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Vol. 81, No. 2, 2010
Issue release date: August 2010
Section title: Original Article
Editor's Choice -- Free Access
Folia Primatol 2010;81:86–95
(DOI:10.1159/000314948)

Predation and Predation Attempts on Red Titi Monkeys (Callicebus discolor) and Equatorial Sakis (Pithecia aequatorialis) in Amazonian Ecuador

de Luna A.G.a · Sanmiguel R.b · Di Fiore A.a, c · Fernandez-Duque E.d, e
aProyecto Primates, bTiputini Biodiversity Station, and cCenter for the Study of Human Origins, Department of Anthropology, New York University and New York Consortium in Evolutionary Primatology (NYCEP), New York, N.Y., and dDepartment of Anthropology, University of Pennsylvania, Philadelphia, Pa., USA; eCentro de Ecología Aplicada del Litoral (CONICET), Buenos Aires, Argentina
email Corresponding Author

Abstract

Anecdotal reports of predation as well as observed predation attempts and rates of animal disappearance provide some of the most relevant data for evaluating the influence that predation risk may have on primate behavioural ecology. Here, we report rates of disappearance from six groups of red titi monkeys (Callicebus discolor) and two groups of equatorial sakis (Pithecia aequatorialis) followed over a period of four and a half years at a lowland site in Amazonian Ecuador. We also describe the first direct observation of a harpy eagle (Harpia harpyja) preying upon a titi monkey, as well as 3 unsuccessful attacks by tayras (Eira barbara) on titi monkeys and 4 unsuccessful attacks by various raptors on sakis. Our data indicate that pitheciid primates may face a wider array of possible predators than previously recognized, and that titi monkeys and sakis are susceptible to different major classes of predators. Our observations also suggest differences in the sex role during predator defence that could be related to the evolution and maintenance of monogamous systems.

© 2010 S. Karger AG, Basel


  

Key Words

  • Predation
  • Harpia harpyja
  • Callicebus discolor
  • Pithecia aequatorialis
  • Antipredator behaviour
  • Amazonia

