National Academy of Agricultural Sciences (NAAS)
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PRINT ISSN : 2319-7692
Online ISSN : 2319-7706 Issues : 12 per year Publisher : Excellent Publishers Email : editorijcmas@gmail.com / submit@ijcmas.com Editor-in-chief: Dr.M.Prakash Index Copernicus ICV 2018: 95.39 NAAS RATING 2020: 5.38 |
Thermoregulation data for four ‘problem’ Nile crocodiles (Crocodylus niloticus) introduced to Lake Ngezi, Zimbabwe were collected from winter through early summer 1986-87 using abdominally implanted radio-transmitters with calibrated thermistors. These remain after 36 years the largest (1.94-3.48 m) wild free-ranging Nile crocodiles thus far evaluated re: body temperatures and thermoregulation. Both cooling and heating rates were highest in the smallest subjects, progressively lower in larger individuals. Body temperatures (Tb’s) cooled at night, but remained above or equal to water temperatures (Tw). All Tbmax’s exceeded maximum air temperatures (Ta) by 10 oC during daytime with the highest recorded Tb being 36.4 oC. Daily Tb amplitude’s of >10 oC were routinely exhibited in all specimens, regardless of size or sex. Both Tbmax and Tbmin generally lagged Tamax’s and Tamin’s by about two hours, respectively. The mean Tb’s increased ~2 oC monthly from June through October 1986 for each individual regardless of size or sex with supplemental data inferring Tb‘s increased through January-February 1987.
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