Habitat Degradation and Seasonality Affect Physiological Stress Levels of Eulemur collaris in Littoral Forest Fragments.

PLoS ONE 9(9): e107698. https://doi.org/10.1371/journal.pone.0107698

Abstract:

The littoral forest on sandy soil is among the most threatened habitats in Madagascar and, as such, it represents a hot-spot within a conservation hot-spot. Assessing the health of the resident lemur fauna is not only critical for the long-term viability of these populations, but also necessary for the future re-habilitation of this unique habitat. Since the Endangered collared brown lemur, Eulemur collaris, is the largest seed disperser of the Malagasy south-eastern littoral forest its survival in this habitat is crucial. In this study we compared fecal glucocorticoid metabolite (fGCM) levels, a measure of physiological stress and potential early indicator of population health, between groups of collared brown lemurs living in a degraded forest fragment and groups occurring in a more preserved area. For this, we analysed 279 fecal samples collected year-round from 4 groups of collared brown lemurs using a validated 11-oxoetiocholanolone enzyme immunoassay and tested if fGCM levels were influenced by reproductive stages, phenological seasons, sex, and habitat degradation. The lemurs living in the degraded forest had significantly higher fGCM levels than those living in the more preserved area. In particular, the highest fGCM levels were found during the mating season in all animals and in females during gestation in the degraded forest. Since mating and gestation are both occurring during the lean season in the littoral forest, these results likely reflect a combination of ecological and reproductive pressures. Our findings provide a clear indication that habitat degradation has additive effects to the challenges found in the natural habitat. Since increased stress hormone output may have long-term negative effects on population health and reproduction, our data emphasize the need for and may add to the development of effective conservation plans for the species.

balestri-biblio

Freigegeben in B

L'écologie de la mone de Campbell (Cercopithecus campbelli lowei) en Côte d'Ivoire.

La Terre et la Vie 1969/2: 135-163.

Summary:

Lowe's guenon (Cercopithecus campbelli lowei) is still one of the commonest monkeys of the Ivory Coast. It is found in all forest types, from old mature rain forest to secondary growth. Although these monkeys spend most of their time in the middle and lower layers of the forest, they occasionally visit the canopy or descend to the ground. The various types of locomotion are described and illustrated. Most of the detailed information obtained on the ecology and behaviour of the Lowe's guenon is based upon observations made from 1967 to 1969 on a wild troop living on the grounds of the Swiss Research Center, at Adiopodoumé. The history of this group has been recorded since 1964. Comparative observations were made on various wild troops in western Ivory Coast, and on 2 free ranging pets at the Lamto field station in 1967. The home range of the Adiopodoumé troop is small, covering about 3 hectares. The monkeys use the same sleeping trees for long pcriods of time and regularly visit fruit trees and places where they are given bananas. There is no rigid daily time schedule, and most of the home range is visited every day. The wild troop does not allow adult foreign conspecifics to settle on its territory, but a one year old male infant was accepted in February 1969. The staple food of the Lowe's guenon consists of fruits, flowers and leaves. Thirty two species of food plants are recorded. The monkeys are also very fond of insects, which they activcly hunt both in trces and on the ground. Insect hunting is selective, some unpalatable species being deliberately rejected. Water is licked from leaves and branches, or scooped out of tree holes. Breeding is seasonal, all infants bcing born between mid­November and mid-January, at the very end of the long rains and the beginning of the dry season. Thus the females appear ta conceive during the annual peak in rainfall and during the annual decline in temperature. The social structure of the troop is described. Although it includes more males than females, the Adiopodoumé troop is a «one male group», centered around the adult male. He acts as a leader and spends a great deal of time watching. The «warning bark» is his prerogative. Unlike mature females who readily act as «aunts», the adult male does not show interest in infants, even newborn ones, and juveniles. However he allows them to play close to him. Subadult males are bolder and more inquisitive than any other troop member. Juveniles and infants are very active players. No overt and rigid social hierarchy exists within the troop, although in certain circumstances younger individuals give way ta older ones. Early in 1969 a splitting of the group was observed. It took place progressively and quietly. In February, two males, 4 and 3 years old, and one 4 year old female, began to separatc from the rest of the troop during the day, returning to the traditional sleeping trees at night. They left the troop's home-range for good around the lst of March. Lowe's guenon often associates with other species of Cercopithecus (C. petaurista mainly) and Colobines (Colobus polykomos and C. badius). These mixed troops are more than chance aggregations of different species on the same food trees. In Lamto, the two free ranging male Cercopithecus campbelli lowei reacted immediately to the distress calls of a young female C. petaurista living with them, and would come to her rescue if she was in danger. Interactions with other Vertebrates are described. Reactions to soaring birds of prey are not stereotyped: in Adiopodoumé, the monkeys were not afraid of the common black kites, whereas an approaching buzzard sent them «diving» into thick foliage. Play interactions were observed with roosting hornbills, and even a pet mongoose. Breeding periodicity, which permits an eventual use of seasonal food surpluses, and the ability to descend to the ground and cross open spaces, might « pre-adapt » this forest monkey to life in wooded savannas. These two characteristics certainlv help one to understand the wide range of Lowe's guenon and its ability to live in the forest-savanna boundary.

bourilere-biblio

Freigegeben in B
Sonntag, 28 Februar 2021 07:22

GONZALEZ KIRCHNER, J. P. (2004)

Habitat preference of the Preuss's guenon (Cercopithecus preussi), on Bioko island, Equatorial Guinea.

