. (2009). The new frog and snail species discovered in New York and São Paulo are in Feinberg et al. (2014) and Martins & Simone (2014), respectively. The new subterranean water beetles from cities in Japan are described in Uéno (1995). The numbers of beetle species from the Amsterdamse Bos are in Nonnekens (1961, 1965), and the flora of Brussels is mentioned in Godefroid (2001). A meta-analysis of 105 rural-to-urban gradient studies is in McKinney (2008).
CHAPTER 5: CITY SLICKERS
The reference to Schouw (1823) is in Sukopp (2008). The “luxury effect” is described in Hope et al. (2003). I found information on why urban centers are located in pre-existing biodiversity hotspots in Secretariat of the Convention on Biological Diversity (2012). The study from the Czech Republic that I mention is in Chocholoušková & Pyšek (2003). Higher biodiversity because of a greater variety of (micro)habitats is reviewed in Kowarik (2011). For the paragraphs on large vertebrates, I used Vyas (2012), Hoh (2016), Bateman & Fleming (2012), Soniak (2014), Mahoney (2012), Gehrt (2007), Jones (2009), and Baggaley (2014). The quote by Gehrt was taken from Mahoney (2012). The homepage of the BUGS project of the University of Sheffield is at http://www.bugs.group.shef.ac.uk. Later, when other cities were also included, the project was renamed Biodiversity of Urban GardenS. Here, I mainly used the following papers resulting from this project: Gaston et al. (2005), Smith et al. (2006a, 2006b). Kevin Gaston proofread the section on the BUGS project. Results similar to those of the BUGS project were obtained for Bangalore (Jaganmohan et al., 2013) and Berlin (Zerke, 2003).
CHAPTER 6: IF I CAN MAKE IT THERE
The walk with Geerat Vermeij took place on June 17, 2014, whereas his quotes on pre-adaptation are from an email exchange with him in late September 2016. He also proofread and approved the text. Information on the house sparrow was taken from Anderson (2006). I used SOVON Vogelonderzoek Nederland (2012) for some details on natural and urban habitats of Dutch birds. Details on domestic arthropods are found in Bertone et al. (2016). The work on birds from Chilean cities is in Silva et al. (2016), and Carmen Paz and Olga Barbosa proofread this for me. The study on birds pre-adapted to human-generated noise is Francis et al. (2011), and Clint Francis proofread this section; I also used Woodsen (2011). The final paragraphs are based on Parker (2016), who also proofread this section for me.
CHAPTER 7: THESE ARE THE FACTS
The story on Albert Farn is based on Hart et al. (2010), Jenkinson (1922), Salmon et al. (2000), the website http://butterflyzoo.co.uk/farnfestival.html, and email correspondences with Adam Hart in June 2016, Stephen Sutton in June and October 2016, and Erik van Nieukerken in October 2016. The letter from Farn is under registration DCP-LETT-11747 at www.darwinproject.ac.uk (Darwin Correspondence Project, 2017). The section of this chapter on Farn was proofread by Adam Hart. Regarding Darwin’s assessment of the speed of evolution, Hooper (2002: 55), citing Mayr & Provine (1980), writes that Darwin’s son, Leonard Darwin, recalls that his father thought that it would take at least fifty generations for a change due to natural selection to be observable, suggesting that he could imagine evolution taking place within a human lifetime after all. For the various versions of On the Origin of Species, I consulted van Wyhe (2002). The online simulation of natural selection I did can be performed via http://www.radford.edu/~rsheehy/Gen_flash/popgen/.
CHAPTER 8: URBAN MYTHS
For the history of the peppered moth case, I used Cook (2003), Cook & Saccheri (2013), White (1877), Tutt (1896: 305–307), Haldane (1924), Cook et al. (1970, 1986, 2012), Kettlewell (1955, 1956), Coyne (1998), Hooper (2002), Van ‘t Hof et al. (2016), Rudge (2005), and Majerus (1998, 2009). The quote by Saccheri is from the Nature podcast at http://www.nature.com/nature/journal/v534/n7605/abs/nature17951.html. Laurence Cook read the whole chapter and helped me with some of the finer points.
CHAPTER 9: SO IT REALLY IS
The information on natural melanism in moths comes from Kettlewell (1973) and from email correspondence with Stephen Sutton on October 28, and November 3, 2016. Stephen Sutton also proofread those paragraphs. The biomechanics of bird wing shape is in Swaddle & Lockwood (2003). Wing shape evolution in starlings is based on Bitton & Graham (2015) and in cliff swallows on Brown & Bomberger-Brown (2013). Mary Bomberger-Brown read and corrected my text about the cliff swallow work. In an email to me of December 12, 2016, Pierre-Paul Bitton (who kindly checked my text about his work) expresses doubt that traffic, rather than pets, was behind the starling wing shape evolution. The work on Crepis sancta in Montpellier is described in Cheptou et al. (2008), while similar evolution on islands is in Cody & Overton (1996). Pierre-Olivier Cheptou kindly proofread my text about his work. My coverage of the work on rapid evolution in Caribbean Anolis is based on Losos et al. (1997), Marnocha et al. (2011), Tyler et al. (2016), and Winchell et al. (2016). As a source for Anolis biology in general, I used Losos (2009). Gingerich (1993) is the source for the rule-of-thumb calculation of the darwin unit. Kirstin Winchell read through my Anolis text and provided many useful comments.
