Feeding Ecology of Northern Pintails and Green-winged Teal Wintering in California
Tables
Food item | Pintail | Green-winged teal | ||||||||
Habitat typesa | Habitat types | |||||||||
BG | ST | AB | A | ALL | BG | ST | AB | A | ALL | |
Plant | ||||||||||
Red maids (Calandrinia
ciliata) |
trb | 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% |