Primate Update E-Newsletter, Vol. 4, Issue 6, Part 3

CONTINUING EDUCATION 

 Special Topic: Intern Mary 
Spider Monkeys: Demography and group composition of Ateles 

The distribution of spider monkeys ranges from Central to South America. The size, density, and composition of spider monkey groups differ greatly throughout this range and throughout the Ateles species. Eighteen groups, of four different Ateles species, were observed in a study and showed a wide variety of group sizes. The size of these groups ranged from fifteen to fifty-six individuals with a varying numbers of females to males, infants, adults, and juveniles.

 These drastic variations are caused by several factors. Accidental injuries, such as falling out of a tree, predation, and aggression by conspecifics all play a role. However, the main factor that creates variation among Ateles species is habitat. Habitat disturbance, such as deforestation, impacts that habitat’s carrying capacity. If a habitat cannot support over fifty spider monkeys in one area it makes sense that the size of a spider monkey groups found in that area is going to be smaller.

Brothers Carlos and Montana are 

very content as an all male subgroup!

Black-handed spider monkeys, Ateles geoffroyi, the species here at Pacific Primate Sanctuary have been shown to form medium sized groups, with an occasional larger group. When larger groups are formed there are typically more females in the group than males and it is very common to see subgroups made up entirely of adult males. A geoffroyi groups typically consist of more juveniles and infants than groups of other spider monkey species. The reason for this is not clear but one main cause may be due to the fragmentation of the forest where this species is located in Central America. Fragmented forests cause predator communities to be more widely distributed, which means that not as many predators are found together in one area of forest. This gives the spider monkeys a better chance of avoiding predators, and in turn, increases the survival of infants and juveniles. Since younger monkeys are more vulnerable, they are usually the first animals taken by predators. It is important that many young of this species survive, as Black-handed Spider monkeys are currently listed as an Endangered Species. 

-Campbell, Christina J. Spider Monkeys: Behavior, Ecology, and Evolution of the Genus Ateles (Cambridge Studies in Biological and Evolutionary Anthropology). UK. Cambridge University Press. 2008.


Special Topic: Intern Annabel:
Defining and Identifying Bacteria 

The monkeys at PPS occasionally develop bacterial infections that need to be treated with a course of antibiotics. Different antibiotics are used to treat different types of bacteria and infections. It is important to know which type of antibiotics to use when treating the monkeys in order to ensure they have a speedy recovery, we can determine this best by understanding the different forms of bacteria.

Definition of Bacteria 
Bacteria are microscopic single-celled organisms. They possess a prokaryotic type of cell structure, which means that their cells are non–compartmentalized, and their DNA (usually circular) can be found throughout the cytoplasm rather then within a membrane bound nucleus. They reproduce through fission (splitting) or by forming spores. Bacteria are present in most habitats on Earth, growing in soil, acidic hot springs, radioactive waste, water, and deep in the Earth’s crust, as well as in organic matter and the live bodies of plants and animals. There are typically 40 million bacterial cells in a gram of soil and a million bacterial cells in a milliliter of fresh water. There are approximately five nonillion (5 followed by 30 zeros!) bacteria on Earth, forming a biomass that exceeds that of all plants and animals.

Bacteria are vital in recycling nutrients, with many steps in the nutrient cycle depending on these organisms. The vast majority of the bacteria in the body are rendered harmless by the protective effects of the immune system, and a few are beneficial. However, a few species of bacteria are pathogenic and cause infectious diseases, including cholera, syphilis, anthrax, leprosy, and bubonic plague. The most common fatal bacterial diseases are respiratory infections, with tuberculosis alone killing about 2 million people a year, mostly in sub-Saharan Africa. In developed countries, antibiotics are used to treat bacterial infections and in agriculture, so antibiotic resistance is becoming common. In industry, bacteria are important in sewage treatment and the breakdown of oil spills, the production of cheese and yogurt through fermentation, the recovery of gold, palladium, copper and other metals in the mining sector as well as in biotechnology, and the manufacture of antibiotics and other chemicals.

