Interspecific interactions between wild black and gold howlermonkeys (<Emphasis Type="Italic">Alouatta caraya</Emphasis>) and other mammals in northeastern Argentina

We studied the interactions between wild black and gold howler monkeys (Alouatta caraya) and other mammals at three sites with different human disturbance levels and forest structures in northeastern Argentina. The main goal was to evaluate the effects of the study site and type of interaction (agonistic or non-agonistic) on the rate of interaction. In addition, we also described the associations between interspecific interaction rate, species involved, howler monkeys’ activity, and seasonality. We present 50 group-years for 14 groups, collected between 2003 and 2012. We registered a total of 29 interactions (0.22 ± 0.26 interactions/100 h). Most interactions (56.7%) were agonistic (12% of high intensity and 88% of low intensity), 41.9% were neutral, and 1.5% were affiliative. We found that both factors, site and type of interaction, have an effect on the rate of interaction. Interspecific interactions were more frequent at the two sites without human settlement than in the rural site. Interspecific interactions occurred during resting (46.73%), traveling (27.40%), and feeding (25.87%). Interactions occurred throughout the year but were concentrated in August (late winter) and September (beginning of spring). Our results suggest that both site and type of interaction affected the rate of interaction between howler monkeys and other mammals in northeastern Argentina. Agonistic interactions were more frequent that non-agonistic ones, and monkeys reacted agonistically to several mammalian species, but these interactions were mainly of low intensity.     

Nutritional status of free‐ranging Mexican howler monkeys (Alouatta palliata mexicana) in Veracruz,Mexico: Serum chemistry; lipoprotein profile; vitamins D,A, and E; carotenoids; and minerals

The purpose of this work was to measure important nutritional status parameters for a group of free‐ranging Mexican mantled howler monkeys (A. palliata mexicana) and compare those data to published data for primates. The nutritional status of six free‐ranging Mexican mantled howler monkeys was examined using biochemical analysis. Blood samples were analyzed for serum chemistry; lipids; vitamins D, A, and E; carotenoids; and minerals. Serum chemistries were somewhat different from published values, but did not indicate clear abnormalities. Circulating lipids were not different from those in captive primates. Circulating vitamin D metabolites (83±16.3 for 25(OH)D ng/mL; 563±53.8 for 1,25(OH)₂D pg/mL) were similar to those in wild‐caught tamarins (Saguinus oedipus), lower than some published data for captive Cebidae and Callitrichidae, and higher than for Old World primates. Serum concentrations of retinol (16.5±1.64 μg/dl) were similar to those in captive spider monkeys (Ateles geoffroyi). Retinyl palmitate and retinyl stearate was present in howler samples and may have reflected recent dietary intake. Circulating α‐tocopherol (997±97.6 μg/dl) was similar to published values for other primates. Carotenoid levels in howlers were within the ranges reported for many primates. A significant finding was the presence of cadmium in samples that should be further studied. The number of individuals sampled was limited, and further investigation into the effects of seasonality is needed. However, this information provides new data for howler monkeys and for free‐ranging primates in general. Zoo Biol 22:239–251, 2003. © 2003 Wiley‐Liss, Inc.     

Lead levels in long-tailed macaque (<Emphasis Type="Italic">Macaca fascicularis</Emphasis>) hair from Singapore

Nonhuman primates are potentially good sentinels of environmental toxicants because they share a similar physiology and life history with humans. In this report we present the results of an analysis of lead concentrations in hair from long-tailed macaques in Singapore. We hypothesized that because Singapore is highly urbanized, its macaque population may be exposed to higher levels of lead. The results of our study indicated that Singapore’s macaque population has not been exposed to high levels of environmental lead. Compared with previous studies of lead levels in human and nonhuman primate hair, the results of our analysis indicate a low level of exposure of monkeys to environmental lead (n = 27, arithmetic mean = 2.51 ppm, max = 6.45, min = 0.21 ppm). Hair lead concentrations varied both within social groups and by geographic location, with the highest concentrations observed in monkeys residing within an area containing a small-arms firing range and a manufacturing facility. Although lead exposure in this area seems to be low, additional monitoring and possible remediation may be warranted. Our study is among the first to illustrate how primates can serve as potential sentinels of environmental toxicants such as lead. Future research examining the efficacy of primates as sentinels of lead exposure should include monitoring of environmental lead levels, and comparison of hair lead levels with levels measured in blood samples.     

