scholarly journals Fighting back: Population recovery and expansion of the range size of the Mitumba chimpanzee community in Gombe National Park, Tanzania

2016 ◽  
Author(s):  
Deus Mjungu ◽  
Michael L Wilson ◽  
Steffen Foerster ◽  
Anne E Pusey
Keyword(s):  
National Park ◽  
Decisive Role ◽  
Adult Males ◽  
Playback Experiments ◽  
Intergroup Interactions ◽  
Naturally Occurring ◽  
Number Of Males ◽  
Numerical Advantage ◽  
Long Term Studies

Chimpanzees (Pan troglodytes) compete aggressively for territory with their neighbors. Results from playback experiments and observations of naturally occurring intergroup interactions indicate that success in territorial competition depends mainly on the number of adult males on each side. Communities with more males are therefore expected to win more intergroup contests and, as a result, expand their range. Demography is thus expected to play a decisive role in intergroup competition. Testing this hypothesis, however, has proven difficult. Most studies have focused on a single community, so that the actual number of males is known for only one side. Additionally, because chimpanzees reproduce and grow slowly, many years of data are needed to test the effects of demographic change on territorial behavior. Here we report on 20 years of data from two habituated neighboring communities. We found that numerical advantage plays an important role in territorial competition. During the first part of the study period, the Mitumba community suffered a demographic decline. As a result, males from the larger Kasekela community won the majority of intergroup interactions and expanded their range deep into areas previously used by Mitumba. However, during the last five years, the Mitumba community increased in size, and subsequently recovered a substantial portion of their range from the Kasekela chimpanzees. This study highlights the importance of long-term studies for understanding territorial dynamics.

scholarly journals Fighting back: Population recovery and expansion of the range size of the Mitumba chimpanzee community in Gombe National Park, Tanzania

2016 ◽  
Author(s):  
Deus Mjungu ◽  
Michael L Wilson ◽  
Steffen Foerster ◽  
Anne E Pusey
Keyword(s):  
National Park ◽  
Decisive Role ◽  
Adult Males ◽  
Playback Experiments ◽  
Intergroup Interactions ◽  
Naturally Occurring ◽  
Number Of Males ◽  
Numerical Advantage ◽  
Long Term Studies

Chimpanzees (Pan troglodytes) compete aggressively for territory with their neighbors. Results from playback experiments and observations of naturally occurring intergroup interactions indicate that success in territorial competition depends mainly on the number of adult males on each side. Communities with more males are therefore expected to win more intergroup contests and, as a result, expand their range. Demography is thus expected to play a decisive role in intergroup competition. Testing this hypothesis, however, has proven difficult. Most studies have focused on a single community, so that the actual number of males is known for only one side. Additionally, because chimpanzees reproduce and grow slowly, many years of data are needed to test the effects of demographic change on territorial behavior. Here we report on 20 years of data from two habituated neighboring communities. We found that numerical advantage plays an important role in territorial competition. During the first part of the study period, the Mitumba community suffered a demographic decline. As a result, males from the larger Kasekela community won the majority of intergroup interactions and expanded their range deep into areas previously used by Mitumba. However, during the last five years, the Mitumba community increased in size, and subsequently recovered a substantial portion of their range from the Kasekela chimpanzees. This study highlights the importance of long-term studies for understanding territorial dynamics.

scholarly journals Intercommunity interactions and killings in central chimpanzees (Pan troglodytes troglodytes) from Loango National Park, Gabon

Primates ◽  
2021 ◽  
Author(s):  
Laura Martínez-Íñigo ◽  
Pauline Baas ◽  
Harmonie Klein ◽  
Simone Pika ◽  
Tobias Deschner
Keyword(s):  
Pan Troglodytes ◽  
National Park ◽  
Camera Traps ◽  
Encounter Rate ◽  
Visual Contact ◽  
Intergroup Interactions ◽  
Killing Rate ◽  
The Core ◽  
Pan Troglodytes Troglodytes

