Archives: Biodiversity

Pacific Tree Frog

The Pacific Tree Frog (Pseudacris regilla) is a very common species of chorus frog, with a range from the West Coast of the United States (from North California, Oregon, and Washington) to British Columbia in Canada. Living anywhere from sea level up to over 11,000 feet, they are found in shades of greens or browns and even have been known to change between them. They live in many types of habitats and reproduce in aquatic settings.

Blue-sided Tree Frog

Agalychnis annae is a moderately large and slender frog. Males have a maximum snout-vent length of 73.9 mm, and females 84.2 mm. The head is slightly convex and is narrower than the body. Males have a softly sloping snout from the eyes to the nostrils in lateral profile. Females have a blunt snout in lateral profile (Duellman 2001). The eyes are large and the lower eyelid is reticulate. The dorsal surface is smooth and the venter is faintly granulate (Savage 2002). The tympanum is distinct, besides the upper and posterior edges which are covered by a heavy dermal fold. This fold extends from the posterior corner of the orbit to a point posterior to the angle of the jaw. A narrow dermal fold also extends from the elbow along the ventrolateral edge of the forearm onto the base of the fourth finger. A weak tarsal fold is observed along the entire length of the tarsus. Another thin dermal fold is present from the heel along the ventrolateral edge of the tarsus to the fifth toe. The upper arm is slim and the forearm robust, while the hind limb is slender. The fingers of A. annae are short with large discs. The diameter of the disc on the third finger is equal to that of the tympanum. The toes are somewhat slim and the terminal discs are only slightly smaller than those on the hand. Fingers are about 2/3 webbed and toes are webbed (Duellman 2001). There is a brown nuptial pad on the base of the thumb in adult males (Savage 2002). The vocal sac is unpaired, median, subgular and not markedly distensible (Duellman 2001). This frog is quite colorful. In contrast to the uniform green upper surfaces, the proximal dorsal portion of the upper arm is pink to lavender and the distal portion is blue. The flanks and anterior and posterior thigh surfaces are blue. The upper surface of the hands and feet are green, orange, and blue. There are vivid creamy yellow stripes along the ventrolateral margin of the forearm, tarsus and foot. The venter is creamy yellow to orange. This species is able to undergo metachrosis (color change), and the colors darken at night to a darker green and bluish purple. Metamorphs lack blue coloring and turn reddish brown at night and in preservatives (Savage 2002). Larvae are moderately sized and have a total length of 33 mm at stage 31. The eyes are dorsolateral and directed laterally and the nostrils are dorsolateral and directed anterolaterally. The tail is moderate, caudal fins are high and the tail tips are short. The oral disc is small and entire, with large, serrated beaks and 2/3 rows of denticles. The mouth is located anteroventrally and directed anteriorly. Papillae border the mouth in two rows and laterally scattered small papillae lie medially to the fringing row. The spiracle is ventral and sinistral to the midline (Duellman 2001). Tadpoles have a heavily pigmented snout, top of head, and body, appearing grayish brown. The sides of the body are bluish gray, and the venter is light blue-gray with a silvery cast. The larval caudal musculature is a light gray brown. The caudal fins are clear with brown dashes on the proximal edges of the anterior half of the dorsal and ventral fins. During development, the pigmentation increases on the dorsal surface of the body and the caudal musculature, while the pigment in the caudal fins decreases. The iris is yellow (Duellman 2001).

Yellow-billed Stork

The Yellow-billed Stork, Mycteria ibis, is a large wading bird in the stork family Ciconiidae. It occurs in sub-Saharan Africa and in Madagascar. Its a medium-sized stork (length: 97 cm; average body weight for males: 2.3 kg; for females: 1.9 kg.) Its plumage mainly pinkish-white with black wings and tail. Its bill is yellow, blunt, and decurved at the tip. Immature birds are greyish brown with a dull greyish brown bill, dull orange face, and brownish legs.

