Cuniculus paca

Taxonomy:

Kingdom Animalia

Phylum Chordata

Class Mammalia

Order Rodentia

Family Cuniculidae

Common Names:

The following is a listing of common names of the Cuniculus paca as well as the area in which they are used if they are associated with a particular area:

One unique name not shown on the chart is the “royal rat." The Cuniculus paca was given this name because it was fed to Queen Elizabeth when she visited Belize. It is also important to note that the Cuniculus paca was formerly classified as the Agouti paca under Linnaean taxonomy.

Description:

As seen above, the Cuniculus paca is a large, pig-like rodent with a tiny tail and it has brown or blackish fur containing horizontal rows of whitish spots. This fur is coarse and lacks underfur. The Cuniculus paca usually has four of the horizontal rows of the white spots on its sides and it has a white belly. The forefeet have four digits and the hind feet have five digits. The zygomatic arch is expanded laterally and dorsally and is used as a resonating chamber. They are endothermic and have bilateral symmetry, as seen above (Fox, 2011). They have an acute sense of smell and hearing. They can grow to be 60-80cm (24-31inches) and they usually weigh between 6-12kg (Jrank.org).

For a view of a live Cuniculus paca, follow the below link to a video of a paca foraging for Malay apples in the Cockscomb Basin Wildlife Sanctuary.
http://www.youtube.com/watch?v=WODv2IEjcGA&feature=related

Life History/Ecology:

The Cuniculus paca occurs from east-central Mexico to Paraguay. They live in forested habitats near water with a preference for small, swift streams. These habitats can be found in low and middle elevation wet forests. However, the paca can also be seen living in drier areas that are near water. These animals are nocturnal and during the day they live in their burrows. Their burrows are simple and go about two meters below the surface (Fox, 2011). They usually contain more than one escape exit (Scientific Web). Pacas may also live in another animal’s burrow (Queirolo et al., 2011).

When it is out during the night, the Cuniculus paca forages for plants, maintaining a herbivorous diet which includes leaves, stems, roots, seeds and fruit (avocados and mangos are favored) (Fox, 2011). They often forage for underbrush to help keep their burrow warm as well (Sabatini and Paranhosdacosta, 2006).

The Cuniculus paca may have two litters per year with usually a single young and rarely twins. Unfortunately, the details of reproduction are not well known. However, it is known that Mexico pacas mate primarily in the water. The gestation period is around 118 days and the females become sexually mature around 1 year old (Fox, 2011).

Generally, the Cuniculus paca is solitary with little interaction between individual pacas. They also do not vocalize very much. One of their escape mechanisms is to swim away. As stated before, the paca is nocturnal (Fox, 2011).

A Summary of Recent Research:

n 2003, the Smithsonian Tropical Research Institute in Panama researched the possibility of using the Cuniculus Paca as a domestic source of protein. The research included the description of the characteristics of the paca in relation to domestication. It concluded that making manageable breeding stocks with a modification of undesirable traits was a possibility (Froese).

As pacas are beginning to be bred in captivity, various researches have spawned from the need to know more about them. In 2006, Vera Sabatini and Mateus J.R. Paranhos da Costa researched the straw collecting behaviour exhibited by pacas in captivity. The aim was to see if different strategies of straw supply affected the behavior and welfare of captive pacas. After analyzing the behaviors of the pacas and the amount of straw collected, it was concluded that providing straw to pacas in captivity in a way that they collect it by themselves promotes an effective environmental enrichment for them (Sabatini and Paranhosdacosta, 2006).

Another interesting research regarding captive paca focused on the genetic diversity of captive spotted paca (Agouti paca) from three comercial breeding stocks in Brazil. It was found that there was a higher diversity in two of the sites that shared reproduction males and females, whereas, there was a lower diversity in the site that did not share animals and only used a dozen animals to breed with. This result suggested that variability is better conserved in larger breeding flocks of fifty or sixty animals. This study also showed that there is a need for periodic reproductive male replacement (Antunes, 2010).

