November 18th, 2009
A ubiquitous pattern in nature is that populations are patchy: species are restricted to a subset of the habitats available to them. Understanding the processes that underlie these patterns is a long-standing goal in both ecology and evolutionary biology. In an upcoming issue of the American Naturalist, a study conducted by Dr. Nancy Emery examines the role of pollen movement in restricting one particular wildflower species to vernal pool wetlands in California. The study, conducted during the 2004-2005 growing season, represents one of the first attempts to examine the evolutionary limits to plant distribution patterns in a natural population.
California vernal pools are ephemeral wetlands that accumulate rain during the fall and winter, and dry in the spring as rain ceases and temperatures rise. Fremont’s Goldfields (Lasthenia fremontii) are often most abundant in the deepest portions of pools and dwindle in number and size at progressively shallower positions. Emery documented that Goldfields flower as the water recedes in the spring, yielding concentric rings of flowering plants that begin at the edge of the pool and collapse inward as spring progresses. Thus, plants at the center of the pool likely flower much later than plants nearer the pool edge, making it difficult for pollen to move from the center to the edge of the population. The insects that pollinate Goldfields move very locally within these flowering bands, further restricting the potential for pollen to move across the population. A field experiment revealed that seeds generated from edge parents were less likely to germinate that seeds generated from alternative patter
ns of pollen movement. This study provides evidence that patterns of pollen movement relative to the environmental context can play a large role in determining the edges of species’ distributions.
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November 15th, 2009
A recent study conducted in Dr. Esteban Fernandez-Juricic’s lab addressed a relevant question in predator-prey interactions: can variations in the visual system of prey influence their ability to detect a predator attack?
The Authors investigated how predator detection and vigilance 
behavior are related to how far away (visual acuity) and how far around the head (visual coverage) two bird species (European starlings and house sparrows) could perceive objects visually. European starlings can detect objects at greater distances but have less visual coverage (e.g., a larger blind spot at the rear of their heads) than house sparrows. The Authors found that House sparrows reduced their chances of detecting the predator from farther distances compared to European starlings; which could be related to their lower visual acuity. However, the probabilities of predator detection of both species decreased with body positions and head orientations with lower visual coverage despite the between-species differences. European starlings had longer vigilance bouts probably to enhance visual coverage, whereas house sparrows had higher vigilance rates likely to update information about potential predators more often.
These results suggest that sensory systems can play an important role in predator detection, and eventually in the evolution of behavioral, morphological, or physiological strategies to avoid predation.
This paper has been recently published in Behavioral Ecology (Volume 20, Pages: 936-945, 2009).
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November 13th, 2009
It appears that some birds have found a simple solution when they are not looking for a mate in the fall – they just ignore love’s call by muting their hearing.
Purdue University biologists studying how both birds and humans adapt to noise have found that some bird species have degraded hearing ability in the fall – when it’s not mating season – as well as in other select situations. The findings have potential implications for hearing loss in humans, said Jeffrey Lucas, a Purdue professor of biological sciences.
“We’ve been thinking a lot about human hearing,” Lucas said. “The world is getting noisier as the environment gets more urbanized. Noise becomes much more important to understand.”
In ongoing research, Lucas is looking at how birds adapt the precision of their hearing to seasonal changes as well as to disturbances in their environment. His work even goes so far as to suggest hearing ability differs between the sexes.
Read more: http://news.uns.purdue.edu/x/2009b/091103LucasAuditory.html
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September 14th, 2009
Two Purdue graduate students have developed sampling kits and educational materials for three Native Alaskan villages as part of an interdisciplinary partnership between Purdue faculty and the Alaska Native Youth Institute. Leila Nyberg (Civil Engineering/Ecological Sciences and Engineering) and Laurel Royer (Agronomy) became involved with the project in February 2008. Dr. Krista Nichols (Biological Sciences & Forestry and Natural Resources) and Dr. Marisol Sepulveda (Forestry and Natural Resources) have been working with Native Alaskans for 3 years, facilitated by Dr. Mike Smolen (Alaska Native Youth Institute) and Purdue University Center for the Environment. They are studying the fish parasite Ichthyophonus, which is affecting the salmon populations on which the villagers depend for their subsistence.
Tags: Alaska, Nichols, parasite, salmon
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May 13th, 2009
From Digital Photography School
Wildlife photography is one of the most challenging yet rewarding forms of nature photography. The best wildlife images create a powerful emotional connection between the viewer and the animal, but success requires planning, timing, and technique. Here are a few tips for getting started:
Read more:http://digital-photography-school.com/four-tips-for-better-wildlife-photography#ixzz0FOfUkPUR&B
Tags: Photography, wildlife
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May 13th, 2009
We hope this will be a useful forum for the Ecology group to share and discuss ecology related news, events, and ideas.
-Bio IT Team
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