Superb Lyrebird

A Pheasant-like Songbird

Menura novaehollandiae, the Superb Lyrebird, is a medium-sized lyrebird that has a peculiar way of finding songs to sing. It actually imitates songs it hears in nature. In the BBC documentary featured above, you can see the superb lyrebird mimicking the sounds of a camera shutter and a car alarm.

Reproduction

Polygamous males have long elegant tails they use in elaborate courtship displays whereby the tail is fanned toward the head, forming a silvery white canopy. After mating, the females build a domed nest to lay a single egg.

Fun Facts

Lyrebirds have been in Australia for over 15 million years.
The Superb Lyrebird is on the Australian ten cent coin.

Snowy Owl

Graceful White Hunter

Snowy Owls are by far one of the easiest birds of prey to recognize. This has a lot to do with the fact that males are totally white (females and juveniles are barred brown and mimic the ground of the arctic tundra). They are also one of the most graceful birds, swooping to catch lemurs in the arctic tundra.

Species Description

Size: 20 to 27 inches
Weight: 59 to 70 ounces (3.5 to 4.5 pounds)
Niche/Habitat: It is often believed that Snowy Owls, like other owls, live in trees. However, these are one of the few owls that breed on the ground in the arctic tundra. In the winter they fly to more southerly locations whereby they gather in coastal and agricultural regions. Not all Snowy Owls migrate, but there have been reports of some traveling as far south as the Caribbean.
Natural History: Snowy Owls begin as a small egg. They have a 32-day incubation inside their shell before emerging. Upon hatching, it takes about 50 to 60 days to fledge (fly) from the nest. Juveniles are more likely to migrate south than adults. In the spring, around May and June, the Snowy Owls begin their breeding season.
Food Habits: The primary food of the Snowy Owl is voles and lemmings, but they are able to capture rabbits, hares, geese, ducks, ptarmigan, and mice. One study showed that Snowy Owls are often found feeding in and around airports where the vole populations are naturally higher.

Useful Snowy Owl Links

The Owl Research Institute
A free video about Snowy Owls by Elliot Kennerson
Snowy Owl page on WhatBird.com
Snowy Owl Description

Peregrine Falcon

The Peregrine Falcon (Falco peregrinus) is a circumglobal bird of prey in the family Falconidae. Another name for the Peregrine is the “Duck Hawk.” It can reach speeds over 200 miles an hour in a dive.

Peregrine Behavior

The peregrine falcon is a diurnal bird. In non-breeding periods, the peregrine falcon is a solitary bird, establishing and defending home territories. The territory size can vary depending on the availability of food. The largest population densities occur in northern populations where nests average about 3.3 to 5.6 km apart. (reference: White et al. 2002)
Peregrine Falcon home ranges are estimated to be from 177 to 1508 square kilometers. Both males and females will regularly hunt up to 5 km from a nesting site.

What do Peregrine Falcons eat?

Peregrine Falcons are bird predators. While they may eat some other prey, such as small mammals, more than 75 percent of its diet are birds. In particular, peregines enjoy pigeons and doves.

Video: Skydiving to record Peregrine Falcon Speeds

I’m not really sure why it is that both National Geographic and the BBC have decided to do features on peregrines while skydiving, but I could take a guess. Watch the clip below as they take a peregrine falcon high into the air in a hot air balloon, release it, and sky dive with it to the drop zone.

Peregrine Researcher Questionnaire

Byron Crow

Byron is the Director/Research biologist of Field Worx Consulting. He spends all his time studying Peregrine Falcons. The following is a series of questions asked by Untamed Science about what he does.

Untamed Science (US): What do you study now?
Byron Crow (BC): Peregrine Falcons (Falco peregrinus) behavior ecology, Predator / Prey interactions

US: What’s the best thing about your job?

BC: Being involved in the environment. Being right there to witness what the outdoors has to offer and sharing these experiences with others. Seeing the expression on people’s faces when “it” hits them that there is a great big, exciting world out there that is actively LIVING.