References

  1. Anderson CM (1986). Predation and primate evolution. Primates 27: 15–39.
  2. Arlet ME, Isbell LA (2009). Variation in behavioral and hormonal responses of adult male gray-cheeked mangabey (Lophocebus albigena) to crowned eagles (Stephanoaetus coronatus) in Kibale National Park, Uganda. Behavioral Ecology and Sociobiology 63: 491–199. See http://anthropology.ucdavis.edu/people/lynne-a.-isbell-1/pdf/Arlet%20and%20Isbell%20BES%202009.pdf
  3. Bezerra BM, Barnett AA, Souto A, Jones G (2009). Predation by the tayra on the common marmoset and the pale-throated three-toed sloth. Journal of Ethology 27: 91–96.
  4. Bianchi RC (2001). Estudo comparativo da dieta da jaguatirica, Leopardus pardalis (Linnaeus, 1758), em Mata Atlântica. Disseration, Universidade Federal do Espírito Santo, Vitória.
  5. Bianchi RDC, Mendes SL (2007). Ocelot (Leopardus pardalis) predation on primates in Caratinga Biological Station, Southeast Brazil. American Journal of Primatology 69: 1173–1178.
  6. Blake JG (2007). Neotropical forest bird communities: a comparison of species richness and composition at local and regional scales. The Condor 109: 237–255.
  7. Boinski S, Chapman C (1995). Predation on primates: Where are we and what’s next? Evolutionary Anthropology 4: 1–3.
  8. Bossuyt F (2002). Natal dispersal of titi monkeys (Callicebus moloch) at Cocha Cashu, Manu National Park, Peru. American Journal of Physical Anthropology 34: 47.
  9. Carrillo-Bilbao G, Di Fiore A, Fernandez-Duque E (2005). Dieta, forrajeo y presupuesto de tiempo en cotoncillos (Callicebus discolor) del Parque Nacional Yasuní en la Amazonia Ecuatoriana. Neotropical Primates 13: 7–11.
  10. Cheney D, Wrangham RW (1987). Predation. In Primate Societies (Smuts BB, Cheney DL, Seyfarth RM, Struhsaker TT, eds.), pp 227–239. Chicago, University of Chicago Press.
  11. Cisneros-Heredia D, Leon-Reyes A, Seger S (2005). Boa constrictor predation on a titi monkey, Callicebus discolor. Neotropical Primates 13: 11–12.
  12. Defler T (2004). Primates de Colombia. Bogotá, Conservación International.
  13. Di Fiore A (2001). Investigación ecológica y de comportamiento de primates en el Parque Nacional Yasuní. In Conservación y desarollo sostenible del Parque Nacional Yasuní y su área de influencia: memorias del seminario-taller Yasuní (Jorgenson J, Coello Rodríguez M, eds.), pp 165–173. Quito, Simbioe.
  14. Di Fiore A, Fernandez-Duque E, Hurst D (2007). Adult male replacement in socially monogamous equatorial saki monkeys (Pithecia aequatorialis). Folia Primatologica 78: 88–98.
  15. Di Fiore A, Fleischer RC (2005). Social behavior, reproductive strategies, and population genetic structure of Lagothrix poeppigii. International Journal of Primatology 26: 1137–1173.
  16. Di Fiore A, Link A, Schmitt CA, Spehar SN (2009). Dispersal patterns in sympatric woolly and spider monkeys: integrating molecular and observational data. Behaviour 146: 437–470.
  17. Dunbar RIM (1988). Primate Social Systems. London, Chapman & Hall.
  18. Dunbar RIM (1995a). The mating system of the callitrichid primates. 1. Conditions for the coevolution of pair bonding and twinning. Animal Behaviour 50: 1057–1070.
  19. Dunbar RIM (1995b). The mating system of callitrichid primates. 2. The impact of helpers. Animal Behaviour 50: 1071–1089.
  20. Eason P (1989). Harpy eagle attempts predation on adult howler monkey. The Condor 91: 469–470.
  21. Fernandez-Duque E, Di Fiore A, Carrillo-Bilbao G (2008). Behavior, ecology, and demography of Aotus vociferans in Yasuni National Park, Ecuador. International Journal of Primatology 29: 421–431.
  22. Fernandez-Duque E, Rotundo M (2003). Field methods for capturing and marking azarai night monkeys. International Journal of Primatology 24: 1113–1120.
  23. Ferrari SF (2009). Predation risk and antipredator strategies. In South American Primates: Comparative Perspectives in the Study of Behavior, Ecology, and Conservation (Garber PA, Estrada A, Bicca-Marques JC, Heymann EK, Strier KB, eds.), pp 251–277. New York, Springer.
  24. Ferrari SF, Pereira WLA, Santos RR, Veiga LM (2004). Fatal attack of Boa constrictor on a bearded saki (Chiropotes satanas utahicki). Folia Primatologica 75: 111–113.
  25. Ferrari SF, Port-Carvalho M (2003). Predation of an infant collared peccary by a harpy eagle in Eastern Amazonia. Wilson Bulletin 15: 103–104.
  26. Fowler J, Cope J (1964). Notes on the harpy eagle in British Guiana. The Auk 81: 257–273.
  27. Franklin SP, Hankerson SJ, Baker AJ, Dietz JM (2007). Golden lion tamarin sleeping-site use and pre-retirement behavior during intense predation. American Journal of Primatology 69: 325–335.
  28. Galef Jr BG, Mittermeier RA, Bailey RC (1976). Predation by the tayra (Eira barbara). Journal of Mammalogy 57: 760–761.
  29. Galetti M, de Carvalho O (2000). Sloths in the diet of a harpy eagle nestling in eastern Amazon. Wilson Bulletin 112: 535–536.
  30. Hart D (2007). Predation on primates: a biogeographical analysis. In Primate Anti-Predator Strategies (Gursky S, Nekaris KAI, eds.), pp 27–59. Chicago, Springer.
