Week 4 Questions - 4a Flashcards
Habitat
resources and conditions present in an area that produce occupancy by an organism
habitat selection
the process by which an animal chooses which habitat components to use
habitat preference
- the consequence of the habitat selection process
- resulting in the disproportional use of some resources over others
habitat availability
the accessibility and ability of an individual to obtain physical and biological components of the environment
habitat quality
ability of the environment to provide conditions appropriate for individual and population persistence
Macrohabitat
- large spatial extent that equates to the first level (order) of habitat selection,
- i.e., landscape-scaled features such as seral stages or zones of specific vegetation associations (CWH, ESSF, etc.).
Microhabitat
- finer-scaled habitat features, such as
- home range, specific sites scale, or for specific components within their home ranges; and the resources/microsites level
realized niche
- the observed abundance or distribution of a species
o usually will not include the full range of conditions the species could inhabit,
o It will likely not include the physical conditions where the species does best
Potential niche
the potential abundance or distribution
Why is geographic scale important (1)
Different animals operate at different levels of scale
What are the four levels of scale?
- Geographic range
- Home range
- Specific sites for specific components within home ranges (winter range, breeding grounds)
- Resources/microsite level
What are three concerns about the ‘resource use/habitat use’ concept that needs to be acknowledged and removed?
- temporal variation in resource use is often ignored by biologists/restorationists.
- fundamental concepts should be well defined and understood
- habitat terms are imprecise and ambiguous
How can conspecific attraction benefit restoration goals (1) or possibly significantly bias our understanding of animals’ use of ‘habitat’ (2)?
- can be used to enhance the occupation of restoration sites (choose sites that already have individuals on it)
- but, the absence of individuals does not mean a site is inappropriate for occupancy -> need to understand why they use some habitat and not others
-> critically evaluate baseline information
What should you look for/do to identify potential bias due to conspecific attraction?
- are there inconsistencies in the results of similar studies?
Specifically in observations and study results?
When measuring animal-habitat attributes, what are you measuring?
- sum of the specific resources needed by organisms
i. movement corridors (e.g., migration and dispersal), and
ii. the land animals occupy during breeding and nonbreeding seasons.
Does habitat availability equal habitat?
No
- we can measure the abundance of food for a predator,
i. but we cannot say that all of the prey present in the habitat are available,
ii. there are likely many factors that restrict their accessibility
- Animals go through a series of increasingly refined selection decisions
a. Describe the hierarchy of these decisions
b. Explain why restorationists need to identify this hierarchy
- beginning with the selection of a geographic area;
- followed by selection of a specific combination of elevation, slope, and vegetation type;
- followed by selection of specific locations to forage, breed, or rest;
- followed by selecting specific items (e.g., food type, mate choice, den site).
as we step down this hierarchy of habitat selection from broad to specific, we can understand an increasingly detailed amount of information about animals, which matches the spatial scale of study - thus, we must match the goal of a restoration plan properly with the appropriate scale of study
Should restorationists focus on the realized or optimal physiological niche? Why?
Restorationists need to know the optimal physiological niche
‘Does the animal occur here?’ vs. ‘Should the animal occur here?’
Should restorationists focus on restoring ‘habitat’? Why or why not?
- restorations need much more detail than typical wildlife management
- ideally, we need to measure the functional aspects of ‘habitat’,
i. otherwise, we fail to measure critical limiting resources in ‘habitat’,
ii. our restoration might fail because we have not identified constraints on the exploitation of critical limiting factors,
- When should you measure resource use by a species?
the preferred study design is the repetition of a study for every appropriate biological period (e.g., breeding, wintering, dispersal, migration, etc.).
- What should you measure in the habitat, and how should you measure it?
- spatial & temporal variability in biotic & environmental variables,
- feasibility of sampling with precision
- relevance to the impact effects
- economic or aesthetic value