CHAPTER 10: TOWN MOUSE, COUNTRY MOUSE
I viewed the ring-necked parakeets in Paris on December 15–17, 2016. The story that Jimi Hendrix released parakeets in London can be found in Brennan (2016). Human phylogeography is outlined in Harcourt (2016). The quotes by Ariane Le Gros are from email correspondence on December 14, 2016 and May 17, 2017. My sources for generalities on the species, including its invasion history and competition with nuthatches, are Strubbe & Matthysen (2009), Strubbe et al. (2010), Le Gros et al. (2016), the species page on the IUCN Red List (http://www.iucnredlist.org/details/22685441/0), its Wikipedia page https://en.wikipedia.org/wiki/Rose-ringed_parakeet, and the materials available via the homepage of ParrotNet (https://www.kent.ac.uk/parrotnet/). The relevant texts were read and approved by Ariane Le Gros. The information on bobcats comes from Serieys et al. (2015) and Riley et al. (2007), and the text was checked by Laurel Serieys. The information on global habitat fragmentation by roads is from Ibisch et al. (2016). My interview with Jason Munshi-South took place on December 10, 2016, and I also took some quotes from his TED-Ed lesson at http://ed.ted.com/lessons/evolution-in-a-big-city. His white-footed mouse publications that I used are: Munshi-South & Kharchenko (2010), Munshi-South & Nagy (2013), Harris & Munshi-South (2013, 2016) and Harris et al. (2016). Jason Munshi-South read and checked my text about his work. The spider work is in Schäfer et al. (2001). A recent article shows fragmentation and adaptation in lizards in city parks in Brisbane (Littleford-Colquhoun et al., 2017).
CHAPTER 11: POISONING PIGEONS IN THE PARK
The work on pollution-tolerant killifish is based on Whitehead et al. (2010, 2011, 2016) and Reid et al. (2016). I also used Kaplan (2016) and Carson (1962). The effects of PCBs and PAHs on AHR are based on the website of the Hahn lab at Woods Hole Oceanographic Institution (http://www.whoi.edu/sci
ence/B/people/mhahn/). Andrew Whitehead kindly proofread and corrected the section on the mummichog work; the quote at the end of this section is from an email of May 25, 2017. The section on de-icing salt is based on Coldsnow et al. (2017) and Houska (2016), whereas the principles of salt stress are from Mäser et al. (2002). Kayla Coldsnow kindly checked the paragraph I wrote about her work. Copper tolerance in monkey flowers is covered on pages 160–3 of my previous book, Frogs, Flies and Dandelions (Schilthuizen, 2001) and also in Wright et al. (2015). The zinc tolerance in grasses is from Al-Hiyali et al. (1990), and the work on melanic urban pigeons from Obhukova (2007) and Chatelain et al. (2014, 2016). Marion Chatelain proofread the section I wrote about her work.
CHAPTER 12: BRIGHT LIGHTS, BIG CITY
The attraction of birds by the 9/11 memorial lights was highlighted in a lecture by Kamiel Spoelstra in Haren, the Netherlands, on August 27, 2016. I also used the information on http://www.audubon.org/news/making-911-memorial-lights-bird-safe and https://www.sott.net/article/266370-Thousands-of-migrating-birds-attracted-to-9-11-memorial-lights. The quotes by Michael Ahern were taken from a video at https://www.youtube.com/watch?v=LKPkJ08CBdc. The information on Euro 2016 and Silver-Y migration is from www.uefa.com, Moeliker (2016) and Chapman et al. (2012, 2013). For general information on light pollution I used a discussion on ResearchGate entitled, “Is there any convincing explanation yet about why moths are attracted to artificial light,” Longcore & Rich (2004), Gaston et al. (2014) and a lecture by Kevin Gaston at Leiden University on June 30, 2016. Kevin Gaston also proofread part of this section. The anecdotal data on bird deaths due to light come from Guynup (2003) and those on insect deaths from Eisenbeis (2006). The example of birds killed at a lighthouse is from Jones & Francis (2003). A list of International Dark-Sky Parks is at http://darksky.org/idsp/parks/. The papers on adaptation to light in moths and spiders, respectively, are Altermatt & Ebert (2016) and Heiling (1999). I used information from an email correspondence with Florian Altermatt in February 2017, and he also proofread the text I wrote on his work.
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