Georgia Southern University Digital Commons@Georgia Southern Electronic Theses and Dissertations Graduate Studies, Jack N. Averitt College of Fall 2012 Role of Provisions and Season on Foraging and Female Dominance Behavior in Ring-Tailed Lemurs (Lemur Catta) on St. Catherine's Island Timothy Moore Follow this and additional works at: https://digitalcommons.edu/etd Part of the Biology Commons, and the Ecology and Evolutionary Biology Commons Recommended Citation Moore, Timothy, "Role of Provisions and Season on Foraging and Female Dominance Behavior in Ring-Tailed Lemurs (Lemur Catta) on St. Electronic Theses and Dissertations.edu/etd/11 This thesis (open access) is brought to you for free and open access by the Graduate Studies, Jack N.
Averitt College of at Digital Commons@Georgia Southern. It has been accepted for inclusion in Electronic Theses and Dissertations by an authorized administrator of Digital Commons@Georgia Southern. For more information, please contact digitalcommons@georgiasouthern. ROLE OF PROVISIONS AND SEASON ON FORAGING AND FEMALE DOMINANCE BEHAVIOR IN RING-TAILED LEMURS (LEMUR CATTA) ON ST.
CATHERINE’S ISLAND by TIMOTHY MOORE (Under the Direction of Michelle Cawthorn) ABSTRACT Madagascar is undergoing habitat destruction and degradation that is threatening its unique species, including ring-tailed lemurs. Ring-tailed lemurs (Lemur catta) live in matriarchal groups composed of a dominant female, adult males, subadult males and females, and young. Due to their dominance, it has been suggested that female ring- tailed lemurs have access to the highest quality resources and can monopolize food patches. Lemurs on St.
Catherine’s are free ranging and have unlimited access to natural food sources, but they are also provisioned with supplementary food to ensure a balanced diet. My study aimed to determine the impact of provisions on female dominance behavior and individual foraging behavior and whether or not this varied seasonally. During the summer of 2011, lemurs were presented with doubled amount of provisions; differences in foraging behavior and female dominance were determined. To assess the effect of season on foraging behavior and provision use, data collected in the summer (July-August 2011) were compared with winter (January 2012).
Gender had no effect on type of food consumed naturally, but females spent more time at provision sites overall and during the first half of a provisioned feeding bout. Doubling of provisions resulted in equal time spent at provision sites for males and females, but no difference in activity pattern occurred. No difference was been found in food type consumed between genders, 1 but acorns seemed to be the favorite in both seasons. Lemurs were less active during the winter, and spent less time at provision sites.
Overall, females are spending more time at provisioned food bowls than males suggesting females are consuming more. However, they are spending the same amount of time naturally foraging and foraging on the same types of natural food items. Overall, females seem to be eating more than males during the summer, indicating a possible increased need for sustenance by females possibly due to lactation. Season had an apparent effect on interest in provisions, on number of species consumed, and on activity type.
My results provide valuable information to be used in future ring-tailed lemur translocations. INDEX WORDS: Ring-tailed lemur, Female dominance, Foraging behavior, Provision use, Seasonality 2 ROLE OF PROVISIONS AND SEASON ON FORAGING AND FEMALE DOMINANCE BEHAVIOR IN RING-TAILED LEMURS (LEMUR CATTA) ON ST. CATHERINE’S ISLAND by TIMOTHY MOORE B., Auburn University, 2010 A Thesis Submitted to the Graduate Faculty of Georgia Southern University in Partial Fulfillment of the Requirements for the Degree MASTER OF SCIENCE STATESBORO, GEORGIA 2012 3 © 2012 TIMOTHY MOORE All Rights Reserved 4 ROLE OF PROVISIONS AND SEASON ON FORAGING AND FEMALE DOMINANCE BEHAVIOR IN RING-TAILED LEMURS (LEMUR CATTA) ON ST. CATHERINE’S ISLAND by TIMOTHY MOORE Major Professor: Michelle Cawthorn Committee: C.