US: What is the worst thing about your job?

BC: Frustration. There is so much taking place in the environment I always miss something cool happening that others witness. Seeing activities take place without regard to long-term impact. Close-minded people.

US: What inspired you to first study science?

BC: A great biologist who took me to the 50 Mountain region of Glacier National Park to survey for raptors, and said, “I want you to see something”. I have never stopped looking.

US: What do you do in a typical field day?

BC: Is this the part where I say something cool? Well truth be known, I hike through miles of Horse-fly infested Alder, carrying enough equipment to open my own photography studio, so I can sit for hours, baking in the hot sun, under some forsaken cliff, feeding mosquitoes and ticks, looking for the proverbial needle-in-the-haystack.

Scared? It’s not that bad. I drive, hike, and river raft, all over Montana (The Last Great Place) surveying cliffs for Peregrine Falcons, Prairie Falcons, Golden Eagles, Red-tailed Hawks, or other raptors that may have established a nest on the cliff. I then observe their activities, production, and note nesting sites.

In 2007, I began a research project that has never been done before, I placed micro-cams in a natural eyrie (in the wilderness, not on a man-made structure) and observed activity that had never been witnessed before. As a friend said, “my “Chuck Yeager” moment”.

US: What advice would you give to someone interested in becoming a biologist?

BC: We are educators to ourselves as well as others. Never be afraid to discover, experience, learn, share, and above all, prove yourself wrong. Stay focused, and keep the faith. Remember what your goal is. We are all explorers who want to discover the “new world”, but it is a great big place with a lot of obstacles, so do not be afraid (or too egotistical) to ask for help, and always be ready to lend a hand.

Remember: Life is not a journey to the grave with the intention of arriving safely in a pretty & well preserved body, but rather to skid in broadside, totally worn out & proclaiming, “WOW, what a ride!” ~ Unknown

Check out this article written about Byron and his work peering into the lives of Peregrin Falcons.

FIELD WORX CONSULTING

The mission of Field Worx Consulting is to engage in scientific research, conservation, and education activities involving cliff nesting raptors. The scope of research ranges from fundamental to problem solving. FWC research serves to increase an understanding of biological and ecological mechanisms that provide conservationists and wildlife managers with information essential to successful natural resource conservation in today’s dynamic, ever-changing world. The Institutes conservation biology goal is to encourage and develop strategies that employ the results of research to help address ecological issues. The institute also serves to educate the public about the needs of raptor species and their natural resources. The goal of the education venue is to promote the idea that the natural world and all its living organisms possess intrinsic worth. Inherent to this idea is the understanding that humans are not disjunctive from the natural world, but are a part of it, integral members that possess the responsibility of ethically sound stewardship.

American White Ibis

Adults are 65 cm long with a 95 cm wingspan. They have reddish bills and legs and white plumage, except for black wingtips that are visible during flight. They are commonly found in coastal marshland or in areas of mowed grass such as lawns or golf courses. Their distribution extends from the Mid-Atlantic coast of the United States down through the tropics of Central and South America. They eat fish, frogs, and insects and live in mixed colonies with other wading birds.

Woolly False Vampire Bat

The Woolly False Vampire bat is one of the largest bats in the neotropics. The only larger bat is the Spectral Bat. Oddly, False Vampire Bats are not closely related to vampire bats. Instead they are leaf-nosed bats in the family Phyllostomidae.

What do Woolly False Vampire Bats eat?

These bats are predatory, feeding on beetles, moths, lizards, small mammals (like rodents and opossums), birds, and other bats.

Wild Boar

The wild boar (Sus scrofus) is the largest of the 19 pig species, with wild species weighing in upwards of 700 pounds. The domesticated wild boar is the modern pig (which supplies us with bacon and pork loin). The domestic pig is usually considered a subspecies of the wild boar (Sus scrofus domesticus). Other experts consider the domestic pig its own species, Sus domesticus.

Where is the Wild Boar found?