Ovarian cycle of southern brown howler monkey (<Emphasis Type="Italic">Alouatta guariba clamitans</Emphasis>) through fecal progestin measurement

The ovarian cycle in howler monkeys (genus Alouatta) has beean investigated through several biological parameters (ranging between 16.3 and 29.5 days); however, no data exist concerning the ovarian activity of the southern brown howler monkey (Alouatta guariba clamitans). This study aimed to describe the ovarian cycle of A. g. clamitans by profiling fecal progestin concentrations. Over 20 weeks, fecal samples of eight captive adult females of A. g. clamitans were collected. The collections were made at dawn, 5 days a week, and the samples were frozen immediately following collection. Next, they were dried, pulverized and hormonal metabolites were extracted to determine progestin concentrations by enzyme immunoassay. Of the 758 samples tested, the mean concentration of fecal progestins was 2866.40 ± 470.03 ng/g of dry feces, while the mean concentration at baseline was 814.47 ± 164.36 ng/g of dry feces. Among the eight females, one showed no ovarian cyclicity and three presented periods of probable absence of cyclicity and low progestin concentrations. A mean duration of 16 ± 0.52 days was observed for the 35 cycles studied. The interluteal phase lasted 4 ± 0.37 days on average, with a mean concentration of fecal progestins of 467.98 ± 29.12 ng/g of dry feces, while the luteal phase lasted 11 ± 0.50 days, with a mean concentration of 4283.27 ± 193.31 ng/g of dry feces. Besides describing the characteristics of the ovarian cycle, possible causes for the low concentrations of fecal progestins and periods of absence of cyclicity are also discussed.     

Anesthesia of wild red howler monkeys (Alouatta seniculus) with medetomidine/ketamine and reversal by atipamezole

Wild red howler monkeys (Alouatta seniculus) were translocated during the flooding of the forest at a hydroelectric dam site in French Guiana. For a variety of minor clinical procedures, 96 monkeys were anesthetized with various intramuscular injections of combinations of medetomidine and ketamine. The howler population was composed of healthy animals (42 males and 54 females) of various ages. Medetomidine (150 μg/kg) associated with ketamine (4 mg/kg) gave the best results and was used on 63 animals. The injection rapidly resulted in complete immobilization with good to excellent myorelaxation. The induction stage was quiet, with absence of both corneal and pedal withdrawal reflexes in 57 animals after 2.9 ± 1.4 min. Six animals required an additional injection. Rectal temperature and respiratory and heart rates decreased during anesthesia, whereas relative oxyhemoglobin saturation increased. One death occurred during anesthesia. One abortion and one death also occurred the day following anesthesia but were more probably a result of capture stress. Atipamezole given i.m. at a dose of five times the medetomidine dose 38.4 ± 8.0 min after the anesthetic injection led to standing recovery in 7.1 ± 4.5 min. Spontaneous recovery occurred in 17 animals before the atipamezole injection after an average of 30.6 ± 9.6 min. Total recovery time was shorter in young animals. Medetomidine/ketamine induced good myorelaxation and provided considerably shortened immobilization duration, which are two notable advantages for field studies. We recommend this association for short procedures including minor surgery in red howler monkeys. Am. J. Primatol. 45:399–410, 1998. © 1998 Wiley-Liss, Inc.     

