11. Endre Grastyn and Lajos Vereczkei, "Effects of Spatial Separation of the Conditioned Signal from the Reinforcement: A Demonstration of the Conditioned Character of the Orienting Response or the Orientational Character of Conditioning," Behavioral Biology 10 (1974): 12146.

12. dam Miklsi, Peter Pongrcz, Gabriella Lakatos, Jzsef Topl, and Vilmos Csnyi, "A Comparative Study of the Use of Visual Communicative Signals in Interactions Between Dogs (Canis familiaris) and Humans and Cats (Felis catus) and Humans," Journal of Comparative Psychology 119 (2005): 17986; available online at www.mtapi.hu/userdirs/26/Publikaciok_Topal/Miklosietal2005JCP.pdf.

13. Nicholas Nicastro and Michael J. Owren, "Cla.s.sification of Domestic Cat (Felis catus) Vocalizations by Naive and Experienced Human Listeners," Journal of Comparative Psychology 117 (2003): 4452.

14. Edward L. Thorndike, Animal Intelligence: An Experimental Study of the a.s.sociative Processes in Animals, Chapter 2 (New York: Columbia University Press, 1898); available online at tinyurl.com/c4bl6do.

15. Emma Whitt, Marie Douglas, Britta Osthaus, and Ian Hocking, "Domestic Cats (Felis catus) Do Not Show Causal Understanding in a String-pulling Task," Animal Cognition 12 (2009): 73943. The same scientists had earlier shown that the crossed-strings arrangement defeats most dogs, even those which, unlike the cats, had earlier successfully solved the parallel-strings problem-thus, dogs' understanding of physics seems to be better than cats'.

16. Claude Dumas, "Object Permanence in Cats (Felis catus): An Ecological Approach to the Study of Invisible Displacements," Journal of Comparative Psychology 106 (1992): 40410; Dumas, "Flexible Search Behavior in Domestic Cats (Felis catus): A Case Study of Predator-Prey Interaction," Journal of Comparative Psychology 114 (2000): 23238.

17. For other works by this cartoonist, visit www.stevenappleby.com.

18. George S. Romanes, Animal Intelligence (New York: D. Appleton & Co., 1886); available online at www.gutenberg.org/files/40459/40459-h/40459-h.htm.

19. C. Lloyd Morgan, An Introduction to Comparative Psychology (New York: Scribner, 1896); available online at tinyurl.com/crehpj9.

20. Paul H. Morris, Christine Doe, and Emma G.o.dsell, "Secondary Emotions in Non-primate Species? Behavioural Reports and Subjective Claims by Animal Owners," Cognition and Emotion 22 (2008): 320.

21. More detail of the causes of such problematic behavior can be found in chapters 11 and 12 of my book, The Behaviour of the Domestic Cat, 2nd ed., coauth.o.r.ed with Rachel Casey and Sarah Brown (Wallingford, UK: CAB International, 2012).

22. Anne Seawright et al., "A Case of Recurrent Feline Idiopathic Cyst.i.tis: The Control of Clinical Signs with Behavior Therapy," Journal of Veterinary Behavior: Clinical Applications and Research 3 (2008): 3238. For background information on feline cyst.i.tis, see the Feline Advisory Bureau's website, www.fabcats.org/owners/flutd/info.html.

23. Alexandra Horowitz, a professor of cognitive psychology at New York's Barnard College, performed this study. See her paper "Disambiguating the 'Guilty Look': Salient Prompts to a Familiar Dog Behaviour" in Behavioural Processes 81 (2009): 44752, and her book Inside of a Dog: What Dogs See, Smell, and Know (New York: Scribner, 2009).

Chapter 7.

1. "The Curious Cat," filmed for the BBC's The World About Us series (1979). A delightful account of the making of this film is included in its companion volume of the same t.i.tle, written by Michael Allaby and Peter Crawford (London: M. Joseph, 1982). Similar studies were being conducted at roughly the same time by Jane Dards in Portsmouth dockyard (UK), Olof Liberg in Sweden, and Masako Izawa in j.a.pan.