AbstractIntercommunity competition in chimpanzees (Pan troglodytes) has been widely studied in eastern (P. t. schweinfurthii) and western (P. t. verus) communities. Both subspecies show hostility towards neighboring communities but differ in rates of lethal attacks and female involvement. However, relatively little is known about the territorial behavior of the two other subspecies, central (P. t. troglodytes) and Nigeria-Cameroon chimpanzees (P. t. ellioti). Here, we present the first insights into intercommunity interactions of individuals of a community of central chimpanzees living in the Loango National Park in Gabon. The presence of individuals of neighboring communities in the Rekambo home range was assessed using 27 camera traps. Information was compiled on intergroup interactions recorded before (2005–2016) and after (January 2017–June 2019) the habituation of the community. Individuals from neighboring communities entered the core area, where nine out of 16 recorded intercommunity encounters occurred. Males were the main participants in territorial patrols and intercommunity aggressions. Females were part of all six territorial patrols recorded and dependent offspring participated in five patrols. Females were involved in intercommunity aggression in five out of twelve recorded encounters in which there was visual contact between communities. While the intercommunity encounter rate was lower than that reported across most other long-term chimpanzee sites, the annual intercommunity killing rate was among the highest. These results suggest that the frequency of lethal attacks at Loango is comparable to that reported for the eastern subspecies. In contrast, female involvement in intercommunity interactions mirrors that of the western subspecies.

scholarly journals How accurately do behavioural observations predict reproductive success in free-ranging lizards?

2019 ◽  
Vol 15 (2) ◽  
pp. 20190030 ◽  
Author(s):  
Mats Olsson ◽  
Tonia S. Schwartz ◽  
Erik Wapstra ◽  
Richard Shine
Keyword(s):  
Reproductive Success ◽  
Adult Males ◽  
Microsatellite Data ◽  
Term Study ◽  
Long Term Study ◽  
Lacerta Agilis ◽  
Free Ranging ◽  
Number Of Males ◽  
Variance In Reproductive Success

Behavioural ecologists often use data on patterns of male–female association to infer reproductive success of free-ranging animals. For example, a male seen with several females during the mating season is predicted to father more offspring than a male not seen with any females. We explored the putative correlation between this behaviour and actual paternity (as revealed by microsatellite data) from a long-term study on sand lizards ( Lacerta agilis ), including behavioural observations of 574 adult males and 289 adult females, and paternity assignment of more than 2500 offspring during 1998–2007. The number of males that contributed paternity to a female's clutch was correlated with the number of males seen accompanying her in the field, but not with the number of copulation scars on her body. The number of females that a male accompanied in the field predicted the number of females with whom he fathered offspring, and his annual reproductive success (number of progeny). Although behavioural data explained less than one-third of total variance in reproductive success, our analysis supports the utility of behavioural-ecology studies for predicting paternity in free-ranging reptiles.

scholarly journals Hunting of mammals by central chimpanzees (Pan troglodytes troglodytes) in the Loango National Park, Gabon

Primates ◽  
2021 ◽  
Author(s):  
Harmonie Klein ◽  
Gaëlle Bocksberger ◽  
Pauline Baas ◽  
Sarah Bunel ◽  
Erwan Théleste ◽  
...  
Keyword(s):  
Pan Troglodytes ◽  
National Park ◽  
Democratic Republic Of Congo ◽  
Adult Males ◽  
Mammal Species ◽  
Monkey Species ◽  
Hunting Behaviour ◽  
Pan Troglodytes Troglodytes ◽  
Hunting Frequency

AbstractThe predation and consumption of animals are common behaviours in chimpanzees across tropical Africa. To date, however, relatively little is known concerning the hunting behaviour of central chimpanzees (Pan troglodytes troglodytes). Here, we provide the first direct observations of hunting behaviour by individuals of the newly habituated Rekambo community in the Loango National Park, Gabon. Over a period of 23 months (May 2017 to March 2019), we observed a total of 61 predation attempts on eight mammal species, including four monkey species. The two most frequently hunted species were two monkey species (Cercocebus torquatus,Cercopithecus nictitans), which are not hunted at other long-term field sites. The majority of predation events observed involved parties of an average of eight individuals, mainly adult males, with hunting success being higher with increasing numbers of participants. Hunting occurred all year round, but hunting rates increased in the dry season, the period of high fruit availability in the Loango National Park. These results are in line with the nutrient surplus hypothesis which explains seasonal variation in hunting behaviour in several populations of eastern chimpanzees (Pan troglodytes schweinfurthii: e.g., Mahale, Tanzania; Ngogo, Uganda). Finally, with a hunting frequency of 2.65 hunts per month, the Rekambo community had higher hunting rates than other sites (Bossou, Republic of Guinea; Kahuzi-Biega, Democratic Republic of Congo; Budongo, Uganda) where red colobus monkeys are also absent. We discuss these results and compare them to patterns at other long-term sites.