There are many other interesting researches pertaining to the Cuniculus paca. One such research showed that the right superior cervical ganglions are bigger than the left ones, irrespective of age. This study opens up further study on the the superior cervical ganglion quantitative changes regarding the asymmetry (Abrahao et al., 2009). Also, characterization of the teeth of pacas was done with the purpose of broadening our knowledge of the paca (Oliveira et al., 2007).

Economic/Ecological service:

The Cuniculus paca are considered agricultural pests, causing damage to yam, cassava, sugar cane, corn and other crops. They are sometimes killed because of this, but they are also killed for their meat, which brings a high price at the market (Fox, 2011). In fact, due to hunting, the paca population outside of preserved areas has been greatly reduced (Scientific Web). Other animals that feed on pacas are the jaguars and pumas. In the past, the Awa hunters of Brazil used Paca teeth to make their arrows (Gonzalez-Ruibal et al., 2011).

Personal Interest

Four years ago, during my first trip to Peru, I was exposed to the Cuniculus paca for the first time. We were traveling along the Marañón River and woke up one day to find a dead paca hanging from our hut ceiling from the hunt of the previous night. We kept trying to figure out what type of animal it was that we were eating, but, due to the language barrier, only came up with the name “jungle rat”. That is why, when I saw a labeled picture of a Cuniculus paca in a field guide, I knew that I wanted to do research on it. I had to find out more about the delicious meat that I had once tasted.

References:

Please note that the following references may have either been removed or relocated by the webpage owners since the time this student report was created.

Abrahao, L., J. Nyengaard, T. Sasahara, S. Gomes, F. Oliveira, F. Ladd, A. Ladd, M. Melo, M. Machado, and S. Melo. "Asymmetric Post-natal Development of Superior Cervical Ganglion of Paca (Agouti Paca)." International Journal of Developmental Neuroscience 27.1 (2009): 37-45.

Antunes, Karine V. "Genetic Diversity of Captive Spotted Paca (Agouti Paca) from South East Brazil Assessed by the RAPD-PCR Technique." Zootec 39 (2010): 268-72.

"Cuniculus Paca." Scientific Web. Web. 23 May 2011. <http://www.scientific-web.com>.

Fox, David L. "Cuniculus Paca - Encyclopedia of Life." Encyclopedia of Life. Web. 23 May 2011.< http://www.eol.org/pages/2922643>.

González-Ruibal, Alfredo, Almudena Hernando, and Gustavo Politis. "Ontology of the Self and Material Culture: Arrow-making among the Awá Hunter–gatherers (Brazil)." Journal of Anthropological Archaeology 30.1 (2011): 1-16.

Oliveira, F. S., J. C. Canola, P. T. Oliveira, J. D. Pécora, and A. Capelli. "Microscopic Characterization of Teeth of Pacas Bred in Captivity (Agouti Paca, Linnaeus, 1766)." Anatomia, Histologia, Embryologia: Journal of Veterinary Medicine Series C 36.5 (2007): 371-74.

"Pacas: Agoutidae - Paca (agouti Paca): Species Account." Jrank.org. Net Industries and Its Licensors. Web. 26 May 2011.< http://animals.jrank.org/pages/3469/Pacas-Agoutidae-PACA-Agouti-paca-SPECIES-ACCOUNT.html>.

Queirolo, D., Vieira, E., Emmons, L. & Samudio, R. 2008. Cuniculus paca. In: IUCN 2010. IUCN Red List of Threatened Species. Version 2010.4.< www.iucnredlist.org>. Downloaded on 23 May 2011.

Sabatini, V., and M. Paranhosdacosta. "Straw Collecting Behaviour by Pacas (Agouti Paca) in Captivity." Applied Animal Behaviour Science 97.2-4 (2006): 284-92.

External Links:

http://www.youtube.com/watch?v=WODv2IEjcGA&feature=related