Human Evolution: 19, Artikelnummer: 239 (2004)

Abstract:

The Press's guenon (Cercopithecus preussi) is considered to be one of the most threatened African primates. There is little information on the ecology and status of this primate on Bioko island, where it is found in the form of an endemic subspecies. The Press's, guenon shows preference for the Schefflera forest and the mountain habitat on Bioko island. As on the mainland they also have semitterrestrial habits and are found usually at the understorey of the forest. Competitive exclusion between this guenon and other guenon species could be an explanation of these ecological preferences. Habitat use and vertical stratification of the activity in the forest canopy seem to reduce competition with other sympatric primate species that inhabit on the island. Habitat destruction, and isolation in a reduced habitat, show to be the major threats for the survival of this primate on Bioko island.

gonzalez-biblio

Freigegeben in G

Predicted distributions and conservation status of two threatened Southeast Asian small carnivores: The banded civet and Hose 's civet.

Mammalia 77(3): 261–271. DOI 10.1515/mammalia-2012-0110  

Abstract:

Knowledge of the distribution and habitat preferences of a species is of paramount importance when assessing its conservation status. We used accurately recorded occurrence records and ecological niche modelling to predict the distribution of two threatened and poorly known small carnivore species that occur in Southeast Asia, the banded civet (Hemigalus derbyanus) and Hose’s civet (Diplogale hosei), and analysed their spatial niche differentiation for habitat and elevation. We then identified possible anthropogenic threats, and used our modelling predictions to recommend surveying priorities. The predicted distribution of the banded civet was principally in lowland evergreen forest in southern Myanmar/Thailand, Peninsular Malaysia, Sumatra, Borneo and three Mentawai Islands (Siberut, Sipora and South Pagai), and for Hose ’ s civet in evergreen forest across the higher elevation regions of Borneo. Our niche analyses suggested that there is a tendency for these two species to separate spatially along an elevation gradient: the banded civet is mainly found in lowland areas, whereas Hose ’ s civet primarily occurs at higher elevations. Our study strongly indicated that these two viverrids are forest-dependent species that may be threatened by forest loss, degradation and fragmentation. Field surveys should be prioritised in areas where each species is predicted to occur and no records currently exist.

jennings-biblio

Freigegeben in J

Rediscovery of the Mount Nimba Reedfrog, Hyperolius nimbae LAURENT, 1958, in western Ivory Coast (Anura: Hyperoliidae).

HERPETOZOA 29(1/2): 3-13

Kurzfassung:

Die vorliegende Arbeit berichtet über die Wiederentdeckung von Hyperolius nimbae LAURENT, 1958, einer Riedfroschart, die nur vom Fuß der östlichen Flanke des Mount Nimba im Westen der Elfenbeinküste bekannt ist. Die Art wurde 1958 beschrieben und 1963 zum letzten Mal beobachtet. Siebenundvierzig Jahre später wurden innerhalb des bekannten Verbreitungsgebietes kleine Populationen dieses Riedfrosches in der Nähe der Dörfer Dagbonpleu, Danipleu, Kouan-Houlé und Zéalé wiederentdeckt. Allerdings konnten nur insgesamt sieben Exemplare registriert werden. Die Lebensräume zeigten unterschiedliche Grade der degradierung von Sumpfwäldern bis zu Reisfeldern in degradiertem Wald oder Sekundärwuchs. Der starke menschliche Einfluß im Gebiet, besonders seine landwirtschaftliche Nutzung, könnte das langfristige Überleben der Art gefährden. Die Autoren empfehlen eine intensive weitere Suche nach bestehenden Populationen und deren Monitoring, um die Gefährdung für das Überleben von H. nimbae abzuschätzen.

n'goran-biblio

Freigegeben in N
Freitag, 04 Januar 2019 15:50

KUMMER, H. (1968)

Social organization of hamadryas baboons: A field study.

187 Seiten, 68 Abbildungen, 17 Tabellen.
Bibliothec Primatologica No. 6.
S. Karger Verlag, Basel, New York.

Inhalt:

Die Arbeit ist das Ergebnis einer Feldstudie, die von Fred KURT† und Hans KUMMER† 1960/61 in Äthiopien durchgeführt wurde. Sie klärt die soziale Organisation des Mantelpavians: Mantelpaviane sind in einem komplexen, mehrschichtigen Sozialsystem organisiert. Die kleinsten sozialen Einheiten sind Harems, die bis zu 15 Tiere umfassen können und aus einem Alpha-Mann, mehreren von ihm monopolisierten Weibchen, deren Jungtieren und einigen jungen Männchen bestehen. Zwei bis drei solcher Ein-Mann-Gruppen bilden zusammen einen Clan, dessen Mitglieder zusammen auf Futtersuche gehen und sozial interagieren. Mehrere Clans schließen sich zu einer bis zu 100 Individuen bestehenden Bande zusammen, die zusammen in einem gemeinsamen Streifgebiet von 10-40 km2 umherziehen. An Schlafplätzen können sich mehre Banden zu einer großen Herde treffen und die Nacht gemeinsam verbringen. Ferner gibt es ein Kapitel zur Fortpflanzung und ein Ethogramm.

kummer-biblio

Freigegeben in K
© Peter Dollinger, Zoo Office Bern hyperworx