The impact of man-made earthen barriers on the physical structure of New England tidal marshes (USA)

In New England salt marshes, man-made earthen barriers, or berms, are generally historic, small-scale (average height = 0.71 m ± 0.12 SE; average length = 166 m ± 41 SE) tidal restrictions which originated from past agricultural, industrial, and environmental practices. The orientation and size depends primarily on the original purpose of the barrier, but this study examines the effects of berms oriented parallel to the incoming tide such that some landward portion of the marsh receives a different tidal signal than the seaward portion. Our hypotheses considered the impacts of the altered hydrology on pore water chemistry and edaphic characteristics. The results indicate that the effect of berms on salt marsh physical structure varies significantly by site. Where the tidal flooding frequency is restricted and drainage is poor, the landward marsh shows pool development, high salinity and sulfide concentrations, and low vegetation cover. In contrast, where tidal flooding is inhibited but the marsh soils are well-drained, salinity and sulfide concentrations decrease and accelerated decomposition results in subsidence and reduced soil organic matter. Given these findings, impacts from berms may impair salt marsh function and resilience to invasive plants and sea level rise.     

Survey of Alouatta caraya, the black-and-gold howler monkey, and Alouatta guariba clamitans, the brown howler monkey, in a contact zone, State of Rio Grande do Sul, Brazil: evidence for hybridization

Sympatry and natural hybridization between howler monkey taxa (Alouatta spp.) has only recently being confirmed in the wild. Surveys in areas of potential contact between the distribution of two taxa have shown that sympatry is rare, although more common than previously known. Here we report the results of a survey conducted in a contact zone between the only two sexually dichromatic howler monkey taxa, Alouatta caraya and A. guariba clamitans, in São Francisco de Assis, State of Rio Grande do Sul, Brazil. Our survey, covering an area of about 400 ha at the Cerro dos Negros (29°33′50″–29°35′10″S, 54°58′40″–54°59′50″W; ~100–279 m a.s.l.), was successful in locating seven black-and-gold and one brown howler monkey social groups living syntopically. Black-and-gold group size ranged from 5 to 15 individuals, whereas the brown group was composed of 7 individuals. The pelage color of three adult males belonging to different black-and-gold groups and another adult male belonging to the brown howler group presented a mosaic of red or rufous and black. These adult males and an adult female living in another black-and-gold group are putative hybrids. Therefore, it appears that pre-zygotic reproductive isolation has not evolved, at least not completely, between these howler monkey species, corroborating previous reports for these and other Alouatta taxa. Future genetic studies need to confirm the occurrence of hybridization in this contact zone, and to determine the viability and fertility of hybrids and their possible offspring. In addition, there is no evidence supporting the existence of significant segregation in habitat and resource utilization by black-and-gold and brown howler monkeys.     

The effect of low- and high-power microwave irradiation on in vitro grown <Emphasis Type="Italic">Sequoia</Emphasis> plants and their recovery after cryostorage

Two distinct microwave power levels and techniques have been studied in two cases: low-power microwave (LPM) irradiation on in vitro Sequoia plants and high-power microwave (HPM) exposure on recovery rates of cryostored (?196°C) Sequoia shoot apices. Experimental variants for LPM exposure included: (a) in vitro plants grown in regular conditions (at 24 ± 1°C during a 16-h light photoperiod with a light intensity of 39.06 μEm^?2 s^?1 photosynthetically active radiation), (b) in vitro plants grown in the anechoic chamber with controlled environment without microwave irradiation, and (c) in vitro plants grown in the anechoic chamber with LPM irradiation for various times (5, 15, 30, 40 days). In comparison to control plants, significant differences in shoot multiplication and growth parameters (length of shoots and roots) were observed after 40 days of LPM exposure. An opposite effect was achieved regarding the content of total soluble proteins, which decreased with increasing exposure time to LPM. HPM irradiation was tested as a novel rewarming method following storage in liquid nitrogen. To our knowledge, this is the first report using this type of rewarming method. Although, shoot tips subjected to HPM exposure showed 28% recovery following cryostorage compared to 44% for shoot tips rewarmed in liquid medium at 22 ± 1 °C, we consider that the method represent a basis and can be further improved. The results lead to the overall conclusion that LPM had a stimulating effect on growth and multiplication of in vitro Sequoia plants, while the HPM used for rewarming of cryopreserved apices was not effective to achieve high rates of regrowth after liquid nitrogen exposure.     

