tailieunhanh - CAPTURE-RECAPTURE ANALYSIS FOR ESTIMATING MANATEE REPRODUCTIVE RATES

The second reason why contraception has gained importance is due to disease. As we will see at the end of this chapter,many serious diseases can be passed between people during sex. Some birth control methods are also important ways to reduce the transmission of certain diseases. Over time, various methods of birth control have been developed. Some methods are more effective than others. The most effective means of birth control is abstinence, that is, not having sexual intercourse. Abstaining from sexual intercourse prevents sperm from reaching an egg and also limits the spread of sexually transmitted diseases | Unauthorized uses of copyrighted materials are prohibited by law. The PDF file of this article is provided subject to the copyright policy of the journal. Please consult the journal or contact the publisher if you have questions about copyright policy. MARINE MAMMAL SCIENCE 20 3 424 437 July 2004 2004 by the Society for Marine Mammalogy CAPTURE-RECAPTURE ANALYSIS FOR ESTIMATING MANATEE REPRODUCTIVE RATES William L. Kendall USGS Patuxent Wildlife Research Center 11510 American Holly Drive Laurel Maryland 20708 . E-mail william_kendall@ Catherine a. Langtimm Cathy A. Beck USGS Florida Integrated Science Center Sirenia Project 412 NE 16th Avenue Gainesville Florida 32601 . Michael C. Runge USGS Patuxent Wildlife Research Center 11510 American Holly Drive Laurel Maryland 20708 . Abstract Modeling the life history of the endangered Florida manatee Trichechus manatus latirostris is an important step toward understanding its population dynamics and predicting its response to management actions. We developed a multi-state mark-resighting model for data collected under Pollock s robust design. This model estimates breeding probability conditional on a female s breeding state in the previous year assumes sighting probability depends on breeding state and corrects for misclassification of a cow with first-year calf by estimating conditional sighting probability for the calf. The model is also appropriate for estimating survival and unconditional breeding probabilities when the study area is closed to temporary emigration across years. We applied this model to photo-identification data for the Northwest and Atlantic Coast populations of manatees for years 1982 2000. With rare exceptions manatees do not reproduce in two consecutive years. For those without a first-year calf in the previous year the best-fitting model included constant probabilities of producing a calf for the Northwest SE and Atlantic SE populations. The approach we