  31. Hill R, Dunbar R (1998). An evaluation of the roles of predation rate and predation risk as selective pressures on primate grouping behaviour. Behaviour 135: 411–430.
  32. Hill RA, Lee PC (1998). Predation risk as an influence on group size in cercopithecoid primates: implications for social structure. Journal of Zoology 245: 447–456.
  33. Isbell L (1994). Predation on primates: ecological patterns and evolutionary consequences. Evolutionary Anthropology 3: 61–71.
  34. Isbell LA, Young TP (1993). Human presence reduces predation in a free-ranging vervet monkey population in Kenya. Animal Behaviour 45: 1233–1235.
  35. Izor RJ (1985). Sloths and other mammalian prey of the harpy eagle. In Conservation and Ecology of the Armadillos, Sloths and Vermilinguas (Montogomery GG, ed.), pp 343–346. Washington, Smithsonian Institution Press.
  36. Janson C (1998). Testing the predation hypothesis for vertebrate sociality: prospects and pitfalls. Behaviour 135: 389–410.
  37. Kleiman DG (1977). Monogamy in mammals. The Quarterly Review of Biology 52: 39–69.
  38. Klein BC, Harper LH, Bierregaard RO, Powell GVN (1988). The nesting and feeding behavior of the ornate hawk-eagle near Manaus, Brazil. The Condor 90: 239–241.
  39. Lawrence J (2003). Preliminary report on the natural history of brown titi monkeys (Callicebus brunneus) at Los Amigos Research Station, Madre de Dios, Peru. American Journal of Physical Anthropology Supplement 36: 136.
  40. Ludwig G, Aguiar LM, Miranda JMD, Teixeira GM, Svoboda WK, Malanski LS, Shiozawa MM, Hilst CLS, Navarro IT, Passos FC (2007). Cougar predation on black-and-gold howlers on Mutum Island, Southern Brazil. International Journal of Primatology 28: 39–46.
  41. Martins SS, Lima EM, Silva Jr JS (2005). Predation of a bearded saki (Chiropotes utahicki) by a harpy eagle (Harpia harpyja). Neotropical Primates 13: 7–10.
  42. Matsuda I, Izawa K (2008). Predation of wild spider monkeys at La Macarena, Colombia. Primates 49: 65–68.
  43. Miranda J, Bernardi I, Abreu K, Passos F (2005). Predation on Alouatta guariba clamitans Cabrera (Primates, Atelidae) by Leopardus pardalis (Linnaeus) (Carnivora, Felidae). Revista Brasileira de Zoologia 22: 793–795.
  44. Norconk MA (2006). Long-term study of group dynamics and female reproduction in Venezuelan Pithecia pithecia. International Journal of Primatology 27: 653–674.
  45. Norconk M (2007). Sakis, uakaris, and titi monkeys: behavioral diversity in a radiation of primate seed predators. In Primates in Perspective (Campbell CJ, Fuentes A, MacKinnon KC, Panger M, Bearder SK, eds.), pp 123–138. New York, Oxford University Press.
  46. Peetz A, Norconk M, Kinzey W (1992). Predation by jaguar on howler monkeys (Alouatta seniculus) in Venezuela. American Journal of Primatology 28: 223–228.
  47. Peres C (1990). A harpy eagle successfully captures an adult male red howler monkey. Wilson Bulletin 102: 560–561.
  48. Presley SJ (2000). Eira barbara. Mammalian Species 636: 1–6.
  49. Rettig N (1978). Breeding behavior of the harpy eagle (Harpia harpyja). The Auk 95: 629–643.
  50. Robinson J (1979). An analysis of the organization of vocal communication in the titi monkey Callicebus moloch. Zeitschrift für Tierpsychologie 49: 381–405.
  51. Sampaio DT, Ferrari SF (2005). Predation of an infant titi monkey (Callicebus moloch) by a tufted capuchin (Cebus apella). Folia Primatologica 76: 113–115.
  52. Schmitt C, Di Fiore A, Hurst D, Fernandez-Duque E (2005). Maternally-Initiated Babysitting by Wild Adult Male Equatorial Sakis (Pithecia aequatorialis) in Yasuní National Park, Ecuador. 1st Annual NYCEP Symposium: ‘Monkeys: Old and New’, New York.
  53. Shahuano Tello NS, Huck M, Heymann EW (2002). Boa constrictor attack and successful group defence in moustached tamarins, Saguinus mystax. Folia Primatologica 73: 146–148.
  54. Sherman PT (1991). Harpy eagle predation on a red howler monkey. Folia Primatologica 56: 53–56.
  55. Stanford CB (2002). Avoiding predators: expectations and evidence in primate antipredator behavior. International Journal of Primatology 23: 741–757.
  56. Terborgh J (1983). Five New World Primates: A Study in Comparative Ecology. Princeton, Princeton University Press.
  57. Terborgh J, Janson C (1986). The socioecology of primate groups. Annual Review of Ecology and Systematics 17: 111–135.
  58. van Schaik CP (1983). Why are diurnal primates living in groups? Behaviour 87: 120–144.
  59. Van Schaik CP, Dunbar RIM (1990). The evolution of monogamy in large primates: a new hypothesis and some crucial tests. Behaviour 115: 30–61.
  60. van Schaik CP, Hörstermann M (1994). Predation risk and the number of adult males in a primate group: a comparative test. Behavioral Ecology and Sociobiology 35: 261–272.
  61. Van Schaik CP, Kappeler PM (2003). The evolution of social monogamy in primates. In Monogamy: Mating Strategies and Partnerships in Birds, Humans and Other Mammals (Reichard UH, Boesch C, eds.), pp 59–80. Cambridge, University of Cambridge.