Fractionation,Source Identification and Risk Assessments for Heavy Metals in Soils near a Small-Scale Industrial Area (Çanakkale-Turkey)

Contamination of soils by heavy metals due to urbanization increases various environmental concerns. The objective of this research was to determine the potential sources of heavy metals in agricultural soils in the vicinity of a small-scale industrial area and to assess their environmental impacts. Soil samples were obtained from 15 different locations near a small industrial area in the Çanakkale province of Turkey. Heavy metal (Cd, Co, Cu, Ni, Pb, Zn) contents of soil samples were determined with four different geochemical fractions via a sequential extraction procedure. The results revealed that pseudo-total heavy metal concentrations were ordered in decreasing order as Zn > Pb > Cu > Ni > Co > Cd. Considering the results, Cd (1.95 ± 0.12 µg/g), Pb (39.21 ± 2.14 µg/g) and Zn (64.99 ± 8.16 µg/g) values were above the normal values specified for agricultural lands. The findings obtained from sequential extraction procedure showed that Cd (78%) and Pb (65%) existed mostly in mobile phases. Such mobile phases originated mostly from anthropogenic sources. These findings were also supported by chemometric analyses. Risk assessments pointed out that while Pb and Zn have moderate risks on the environment, Cd creates high risks.     

Timing of births in sympatric brown howler monkeys (Alouatta fusca clamitans) and northern muriquis (Brachyteles arachnoides hypoxanthus).

We monitored the birth patterns of sympatric brown howler monkeys (Alouatta fusca clamitans) and northern muriquis (Brachyteles arachnoides hypoxanthus) during a 4‐yr period from October 1996 to August 2000 at the Estação Biológica de Caratinga, Minas Gerais, Brazil. Brown howler monkey births (n = 34) occurred throughout the year, and birth frequencies did not differ between rainy and dry season months. The aseasonal birth patterns of the howler monkeys differed significantly from the dry season concentration and dry month peak in muriqui births (n = 23). We found no effects of infant sex or the number of females on interbirth intervals (IBIs) in our 10 howler monkey study troops. IBIs of brown howler monkeys averaged 21.2 ± 2.5 mo (n = 8, median = 21.0 mo), and were significantly shorter following dry season births than rainy season births. Their IBIs and yearling survivorship (74%) were similar to those reported for other species of howler monkeys, but yearling survivorship was much lower than that of muriquis (94%), whose IBIs were more than 12 mo longer than those of the howler monkeys. Our study extends comparative knowledge of birth patterns in Alouatta to a poorly known species, and provides insights into the different ways in which diet and life history may affect the timing of births in large‐bodied platyrrhines under the same seasonal ecological conditions. Am. J. Primatol. 55:87–100, 2001. © 2001 Wiley‐Liss, Inc.     

Cascading Effects of Climate Change: Do Hurricane‐damaged Forests Increase Risk of Exposure to Parasites?

Increased parasitism in animals in disturbed habitats is often understood to be the result of increased disease susceptibility due to low food availability resulting in nutritionally stressed and immunocompromised individuals. Such habitat change, however, might also lead to increased exposure to disease. In this article, we test measures of susceptibility and exposure to explain the prevalence and intensity of directly and indirectly transmitted helminths in black howler monkeys (Alouatta pigra) following a hurricane in Belize. None of these parasites were predicted by direct measures of susceptibility (as measured by fruit consumption and fecal cortisol levels). Rather, directly transmitted parasites (Trichuris sp. and strongylid type eggs.) were predicted by host density and group size, both measures of exposure. Similarly, only the consumption of Cecropia peltata, a fast growing pioneer that has a mutualistic relationship with ants predicted levels of the indirectly transmitted trematode Controrchis spp., also suggesting exposure. Cecropia peltata also increased in density post‐hurricane, was high in digestible protein, sugar, and salt and eaten by monkeys more frequently than predicted based on distribution. These data suggest that in this hurricane‐damaged forest the ingestion of this abundant and nutritious pioneer species increased exposure of the monkeys to Controrchis through ingestion of ant intermediate hosts. These results may point to a pattern true of pioneer species in general, leaving animals in disturbed forests with higher levels of parasitism as a result of changes to forest structure. As severe weather events are expected to increase, this suggests a cascading effect of climate change on ecosystem interactions and disease ecology.     