The wild boar is an old world pig, like all pigs in the family Susidae. Its native range is Asia, Southern Europe, and North Africa. It has been introduced to Australia, the US, parts of South America and several small islands in the Atlantic and Pacific Oceans.

Predators: What eats the Wild Boar?

When discussing predators of the wild boar, it should be understood that the wild boar has a huge range; any large predator in those regions can potentially put pigs on their diet. The only animal that preys on the wild pig throughout its entire range are humans.

In eastern Asia, tigers will hunt packs of wild boar, picking off one at a time. Occasionally, hunters report that a tiger has been killed by a large male boar. In Africa, the larger subspecies of hyaenas are known to take wild boar, in addition to leopards, other large felids, and crocodiles. In Australia, dingos will pick off piglets. Wolves in their native range will hunt pigs as well. Bears also will eat pigs.

Piglets seem to be on the menu for many more species. Large snakes, such as the reticulated python, will eat young pigs. Birds of prey will also consume small pigs as part of their diet.

Reproductive Biology

Pigs reach sexual maturity at just under one year of age. Females can give birth to litters of up to 12 individuals but a half dozen is more typical. Gestation time is four months, and females can give birth to small liters up to two times a year. Because of this high reproductive rate, wild pigs can become a nuisance species quickly.

Feral Pigs

Feral pigs are pigs that have escaped captivity. It is next to impossible to tell whether a wild pig is a pure wild boar or whether it has domestic origins mixed in as well. Often, observers must take the history of pigs in the area into account. For instance, most of the wild feral pigs in the US have domesticated roots mixed with a bit of wild boar.

They are also quite dangerous. There are ways to avoid and survive a feral hog attack, outlined here via StoneAgeMan.

When domesticated species mix with wild boar they often have a crest of hair running down their backs. Arkansas razorbacks are an example of wild feral pigs of this origin.

Silky Sifaka Lemur

One of the 25 most endangered Primates

The Silky Sifaka is a rare species of lemur found in northeastern Madagascar. It is listed as one of the 25 most endangered primates in the world. This species is being studied by researcher Erik Patel. We’ve created this page to help highlight his work on silky sifakas and share the video that Sharon Pieczenik created on the same topic.

Angels of the Forest: Silky Sifaka Lemurs of Madagascar

In this documentary, produced by Sharon Pieczenik and WYCTL Media, Erik Patel, PhD Candidate at Cornell University, discusses his efforts to save silky sifaka lemurs in Madagascar. Ninety-eight percent of Madagascar’s mammals, including the rare silky sifaka lemurs, exist nowhere else on Earth. Because of their white fur and their amazing ability to fly through the forest, silky sifaka lemurs are called “angels of the forest.” If silky sifaka lemurs were to disappear from Madagascar, they would disappear from the world. International scientists and local Malagasy conservationists are fighting for the survival of this exceptional species and its irreplaceable habitat.

More about the Filmmaker: Sharon Pieczenik

Sharon is a recent graduate of Montana State University’s Science and Natural History Filmmaking department, a program which takes scientists and trains them to become wildlife filmmakers. Sharon has produced films on polar bears as well as wildlife in Madagascar. She was a contestant of the Discovery Channel’s Reel Race and was second camera for Dateline.

Silky Sifaka Biology

What do they eat?

Most of the time silky sifakas are folivorous meaning they eat primarily leaves, flowers, and other foliage of over 100 types of trees and vines. They are also seed predators which means they often prefer to eat the hard inner seed rather the flesh of the fruit. But when fruits are ripe, they will travel extra long distances to feed on ripe fruit. Though they live in the trees, occasionally they actually come to the ground to feed on dirt and the immature flowers of some parasitic plants.

What eats them?

The only documented natural predator of the silky sifaka is the fossa, a medium-sized, weasel-like carnivore only found in Madagascar. Silky sifakas are sometimes hunted for food by local residents since there is no local taboo prohibiting lemur hunting where they are found. Sometimes silky sifakas emit loud alarm calls to large raptors, though no predation attempts have ever been observed. Raptors may pose a danger to infant silkies. Several of the largest raptors which posed the greatest threat to silky sifakas recently went extinct in Madagascar.

