Dispersal among male ring‐tailed lemurs (Lemur catta) on St. Catherines Island

Abstract

There are now over 200 red ruffed lemurs (Varecia variegata rubra) housed in captivity in North America. However, housing space is limited thus reproduction of this species has been curtailed. Ruffed lemurs are usually housed in pairs or pairs with their immature offspring. In the wild, large groups of ruffed lemurs have been reported suggesting that there is potential to maintain larger groups in captivity. Quantitative data on the behavior of large groups of ruffed lemurs in captivity is lacking. This study was conducted on an established group of lemurs at Cleveland Metroparks Zoo to document social interactions over an extended period of time. A total of 420 hours of behavioral data were collected on five males and three females over four years. Animals engaged in affiliative behavior nearly six times as frequently as agonistic or reproductive behaviors. MANOVA revealed that females engaged in significantly more social interactions than did males. Over time, aggressive interactions decreased and reproductive behaviors increased, indicating group stability and cohesiveness. The success of this group suggests that larger groups of red ruffed lemurs can be compatible and could be an effective means of increasing captive holding space for this species. Maternal competence is particularly variable among primiparous nonhuman primates, and sufficient quantitative information is lacking on the specific behavioral patterns related to the successful rearing of offspring by primiparous chimpanzees. This study was conducted at multiple institutions to quantify maternal behavior of 24 chimpanzees after the birth of their first infants. Observations were conducted as soon as possible postpar-tum and continued for several weeks. Data were one-zero samples of maternal behavior, infant behavior, their interactions and proximity. The chimpanzees successfully reared 16 of their 24 infants (67%). During the 303 hours of data collected, all mothers in the study contacted their infants during 98% of the intervals, carried them during 96% of the intervals , and nursed them during 12% of the intervals. The infants vocalized during 7% of the intervals and exhibited a strong grip during 72% of the intervals. A MANOVA on 42 hours of data collected on the day of birth revealed that successful mothers showed significantly higher levels of carrying their infants ventrally and responding to their infants than did mothers who were ultimately unsuccessful. Successful mothers showed less inappropriate contact (e.g., dangling infants). There were no differences in the number of intervals in which mothers nursed or were aggressive to their infants. These findings can aid in evaluating the competence of primiparous chimpanzees and in making ethologically based management decisions. Four chimpanzees (Pan troglodytes) and two rhesus macaques (Macaca mulatta) selected either five Arabic numerals, five colored squares, or five lexigrams on a computer monitor in a specific, learned sequence. On probe trials in one condition, the locations of the sec...

Evaluation of Male Inter-Troop Transfer as a Mating Strategy among Ring-Tailed Lemurs on St. Catherines Island, USA

“…SCI affords the opportunity to follow radio-collared individuals in a closed population in which lemurs are allowed to transfer between groups unimpeded by human intervention. Previous work has shown that L. catta on SCI exhibit species-typical social and reproductive behaviors [KeithLucas et al, 1999;Parga, 2003Parga, , 2006aParga and Lessnau, 2008]. SCI is approximately 16 km long and 3 km wide, and the L. catta groups at this location inhabit the north end of the island [Keith-Lucas et al, 1999].…”

“…Therefore, it was possible to calculate male mating success per breeding season in this study, because all male transfer events on SCI took place distinctly before or after mating periods. Prior research at this location has revealed that males on SCI show dispersal patterns similar to wild populations of L. catta , with the most notable difference being earlier age at natal dispersal on SCI (occurring at 1-2 years instead of 3-4 years of age) due to provisioning in this habitat [Parga and Lessnau, 2008]. L. catta on SCI are also more likely to disperse in pairs than alone, as in the wild [Jones, 1983;Sussman, 1991Sussman, , 1992Gould, 1994Gould, , 1997Gould, , 2006a, and this is especially true of primary dispersal events by natal males, in which males frequently transfer with matrilineally related males [Parga and Lessnau, 2008].…”

“…Lastly, I examined the relationship between male dominance rank, age and male transfer behavior. A previous study [Parga and Lessnau, 2008] investigated patterns of male inter-troop transfer on SCI (the same location as the present study), but no data were presented on male mating behavior, the potential effects of group size on male transfer behavior or the relationship between male dominance rank and transfer behavior. This paper extends the previous analysis by including these variables (mating success, group size and male dominance status) in an evaluation of male dispersal as a potential mating strategy among L. catta on SCI.…”

“…In the Beza Mahafaly Special Reserve in Madagascar, males transfer during several periods, including the months surrounding the mating, birth and lactation seasons [Sau- M ales who transferred between groups for whom mating success data were available in breeding seasons before and/or after transfer S ex ratios were calculated using the number of non-natal males and females in the social group (1 year of age and older); the transfer male is excluded from both counts, and males' transfer partners were excluded from the post-transfer group count; note that this sex ratio is differently calculated than in Parga and Lessnau [2008], wherein only females 2 years of age and older were counted in group sex ratios. Group size count included all group individuals 1 year of age and older, including natal males (which is why it is greater than the sum of male and female values as listed in the group sex ratio columns).…”

“…Parga ther, 1991;Sussman, 1991Sussman, , 1992Gould, 1994Gould, , 1997Gould, , 2006a. In contrast, in Berenty, Madagascar, and on SCI, male transfer shows a clear seasonality, with the majority of males transferring during the birth season and far fewer males transferring during the mating season [Budnitz and Dainis, 1975;Jones, 1983;Parga and Lessnau, 2008]. In fact, in the years dating back to 1997 in the SCI colony, only 3 male transfer events occurred during the breeding season: 2 males leaving their natal groups, and a single non-natal male transfer that occurred at the very end of the breeding season, in late January [Parga and Lessnau, 2008].…”