Comparative daily activity patterns of Nilgai, Boselaphus tragocamelus and white-tailed deer, Odocoileus virginianus in South Texas

Authors: SINGH, NIRBHAY - Guru Angad Dev Veterinary & Animal Sciences University; Goolsby, John; ORTEGA, ALFONSO - East Foundation; HEWITT, DAVID - Non ARS Employee; CAMPBELL, TYLER - East Foundation; Perez De Leon, Adalberto - Beto

Submitted to: Subtropical Agriculture and Environments
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/1/2017
Publication Date: 7/14/2017
Citation: Singh, N., Goolsby, J., Ortega, A., Hewitt, D., Campbell, T., Perez De Leon, A.A. 2017. Comparative daily activity patterns of Nilgai, Boselaphus tragocamelus and white-tailed deer, Odocoileus virginianus in South Texas. Subtropical Agriculture and Environments. 68:7-12.

Interpretive Summary: The cattle fever ticks (CFT) Rhipicephalus (=Boophilus) microplus, and R. annulatus are livestock pests that are established in Mexico, and invasive along the south Texas – Mexico border. Acaricide resistance, alternate wildlife hosts, and pathogenic landscape forming weeds present challenges for sustainable eradication of this pest in the U.S. CFT are the vector for bovine babesiosis, a lethal disease causing high mortality particularly in susceptible European breeds of cattle and severely affecting the beef cattle industry. Efforts to eradicate CFT from the United States have been successful; however, a permanent quarantine zone (PQZ) is maintained between Texas and Mexico to prevent incursions of CFT from wildlife and stray cattle. In recent years, there has been an increase in CFT infestations outside of the PQZ in Texas. One of the alternate wildlife hosts for CFT in South Texas are nilgai (Boselaphus tragocamelus), an exotic Asian antelope. Nilgai are highly mobile with large home ranges and are implicated in the spread of CFT, through the landscape. Currently, there are no methods for control of CFT on nilgai other than culling. We conducted field studies in South Texas to determine when nilgai were most active in their environment and determined that they were most active at night between 9 pm and 3 am. Remote field sprayers are being developed to control CFT on nilgai and they will be designed to operate at night when nilgai are most active. Treatment at night optimizes the control of CFT on nilgai and minimizes treatment of non-target animals such as white-tailed deer and cattle that are not active during this time period.

Technical Abstract: Nilgai antelope, Boselaphus tragocamelus, and white-tailed deer (WTD), Odocoileus virginianus, are hosts of the cattle fever ticks, Rhipicephalus (Boophilus) microplus, and R. (B.) annulatus in south Texas. Daily activity patterns were studied to develop optimum timing for field treatment methods for cattle fever ticks on these wildlife hosts. Motion detecting game cameras (n=160) were deployed between Aug and Oct 2016 at the East Foundation’s Santa Rosa Ranch, Kleberg Co., TX. A total of 218 animal images comprising of 114 nilgai and 104 WTD were recorded by time of the day. WTD showed two distinct peaks in activity during morning and evening whereas, nilgai activity showed multiple peaks throughout the day. Both species were active during morning followed by evening, whereas, minimum activity was seen in the heat of the afternoon. Nilgai were more active at night than WTD, with 30% and 17% of the images recorded respectively. Treatment of nilgai may be most efficient at night when they are most active.