1 / 17

Fig - Fig Wasp Natural History

Fig - Fig Wasp Natural History. 750 spp. of fig, most with a single sp. of pollinator!!. http://129.31.3.171/index.html. Fig - Fig Wasp Model. MVP: ~ 170 fig trees are required to eliminate a gap in flowering among trees - i.e., 99% probability of persistence for 1000 years.

parrish
Télécharger la présentation

Fig - Fig Wasp Natural History

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Fig - Fig Wasp Natural History 750 spp. of fig, most with a single sp. of pollinator!! http://129.31.3.171/index.html

  2. Fig - Fig Wasp Model MVP: ~ 170 fig trees are required to eliminate a gap in flowering among trees - i.e., 99% probability of persistence for 1000 years.

  3. Big-Blue ButterflyAn obligate parasite of ant colonies Butterfly oviposits on thyme Caterpillar becomes a beautiful butterfly Caterpillar feeds on thyme Caterpillar is fed by / feeds on ants Caterpillar enters Myrmica ant nest http://faculty.plattsburgh.edu/thomas.wolosz/metapop.htm

  4. Big-Blue Butterfly • First started disappearing in the 19th century • Hypotheses • Over-collecting by insect collectors • Insecticides • Fragmentation • Climate change • Air pollution • Rapid decline in the 1950’s, extinct by 1979.

  5. Big-Blue Butterfly THYME BUTTERFLY SHORT GRASSY FIELDS ANTCOLONY (Myrmica sabuleti) GRAZING MYXOMATOSIS RABBITS

  6. Migratory Birds • Studies have identified a decrease in U.S. neotropical migrants • Decreasing at the rate of 0.5 to 1.0% per year • Hypotheses • Deforestation in tropics or breeding ground • Susceptibility to predation or cowbird parasitism on breeding grounds

  7. Brown-headed cowbird

  8. The Evidence • Based on taxonomically diverse community in eastern U.S. • Decline of migrants equal to ~ 1% / year. • Based on wood warblers, vireos, gnatcatchers, kinglets, titmice, chickadees, nuthatches, brown creeper, wrens, bluebirds across U.S. • No decline for migrants • Recent declines in birds with high susceptibility to predation / cowbird parasitism

  9. Black-Footed FerretThe most endangered mammal in N. America http://www.ngpc.state.ne.us/wildlife/ferret.html

  10. Inter-relationship of species “The number of bumblebees in any district depends in a great measure upon the number of field-mice, which destroy their combs and nests”. “[Because] the number of mice is largely dependent, as everyone knows, on the number of cats . . . It is quite credible that the presence of a feline animal in large numbers in a district might determine, through the intervention first of mice and then of bees, the frequency of certain flowers in that district!” - Charles Darwin, On the Origin of Species

  11. Photo by James M. Cook Keystone Species

  12. Keystone Species Species with a disproportionate effect on community structure. Keystones Dominants strong interactors Total Effect weak interactors Common Cold Abundance From: Meffe and Carroll

  13. Problems with the Keystone Species Concept • Loosely applied • Difficult to test • Questionable application • Conclusion: Focus on interaction strengths

  14. Ecological Niche • Grinnell (1917): where a species lives (habitat) • Elton (1927): what a species does • Hutchinson (1950s): combination of all biotic and abiotic requirements of a species: n-dimensional “hyper-volume” abundance temperature seed size predator density

  15. Competitive Exclusion • If the niches of two competing species overlap by “too much”, then one tends to replace the other. • Corollary: Competition drives the evolution of divergent niches or life-history strategies (i.e., respond or perish) abundance abundance niche niche

  16. Darwin’s Finches:Character Displacement

  17. “The Ghost of Competition / Predation Past” • What we see today may be the result of competition / predation in the past (i.e., implies evolutionary history). • Consider Pleistocene extinctions • Conservation Implication: Exotic species may have their most negative effects after invading communities that lack an analogous evolutionary partner

More Related