The Grey Brocket

Mar 04, 2012 Features / Columnists, Interesting Creatures in Guyana

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The Grey Brocket (Mazama gouazoubira), also known as the Brown Brocket, is a species of brocket deer from northern Argentina, Bolivia, eastern and southern Brazil, Paraguay and Uruguay. It formerly included the Amazonian Brown Brocket (M. nemorivaga) and sometimes also the Yucatan Brown Brocket (M. pandora) as subspecies.
Unlike other species of brocket deer in its range, the grey brocket normally has a grey-brown fur. Important to note is that both Mazama gouazoubira and Mazama gouazoupira refer to the same species.
The original species name of the brown brocket deer comes from the Felix de Azara’s Gouazoubira. Azara was the first to provide a quality description of the small deer population in the Americas, and he referred to the red brocket deer as Gouazoupita, while he referred to the brown brocket deer as Gouazoubira.  Gouazoubira has been maintained in the current species name, Mazama gouazoubira. Though sometimes it is seen as Mazama gouazoupira, this is incorrect, perhaps mistakenly replacing a “b” with a “p” from Azara’s name for the red brocket deer, Gouazoupita.
The coat of a grey brocket can range from grey-brown to dark brown. Lighter, browner coats are seen in those that live in grasslands, whereas greyer, darker colours are more prevalent in forest regions.
Significant variation can be seen between individuals of the same population as well. Their tails are white on the bottom, and on their flanks the hair is of a lighter colour than that of the rest of the body. The body length of a grey brocket deer can range from 85 to 105 cm, while at the shoulder they typically are 50 cm to 65 cm tall. The weight of a grey brocket can range from 8 kg to 25 kg. Male grey brockets do have antlers, ranging in length from 70 cm to 100 cm.
In comparison to Mazama americana (red brocket deer) grey brockets are smaller and have a straighter back; the latter gives the grey brocket a closer appearance to a typical deer. In comparison to the Mazama nemorivaga, the Amazonian brown brocket, the grey brocket can be differentiated by many characteristics, such as its orange hindquarters, bigger rounded ears, wider auditory bulla, and smaller eyes.
Mazama gouazoubira is found in Argentina, Bolivia, Brazil, Uruguay, and Paraguay, though they have been seen in Colombia, Ecuador, French Guiana, Guyana, Peru, Suriname, Venezuela, and San Jose Island in Panama.  Their range starts in the western part of South America, east of dry areas bordering the Andes Mountains in Bolivia and Argentina. It extends westward all the way to the Atlantic Ocean. It does not live in the Amazon Rainforest region, the south of which is the grey brocket’s northern border, and its distribution runs south through all of Uruguay and up to the Entre Rios province of Argentina.
There is tentative agreement between several sources that the grey brocket deer lives in or near forests. One source mentions that it avoids very dense forests, such as the Amazon, where it is replaced by Mazama nemoviraga. Though it avoids very dense forests, it prefers to have high vegetation cover in its habitat and can live in deciduous forests and transitional/edge forests, but not evergreen forests.  Though often seen in forests, one source noted it can also be seen in open areas such as thorn scrub, savannah, and swamplands.  A competing source mentions that it does not live in open areas, but does feed in them.
The grey brocket is a herbivore that chooses what it eats selectively, though it does eat a wide variety of plants. During some periods, the greys brocket may become frugivorous (primarily fruit-eating), but this depends on the season, area, and availability of fruits. Many of the fruits are in dense forests, which it for the most part avoids, but it does find other sources of fruits and also other sources of food.  In the dry season they eat the fruit from trees such as Ziziphus oblongifolia and Caesalpinia paraguariensis, which produce dry, tough fruits. Other sources of food for the grey brocket include, but are not limited to, cacti and roots. Often they eat leaves and roots to obtain water.
Though grey brockets do not prefer dense forests, they do prefer some type of shelter, generally avoiding completely open areas. It may not live in these completely open areas, but is not opposed to feeding in such areas, especially if cover is nearby. At times they find open agricultural plantations in which to feed.
Grey brockets give birth to only one offspring at a time, and reproduction does not seem to correlate with the seasons, as they can mate any time of the year. They reach an age of sexual maturity at 18 months. Gestation periods appear to last around eight months, and there is post partum estrus. Thus, it is possible for a grey brocket to produce two offspring in one calendar year.  After birth, the doe takes care of the fawn until it is weaned, though the time until it is weaned is unknown. During this weaning period, the fawn remains hidden and is fed by the doe.
Four types of scent-marking have been observed as a means of communication, due to their performance of these behaviors in concurrence with certain postures. These scent-marking behaviors include urination, defecation, thrashing, and forehead rubbing. Such scent-marking tactics can be part of a claim on territory if a number of markings are placed within a concentrated area by a single grey brocket.
Grey brockets are diurnal animals that are seen a majority of the time alone, while commonly seen in pairs as well. It is rare to see them in packs of four or more. Unless under cover, they are very shy and nervous when held captive. Though the grey bracket is still abundant in all of its native range, it appears that populations are decreasing due to human infringement on their habitat. Numbers are especially low very near to human settlements. In Argentina, hunting pressures due in part to international expeditions is decreasing the population of grey brockets, along with habitat loss caused by humans. However, in Bolivia the populations are seemingly constant despite having similar hunting pressures. Populations are also decreasing in Brazil and especially in urban areas in Paraguay. The primary motive for hunting grey brockets is not pest control, as they cause a minimal amount of crop damage.  However, hunters can sell the meat from one grey brocket for US$15, which could be a potential motivation.
Actions to prevent further population decline have been taken through the implementation of hunting laws and the creation of protected areas. There are a total of 14 national and provincial reserves in Argentina, as well as seven protected areas in Bolivia to go along with many in Brazil.
However, though hunting is illegal in many areas in the grey brocket’s range, bans are not always enforced. In order to prevent population decline in the future, hunting laws need to be enforced, stray dogs from human populations should be controlled, and local village populations should be educated to preserve the grey brocket populations.  Also, population studies need to be done to determine the status of the grey brocket in order be better equipped to help it.
(Source: Wikipedia – The Free Online Encyclopedia)

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