2. Strictly speaking, the term "gene" refers to a single location on a particular chromosome, and the competing versions of the same gene are alleles; one example already discussed is the blotched and striped alleles of the "tabby" gene.

3. This is likely true even though we know little about how such genes might work, since almost all cooperation between animals occurs between members of the same family. Genes code for proteins, and it is difficult to imagine a protein that could promote family loyalty as such. Rather, many genes must be involved, each contributing a small piece to the whole: for example, one might reduce the threshold for aggression toward other cats in general, while another enables the recognition of odors characteristic of family members, through changes in the accessory olfactory bulb, the part of the brain that processes information coming from the vomeronasal organ.

4. Christopher N. Johnson, Joanne L. Isaac, and Diana O. Fisher, "Rarity of a Top Predator Triggers Continent-wide Collapse of Mammal Prey: Dingoes and Marsupials in Australia," Proceedings of the Royal Society B 274 (2007): 34146.

5. Dominique Pontier and Eugenia Natoli, "Infanticide in Rural Male Cats (Felis catus L.) as a Reproductive Mating Tactic," Aggressive Behavior 25 (1999): 44549.

6. Phyllis Chesler, "Maternal Influence in Learning by Observation in Kittens," Science 166 (1969): 90103.

7. Marvin J. Herbert and Charles M. Harsh, "Observational Learning by Cats," Journal of Comparative Psychology 31 (1944): 8195.

8. Transcribed from the original letter in the British Museum (Natural History) collections.

9. These studies were mainly conducted by my colleagues Sarah Brown and Charlotte Cameron Beaumont. For more detail, see chapter 8 of my book, The Behaviour of the Domestic Cat, 2nd ed., coauth.o.r.ed by Rachel Casey and Sarah Brown (Wallingford, UK: CAB International, 2012).

10. This silhouette trick fooled most cats only once; the second one they came across elicited almost no reaction at all.

11. Researchers think that the retention of juvenile characteristics into adulthood, referred to as neoteny, was a major factor in the domestication of many animals, especially the dog. For example, at first sight the skull of a Pekinese is nothing like that of its ancestor the wolf, but in fact it is roughly the same shape as the skull of a wolf fetus. Although the domestic cat's body has not been neotenized, some of its behavior may have been, including the upright tail and some other social signals.

12. A fuller account of the evolution of signaling in the cat family can be found in John W. S. Bradshaw and Charlotte Cameron-Beaumont, "The Signalling Repertoire of the Domestic Cat and Its Undomesticated Relatives," in Dennis Turner and Patrick Bateson, eds., The Domestic Cat: The Biology of Its Behaviour, 2nd ed. (Cambridge: Cambridge: Cambridge University Press, 2000), 6793.

13. Christina D. Buesching, Pavel Stopka, and David W. Macdonald, "The Social Function of Allo-marking in the European Badger (Meles meles)," Behaviour 140 (2003): 96580.

14. Terry Marie Curtis, Rebecca Knowles, and Sharon Crowell-Davis, "Influence of Familiarity and Relatedness on Proximity and Allogrooming in Domestic Cats (Felis catus)," American Journal of Veterinary Research 64 (2003): 115154. See also Ruud van den Bos, "The Function of Allogrooming in Domestic Cats (Felis silvestris catus): A Study in a Group of Cats Living in Confinement," Journal of Ethology 16 (1998): 113.

15. See my book Dog Sense: How the New Science of Dog Behavior Can Make You a Better Friend to Your Pet (New York: Basic Books, 2011).

16. Feral dogs, the direct descendants of wolves, show little of their ancestors' social sophistication. Although groups of males and females band together to form packs that share common territory, all the adult females attempt to breed, and most of the puppies are cared for only by their mother-although occasionally, two litters may be pooled, and some records show fathers bringing food to their litters.

17. One well-researched instance of explosive speciation is the cichlid fish of Lake Victoria, which despite now being the world's largest tropical lake was dry land only 15,000 years ago. Today it contains many hundreds of cichlid species, none of which are found in any of the other African great lakes, and most of which have evolved in the 14,000 years since the lake last filled with water. See, for example, Walter Salzburger, Tanja Mack, Erik Verheyen, and Axel Meyer, "Out of Tanganyika: Genesis, Explosive Speciation, Key-innovations and Phylogeography of the Haplochromine Cichlid Fishes," BMC Evolutionary Biology 5 (2005): 17.

