| heavy metals and selenium in grebe eggs from agassiz national wildlife refuge in northern minnesota. | metal levels in eggs can often be used as an indicator of exposure and of potential effects. in previous work at agassiz national wildlife refuge, northwestern minnesota, the levels of several heavy metals were shown to be significantly higher in the eggs of eared grebes (podiceps nigricollis) compared to those in the eggs of franklin's gulls (larus pipixcan), black-crowned night-herons (nycticorax nycticorax) and double-crested cormorants (phalacrocorax auritus, except for mercury). in the pres ... | 2005 | 16418918 |
| selenium and metal concentrations in waterbird eggs and chicks at agassiz national wildlife refuge, minnesota. | exceptionally high cadmium (cd) and chromium (cr) concentrations were reported in eggs, feathers, or livers of selected waterbird species nesting at agassiz national wildlife refuge (agassiz) in 1994. ten- to 15-day-old franklin's gull (larus pipixcan), black-crowned night-heron (nycticorax nycticorax), and eared grebe (podiceps nigricollis) chicks were collected in 1998, 1999, and 2001 at agassiz and analyzed for selenium (se) and metals including cd and cr. freshly laid eggs were collected in ... | 2007 | 17464443 |
| heavy metals and selenium in grebe feathers from agassiz national wildlife refuge in northern minnesota. | metal levels in feathers can often be used as an indicator of exposure and of potential effects in birds. in previous work at agassiz national wildlife refuge, northwestern minnesota, pied-billed grebe (podilymbus podiceps) eggs had significantly higher levels of manganese and mercury and significantly lower levels of selenium than eared (podiceps nigricollis) or red-necked grebes (podiceps grisegena), but in 1999, pied-billed grebes had significantly higher levels of mercury, but lower levels o ... | 2007 | 17657451 |
| organochlorine contaminants and eggshell thinning in grebes from prairie canada. | eggs of five species of grebe were collected from manitoba, saskatchewan and alberta during 1982-1987: red-necked (podiceps grisegena), horned (p. auritus), eared (p. caspicus), western (aechmophorus occidentalis) and pied-billed (podilymbus podiceps). dde and pcbs were present in all samples analyzed, whereas dieldrin, mirex and oxychlordane were occasionally present at low levels. mercury was present at low levels in all samples for which it was analyzed. red-necked grebes nesting in manitoba ... | 1994 | 15091684 |
| an integrative taxonomic study reveals a new species of tylodelphys diesing, 1950 (digenea: diplostomidae) in central and northern mexico. | tylodelphys aztecae n. sp. (digenea: diplostomidae) is described from adult specimens obtained from the intestine of the pied-billed grebe (podilymbus podiceps) and the metacercariae found in the body cavity of freshwater fishes of the families goodeidae and cyprinidae in eight localities across central and northern mexico. the new species is mainly distinguished from the other four described species of tylodelphys from the americas (t. adulta, t. americana, t. elongata and t. brevis) by having ... | 2016 | 26508032 |
| taxonomic revision of tatria kowalewski, 1904 (cestoda: amabiliidae): redescriptions of t. appendiculata fuhrmann, 1908 and t. duodecacantha olsen, 1939, a key and an amended diagnosis of tatria (sensu stricto). | tatria appendiculata fuhrmann, 1908 is redescribed on the basis of syntypes from tachybaptus dominicus in brazil and voucher specimens from the same host species in cuba previously recorded by rysavy & macko (1971). paratypes of t. duodecacantha olsen, 1939 from podilymbus podiceps in the usa are also redescribed and, in contrast with the opinion of ryzhikov & tolkacheva (1981), the species is recognised as valid. the major reliable diagnostic characters of tatria and the distinguishing criteria ... | 2003 | 12815221 |
| life history of petasiger chandleri (trematoda; echinostomatidae) from the pied-billed grebe, podilymbus podiceps podiceps, with sone comments on other species of petasiger. | | 1953 | 13045181 |