  

Author Contacts

Eduardo Fernandez-Duque
Department of Anthropology, University of Pennsylvania
3260 South Street, Philadelphia, PA 19104-6398 (USA)
Tel. +1 215 898 1072, Fax +1 215 898 7460
E-Mail eduardof@sas.upenn.edu

  

Article Information

Received: January 18, 2010
Accepted after revision: May 9, 2010
Published online: July 15, 2010
Number of Print Pages : 10
Number of Figures : 0, Number of Tables : 1, Number of References : 61

  

Publication Details

Folia Primatologica (International Journal of PrimatologyInternationale Zeitschrift für PrimatologieJournal international de Primatologie)

Vol. 81, No. 2, Year 2010 (Cover Date: August 2010)

Journal Editor: Crompton R.H. (Liverpool)
ISSN: 0015-5713 (Print), eISSN: 1421-9980 (Online)

For additional information: http://www.karger.com/FPR


Copyright / Drug Dosage / Disclaimer

Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher or, in the case of photocopying, direct payment of a specified fee to the Copyright Clearance Center.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in goverment regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.

Abstract

Anecdotal reports of predation as well as observed predation attempts and rates of animal disappearance provide some of the most relevant data for evaluating the influence that predation risk may have on primate behavioural ecology. Here, we report rates of disappearance from six groups of red titi monkeys (Callicebus discolor) and two groups of equatorial sakis (Pithecia aequatorialis) followed over a period of four and a half years at a lowland site in Amazonian Ecuador. We also describe the first direct observation of a harpy eagle (Harpia harpyja) preying upon a titi monkey, as well as 3 unsuccessful attacks by tayras (Eira barbara) on titi monkeys and 4 unsuccessful attacks by various raptors on sakis. Our data indicate that pitheciid primates may face a wider array of possible predators than previously recognized, and that titi monkeys and sakis are susceptible to different major classes of predators. Our observations also suggest differences in the sex role during predator defence that could be related to the evolution and maintenance of monogamous systems.

