Production, Dieback and Grazing of Heather (Calluna vulgaris) in Relation to Numbers of Red Grouse (Lagopus L. scoticus) and Mountain Hares (Lepus timidus) in North-East Scotland

1976 ◽  
Vol 13 (2) ◽  
pp. 369 ◽  
Author(s):  
Robert Moss ◽  
G. R. Miller
Keyword(s):  
Calluna Vulgaris ◽  
Red Grouse ◽  
Lepus Timidus ◽  
North East

Strategies for nematode transmission: selective migration of Trichostrongylus tenuis infective larvae

2001 ◽  
Vol 75 (4) ◽  
pp. 367-372 ◽  
Author(s):  
L.M. Saunders ◽  
D.M. Tompkins ◽  
P.J. Hudson
Keyword(s):  
Calluna Vulgaris ◽  
Nematode Species ◽  
Food Plant ◽  
Red Grouse ◽  
Selective Migration ◽  
Infective Larvae ◽  
Wide Range ◽  
General Response ◽  
Trichostrongylus Tenuis ◽  
Nematode Transmission

Successful transmission of macroparasites is dependent on exposure of susceptible hosts to free-living infective stages. When these hosts are herbivores that feed mostly on a single food plant then natural selection should favour those infective larvae that selectively ascend this main food plant. Red grouse feed predominantly on heather,Calluna vulgaris, so we predict that the infective larvae (L3) of the caecal nematodeTrichostrongylus tenuisselectively locate and ascend heather plants. To determine whether the presence of heather influences the horizontal dispersal ofT. tenuisL3 across soil, the movement of L3 across trays of soil with and without heather was investigated in the laboratory. MoreT. tenuisL3 were recovered from soil when heather was present, implying that larval migration may be influenced by chemical cues produced by heather plants. This was investigated in a second experiment, in which the horizontal dispersal ofT. tenuislarvae was examined in the presence of heather and grass vegetation. This trial was repeated with larvae of a second species,Haemonchus contortus, a nematode whose hosts feed on a wide range of grass and shrub species. Significantly more larvae of both nematode species were recovered in the region of the heather than the grass or controls. This implies thatT. tenuisandH. contortusL3 exhibit selective migration towards heather, perhaps reflecting a general response to plant cues which may be stronger for heather than for grass.

scholarly journals Population responses of Red Grouse Lagopus lagopus scotica to expansion of heather Calluna vulgaris cover on a Scottish grouse moor

2018 ◽  
Vol 13 (2) ◽  
Author(s):  
Sonja C. Ludwig ◽  
Nicholas J. Aebischer ◽  
Damian Bubb ◽  
Michael Richardson ◽  
Staffan Roos ◽  
...  
Keyword(s):  
Calluna Vulgaris ◽  
Red Grouse ◽  
Lagopus Lagopus ◽  
Population Responses

The dynamics of nematode transmission in the red grouse (Lagopus lagopus scoticus) : studies on the recovery of Trichostrongylus tenuis larvae from vegetation

1999 ◽  
Vol 73 (2) ◽  
pp. 171-175 ◽  
Author(s):  
L.M. Saunders ◽  
D.M. Tompkins ◽  
P.J. Hudson
Keyword(s):  
Control Plant ◽  
Structural Complexity ◽  
Calluna Vulgaris ◽  
Red Grouse ◽  
Infective Larvae ◽  
Third Stage ◽  
Lagopus Lagopus Scoticus ◽  
Trichostrongylus Tenuis ◽  
Nematode Transmission ◽  
Larval Recovery

Attempts to recover the infective third-stage larvae of Trichostrongylus tenuis from heather (Calluna vulgaris) vegetation in the field are rarely successful because the larvae may be: (i) concealed within heather leaflets; (ii) concentrated in dew droplets which are lost from the plants upon sampling; or (iii) simply highly aggregated in the field. Heather plants were exposed to T. tenuis larvae in the laboratory and kept under suitable conditions for larval migration. Few larvae were found in dew droplets or concealed within heather leaflets; most larvae were recovered from the plant surface. This suggests that the low larval recovery from vegetation in the field simply reflects a highly aggregated distribution of few larvae. In a second experiment, the efficiency with which infective larvae migrate up the structurally complex heather plants was compared with migration up two control plant species with simpler structures: a monocotyledon, wheat, and a dicotyledon, hebe. After constant exposure, significantly more larvae were recovered from heather than from either of the control plants. This implies that the structural complexity of heather causes no problems for the infective larvae.

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