18. Kipling, Just So Stories for Little Children (New York: Doubleday, Page & Co., 1902); available online at www.boop.org/jan/justso/cat.htm.

19. Our noses are particularly sensitive to thiols: minute traces are added to natural gas, which in itself is completely odorless, to make it easier to detect leaks.

20. Ludovic Say and Dominique Pontier, "s.p.a.cing Pattern in a Social Group of Stray Cats: Effects on Male Reproductive Success," Animal Behaviour 68 (2004): 17580.

21. See, for example, the policies of Cats Protection, which is as of 2011 "the largest single cat neutering group in the world": www.cats.org.uk/what-we-do/neutering/.

Chapter 8.

1. Gary D. Sherman, Jonathan Haidt, and James A. Coan, "Viewing Cute Images Increases Behavioral Carefulness," Emotion 9 (2009): 28286; available online at tinyurl.com/bxqg2u6.

2. Robert A. Hinde and Les A. Barden, "The Evolution of the Teddy Bear," Animal Behaviour 33 (1985): 137173.

3. See www.wwf.org.uk/how_you_can_help/the_panda_made_me_do_it/.

4. Kathy Carlstead, Janine L. Brown, Steven L. Monfort, Richard Killens, and David E. Wildt, "Urinary Monitoring of Adrenal Responses to Psychological Stressors in Domestic and Nondomestic Felids," Zoo Biology 11 (1992): 16576.

5. Susan Soennichsen and Arnold S. Chamove, "Responses of Cats to Petting by Humans," Anthrozos: A Multidisciplinary Journal of the Interactions of People & Animals 15 (2002): 25865.

6. Karen McComb, Anna M. Taylor, Christian Wilson, and Benjamin D. Charlton, "The Cry Embedded within the Purr," Current Biology 19 (2009): R50708.

7. Henry W. Fisher, Abroad with Mark Twain and Eugene Field: Tales They Told to a Fellow Correspondent (New York: Nicolas L. Brown, 1922), 102. It's worth noting the end of the quotation as well: " . . . outside of the girl you love, of course."

8. Some manufacturers add salt to dry cat food, but not for its taste: it's mainly there to stimulate cats to drink, thereby minimizing their risk of developing bladder stones.

9. The late Penny Bernstein conducted a detailed study of stroking, details of which sadly remained unpublished when she died in 2012. For a summary, see Tracy Vogel's "Petting Your Cat-Something to Purr About" at www.pets.ca/cats/articles/petting-a-cat/, and Bernstein's own review, "The Human-Cat Relationship," in The Welfare of Cats, ed. Irene Rochlitz (Dordrecht, the Netherlands: Springer, 2005), 4789.

10. Soennichsen and Chamove, "Responses of Cats," note 5.

11. Mary Louise Howden, "Mark Twain as His Secretary at Stormfield Remembers Him: Anecdotes of the Author Untold until Now," New York Herald, December 13, 1925, 14; available online at www.twainquotes.com/howden.html.

12. Sarah Lowe and John W. S. Bradshaw, "Ontogeny of Individuality in the Domestic Cat in the Home Environment," Animal Behaviour 61 (2001): 23137.

13. To hear two Bengal cats yowling and chirruping to each other, go to tinyurl.com/crb5ycj. The noise that many cats make when they see birds through a window is sometimes referred to as "chirping," but is more correctly "chattering"; see tinyurl.com/cny83rd.

14. Mildred Moelk, "Vocalizing in the House-cat: A Phonetic and Functional Study," American Journal of Psychology 57 (1944): 184205.

15. Nicholas Nicastro, "Perceptual and Acoustic Evidence for Species-level Differences in Meow Vocalizations by Domestic Cats (Felis catus) and African Wild Cats (Felis silvestris lybica)," Journal of Comparative Psychology 118 (2004): 28796. When this paper was published, it was common practice to refer to all African wildcats as lybica; however, these southern African wildcats, now known as cafra, are not particularly closely related to domestic cats, having diverged from the Middle-Eastern/North-African lybica more than 150,000 years ago.