Ray Chandler Lissa M. Leege Electronic Version Approved: December, 2012 5 6 ACKNOWLEDGMENTS I would like to thank St. Catherine’s Island for allowing me to stay on the island and observe the lemurs as well as Royce Hayes and all the zoo staff on the island for providing help and assistance while I was on the island. I want to thank my advisor, Dr.
Michelle Cawthorn, for all her help in designing a project, writing, editing, and equipment. I also want to thank my committee members, Dr. Ray Chandler and Dr. Lissa Leege, for their help in designing my project and editing my thesis.
Finally, I want to thank all my friends and family for their support and encouragement throughout this process. 6 TABLE OF CONTENTS ACKNOWLEDGMENTS .6 LIST OF TABLES .9 LIST OF FIGURES .21 Ring-tailed Lemur Basic Biology. Catherine's Island Population .29 Summer and Amount of Provisions .31 Effects of Doubled Provisions .35 Summer and Provisioning Use.68 8 LIST OF TABLES Table 1: Age and sex ratios for troops of ring-tailed lemurs observed in this study (Summer 2011) .56 Table 2: Age and sex ratios for troops of ring-tailed lemurs observed in this study (Winter 2012) .56 Table 3: Analysis of percent of time spent at provision sites in summer .57 Table 4: Analysis of activity type within pre-treatment phase and across phases .58 Table 5: Analysis for food type within phase .59 Table 6: Analysis of plant species consumed within phase .60 Table 7: Significance of time spent consuming provisioning across seasons .60 Table 8: Percent of time spent in activity patterns across a number of variables .61 Table 9: Analysis of percent of time spent consuming food types within both seasons .62 Table 10: Analysis of food types across season for females .63 Table 11: Analysis of food types across season for males.64 Table 12: Analysis of plant species within season.65 Table 13: Comparison of plant species foraged on by ringtailed lemurs in five studies conducted on St.66 9 LIST OF FIGURES Figure 1: Percent of time spent consuming provisions in males and females is shown for all three phases (±1 SE) .52 Figure 2: Differences in percent of time spent engaging in active, foraging (FG) and inactive behaviors are shown for both genders (±1 SE) for pre-treatment phase.53 Figure 3: Percent of time spent in each activity is shown for each of the three troops observed in winter (±1 SE) .54 Figure 4: Percent of time spent in each activity type across season is shown for males and females combined (±1 SE) .55 10 CHAPTER 1 INTRODUCTION According to the International Union for the Conservation of Nature (IUCN 2012), over 10,000 animal species are threatened with extinction. Of these, approximately 5,000 are considered vulnerable, 3,000 are considered endangered, and 2,000 are considered critically endangered.
Over 700 modern species are extinct or extinct in the wild. Globally, extinction rates are as high 1000 times that of the background rate. This is due to increasing habitat destruction (which affects nearly 90% of all threatened species), pollution, and over exploitation (as well as other threats) (Baillie et al. 2004; IUCN 2007; Seddon et al.
2007; Wake and Vrendenburg 2008). Tropical forests have been especially hard hit. Estimates suggest that about half of the world’s tropical forests have been lost (Skole and Tucker 1993). A common tactic of animal conservation involves reintroduction of animals into native habitat, and understanding basic biology of species is critical to creating accurate and realistic species survival plans (AZA 2009).
Reintroductions are a type of translocation, or “movement of living organisms from one area to another” (IUCN 1987). Other types of translocations are re-stocking and introducing species into non-native habitat (IUCN 1987). Reintroductions of representatives of diverse taxa have been attempted, including birds, mammals, fish, and invertebrates (Seddon et al. One review found that over 50% of reintroductions were mammals (Fischer and Lindenmayer 2000); another found 35% of 489 total reintroductions as of 2005 were mammals (Seddon et al.