scholarly journals Climatic Factors, Reproductive Success and Population Dynamics in the Montane Vole, Microtus montanus

1997 ◽  
Vol 21 ◽  
pp. 57-59
Author(s):  
Aelita Pinter
Keyword(s):  
Population Dynamics ◽  
Population Density ◽  
National Park ◽  
Climatic Factors ◽  
Term Study ◽  
Microtus Montanus ◽  
Long Term Study ◽  
Small Measure ◽  
Long Term Studies

Multiannual fluctuations ("cycles") in population density of small rodents doubtless result from the interaction of a multitude of factors, as evidenced by the variety of hypotheses proposed to explain the phenomenon (for reviews see Finerty 1980, Taitt and Krebs 1985). However, the inability of these hypotheses - alone or in combination - to explain the causality of cycles rests in no small measure with the fact that long-term studies of the phenomenon are notoriously uncommon. The objectives of this project are to continue a long-term study of the population dynamics of the montane vole, Microtus montanus, in Grand Teton National Park. On the basis of earlier observations (Pinter 1986, 1988) particular emphasis will be placed on how environmental variables, possibly acting through reproductive responses, contribute to the population density cycles of these rodents.

scholarly journals Climatic Factors, Reproductive Success and Population Dynamics in the Montane Vole, Microtus montanus.

2003 ◽  
Vol 27 ◽  
pp. 42-44
Author(s):  
Aelita Pinter
Keyword(s):  
Population Dynamics ◽  
Population Density ◽  
National Park ◽  
Climatic Factors ◽  
Term Study ◽  
Microtus Montanus ◽  
Long Term Study ◽  
Small Measure ◽  
Long Term Studies

A variety of hypotheses have been proposed to explain multiannual fluctuations in population density ("cycles") of small rodents (for reviews see Finerty 1980, Taitt and Krebs 1985). Doubtless, such cycles - known since antiquity (Elton 1942) - result from an interaction of a multitude of factors. However, the inability of extant hypotheses, alone or in combination, to explain the causality of cycles rests in no small measure with the fact that long-term studies of the phenomenon are notoriously uncommon. The objectives of this project are to continue the long-term study of population dynamics of the montane vole, Microtus montanus, in Grand Teton National Park. Earlier observations (Pinter 1986, 1988) indicate that environmental variables might contribute to the population density cycles of these rodents, possibly by influencing their growth and various aspects of their reproduction.

scholarly journals Woody vegetation change over more than 30 years in the interior duneveld of the Kalahari Gemsbok National Park

Bothalia ◽  
2020 ◽  
Vol 50 (Volume 50 No. 1) ◽  
Author(s):  
H. van der Merwe ◽  
N. van Rooyen ◽  
H. Bezuidenhout ◽  
J. du P. Bothma ◽  
M.W. van Rooyen
Keyword(s):  
National Park ◽  
Vegetation Change ◽  
Woody Species ◽  
Woody Vegetation ◽  
Bush Encroachment ◽  
Conservation Area ◽  
Grewia Flava ◽  
Carbon Dioxide Levels ◽  
Long Term Studies

Background and objectives: Long-term studies of woody plants in South Africa are scarce. This study, initiated in the late 1970s, therefore aids understanding of vegetation dynamics in the southern Kalahari by investigating woody vegetation change at and away from a watering point. Methods: At three sites, all woody individuals were counted by species in plots 0.5 or 1 ha in size. Seedlings were noted separately from the >0.2 m group of individuals. Results: Vachellia erioloba and shrub density decreased over time whereas dwarf shrub species’ numbers fluctuated markedly. Additionally, no increase in density of known bush encroaching species (e.g. Grewia flava, Rhigozum trichotomum and Senegalia mellifera) was found in this large conservation area. Discussion and conclusion: The changes in density of the woody species seem to point to the importance of particular rainfall patterns or sequences of events over different years that are responsible for these changes in the southern Kalahari, and the evident lack of bush encroachment in this conservation area supports the notion that bush encroachment in arid savannas is driven primarily by land-use practices and not by elevated carbon dioxide levels that are sometimes provided as cause for encroachment.

