pressure sensory mechanism for prey detection in birds- T.Piersma, R.Aelst

Question 1

what are red knots and where do they occur?

Answer 1

sandpipers in coastal intertidal areas

Question 2

with dry sand could they discriminate between food and non food items?

Answer 2

no

Question 3

what can Herbst corpuscles measure and why?

Answer 3

acceleration due to pressure change

accelerating pressure build up

Question 4

what can the bills detect in soft sediment?

Answer 4

perception of a pressure gradient

object blocks pore water flow

Question 5

what can repeated probing in soft wet sediment allow?

Answer 5

allows the birds to induce residual pressure disturbance from a nearby object

Question 6

where do red knots tend to eat invertebrates?

Answer 6

arctic tundra breeding ground

Question 7

what were the 3 types of buckets?

Answer 7

1. no prey
2. 15 buried bivalves
3. 15 buried stones

Question 8

which feeder would they go to if the bucket had objects?

Answer 8

right

Question 9

what % showed correct choice indicating they could discriminate between buckets?

Answer 9

60%

Question 10

what may be a possible reason for them making mistakes?

Answer 10

strategically to see if there are alternative cues

Question 11

in light microscopy what did the silver staining show?

Answer 11

corpuscular nerve endings

Question 12

what were the scanning electron microscopes used to show?

Answer 12

presence of sensory pits

Question 13

in the training phase how many trials did it take for preference to be significant?

Answer 13

120

Question 14

when buried in dry sand after how many trials were they still on the 50% line?

Answer 14

328

Question 15

what do they have in lacunae sensory pits?

Answer 15

high numbers of Herbst corpuscles

Question 16

where is the largest density of sensory pits?

Answer 16

tip of the bill

Question 17

what is found under keratin spines on the palate and what do these detect?

Answer 17

grandly corpuscles- velocity detectors

Question 18

where is the detection of buried objects weaker?

Answer 18

in dry sand

Question 19

in the dry sand what is the air near the probing bill?

what is the resistance from sand pores?

Answer 19

easily compressed

low resistance

Question 20

in wet sand:

a) what is the interstadial water like?
b) what does the pressure from the probing bill drop over?
c) what is the water resistance like between sand grains?
d) what takes time?

Answer 20

a) nearly incompressible
b) a large distance
c) high
d) relaxation of increased pressure

Question 21

with a hard object why is the pressure pattern not disturbed?

Answer 21

flow must go around the object

Question 22

if sand is loose and mobile what does the probing bill do to the water?

Answer 22

increases pressure

Question 23

when the bill is retreated what happens to the sand grains?

Answer 23

rearranged, denser packing and so an increased pressure build up

Question 24

what is the birds preferred feeding terrain?

Answer 24

sandy with a film of moisture

Question 25

what is pressure pattern dominated by?

Answer 25

radial decay

Question 26

what is darcys law?

Answer 26

pressure gradient balanced by frictional drag of pore water flow
flow is proportional to pressure gradient