A notable success was the American bison Bison bison, one of the first reintroductions on record. Other successful introductions include the 11 Golden Lion Tamarin, Leontopithecus rosalia, Arabian oryx, Oryx leucoryx, and Przewalski’s horse, Equus ferus przewalskii (Kleiman 1989; Stanley Price 1989; Van Dierendonck and Wallis de Vries 1996). Reviews of published reintroduction studies indicate that overall success rate is low, and wild-born animals have more success than captive born (Fisher and Lindenmayer 2000; Kleiman 1989). Reintroductions are not simple and the process raises many questions including how much provisioning, if any, should be given to reintroduced animals and for how long (Fisher and Lindenmayer 2000; Armstrong and Seddon 2007).
The addition of support in the initial phase of mammalian reintroductions in the form of medical care, shelter, or food appears to reduce rate of failure (Fischer and Lindenmayer 2000). This support is part of a “soft” release, in contrast to a “hard” release where animals receive no support. In a successful release of ruffed lemurs, Varecia variegata variegata, food was provided after release and their health and behavior were monitored (Britt et al. There have been many calls and attempts in recent years to establish guidelines before and after the reintroduction in order to refine the process, advance the field, and increase successes (Armstrong and Seddon 2007; Fischer and Lindenmayer 2000; Kleiman 1989; Seddon et al.
Considering the overall expense of reintroduction projects, which can range from hundreds of thousands to millions of dollars (Kleiman 1989), it is critical to understand this relationship and the biology of the species in question both for the animals’ health and for economic reasons. For some species, reintroduction into the original native range may be impossible due to habitat loss. Madagascar is an excellent example of an area with significant habitat loss (Gade 1996) for which successful reintroductions of threatened or endangered species appear unlikely. Only ~7% of primary forest area remains in Madagascar, and tree cover of any kind has been 12 reduced to ~15% by activities like wood cutting and burning.
Consequently, the entire biota of the island is threatened with extinction with over 800 species listed as threatened (Gade 1996; IUCN 2012). The IUCN has recently proclaimed the mammals of Madagascar to be the most threatened in the world (Yoder and Welch 2012). Due to this threat, attempts are in progress to preserve the forest and the species that depend on it (McConnell and Sweeney 2005). An important component of the fauna of Madagascar is the group of primates known as lemurs.
Lemurs live in many zoos around the world and a goal of many zoos is to return some of these species to the wilds of Madagascar (AZA 2009). The Madagascar Fauna Group worked in 1997 to successfully release black and white ruffed lemurs that had been bred in captivity back into Madagascar to restock a native population (Britt et al. Provisions are an important part of reintroductions for primates and captive animals (Fischer and Lindenmayer 2000; Konstant and Mittermeier 1982; Tear and Ables 1999), and were used in the Britt et al. Conservation efforts to preserve habitat, in conjunction with a soft release, suggest that it is a realistic possibility for lemurs to be reintroduced into their former ranges.
Another lemur species, the ring-tailed lemur, has been introduced to St. Catherine’s Island, GA, (SCI) which provides an excellent opportunity to examine their behavior in an introduction setting. Catherine’s Island is privately owned and managed by the St. Catherine’s Island Foundation.
Beginning in 1974, several endangered species of reptiles, birds, and mammals were located on the island due as a joint effort by the SCI foundation and the Wildlife Conservation Society (WCS) (Bell 2001; Wildlife Conservation Society 2012). The WCS ended their involvement with the program in 2003 (Bell 2001), but SCI continues to manage hornbills, hoofstock, and ring-tailed lemurs. The lemurs are semi-free ranging on the northern side of the island and exhibit species-typical behaviors (Keith-Lucas et al. This 13 population provides an opportunity to study and understand the challenges associated with introductions.
Catherine’s Island differs from sites in Madagascar where lemurs remain such as Berenty and Beza Mahafaly in several ways. Climatic differences cause different seasons, and lead to completely different plant communities.