Do migrant and resident species differ in the timing of increases in reproductive and thyroid hormone secretion and body mass? A case study in the comparison of pre-breeding physiological rhythms in the Eurasian Skylark and Asian Short-toed Lark

Table 1 Results of a linear mixed model of the effects of species, time and sex on plasma LH andT₃ and body mass in Asian Short-toed Larks and Eurasian Skylarks in 2014 and 2015

Year	Response variable	Explanatory variable	F	p
2014	LH	Species	3.32	<0.05
		Sample date	13.96	<0.01
		Sex	0.50	0.48
		Species * sample date	0.05	1.00
		Species * sex	1.30	0.26
		Sample date * sex	0.47	0.76
		Species * sample date * sex	0.48	0.75
	T	Species	4.86	<0.05
		Sample date	6.85	<0.01
		Species * sample date	0.81	0.50
	E₂	Species	0.00	0.95
		Sample date	7.63	<0.01
		Species * sample date	0.20	0.90
	T₃	Species	15.52	<0.01
		Sample date	4.50	<0.01
		Sex	0.88	0.35
		Species * sample date	0.58	0.68
		Species * sex	0.72	0.40
		Sample date * sex	0.46	0.77
		Species * sample date * sex	0.12	0.98
	Body mass	Species	1918.50	<0.01
		Sample date	22.25	<0.01
		Sex	8.44	<0.01
		Species * sample date	3.32	<0.01
		Species * sex	22.63	<0.01
		Sample date * sex	0.42	0.87
		Species * sample date * sex	0.64	0.70
2015	LH	Species	4.30	<0.05
		Sample date	14.92	<0.01
		Sex	3.39	0.07
		Species * sample date	1.09	0.37
		Species * sex	1.13	0.29
		Sample date * sex	0.56	0.71
		Species * sample date * sex	1.03	0.39
	T	Species	1.13	0.29
		Sample date	4.22	<0.01
		Species * sample date	0.49	0.76
	E₂	Species	2.96	0.09
		Sample date	3.00	<0.05
		Species * sample date	0.15	0.96
	T₃	Species	20.94	<0.01
		Sample date	6.24	<0.01
		Sex	0.55	0.46
		Species * sample date	1.33	0.7
		Species * sex	0.56	0.48
		Sample date * sex	0.34	0.89
		Species * sample date * sex	3.83	<0.01
	Body mass	Species	1792.43	<0.01
		Sample date	45.30	<0.01
		Sex	0.81	0.37
		Species * sample date	9.60	<0.01
		Species * sex	3.70	0.06
		Sample date * sex	2.78	<0.05
		Species * sample date * sex	1.26	0.28

All Asian Short-toed Larks and Eurasian Skylarks had been captured in the wild and sampled while held in captivity in 2014 and 2015. Data are presented as mean ± SE; italic values expressed probabilities indicate statistically significant differences

ISSN: 2053-7166