Assessment of potential health risk of heavy metals in soils from a rapidly developing region of China

Soil heavy metal contamination is a major environmental concern, and health risk associated with heavy metals is not fully explored. A combination of spatial analysis and Monte Carlo simulation was successfully used to identify the possible sources and health risk of cadmium (Cd), arsenic (As), mercury (Hg), lead (Pb), chromium (Cr), and copper (Cu) in soils collected from a rapidly developing region of China. It was found that mean concentrations of Cd (0.17 mg/kg ), As (8.74 mg/kg ), Hg (0.15 mg/kg ), Pb (27.28 mg/kg ), and Cu (33.32 mg/kg ) were greater than the soil background values. Accumulation and spatial variability of heavy metals were significantly affected by anthropogenic activities and soil properties. The risk assessment indicated that non-carcinogenic risk was not significant. However, 95% of the total cumulative carcinogenic risk of children was greater than 1E-05, implying high potential carcinogenic risk with As and Pb representing the major contributors. Ingestion of heavy metals in the soils was the main exposure pathway compared with the inhalation and the dermal exposure. Concentration of heavy metals in the soils, particulate emission factor, and dermal exposure ratio were the major parameters affecting health risk. This study highlights the importance of assessment of soil direct exposure health risk in studying heavy metal exposures.     

Chromium tolerance,oxidative stress response,morphological characteristics,and FTIR studies of phytopathogenic fungus <Emphasis Type="Italic">Sclerotium rolfsii</Emphasis>

Sclerotium rolfsii is one of the most destructive fungal plant pathogens that can infect over 500 plants and can adapt to diverse environmental conditions. The present research work was carried out to evaluate the impact of both hexa- and trivalent chromium (Cr) on growth, morphology, enzymatic characteristics, and metal accumulation in S. rolfsii under laboratory conditions. Experiments were performed in both malt extract broth and agar growth medium amended with six different concentrations (10, 20, 40, 60, 80, and 100 ppm) of each Cr(III) and Cr(VI) ions inoculated with fungus and incubated for 6–7 days at 25 ± 3 °C. In broth medium, the total protein content was declined and activities of antioxidant enzymes were increased with an increase in metal concentrations. Lower concentrations (10 ppm) of the metal ions stimulated the growth of fungus and higher concentrations (60–100) inhibited it. The Fourier transform infrared spectroscopy (FTIR) assessment showed hydroxyl, carboxyl, and amine groups as major metal binding sites. In agar medium, tolerance index was decreased up to 0.56 at 10–80 ppm of Cr(III) and up to 0.62 at 10–60 ppm of Cr(VI). Considerable modifications were observed in hyphal and sclerotial morphology with an increase in concentration of metal ions. The current study concluded that interference of Cr with growth and physiological process of S. rolfsii could affect its infection level on its host plant. This study provides important information regarding cultivation of susceptible plant varieties in Cr-polluted soil as evidenced by pathogen growth up to 50 ppm of Cr(III) and Cr(VI) ions.     

Isolation of indigenous Staphylococcus sciuri from chromium-contaminated paddy field and its application for reduction of Cr(VI) in rice plants cultivated in pots

