Weather constraints on Burmese python survival in the Florida Everglades, USA based on mechanistic bioenergetics estimates of core body temperature

Figures & data

Table 1. The monthly mean air and soil temperatures for December or January 2009 to 2014 in the data sets used in the models

Year	Month	Air temp mean daily max (°C)	Air temp mean daily min (°C)	Soil temp daily mean at 10 cm (°C)	Soil temp mean daily amplitude (°C)
2009	December	26.5	19.1	21.1	1.7
2010	January	22.4	13.2	16.2	2.1
	December	21.7	10.6	17.0	2.4
2011	January	24.3	14.7	18.5	2.1
	December	26.4	19.4	20.3	2.9
2012	January	24.7	15.9	18.4	3.2
	December	26.3	18.1	18.6	2.7
2013	January	26.5	19.3	19.5	2.8
	December	27.2	20.6	18.8	2.2
2014	January	24.3	15.6	15.8	2.8

Note: For January 2014 soil temperatures were recorded from 1/1 to 1/25.

Figure 1. Hourly air temperature for 9 January 2010 compared to the estimated body temperature of Burmese pythons arranged in a coil of varying dimension exposed above ground to ambient conditions on the same date. Body temperature is dependent on size as the energy balance is dominated by solar short-wave radiation.

Note: Significant mortality has been reported in captive snakes with body temperatures below the horizontal grey line at 10°C. Body temperatures below the horizontal black line at 5°C are perceived as lethal.

Table 2. The number days per month, the average number of hours per day, and the average body temperature of Burmese pythons were estimated to fall between 5 and 10°C for December or January, 2009 to 2014 when the pythons were exposed above ground to ambient climatic conditions

Year	Month	Air temp mean daily max (°C)	Air temp mean daily min (°C)	Body size (m)	Number of days where body temp is >5°C <10°C	Average # of hours >5°C <10°C	Mean body temp >5°C <10°C
2009	December	26.5	19.1	0.81	1	6	8.4 ± 0.3
				0.376	1	5	8.7 ± 0.2
				0.127	1	5	9.3 ± 0.2
				0.091	1	4	9.2+0.1
2010	January	22.4	13.2	0.81	11	8.2	7.3 ± 0.1
				0.376	12	7.7	7.5 ± 0.1
				0.127	12	7.7	7.7 ± 0.1
				0.091	12	7.5	7.7 ± 0.1
	December	21.7	10.6	0.81	19	5.1	7.8 ± 0.2
				0.376	15	5.9	7.8 ± 0.2
				0.127	14	5.8	7.8 ± 0.1
				0.091	13	6.4	7.7 ± 0.2
2011	January	24.3	14.7	0.81	8	6.4	8.2 ± 0.2
				0.376	8	5.2	8.2 ± 0.2
				0.127	7	5.1	8.4 ± 0.2
				0.091	7	5	8.4 ± 0.2
	December	26.4	19.4	0.81	1	2	9.8
				0.376	–
				0.127	–
				0.091	–
2012	January	24.7	15.9	0.81	7	6.6	7.8 ± 0.2
				0.376	7	6.3	8.0 ± 0.2
				0.127	6	5.8	8.1 ± 0.2
				0.091	6	5.5	8.1 ± 0.2
	December	26.3	18.1	0.81	3	4	8.7 ± 0.3
				0.376	3	2.7	8.7 ± 0.3
				0.127	1	5	8.7 ± 0.2
				0.091	1	5	8.8 ± 0.2
2013	January	26.5	19.3	0.81	–
				0.376	–
				0.127	–
				0.091	–
	December	27.2	20.6	0.81	–
				0.376	–
				0.127	–
				0.091	–
2014	January	24.3	15.6	0.81	9	6.3	8.3 ± 0.2
				0.376	8	6	8.5 ± 0.2
				0.127	7	5.5	8.6 ± 0.1
				0.091	7	5.5	8.6 ± 0.1

Note: Dashes denote no estimated body temperature in this range for that month.

Figure 2. Daily average air temperature for January 2010 compared to daily soil temperature on the same date at a soil depth of 30 cm.