Helminth parasites of the Wyoming ground squirrel, Spermophilus elegans Kennicott, 1863

Helminth parasites of the Wyoming ground squirrel, Spermophilus elegans Kennicott, 1863, were surveyed from two environmentally different habitats within Wyoming. A total of four helminth species were identified. Three helminth species were found in 419 hosts collected in a mesic habitat including one species of adult cestode, Hymenolepis citelli, and two species of nematodes, Citellinema bifurcatum and Syphacia citelli. Only larval cestodes ( Taenia taxidiensis ) were found infecting 335 Wyoming ground squirrels collected from a xeric habitat.     

Notes on the ecology of the Clwyd estuary,north Wales

Summary

No previous ecological work having been attempted in the Clwyd estuary, a 13 month survey was made to assess conditions and provide basic data. A notable feature of this estuary is its physical construction, which, being long in relation to its width, appears to limit the diversity of the benthic fauna. Comments are made on the five most abundant species, Macoma balthica, Scrobicularia plana, Nereis diversicolor, Corophium volutator and Gammarus duebeni. The effect of changing climatic conditions on one species, Gammarus duebeni is described.     

Notes on the birds of Cold Spring Mountain, northwestern Colorado

Observations are presented on 117 bird species seen in a 250-km 2 area of northwestern Colorado adjacent to Utah and Wyoming. Three previously unreported species and seven status changes are listed for the Rangely, Colorado, latilong block.     

A new species of Protocladorchis (Paramphistomidae,Dadaytrematinae) from Pangasius nasutus (Bleeker, 1863) in Thailand

Protocladorchis chinabutae sp. nov. from Pangasius nasutus in Thailand differs from Protocladorchis burmanicus mainly in the size, shape and position of the testes and from P. pangasii in body shape, egg size and the shape of the pharyngeal sacs. The genus has not previously been reported from Thailand.     

Notes on the white-tailed antelope squirrel, Ammospermophilus leucurus, and the pinyon mouse, Peromyscus truei, in north central Nevada

A four-season live trapping study in the Whirlwind Valley, on the Lander and Eureka county lines near the Humboldt River, yielded two species previously unrecorded from both counties, Ammospermophilus leucurus and Peromyscus truei. Both records represent minimal airline range extension of 113 and 105 km. It is suggested that the distribution of A. leucurus may include the entire northeastern quadrant of Nevada. The occurrence of P. truei in sagebrush habitat 21 km from the nearest pinyon woodland is unusual and suggests that this species may occur patchily distributed throughout the lower elevation ranges in the northern portion of the state.        

Notes on the reproductive biology of Zigadenus paniculatus, a toxic range plant

Zigadenus paniculatus is a toxic plant common on sagebrush foothills at middle elevations in the western United States. Plants produce several racemes from a single stalk. Flowering commences at the base of each raceme and proceeds upwards. The terminal raceme begins blooming first and is followed by lower racemes in sequential order. Flowers are markedly protandrous and incapable of autogamy. Observations do not support the idea that apomixis is a viable reproductive strategy. Plants are mostly self-incompatible; a few seeds were produced from geitonogamous hand pollinations. The pollen/ovule ratio was high, also suggesting outcrossing as the predominant mode of sexual reproduction. A self-incompatibility mechanism may have evolved because the movements of syrphid flies on the inflorescence render protandry alone insufficient to prevent some selfing. The probable presence of toxic substances in the pollen and nectar appears to have reduced the number of potential pollinator species but increased the flower constancy of those species capable of utilizing the floral rewards.