Feeding Ecology of Northern Pintails and Green-winged Teal Wintering in California

Tables

**Table 1.** Aggregate percent (vol) data for major food items found in 262 northern pintail and 173 green-winged teal esophagi collected in 4 separate habitat types at Kern National Wildlife Refuge, California, during October through February, 1979-80 and 1980-81.
Food item	Pintail					Green-winged teal
	Habitat types^a					Habitat types
	BG	ST	AB	A	ALL	BG	ST	AB	A	ALL
*Plant*
Red maids (Calandrinia ciliata)	tr^b	tr	tr	tr	tr	tr	tr	1	2	tr
Willow weed (Polygonum lapathifolium)	2	tr	tr	2	1	tr	2	1	tr	1
Dock (Rumex spp.)	1	3	1	tr	2	tr	2	tr	2	1
Common fivehook	tr	1	1	1	1	1	2	3	6	3
Amaranth (Amaranthus spp.)	tr	tr	tr	2	tr	tr	tr	tr	1	tr
Ammannia	tr	1	tr	49	6	1	1	2	36	6
Aster (Aster exilis)	tr	tr	tr	tr	tr	1	tr	5	2	2
Alkali bulrush	1	4	13	1	5	tr	4	3	tr	2
Spike-rush (Eleocharis spp.)	1	1	tr	1	1	tr	4	1	tr	2
Swamp timothy	16	53	40	31	37	19	39	18	14	25
Sprangle-top	5	4	10	3	6	4	3	6	5	4
Common barnyardgrass	42	2	tr	2	12	36	4	tr	1	11
Other (7 items)	3	3	3	2	3	1	2	4	14	5
Total plant matter	71	72	68	94	74	63	63	44	83	62
*Animal*
Water fleas (Cladocera)	1	1	1	tr	1	1	2	2	2	2
Seed shrimps	tr	tr	tr	2	tr	1	3	5	2	3
Snails (Gastropoda)	3	tr	tr	1	1	tr	2	1	tr	1
Dragonflies and damselflies (Odonata)	2	tr	tr	1	1	tr	1	tr	3	1
Midges	22	22	27	3	22	29	22	46	11	27
Flower flies (Syrphidae)	1	1	2		1	2	2	1	1	2
Other (4 items)	2	4	2	1	2	3	4	2	tr	3
Total animal matter	31	28	32	8	28	36	36	57	19	39
^a BG = Barnyardgrass, ST = Swamp timothy, AB = alkali bulrush, A = Ammannia, and ALL = All habitats combined. ^b tr = < 0.5%