© 2010 S. Karger AG, Basel


  

Author Contacts

Eduardo Fernandez-Duque
Department of Anthropology, University of Pennsylvania
3260 South Street, Philadelphia, PA 19104-6398 (USA)
Tel. +1 215 898 1072, Fax +1 215 898 7460
E-Mail eduardof@sas.upenn.edu

  

Article Information

Received: January 18, 2010
Accepted after revision: May 9, 2010
Published online: July 15, 2010
Number of Print Pages : 10
Number of Figures : 0, Number of Tables : 1, Number of References : 61

  

Publication Details

Folia Primatologica (International Journal of PrimatologyInternationale Zeitschrift für PrimatologieJournal international de Primatologie)

Vol. 81, No. 2, Year 2010 (Cover Date: August 2010)

Journal Editor: Crompton R.H. (Liverpool)
ISSN: 0015-5713 (Print), eISSN: 1421-9980 (Online)

For additional information: http://www.karger.com/FPR


Article / Publication Details

First-Page Preview
Abstract of Original Article

Received: 1/18/2010
Accepted: 9/5/2010
Published online: 7/15/2010
Issue release date: August 2010

Number of Print Pages: 10
Number of Figures: 0
Number of Tables: 1

ISSN: 0015-5713 (Print)
eISSN: 1421-9980 (Online)

For additional information: http://www.karger.com/FPR


Copyright / Drug Dosage

Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher or, in the case of photocopying, direct payment of a specified fee to the Copyright Clearance Center.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in goverment regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.