16. Nicholas Nicastro and Michael J. Owren, "Cla.s.sification of Domestic Cat (Felis catus) Vocalizations by Naive and Experienced Human Listeners," Journal of Comparative Psychology 117 (2003): 4452.

17. Dennis C. Turner, "The Ethology of the Human-Cat Relationship," Swiss Archive for Veterinary Medicine 133 (1991): 6370.

18. Desmond Morris, Cat.w.a.tching: Why Cats Purr and Other Feline Mysteries Explained (New York: Three Rivers Press, 1993).

19. Of course, many cats do groom their owners, but cats also groom other adult cats.

20. Maggie Lilith, Michael Calver, and Mark Garkaklis, "Roaming Habits of Pet Cats on the Suburban Fringe in Perth, Western Australia: What Size Buffer Zone Is Needed to Protect Wildlife in Reserves?" in Daniel Lunney, Adam Munn, and Will Meikle, eds., Too Close for Comfort: Contentious Issues in Human-Wildlife Encounters (Mosman, NSW, Australia: Royal Zoological Society of New South Wales, 2008), 6572. See also Roland W. Kays and Amielle A. DeWan, "Ecological Impact of Inside/Outside House Cats around a Suburban Nature Preserve," Animal Conservation 7 (2004): 27383; available online at www.nysm.nysed.gov/staffpubs/docs/15128.pdf.

21. The transmitter and its battery could be carried by a bird the size of a thrush, so it was extremely light. These radio collars emit "beeps" every few seconds that are picked up on a portable antenna and receiver; the aerial is directional, producing the strongest signal when pointed directly at the animal. When used for tracking wildlife, the operator keeps at a distance once a reasonably strong signal has been picked up, to avoid disturbing the animal, taking several recordings from different angles to map the animal's exact location. With a pet cat, it's easier to simply walk toward the radio source until the cat is sighted.

22. This feline unfaithfulness was exposed by the University of Georgia's Kitty Cam project: fifty-five cats in Athens, Georgia wore lightweight video recorders, revealing that four often visited second households where they received food and/or affection. See the website for The National Geographic & University of Georgia Kitty Cams (Crittercam) Project: A Window into the World of Free-roaming Cats (2011), www.kittycams.uga.edu/research.html.

23. Adapted from material provided by Rachel Casey. See John W. S. Bradshaw, Rachel Casey, and Sarah Brown, The Behaviour of the Domestic Cat, 2nd ed. (Wallingford, UK: CAB International, 2012), chapter 11.

24. Ibid.

25. Ronald R. Swaisgood and David J. Shepherdson, "Scientific Approaches to Enrichment and Stereotypes in Zoo Animals: What's Been Done and Where Should We Go Next?" Zoo Biology 24 (2005): 499518.

26. Marianne Hartmann-Furter, "A Species-Specific Feeding Technique Designed for European Wildcats (Felis s. silvestris) in Captivity," Sugetierkundliche Informationen 4 (2000): 56775.

27. Adapted from the RSPCA webpage "Keeping Cats Indoors" (2013), www.rspca.org.uk/allaboutanimals/pets/cats/environment/indoors.

28. See Cat Behavior a.s.sociates, The Benefits of Using Puzzle Feeders for Cats (2013), www.catbehaviora.s.sociates.com/the-benefits-of-using-puzzle-feeders-for-cats/.

Chapter 9.

1. Monika Lipinski et al., "The Ascent of Cat Breeds: Genetic Evaluations of Breeds and Worldwide Random-bred Populations," Genomics 91 (2008): 1221.

2. See www.gccfcats.org/breeds/oci.html.

3. Bjarne O. Braastad, I. Westbye, and Morten Bakken, "Frequencies of Behaviour Problems and Heritability of Behaviour Traits in Breeds of Domestic Cat," in Knut Be, Morten Bakken, and Bjarne Braastad, eds., Proceedings of the 33rd International Congress of the International Society for Applied Ethology, Lillehammer, Norway (s: Agricultural University of Norway, 1999), 85.

