INVASIVE STRAY AND FERAL DOGS LIMIT FOSA (CRYPTOPROCTA FEROX) POPULATIONS IN
ANKARAFANTSIKA NATIONAL PARK, MADAGASCAR
Masters project submitted in partial fulfillment of the
requirements for the Master of Environmental Management degree in
the Nicholas School of the Environment of
Duke University
2009
ABSTRACT
The fosa (Cryptoprocta ferox) is a medium sized carnivore of the family Eupleridae which is endemic to
the island of Madagascar. Recent publications have shown that the fosa is under significant pressure
from deforestation and fragmentation, leading to its classification as Threatened under the Endangered
Species Act. A trap study was conducted from 1999 to 2008 in Ankarafantsika National Park,
Madagascar, to ascertain the health of a population and measure additional threats to its survival. Feral
dogs (Canis lupus familiaris) appeared in the park in 2004 and a comparison of trap rates of the two
species shows an inverse relationship between the presence of dogs and the presence of fosa. In this
paper I discuss reasons for this relationship, the effect of the continued presence of dogs, and
implications for the management of the park.
Thursday, November 5, 2009
Domestic dogs and the Bras´ılia National Park
Animal Conservation. Print ISSN 1367-9430
Domestic dogs as an edge effect in the Bras´ılia National
Park, Brazil: interactions with native mammals
Abstract
Edge effects are a well-known result of habitat fragmentation. However, little has
been published on fragmentation, isolation and the intrusive influence from the
surrounding matrix at the landscape level. The objectives of the present study are
to evaluate the presence of dogs in the Brası´ lia National Park (BNP) in relation to
habitat type and the influence from the surrounding matrix. In addition, this study
examines the response of the native mammal fauna to the presence of dogs. Track
stations were built along dirt roads in the BNP and subsequently examined for the
presence or absence of tracks. We used a stepwise logistic regression to model the
occurrence of five mammal species relative to habitat variables, with an a=0.05 to
determine whether to enter and retain a variable in the model. A simulation of each
species occurrence probability was conducted using a combination of selected
habitat variables in a resource selection probability function. Results indicate a
negative relationship between distance from the BNP edge and the probability of
dog occurrences. From an ecological perspective, the presence of dogs inside the
BNP indicates an edge effect. The occurrence of the maned wolf was positively
associated with distance from a garbage dump site and negatively associated with
the presence of dog tracks. The maned wolf and giant anteater seem to avoid areas
near the garbage dump as well as areas with dog tracks. There is no support for the
possible existence of a feral dog population inside the BNP, but the effects of freeranging
dogs on the wildlife population in such an isolated protected area must not
be neglected. Domestic dog Canis familiaris populations and disease control
programs should be established in the urban, sub-urban and rural areas surrounding
the BNP, along with the complete removal of the garbage dump from the BNP
surroundings.
Domestic dogs as an edge effect in the Bras´ılia National
Park, Brazil: interactions with native mammals
Abstract
Edge effects are a well-known result of habitat fragmentation. However, little has
been published on fragmentation, isolation and the intrusive influence from the
surrounding matrix at the landscape level. The objectives of the present study are
to evaluate the presence of dogs in the Brası´ lia National Park (BNP) in relation to
habitat type and the influence from the surrounding matrix. In addition, this study
examines the response of the native mammal fauna to the presence of dogs. Track
stations were built along dirt roads in the BNP and subsequently examined for the
presence or absence of tracks. We used a stepwise logistic regression to model the
occurrence of five mammal species relative to habitat variables, with an a=0.05 to
determine whether to enter and retain a variable in the model. A simulation of each
species occurrence probability was conducted using a combination of selected
habitat variables in a resource selection probability function. Results indicate a
negative relationship between distance from the BNP edge and the probability of
dog occurrences. From an ecological perspective, the presence of dogs inside the
BNP indicates an edge effect. The occurrence of the maned wolf was positively
associated with distance from a garbage dump site and negatively associated with
the presence of dog tracks. The maned wolf and giant anteater seem to avoid areas
near the garbage dump as well as areas with dog tracks. There is no support for the
possible existence of a feral dog population inside the BNP, but the effects of freeranging
dogs on the wildlife population in such an isolated protected area must not
be neglected. Domestic dog Canis familiaris populations and disease control
programs should be established in the urban, sub-urban and rural areas surrounding
the BNP, along with the complete removal of the garbage dump from the BNP
surroundings.
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