References

  1. Anderson CM (1986). Predation and primate evolution. Primates 27: 15–39.
  2. Arlet ME, Isbell LA (2009). Variation in behavioral and hormonal responses of adult male gray-cheeked mangabey (Lophocebus albigena) to crowned eagles (Stephanoaetus coronatus) in Kibale National Park, Uganda. Behavioral Ecology and Sociobiology 63: 491–199. See http://anthropology.ucdavis.edu/people/lynne-a.-isbell-1/pdf/Arlet%20and%20Isbell%20BES%202009.pdf
  3. Bezerra BM, Barnett AA, Souto A, Jones G (2009). Predation by the tayra on the common marmoset and the pale-throated three-toed sloth. Journal of Ethology 27: 91–96.
  4. Bianchi RC (2001). Estudo comparativo da dieta da jaguatirica, Leopardus pardalis (Linnaeus, 1758), em Mata Atlântica. Disseration, Universidade Federal do Espírito Santo, Vitória.
  5. Bianchi RDC, Mendes SL (2007). Ocelot (Leopardus pardalis) predation on primates in Caratinga Biological Station, Southeast Brazil. American Journal of Primatology 69: 1173–1178.
  6. Blake JG (2007). Neotropical forest bird communities: a comparison of species richness and composition at local and regional scales. The Condor 109: 237–255.
  7. Boinski S, Chapman C (1995). Predation on primates: Where are we and what’s next? Evolutionary Anthropology 4: 1–3.
  8. Bossuyt F (2002). Natal dispersal of titi monkeys (Callicebus moloch) at Cocha Cashu, Manu National Park, Peru. American Journal of Physical Anthropology 34: 47.
  9. Carrillo-Bilbao G, Di Fiore A, Fernandez-Duque E (2005). Dieta, forrajeo y presupuesto de tiempo en cotoncillos (Callicebus discolor) del Parque Nacional Yasuní en la Amazonia Ecuatoriana. Neotropical Primates 13: 7–11.
  10. Cheney D, Wrangham RW (1987). Predation. In Primate Societies (Smuts BB, Cheney DL, Seyfarth RM, Struhsaker TT, eds.), pp 227–239. Chicago, University of Chicago Press.
  11. Cisneros-Heredia D, Leon-Reyes A, Seger S (2005). Boa constrictor predation on a titi monkey, Callicebus discolor. Neotropical Primates 13: 11–12.
  12. Defler T (2004). Primates de Colombia. Bogotá, Conservación International.
  13. Di Fiore A (2001). Investigación ecológica y de comportamiento de primates en el Parque Nacional Yasuní. In Conservación y desarollo sostenible del Parque Nacional Yasuní y su área de influencia: memorias del seminario-taller Yasuní (Jorgenson J, Coello Rodríguez M, eds.), pp 165–173. Quito, Simbioe.
  14. Di Fiore A, Fernandez-Duque E, Hurst D (2007). Adult male replacement in socially monogamous equatorial saki monkeys (Pithecia aequatorialis). Folia Primatologica 78: 88–98.
  15. Di Fiore A, Fleischer RC (2005). Social behavior, reproductive strategies, and population genetic structure of Lagothrix poeppigii. International Journal of Primatology 26: 1137–1173.
  16. Di Fiore A, Link A, Schmitt CA, Spehar SN (2009). Dispersal patterns in sympatric woolly and spider monkeys: integrating molecular and observational data. Behaviour 146: 437–470.
  17. Dunbar RIM (1988). Primate Social Systems. London, Chapman & Hall.
  18. Dunbar RIM (1995a). The mating system of the callitrichid primates. 1. Conditions for the coevolution of pair bonding and twinning. Animal Behaviour 50: 1057–1070.
  19. Dunbar RIM (1995b). The mating system of callitrichid primates. 2. The impact of helpers. Animal Behaviour 50: 1071–1089.
  20. Eason P (1989). Harpy eagle attempts predation on adult howler monkey. The Condor 91: 469–470.
  21. Fernandez-Duque E, Di Fiore A, Carrillo-Bilbao G (2008). Behavior, ecology, and demography of Aotus vociferans in Yasuni National Park, Ecuador. International Journal of Primatology 29: 421–431.
  22. Fernandez-Duque E, Rotundo M (2003). Field methods for capturing and marking azarai night monkeys. International Journal of Primatology 24: 1113–1120.
  23. Ferrari SF (2009). Predation risk and antipredator strategies. In South American Primates: Comparative Perspectives in the Study of Behavior, Ecology, and Conservation (Garber PA, Estrada A, Bicca-Marques JC, Heymann EK, Strier KB, eds.), pp 251–277. New York, Springer.
  24. Ferrari SF, Pereira WLA, Santos RR, Veiga LM (2004). Fatal attack of Boa constrictor on a bearded saki (Chiropotes satanas utahicki). Folia Primatologica 75: 111–113.
  25. Ferrari SF, Port-Carvalho M (2003). Predation of an infant collared peccary by a harpy eagle in Eastern Amazonia. Wilson Bulletin 15: 103–104.
  26. Fowler J, Cope J (1964). Notes on the harpy eagle in British Guiana. The Auk 81: 257–273.
  27. Franklin SP, Hankerson SJ, Baker AJ, Dietz JM (2007). Golden lion tamarin sleeping-site use and pre-retirement behavior during intense predation. American Journal of Primatology 69: 325–335.
  28. Galef Jr BG, Mittermeier RA, Bailey RC (1976). Predation by the tayra (Eira barbara). Journal of Mammalogy 57: 760–761.