Where do they live?

Silky Sifakas live in moist forests in a small region of northeastern Madagascar. Most of their of population is found in the high altitude regions (above 700 m of elevation) in Marojejy National Park and Anjanaharibe-Sud Special Reserve. Some are also found in the Makira Forest Protected Area. Silky sifakas are in critical danger of extinction due to habitat loss caused mainly by slash-and-burn agriculture for rice production as well as illegal rosewood logging. Hunting by humans is a growing problem. There is no local taboo against hunting silky sifakas. Silky sifakas are among the top 25 most critically endangered primates in the world and the top 4 rarest lemurs in Madagascar out of over 100 types of lemurs. The work of Erik Patel and others in Madagascar will hopefully be enough to save these amazing creatures.
Text Edited by Eric Patel

Web links

Researcher Erik Patel’s Facts about the Silky Sifakas
University of Wisconsin – Silky Sifaka Fact Sheet

Useful Texts (Citations via Erik Patel)

  • Andrianandrasana, LH; Patel, ER and Wright, PC (2007). A comparison of scent overmarking in two species of wild rainforest sifakas: silky sifakas (Propithecus candidus) and Milne-Edwards’ sifakas (Propithecus edwardsi). Prosimian Congress Abstracts. Ithala, South Africa.
  • Duckworth, J.W ., Evans, M.I ., Hawkins, A. F. A , Safford, R.J ., and Wilkinson, R.J . 1995. The lemurs of Marojejy Strict Nature Reserve, Madagascar: A status overview with notes on ecology and threats.International Journal of Primatology 16(3): 545 – 559.
  • Garbutt N. 2007. Mammals of Madagascar : A Complete Guide. London: A&C Black. 2007.
  • Goodman, S.M., Raherilalao, M.J., Rakotomalala, D., Raselimanana, A., Schütz, H., and Soarimalala, V., 2003. Les Lémuriens. In: Nouveaux résultats d’inventaires biologiques faisant référence à l’altitude dans la région des massifs montagneux de Marojejy et d’Anjanaharibe-Sud, S.M. Goodman and L. Wilmé (eds.). Recherchespour le Développement, série sciences biologiques no. 19, Centre d’Information et de Documentation Scientifique et Technique, Antananarivo, pp. 279–286.
  • Groves, C.P. 2001. Primate Taxonomy. Smithsonian Institution, Washington D.C.
  • Guillaumet, J.L., Betsch, J.M., Blanc, C., Morat, P., and Peyrieras, A., and Paulian, R. 1975. Etude des ecosystems montagnards dansla region malgache. III. Le Marojezy. IV. L’itremo et l’ibity. Geomorphologie, climatologie, faune et flore (Campagne RCP 225, 1972 – 1973). Bulletin du Museum National d’Histoire Naturelle (Paris), serie 3, 309 (Ecologie Generale), 25: 27 – 67.
  • Humbert, H. 1955. Une merveille de la nature a Madagascar. Premiere exploration botanique du massif du Marojejy, et de ses satellites. Memoires de L’Institut Scientifique de Madagascar, serie B, 6: 1 – 210.
  • Irwin MT. 2006. Ecologically enigmatic lemurs: the sifakas of the eastern forests (Propithecus candidus, P. diadema, P. edwardsi, P. perrieri, and P. tattersalli) In Lemurs : Ecology and Adaptation edited by Gould L Sauther ML. New York: Springer. 2006. Pgs: 305-326.
  • Kelley, E . and Mayor, M.I . 2002. Preliminary study of the silky sifaka (Propithecus diadema candidus) in north-east Madagascar. Lemur News 7: 16 – 18.