scholarly journals Retrospective assessment of long-term conservation management of elephants in Addo Elephant National Park, South Africa

Oryx ◽  
2002 ◽  
Vol 36 (3) ◽  
pp. 243-248 ◽  
Author(s):  
Anna M. Whitehouse ◽  
Graham I. H. Kerley
Keyword(s):  
Population Growth ◽  
National Park ◽  
Conservation Management ◽  
Negative Impact ◽  
Demographic Data ◽  
Management Plan ◽  
Adult Males ◽  
Management Actions ◽  
Retrospective Assessment

The elephant population of South Africa's Addo Elephant National Park increased in number from 11 elephants when the park was created in 1931, to 284 elephants in 1998. We studied management records throughout this period in conjunction with demographic data, enabling retrospective assessment of the long-term impacts of management actions. Problem animal control during the 1930s left no sexually mature bulls in the population for a period of 9 years, hindering the population's initial recovery. Population growth prior to 1954 was also limited by high mortality: between 1931 and 1954 inadequate fencing allowed elephants to stray outside their protected area resulting in elephants being shot by farmers or dying from collisions with trains. Secure elephant-proof fencing was constructed in 1954. Subsequently, there was a significant decrease in mortality (from 5.0% to 1.2%) and an increase in population growth (from 3.2% to 6.1%). However, evidence suggests that confinement might have had a negative impact on survival and social behaviour of adult males. We suggest that the concepts of social carrying capacities and behavioural conservation of populations need to be incorporated into management. The case studies described here highlight the importance of treating conservation management and research as necessary partners, and monitoring should be an integral part of any management plan.

scholarly journals Climatic Factors, Reproductive Success and Population Dynamics in the Montane Vole, Microtus montanus

2002 ◽  
Vol 26 ◽  
pp. 38-40
Author(s):  
Aelita Pinter
Keyword(s):  
Population Dynamics ◽  
Population Density ◽  
National Park ◽  
Climatic Factors ◽  
Term Study ◽  
Microtus Montanus ◽  
Long Term Study ◽  
Small Measure ◽  
Long Term Studies

Multiannual fluctuations ("cycles") in population density of small rodents doubtless result from the interaction of a multitude of factors, as evidenced by the variety of hypotheses proposed to explain the phenomenon (for reviews see Finerty 1980, Taitt and Krebs 1985). However, the inability of these hypotheses - alone or in combination - to explain the causality of cycles rests in no small measure with the fact that long-term studies of the phenomenon are notoriously uncommon. The objectives of this project are to continue the long-term study of the population dynamics of the montane vole, Microtus montanus, in Grand Teton National Park. On the basis of earlier observations (Pinter 1986, 1988) particular emphasis will be placed on how environmental variables, possibly acting through reproductive responses, contribute to the population density cycles of these rodents.

Factors affecting individual participation in group-level aggression among non-human primates

Behaviour ◽  
2007 ◽  
Vol 144 (12) ◽  
pp. 1551-1581 ◽  
Author(s):  
Jacinta Beehner ◽  
Dawn Kitchen
Keyword(s):  
Relative Number ◽  
Group Level ◽  
Costs And Benefits ◽  
Factors Affecting ◽  
Intergroup Interactions ◽  
Group Members ◽  
Intergroup Encounters ◽  
Individual Participation ◽  
Long Term Studies

AbstractGroup members do not always act cohesively when facing extra-group rivals. When benefits such as group-defence are not monopolizable, it poses an economics problem: who should contribute to public goods and who should freeload? A collective action framework compliments existing theoretical explanations for cooperation, and provides testable hypotheses about group-level behaviour based on individual costs and benefits. Using this approach, we review research on intergroup encounters in non-human primates published over the last 20 years, focusing on participation by different classes of individuals. While food- and mate-defence explain much between-sex variation in participation, rank and reproductive access frequently explain within-sex variation. In some species, individuals may use intergroup interactions to survey potential transfer locations and mating options, which might coincidently intimidate rivals. Experimental evidence suggests that when intergroup dominance is based on relative number of fighters, individual participation still varies with sex, rank, companion behaviour and dependent offspring presence. Relatively few studies have examined how factors such as relationships within and between groups or individual temperament mediate aggression. Long-term studies of multiple habituated groups and methodological advances (e.g., playback experiments) will continue to improve our understanding of how complex group-level patterns are predictable when viewed from an individual perspective.

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