  29. Galetti M, de Carvalho O (2000). Sloths in the diet of a harpy eagle nestling in eastern Amazon. Wilson Bulletin 112: 535–536.
  30. Hart D (2007). Predation on primates: a biogeographical analysis. In Primate Anti-Predator Strategies (Gursky S, Nekaris KAI, eds.), pp 27–59. Chicago, Springer.
  31. Hill R, Dunbar R (1998). An evaluation of the roles of predation rate and predation risk as selective pressures on primate grouping behaviour. Behaviour 135: 411–430.
  32. Hill RA, Lee PC (1998). Predation risk as an influence on group size in cercopithecoid primates: implications for social structure. Journal of Zoology 245: 447–456.
  33. Isbell L (1994). Predation on primates: ecological patterns and evolutionary consequences. Evolutionary Anthropology 3: 61–71.
  34. Isbell LA, Young TP (1993). Human presence reduces predation in a free-ranging vervet monkey population in Kenya. Animal Behaviour 45: 1233–1235.
  35. Izor RJ (1985). Sloths and other mammalian prey of the harpy eagle. In Conservation and Ecology of the Armadillos, Sloths and Vermilinguas (Montogomery GG, ed.), pp 343–346. Washington, Smithsonian Institution Press.
  36. Janson C (1998). Testing the predation hypothesis for vertebrate sociality: prospects and pitfalls. Behaviour 135: 389–410.
  37. Kleiman DG (1977). Monogamy in mammals. The Quarterly Review of Biology 52: 39–69.
  38. Klein BC, Harper LH, Bierregaard RO, Powell GVN (1988). The nesting and feeding behavior of the ornate hawk-eagle near Manaus, Brazil. The Condor 90: 239–241.
  39. Lawrence J (2003). Preliminary report on the natural history of brown titi monkeys (Callicebus brunneus) at Los Amigos Research Station, Madre de Dios, Peru. American Journal of Physical Anthropology Supplement 36: 136.
  40. Ludwig G, Aguiar LM, Miranda JMD, Teixeira GM, Svoboda WK, Malanski LS, Shiozawa MM, Hilst CLS, Navarro IT, Passos FC (2007). Cougar predation on black-and-gold howlers on Mutum Island, Southern Brazil. International Journal of Primatology 28: 39–46.
  41. Martins SS, Lima EM, Silva Jr JS (2005). Predation of a bearded saki (Chiropotes utahicki) by a harpy eagle (Harpia harpyja). Neotropical Primates 13: 7–10.
  42. Matsuda I, Izawa K (2008). Predation of wild spider monkeys at La Macarena, Colombia. Primates 49: 65–68.
  43. Miranda J, Bernardi I, Abreu K, Passos F (2005). Predation on Alouatta guariba clamitans Cabrera (Primates, Atelidae) by Leopardus pardalis (Linnaeus) (Carnivora, Felidae). Revista Brasileira de Zoologia 22: 793–795.
  44. Norconk MA (2006). Long-term study of group dynamics and female reproduction in Venezuelan Pithecia pithecia. International Journal of Primatology 27: 653–674.
  45. Norconk M (2007). Sakis, uakaris, and titi monkeys: behavioral diversity in a radiation of primate seed predators. In Primates in Perspective (Campbell CJ, Fuentes A, MacKinnon KC, Panger M, Bearder SK, eds.), pp 123–138. New York, Oxford University Press.
  46. Peetz A, Norconk M, Kinzey W (1992). Predation by jaguar on howler monkeys (Alouatta seniculus) in Venezuela. American Journal of Primatology 28: 223–228.
  47. Peres C (1990). A harpy eagle successfully captures an adult male red howler monkey. Wilson Bulletin 102: 560–561.
  48. Presley SJ (2000). Eira barbara. Mammalian Species 636: 1–6.
  49. Rettig N (1978). Breeding behavior of the harpy eagle (Harpia harpyja). The Auk 95: 629–643.
  50. Robinson J (1979). An analysis of the organization of vocal communication in the titi monkey Callicebus moloch. Zeitschrift für Tierpsychologie 49: 381–405.
  51. Sampaio DT, Ferrari SF (2005). Predation of an infant titi monkey (Callicebus moloch) by a tufted capuchin (Cebus apella). Folia Primatologica 76: 113–115.
  52. Schmitt C, Di Fiore A, Hurst D, Fernandez-Duque E (2005). Maternally-Initiated Babysitting by Wild Adult Male Equatorial Sakis (Pithecia aequatorialis) in Yasuní National Park, Ecuador. 1st Annual NYCEP Symposium: ‘Monkeys: Old and New’, New York.
  53. Shahuano Tello NS, Huck M, Heymann EW (2002). Boa constrictor attack and successful group defence in moustached tamarins, Saguinus mystax. Folia Primatologica 73: 146–148.
  54. Sherman PT (1991). Harpy eagle predation on a red howler monkey. Folia Primatologica 56: 53–56.
  55. Stanford CB (2002). Avoiding predators: expectations and evidence in primate antipredator behavior. International Journal of Primatology 23: 741–757.
  56. Terborgh J (1983). Five New World Primates: A Study in Comparative Ecology. Princeton, Princeton University Press.
  57. Terborgh J, Janson C (1986). The socioecology of primate groups. Annual Review of Ecology and Systematics 17: 111–135.
  58. van Schaik CP (1983). Why are diurnal primates living in groups? Behaviour 87: 120–144.
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