 Differences in Bacteria
Bacteria may be classified based on their shape. Different antibiotics are be used to treat different shaped bacteria.
 The different bacteria shapes are:
➢ Spherical (cocci)
➢ Rod-like (bacilli)
➢ Spiral (spirochetes)
➢ Comma Shaped (vibrios)

Bacteria can also be classified as either gram positive or gram negative, aerobic or anaerobic, autotrophic or heterotrophic.

 Aerobic bacteria use oxygen for metabolism. Oxygen can actually be rather toxic, and for a cell to be able to use molecular oxygen, it must be able to manufacture specific enzymes that detoxify oxygen waste products. Anaerobic bacteria are able to live without oxygen, they either do not have the enzymes required to detoxify oxygen waste, or are not able to make enough of these enzymes to be able to live at normal levels of atmospheric oxygen.

Gram-positive and gram-negative bacteria are defined based on how the bacteria reacts to a gram stain. If it takes the initial stain it will be purple in color and will be considered gram positive. If it does not take the initial stain, it will be pink in color and will be considered gram negative. The difference is in the outer casing of the bacteria. Gram-positive bacteria have a thick layer of peptidoglycan (a sugar protein shell) that the stain can penetrate. Gram-negative bacteria have an outer membrane covering a thin layer of peptidoglycan on the outside. The outer membrane prevents the initial stain from penetrating.

Most autotrophic bacteria can synthesize their food from substances like hydrogen sulphide. This process is called chemosynthesis and involves the use of chemical substances for the production of energy. Heterotrophic bacteria, in contrast, cannot synthesize their own energy and must consume organic matter for energy. These include decomposing bacteria, or other groups of bacteria that may be symbiotic or parasitic in nature.

By understanding, and being able to classify bacteria types, we are one step closer to knowing how best to treat any infections that may occur. Next month, we will explore the different types of antibiotics, and what they treat. 

References
http://www.biology-online.org/dictionary/Bacteria
http://tami-port.suite101.com/difference-between-aerobic--anaerobic-bacteria-a132294
Wikipedia
http://www.bioconlabs.com/autoheterobac.html
Antibiotics, Todar, 2000


Special Topic: Intern Linda 
 Marmosets and Tamarins Chapter 12: Habitats, Feeding Ecology, and Home Range Size in the Genus Callithrix 

 Here at the sanctuary we have three different species of the genus Callithrix. They are white-tufted eared marmosets (C. jacchus), black-tufted eared marmosets(C. penicillata), and Weid’s marmosets (C. kuhlii). In the wild they all occupy different niches, but exhibit similarity in their diets.

White-tufted eared marmosets (C. jacchus) live in the riverine (located on or inhabiting the banks of a river) forests of Northeast Brazil and North Atlantic coast. Black tufted eared marmosets (C. penicillata) live in a more seasonal environment, in forest patches and savanna forests of central Brazil. Weid’s marmsoets (C. Kuhlii) live in the Atlantic forest regions of Bahia (east Brazil). 


A white-tufted eared marmoset 

eating a piece of fruit

 The feeding ecology of Calithrix allows for them to have quite small home ranges compared to other New World primates. Being gummivores (gum/exudate eaters) provides them with plenty of food at nearby trees. Marmosets have specialized teeth designed for gouging into trees, which draws the gums to the surface. A single tree can provide food for many individuals. There is not much fruit in the diet of white-tufted eared marmosets or black-tufted eared marmosets in wild populations. However when they do eat fruit, they use edge and secondary forest depending on fruit types and fruiting patterns. When faced with shortages of fruit, Callithrix monkeys have the ability to exploit gums and forage for insects and other animal prey.

-Rylands, A.B. Marmosets and Tamarins. Systematics, Behavior, and Ecology. Oxford, U.K.: Oxford University Press, 1993.

 I don't know what your destiny will be, but one thing I do know: the only ones among you who will be really happy are those who have sought and found how to serve.    -Albert Schweitzer, philosopher, physician, musician, Nobel laureate


 We hope you have enjoyed this issue of Pacific Primate Sanctuary’s E-Newsletter. Thank you for your support of our life saving work. Because of compassionate people, the Sanctuary can continue to provide a place of peace and happiness for 70 primates saved from research laboratories, animal dealers, and tourist attractions. Here they can heal, form families, and live free from exploitation.

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