4. Paola Marchei et al., "Breed Differences in Behavioural Response to Challenging Situations in Kittens," Physiology & Behavior 102 (2011): 27684.

5. See chapter 11 of my book Dog Sense (New York: Basic Books, 2011).

6. Obviously, the mother cat makes genetic contributions to the kittens as well, but she can also influence the development of her kittens' personalities through the way she raises them. Thus, the effects of maternal genetics, while undoubtedly as strong as those of the father, are harder to pin down.

7. For a more detailed discussion, see Sarah Hartwell, "Is Coat Colour Linked to Temperament?" (2001), www.messybeast.com/colour-tempment.htm.

8. Michael Mendl and Robert Harcourt, "Individuality in the Domestic Cat: Origins, Development and Stability," in The Domestic Cat, 4764.

9. Rebecca Ledger and Valerie O'Farrell, "Factors Influencing the Reactions of Cats to Humans and Novel Objects," in Ian Duncan, Tina Widowski, and Derek Haley, eds., Proceedings of the 30th International Congress of the International Society for Applied Ethology (Guelph: Col. K. L. Campbell Centre for the Study of Animal Welfare, 1996), 112.

10. Caroline Geigy, Silvia Heid, Frank Steffen, Kristen Danielson, Andre Jaggy, and Claude Gaillard, "Does a Pleiotropic Gene Explain Deafness and Blue Irises in White Cats?" The Veterinary Journal 173 (2007): 54853.

11. John W. S. Bradshaw and Sarah Cook, "Patterns of Pet Cat Behaviour at Feeding Occasions," Applied Animal Behaviour Science 47 (1996): 6174.

12. For a review, see Michael Mendl and Robert Harcourt, note 8.

13. Sandra McCune, "The Impact of Paternity and Early Socialisation on the Development of Cats' Behaviour to People and Novel Objects," Applied Animal Behaviour Science 45 (1995): 10924.

14. Sarah E. Lowe and John W. S. Bradshaw, "Responses of Pet Cats to Being Held by an Unfamiliar Person, from Weaning to Three Years of Age," Anthrozos 15 (2002): 6979.

15. The technical term for an inveterate cat-hater is an ailurophobe. I carried out my research here with the a.s.sistance of a former colleague, Dr. Deborah Goodwin.

16. Kurt Kotrschal, Jon Day, and Manuela Wedl, "Human and Cat Personalities: Putting Them Together," in Dennis C. Turner and Patrick Bateson, eds., The Domestic Cat: The Biology of Its Behaviour, 3rd ed. (Cambridge: Cambridge University Press, 2014).

17. Jill Mellen, "Effects of Early Rearing Experience on Subsequent Adult s.e.xual Behavior Using Domestic Cats (Felis catus) as a Model for Exotic Small Felids," Zoo Biology 11 (1992): 1732.

18. Nigel Langham, "Feral Cats (Felis catus L.) on New Zealand Farmland. II. Seasonal Activity," Wildlife Research 19 (1992): 70720.

19. Julie Feaver, Michael Mendl, and Patrick Bateson, "A Method for Rating the Individual Distinctiveness of Domestic Cats," Animal Behaviour 34 (1986): 101625.

20. See Patrick Bateson, "Behavioural Development in the Cat," in Turner and Bateson, eds., The Domestic Cat, 2nd ed., 922.

Chapter 10.

1. Michael C. Calver, Jacky Grayson, Maggie Lilith, and Christopher R. d.i.c.kman, "Applying the Precautionary Principle to the Issue of Impacts by Pet Cats on Urban Wildlife," Biological Conservation 144 (2011): 1895901.

2. Michael Woods, Robbie Mcdonald, and Stephen Harris, "Predation of Wildlife by Domestic Cats Felis catus in Great Britain," Mammal Review 33 (2003): 17488; available online at tinyurl.com/ah6552e. This paper does not note that the survey was largely completed by children, nor does it provide any information about the format of the questionnaire used.