  • Lehman, S.M ., Mayor, M ., and Wright, P.C . 2005. Ecogeographic size variations in sifakas: a test of the resource seasonality and resource quality hypotheses. American Journal of Physical Anthropology 126(3): 318 – 328.
  • Mayor, M.I., Sommer, J.A., Houck, M.L., Zaonarivelo, J.R., Wright, P.C., Ingram, C., Engel, S.R., and Louis, E.E. Jr. 2004. Specific status of Propithecus spp. International Journal of Primatology 25(4): 875 – 900.
  • Milne-Edwards, A. and Grandidier, A. 1875. L’Histoire Politique, Physique et Naturelle de Madagascar: Histoire Naturelle des Mammifères, Paris, Impr. nationale.
  • Mittermeier, R.A.; Konstant, W.R.; Hawkins, F.; Louis, E.E.; Langrand, O.; Ratsimbazafy, J.; Rasoloarison, R.; Ganzhorn, J.U.; Rajaobelina, S.; Tattersall, I.; Meyers, D.M. 2006. Lemurs of Madagascar. Conservational International, Washington D.C.
  • Nicoll, M.E., and Langrand, O. 1989. Madagascar: Revue de la conservation et des aires protégées. World Wide Fund for Nature, Gland, Switzerland.
  • Nielsen M and Patel ER. 2008. The role of taste preference and wealth in bushmeat hunting in villages adjacent to Marojejy National Park, Madagascar. Primate Eye. 2008. 96(Sp CD-ROM iss – IPS 2008). Abst #616
  • Owren MJ and Patel ER. 2008. A little of this, a lot of that: specificity and variability in nonhuman primate vocal repertoires. Primate Eye. 2008. 96(Sp CD-ROM iss – IPS 2008). Abst #742
  • Patel, E.R ., Coke, C.S ., Ritchie, A ., Santorelli, C . 2003a. Alloparental care (including allonursing) in free-ranging silky sifakas (Propithecus diadema candidus) in a primary northeastern montane rainforest in Madagascar. American Journal of Primatology 60(1): 71.
  • Patel, E.R ., Coke, C.S ., Ritchie, A ., and Santorelli, C . 2003b.
  • Assessing production specificity of free ranging silky sifaka (Propithecus diadema candidus) “antipredator” vocalizations: Weak evidence for “aerial predator” but not “terrestrial predator” calls. American Journal of Primatology 60(1): 71-72.
  • Patel, E.R . 2005. Silky sifaka predation (Propithecus candidus) by a fossa (Cryptoprocta ferox). Lemur News 10: 25 – 27.
  • Patel, ER, Anderson, JD, and Owren, MJ. 2005a. Sex differences in the acoustic structure of an alarm vocalization in a monomorphic primate: Wild silky sifakas (Propithecus candidus) of Northeastern Madagascar. American Journal of Primatology 66(Suppl 1): 46-47.
  • Patel, E.R ., Anderson, J.D ., Irwin, M.T ., and Owren, M.J . 2005b. Quantifying the vocal repertoire of wild adult diademed sifakas (Propithecus diadema diadema) in Madagascar. American Journal of Primatology 66(1): 48.
  • Patel, E.R ., Marshall, J.J ., and Parathian, H . 2005c. Silky sifaka (Propithecus candidus) conservation education in northeastern Madagascar. Laboratory Primate Newsletter 44(3): 8 – 11.
  • Patel, E.R . 2006a. Scent-marking in wild silky sifakas (Propithecus candidus) in Madagascar: sex differences and seasonal effects in usage and response across multiple scent-mark types. International Journal of Primatology 27(1): Abstract #496.
  • Patel, E.R . 2006b. Activity budget, ranging, and group size in silky sifakas (Propithecus candidus). Lemur News 11: 42 – 45.
  • Patel, E.R ., Anderson, J.D ., and Owren, M.J . 2006. Exploring the function of “Zzuss” alarm vocalizations in wild silky sifakas (Propithecus candidus): moderate evidence for individual distinctiveness. International Journal of Primatology 27(1): Abstract #504.
