Prey protection from predation

1

• Prey protection from predation
• Evolutionary interplay between host and parasite.
• Natural selection prey defenses/predator
  adaptive responses.
• By out-reproducing effects of predation
• Masting (Eucalyptus sps.) see predation.
• Two plots burn vs. control
• 3 weeks following fire
• 405 seeds/m2 on experimental (burn) plot
• 10 seeds/m2 on control plot

2
Masting a defense against predation?
Aha!
3
Cicada masting 13 17 year species density
can reach 4 x 106 individs/ha
Largest recorded biomass for a terrestrial animal.
Bird predators
16 ha study site c. 1 million emerged over
a four day period
4
(No Transcript)
5
Parasitism

• /-
• Prevalance
• About ½ of described species are parasites.
• Generally parasites are highly specialized, with
  narrow niches.
• Evolutionary interplay between host and parasite.
• Natural selection host defenses/parasite
  adaptive responses.
• Affect host populations and play a role in
  community changes.

6
Moose, wolves, and parasites
7
(No Transcript)
8
(No Transcript)
9
(No Transcript)
10
Kill efficiency low
c. 5
11
Winter tick an ectoparasite
12
(No Transcript)
13
Tapeworm life history
14
Hydatid cyst
15
(No Transcript)
16
Bottom-up or Top-down control of
community structure? numbers of wolves, number
of moose, growth rates of balsam fir BF c. 59
of winter forage
17
Some parasites control behavior of the host

• One example from animal hosts
• One example from plant hosts

18
Life cycle of Plagiorhynchus cylindraceus
Acanthocephala Spiny-headed worms
19
Starling predation on Armadillidium vulgare
20
Exploitation of a vascular plant by a fungus
Arabis hoelbollii Rockcress a host Montane and
subalpine zones talus slopes, gravelly
stream-banks
Puccinia monoica a rust pathogenic Population
growth based on spore dissemination Adaptive
strategy control meristematic growth of the host
plant

21
Dispersal of spores
Pseudoflower