Table S1.

Number and elemental composition of wildebeest carcasses entering the Mara River from 2011 to 2015

Year	No. of mass drownings	No. of carcasses	Carcass dry mass,* 103 kg	Average aerial loading,† g of DM per m−2	C, 103 kg	N, 103 kg	P, 103 kg
2011	3	8,000	385	590	137	32	16
2012	6	9,400	453	250	161	37	19
2013	7	7,750	373	360	133	31	16
2014	4	2,700	130	640	46	11	5
2015	3	3,400	164	140	58	13	7
Mean (SD)	4.6 (1.8)	6,250 (3,000)	301 (144)	400 (210)	107 (51)	25(12)	13(6)

DM, dry matter.

^*Total carcass biomass assuming a mean biomass of 175 kg of wet mass and 48 kg of dry mass per carcass.

^†Average aerial loading for mass drownings, where detailed carcass counts could be conducted over a spatially explicit area (12 of 23 mass drownings).