  • Patel ER, Meyers D, and Hawkins F (2007). Silky Sifaka, Propithecus candidus, 1871. In: Primates in Peril: The World’s 25 Most Endangered Primates 2006-2008, R. A. Mittermeier et al. (compilers), In: R. A. Mittermeier, J. Ratsimbazafy, A. B. Rylands, L. Williamson, J. F. Oates, D. Mbora, J. U. Ganzhorn, E. Rodríguez-Luna, E. Palacios, E. W. Heymann, M. C. M. Kierulff, L. Yongcheng, J. Supriatna, C. Roos, S. Walker and J. M. Aguiar (compilers), Primates in Peril: The World’s 25 Most Endangered Primates 2006-2008, pp.11-12, 26-27. Primate Conservation (22): 1-40.
  • Patel, E.R . 2007a. Non-maternal infant care in wild Silky sifakas (Propithecus candidus). Lemur News 12: 39 – 42.
  • Patel, E.R. 2007b. Logging of rare rosewood and palisandre (Dalbergia spp.) within Marojejy National Park, Madagascar. Madagascar Conservation and Development 2: 11-16.
  • Patel, E.R. and Andrianandrasana, L.H. 2008. Low elevation silky sifakas (Propithecus candidus) in the Makira Conservation Site at Andaparaty-Rabeson: Ranging, demography, and possible sympatry with red ruffed lemurs (Varecia rubra). Lemur News 13: 18 – 22.
  • Patel ER and Girard-Buttoz C. 2008. Non-nutritive tree gouging in wild Milne-Edwards’ sifakas (Propithecus edwardsi): description and potential communicative functions. Primate Eye 96(Sp CD-ROM iss – IPS 2008). Abst #283
  • Petter, J.J. and Charles-Dominique, P. 1979. Vocal communication in prosimians. In The Study of Prosimian Behavior edited by G.A. Doyle and R.D. Martin. Academic Press. Pgs: 247-305.
  • Queslin, E. and Patel, E.R. 2008. A preliminary study of wild silky sifaka (Propithecus candidus) diet, feeding ecology, and habitat use in Marojejy National Park, Madagascar. International Primatological Society. Abstract #143.
  • Rasolofoson, D., Rakotondratsimba, G ., Rakotonirainy, O ., Rakotozafy, L.M.A ., Ratsimbazafy, J.H ., Rabetafika, L ., Randrianarison, R.M . 2007. Influence of human pressure on lemur groups on the Makira Plateau, Maroantsetra, Madagascar. Madagascar Conservation and Development 2: 21 – 27.
  • Richard, A. 2003. Propithecus, sifakas. In The Natural History of Madagascar edited by Goodman, SM and Benstead JP. Chicago: Univ Chicago Press. 2003. Pgs: 1344-1348.
  • Ritchie, A . and Patel, E.R . 2006. The existence and potential function of “totem-tree” scent-marking in silky sifakas (Propithecus candidus). International Journal of Primatology 27(1): Abstract #361.
  • Schmid, J. and Smolker, R. 1998. Lemurs of the Reserve Speciale d’Anjanaharibe-Sud, Madagascar. Fieldiana Zoology 90: 227 – 240.
  • Sterling, E . and McFadden, K . 2000. Rapid census of lemur populations in the Parc National de Marojejy, Madagascar. Fieldiana Zoology 97: 265 – 274.
  • Sussman, RW. 2000. Primate Ecology and Social Structure. Val. 1 : Lorises, Lemurs, and Tarsiers. Pearson Custom Publishing. Heights,MA.
  • Tattersall, I. 1982. The Primates of Madagascar. New York: Columbia University Press.
  • Tattersall, I. 2007. Madagascar’s lemurs: cryptic diversity or taxonomic inflation? Evolutionary Anthropology 16(1): 12 – 23.
  • Wilme, L . and Callmander, M.W . 2006. Relic populations of primates:sifakas. Lemur News 11: 24 – 31.