Chapter 10: Connectivity Flashcards
how do wildlife species occur?
as multiple populations distributed across landscapes
connectivity equation
N t+1 = Nt + B + I - D - E
E
emigration
I
immigration
one migrant per generation rule
- typically maintains genetic diversity
- balances local adaptation
- independent of population size
- migrant has to have the same probability of breeding
demographic connectivity
change in population size due to immigration and emigration
impact of demographic connectivity
a function of the migration rate & the local demographic rates
migration
- movement of large numbers of one species from one place to another
- often round trip
dispersal
permanent movement away from population of origin to another population
types of dispersal
- immigration
- emigration
immigration
dispersal into a target population
emigration
dispersal out of a target population
example of migration
movement of eels between lakes & rivers & Sargasso Sea
example of dispersal
movement of mountain lions from W. USA to the midwest
why is connectivity important?
- persistence & fluctuation of populations
- colonization & recolonization of empty sites
persistence & fluctuation of populations
- rescue effects
- synchrony
rescue effects
- genetic
- demographic
- evolutionary
synchrony
- of population dynamics to dampen fluctuations
- can have negative consequences
colonization of new sites
permits response to changing environmental conditions
example of colonization of new sites
global climate change
recolonization
increase persistence of suite of populations
how to measure connectivity?
- using mark-recapture methods
- radio telemetry
CMR: Roseate Terns
- band a large number of birds at colonies
- colonies search each year for marked birds
- identify which birds moved
- need to know where to look
Jolly Seber
open population type models
CMR for measuring dispersal & connectivity
- great for tightly colonial species
- great for heavily harvested animals
- need to know where to look for dispersing animals
for which of the following would it be challenging to measure movement using mark recapture?
- praire dogs
- white tailed deer
- raccoons
raccoons
radio telemetry
- mark animals with a radio transmitter
- follow them
different types of radio telemetry
- VHF
- acoustic
- satellite
VHF & acoustic telemetry
- easier to find dispersers than CMR
- limited by the range of the transmitter
VHF & acoustic telemetry: limited by range of transmitter
- limited by size
- aircrafts & drones can help search
- freshwater & marine
The Motus Wildlife Tracking System
- automated radio telemetry to simultaneously track hundreds of individuals of numerous species of birds, bats, & insects
- international collaborative network
satellite transmitters
- marks animals with transmitters
- sit at your desk & let a satellite track them
pros of satellite transmitters
good for broad scale movement
cons of satellite transmitters
- not always extremely accurate
- expensive
- relatively heavy
Genetic Method: assignment test
designed to directly detect individuals that disperse from their population of birth
Brook Trout
- native to Lake Erie tributary system
- reintroductions began in late 90’s
metapopulation
population of populations
metapopulation details
- habitat occurs in discrete patches
- dispersal occurs between patches
- not all patches are created equal
source population
serve as a net contributor to the metapopulation
sink population
population that drains the metapopulation
Snowshow hares cycle across Canada & AK
source sink dynamics are one of the reasons that snowshow hares do not cycle in the US