Accumulation of Cr(VI) in rice seeds cultivated in Cr-contaminated soil of the Sundarbans (India) is an environmental problem. Cr(VI) concentration in this soil was 6.2 ± 0.3 mg/kg, whereas total chromium was 32.04 ± 1.60 mg/kg. A Cr(VI)-removing bacterium isolated from Cr-contaminated paddy field soil of Sundarbans was identified as Staphylococcus sciuri. Enrichment culture of S. sciuri was applied to pot cultivation of rice in Cr-contaminated soil. After 8 weeks, 71 ± 3% Cr(VI) (final concentration 2.15 ± 0.01 mg/kg) and 65 ± 2% total Cr removal (end concentration 11.3 ± 0.5 mg/kg) were attained in bacterium-treated soils. Growth parameters indicated healthy development of plants cultivated in bacterium-treated soils that was not observed in control plants. Total Cr removal attained in rice seeds of plants cultivated in bacterium-treated soils compared with control rice seeds was 78 ± 4%. Total Cr concentration in test seeds was 0.72 ± 0.05 mg/kg (World Health Organization [WHO] permissible limit: 1.30 mg/kg), whereas the same in control seeds was 3.27 ± 0.16 mg/kg. Cr(VI) reduction achieved in rice seeds cultivated in bacterium-treated soil compared with control rice seeds was 95 ± 5%. Cr(VI) concentration in rice seeds cultivated in treated soil was 0.050 ± 0.003 mg/kg, whereas the same in untreated control was 0.93 ± 0.05 mg/kg. Successful paddy field soil bioremediation by any Staphylococcus species was demonstrated for the first time.     

Phytoremediation of lead by a wild,non-edible Pb accumulator Coronopus didymus (L.) Brassicaceae

Coronopus didymus was examined in terms of its ability to remediate Pb-contaminated soils. Pot experiments were conducted for 4 and 6 weeks to compare the growth, biomass, photosynthetic efficiency, lead (Pb) uptake, and accumulation by C. didymus plants. The plants grew well having no visible toxic symptoms and 100% survivability, exposed to different Pb-spiked soils 100, 350, 1500, and 2500 mg kg^?1, supplied as lead nitrate. After 4 weeks, root and shoot concentrations reached 1652 and 502 mg Pb kg^?1 DW, while after 6 weeks they increased up to 3091 and 527 mg Pb kg^?1 DW, respectively, at highest Pb concentration. As compared to the 4 week experiments, the plant growth and biomass yield were higher after 6 weeks of Pb exposure. However, the chlorophyll content of leaves decreased but only a slight decline in photosynthetic efficiency was observed on exposure to Pb at both 4 and 6 weeks. The Pb accumulation was higher in roots than in the shoots. The bioconcentration factor of Pb was > 1 in all the plant samples, but the translocation factor was < 1. This suggested C. didymus as a good candidate for phytoremediation of Pb-contaminated soils and can be used for future remediation purposes.     

Contamination features and health risk of heavy metals in suburban vegetable soils,Yanbian, Northeast China

In recent years, heavy metal contamination in suburban vegetable soils calls for significant concerns due to the rapid urbanization and industrialization. In present study, 110 suburban vegetable soil samples from Yanbian, Northeast China, were collected. Concentration characteristics, pollution level, health risk, and source identification were evaluated by using different quantitative indices. Concentrations of Pb, Cr, Cu, Ni, Zn, Cd, and As in suburban soils were measured. Mean concentrations of Pb, Cr, Cu, Ni, Zn Cd, and As were 34.9 ± 10.5, 73.5 ± 44.4, 29.6 ± 19.4, 23.4 ± 12.0, 88.5 ± 26.7, 0.16 ± 0.16, and 9.24 ± 3.79 mg/kg, which were showed significantly higher than corresponding background values of Jilin province, respectively. The soils were moderately heavy polluted by Cu and Cd based on the results of geo-accumulated index and pollution indices. The pollution load index indicated that almost all of the study area were middle or heavy polluted, especially in Antu County and Helong City. Children in Yanbian may pose non-carcinogenic and carcinogenic risks with the major exposure pathway of ingestion. Principle component analysis results suggested that Pb, Cu, Zn, and Cd were mainly associated with agricultural activities, Ni and Cr were defined as combined source (lithogenic and anthropogenic), and As was tended to be from excessive application of pesticides and industrial activities.     

