24 May 2017
Breeding activity by the chickadees has waned, but Carolina wrens and prothonotary warblers are nesting in earnest (and being monitored by cowbirds). Also, exposing curious students to new things might be the coolest thing in the world.
Kelly Miller Joins the Lab
06 April 2017
We are pleased to welcome Kelly Miller to the lab this fall to begin a PhD program at Memphis. Kelly is currently finishing her undergraduate work at Indiana University, Bloomington, completing degrees in both Animal Behavior and Psychology (honors), with a minor in Biology. She is pondering exactly how she’ll change the way people think about the evolutionary and behavioral ecology of birds. Stay tuned for updates on her research!
Alex gets money!
30 March 2017
Congratulations to Alex, who has just received a grant from the Tennessee Ornithological Society for his project entitled, “Experimental manipulation of environmental temperature and its effect on nestling development in the Carolina chickadee (Poecile carolinensis).” The Tennessee Ornithological Society promotes the enjoyment, scientific study, and conservation of birds, and generously funds research grants dedicated to helping protect and understand the birds of Tennessee. Thanks to the TOS, and congratulations Alex!
New paper on sexual selection and parental care
09 December 2016
A new paper led by undergraduate researcher Darren Will in a forthcoming issue of the Journal of Zoology investigates parental food provisioning in relation to a male’s sexual attractiveness. Male parental care for offspring should generally vary inversely with sexual attractiveness, as attractive males could maximize fitness by producing many offspring with multiple females, wheres unattractive males should invest a heavier level of care into what few offspring they are able to produce. Unattractive males did indeed provision their offspring with more food, but male and female provisioning rates were negatively correlated, suggesting sexual conflict over biparental care. But while females provisioned less food to offspring as their mates delivered more food, these females also spent more time brooding their nestlings, thereby altering the mode of care they provided when paired with males that put forth greater effort. The paper sheds new light on the potential for sexual selection to shape parental effort, and suggests that sexual conflict over biparental care may not be as simple as the assessment of food provisioning alone might suggest. Read the paper here ahead of print.
Study area taking shape
16 Nov 2016
Under beautiful weather for fieldwork, we are establishing our study area. In just three days, and with the help of eight terrific AmeriCorps members, we made 350 nestboxes for use at the Meeman Biological Station. We have more boxes to build, but are now deploying boxes in the field, and our resident birds have taken notice!
We send very special thanks to Dr. Goudie and Dr. Kennedy of the Department of Biological Sciences and Edward J. Meeman Biological Station at the University of Memphis and to the “Delta Five Unit” of the AmeriCorps for helping us get established!
Photos at right: A) AmeriCorps team members constructing nestboxes. B) Kelly Bowers, staff accountant in the Biology Department at the UofM, preparing completed nestboxes for deployment in the field. C) AmeriCorps team members ready for fieldwork. D) Keith with 501 boards (enough to make about 700 nestboxes). E) Grad students Jonathan Jenkins and Alex Mueller setting up a nestbox. F) A nestbox atop a predator baffle (20-inch pizza dish), resting five feet above the ground and ready for many years of ornithological research.
And we’re off
25 Oct 2016
It’s been a busy fall already, but we’re now constructing nestboxes and mapping out where they’ll go. These aren’t the finished product, but a good start. These currently have an entrance diameter of 1.75 inches. They’ll eventually get an additional piece of wood on the front with a particular size of hole to allow certain species to nest inside. The 1.75-inch entrances are for the Great Crested Flycatcher, we’ll also be using holes with a 1.25-inch diameter and a 1.125-inch diameter for Tufted Titmice and Carolina Chickadees, respectively. We only have hundreds more to build.
The early bird doesn’t always get the worm: Spring temperatures influence selection on breeding date and the potential for phenological mismatch in a migratory bird
09 July 2016
A new paper in Ecology indicates that spring temperatures have recently increased locally by a small but statistically significant extent, and that this increase has been accompanied by an advance in the timing of reproduction for one of our favorite birds, the House Wren. Several important stages in the lives of these birds have been altered, including the strength and shape of natural selection acting on breeding date. Selection generally favors earlier breeding, but variable spring conditions can reduce the fitness of the earliest birds, generating stabilizing selection on the timing of reproduction. Climatic variability is greater now than it has been previously, and will constrain the extent to which these seasonal organisms can respond to changes in their environment. Read the paper here ahead of print.
Elevated corticosterone during egg production elicits increased
maternal investment and promotes nestling growth in a wild songbird
05 June 2016
A new paper in Hormones and Behavior investigates effects of in ovo corticosterone elevation on offspring development. We experimentally elevated the maternal transfer of corticosterone to eggs using a non-invasive approach (i.e., feeding females corticosterone-injected mealworms). Elevated corticosterone within breeding females increased the number of eggs per clutch, the concentration of this steroid in eggs, and the amount of yolk allocated to eggs. Elevated in ovo corticosterone also enhanced offspring begging for food and growth after hatching. Read the paper here.
A mother’s natal environment and breeding territory predict the condition and sex ratio of her offspring
20 April 2016
A new paper in Evolutionary Biology investigates variation in the sex ratio of offspring produced by females of known age and ontogeny in a wild population. For females hatched and reared in the study population, the body condition and sex ratio of offspring they produced as adults was correlated with conditions under which these mothers were reared as nestlings. Sons tend to require a greater share of parental investment than their sisters in order to become successful breeders; as expected, the proportion of male offspring produced also varied positively with the quality of a female’s current breeding territory. However, increases in the production of sons was associated with a reduction in the rate at which these mothers returned to breed in the population in subsequent years, suggesting an increased cost of reproduction to parents associated with producing sons instead of daughters. Read the paper here.
No effect of blood sampling or immune activation on survival of young birds.
4 April 2016
Our new paper in Ecology and Evolution investigates potential effects of blood sampling and immune activation on survival in fledgling house wrens. Analysis of over 20,000 birds reveals no adverse effects of these techniques on their long-term survival. Read the paper here.
Keith selected for John Maynard Smith Prize.
13 March 2016
Keith was selected as the 2016 recipient of the John Maynard Smith Prize from the European Society for Evolutionary Biology. ESEB is a large academic society dedicated to the promotion of research and education in evolutionary biology. Many thanks to ESEB! Looking forward to visiting the Wissenschaftskolleg and the 2017 ESEB Congress in Groningen!