Birds
Week 9
Chris Foster
Ecology of Populations and Communities
Avian populations;
- Density independent / density dependent / social behavior
- Censusing Bird Populations; standard methods/ point counts/ transect counts/ more
surveys [volunteers]
- North American Christmas Bird Count, started 1990/ 2,585 counts in 2018 // N.
American BBS, started in 1966, continent wide breeding bird survey.
Senescence and Longevity;
- Bird ageing; 3 x longer than mammals, large sea birds = live longer
UK Bird Recording;
- 100years, 900,000 birds recorded a year
- Constant effort sites [CES]; same nets set up in same place = standard measure of
population size and age structure
- Retrapping Adults for Survival Schemes [RAS]; try and catch the same individuals.
Niches;
- Ecological niches; 2 species coincide
- Joseph Grinnell, 1917 [conditions in which species exist] = niche modelling
- Limiting Factors;
1. Food; birds increase winter fattening to survive cold/ experimental provision of
supplementary food
2. Nest sites; especially in cavity nesters/ cliff nesters/ restricted sites.
3. Predation; ever present risk/ 18-34% young great tits killed by sparrowhawks //
introduced predators have big effect on populations
4. Parasites and pathogens; pathogens cause sickness and disease and death
5. Brood parasitism; conspecific brood parasitism in >200 spp, 36% Goldeneye eggs
in Southern Sweden/ interspecific cases studied well
Populations in time and space;
- Stable but fluctuate/ population cycles/ prey switching
Bird communities;
- Classifying assemblages
- Community; set of ecologically interacting organisms
- Assemblage; all those which inhabit a place [biomes and Life zones]
- Latitudinal pattern of diversity;
o Stable tropical environment
o Sedentary lifestyle = lower gene flow
o Ecological factors; higher diversity near equator
- Habitat change;
o Predictable changes/ communities of modified habitats
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller jemradford011. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for £3.49. You're not tied to anything after your purchase.