Births during 7 years after the translocation of a pair of black-and-gold howler monkeys (<Emphasis Type="Italic">Alouatta caraya</Emphasis>) to a forest fragment in southeast Brazil

Fecundity in female primates is influenced by the nutritional condition. If when translocated howler monkeys exhibit the same breeding patterns as non-translocated members of the same genus, it is an indication that the translocated monkeys have become well adapted to their release site and that they are likely in good nutritional condition. The objective of this study was therefore to investigate this pattern by recording copulations (over 5 years) and births (over 7 years) after the translocation of a pair of black-and-gold howler monkeys (Alouatta caraya) and to evaluate their gestation period, seasonality of births, and intervals between births. The pair was released in November 2009 on the campus of the University of São Paulo in Ribeirão Preto, São Paulo State, Brazil. Data on copulations were collected from January 2010 to March 2011 and from January 2012 to December 2014. Births were collected from January 2010 to December 2016. During the 5-year observation period, 25 copulations were recorded. Seven births were recorded over a period of 7 years, which included reproduction of the offspring of the translocated pair. Births occurred in the dry season between April and August. The interval between births was approximately 1 year. Our data provide insight into the reproduction of howler monkeys that have been translocated to a new habitat. Translocation can provide a valuable approach for rescuing or restoring Alouatta, whose populations have been detrimentally impacted by long-term habitat fragmentation.     

Modeling the distribution of wild rabbits (Oryctolagus cuniculus) on a Mediterranean island

The European rabbit (Oryctolagus cuniculus) is a widely distributed mammal with an often contradictory ecological role, imposing the need for population management. Sound management requires an in-depth understanding of the complex species–habitat relationships. In this study, CART analysis was employed to identify the most important environmental and anthropogenic factors affecting the spatial distribution of wild rabbit on Lemnos Island, northeastern Aegean Sea in Greece. On Lemnos, this species is considered an agricultural pest due to its overabundance resulting from the long-term absence of viral diseases, limited predation pressure, and lack of effective management. The study was carried out during the summer of 2008 by surveying rabbit densities in 181 2 × 2-km squares. Seven environmental and 14 anthropogenic variables, measured at two spatial scales, were used as explanatory variables. Soil hardness was the most influential variable, dividing the island into two distinct areas, namely the rabbit-poor areas with hard rocky soils and the rabbit-rich areas where soft soils prevail. In the former, the presence of a sharp relief can lead to complete absence of the species, while a combination of gentle relief, low altitudes, and low presence of arable land can lead to moderate rabbit density. In the latter, human-caused disturbance can reduce the number of rabbits, while a high density of ecotones and streams and a high presence of riparian vegetation can increase population densities to its highest levels observed. Our findings can formulate a scientific basis for the development of an effective management strategy for its population control.     

Fruit choice by red howler monkeys (Alouatta seniculus) in a tropical rain forest

This paper presents and discusses aspects of fruit selectivity by red howler monkeys (Alouatta seniculus) in relation with morphological characteristics of fruits. These data are used to provide an answer to the following questions: which are the fruit characteristics that lead fruit choice of howler monkeys and to what extent fruit characteristics play a role in seed dispersal by monkeys? The frugivorous diet of a troop of red howler monkeys was determined during a 2-year field study in French Guiana. The selection of fruit by howler monkeys was analyzed in relation to the fruit availability. Results showed that, although consumption followed availability, fruit species could be classified in three categories according to their selection ratio (percentage of consumption/percentage of abundance) as “high ranking,” “middle ranking,” and “low ranking” species. Also, the 97 species of fruit eaten by the monkeys were grouped according to the morphological characteristics thought to influence the monkeys' choice. This showed that howler monkeys consumed essentially fruits with juicy pulp, bright color, and a small number of well-protected seeds. Most of high ranking species had medium-sized fruits with yellow color, and low ranking species often had small fruits. However, howler monkeys are associated with the dispersal of seeds from fruit with a hard and indehiscent pericarp and/or large seeds, like those of the Sapotaceae family. Consequently, they can be considered as “specialized” frugivores for this fruit syndrome. © l996 Wiley-Liss, Inc.     

Squirrel monkey cytomegalovirus antibodies in free-ranging black howler monkeys (Alouatta caraya), Misiones, Argentina

Serum from four black howler monkeys (Alouatta caraya) was screened for antibodies to seven viruses by dot immunoassay. Cytomegalovirus antibodies were detected in three of four individuals and provide the first evidence of exposure by black howler monkeys to this virus.