Female Greater Prairie-Chickens Research Articles

Patterns of nest attendance by female Greater Prairie-Chickens (Tympanuchus cupido) in northcentral Kansas

Nest attendance behavior is a critical component of avian ecology that influences nest survival and population productivity. Birds that provide uniparental care during incubation and brood-rearing must balance the benefit of reproductive success with the costs of physiological needs and predation risk. We used miniature nest cameras to record 5904 h of video footage at 33 nests of Greater Prairie-Chickens (Tympanuchus cupido) during 2010 and 2011 in northcentral Kansas. We quantified the timing and duration of incubation bouts to address alternative hypotheses about physiological requirements and predation risk as drivers of incubation behavior. We also identified nest predators and determined timing of predation events, and tested for effects of nest attendance and monitoring technique on nest survival (video vs. telemetry). Female prairie chickens exhibited high incubation constancy per day (~95 %) and typically took two ~40-min recesses per day: one after sunrise and one before sunset. Mesocarnivores were responsible for 75 % (18 of 24) of nest losses, and most nest predation events occurred during crepuscular or overnight hours. Controlled comparisons provided no evidence that video surveillance attracted predators to nests. Variation in nest attendance had a minimal effect on nest survival compared to height of vegetative cover at the nest site. Timing of recesses did not indicate avoidance of predator activity in our study system. The bimodal pattern of incubation breaks observed in most grouse species is likely driven by physiological requirements of the female rather than predation pressure. Female Greater Prairie-Chickens appear to prioritize their metabolic needs and future reproductive potential over current nest survival.

Effects of Sexual Dimorphism and Landscape Composition on the Trophic Behavior of Greater Prairie-Chicken

Partitioning of ecological niche is expected in lekking species that show marked sexual size dimorphism as a consequence of sex-specific ecological constraints. However, niche partitioning is uncertain in species with moderate sexual dimorphism. In addition, the ecological niche of a species may also be affected by landscape composition; particularly, agricultural fragmentation may greatly influence the trophic behavior of herbivores. We studied trophic niche variation in Greater Prairie-Chickens (Tympanuchus cupido), a grouse species that shows moderate sex-dimorphism. Greater Prairie-Chickens are native to tallgrass prairies of North America, although populations persist in less natural mosaics of cropland and native habitats. We used stable isotope analysis of carbon and nitrogen in blood, claws and feathers to assess seasonal differences in trophic niche breadth and individual specialization between male and female Greater Prairie-Chickens, and between birds living in continuous and fragmented landscapes. We found that females showed broader niches and higher individual specialization than males, especially in winter and autumn. However, differences between females and males were smaller in spring when birds converge at leks, suggesting that females and males may exhibit similar feeding behaviors during the lekking period. In addition, we found that birds living in native prairies showed greater annual trophic variability than conspecifics in agricultural mosaic landscapes. Native habitats may provide greater dietary diversity, resulting in greater diversity of feeding strategies.

First Case of Renesting After Brood Loss by a Greater Prairie-Chicken

Abstract Production of a second brood, or double brooding, by a single female in one breeding season has not been reported for any species of grouse in North America. We describe the breeding history of one of 55 radio-marked female Greater Prairie-Chickens (Tympanuchus cupido) that successfully renested after losing a brood from a first nesting attempt during the 2011 breeding season in Kansas. Observations of double brooding by grouse might only be possible in areas like the Flint Hills of Kansas, where populations have a long breeding season in combination with a high rate of brood loss.

Movement and Lek Visitation by Female Greater Prairie-Chickens in Relation to Predictions of Bradbury’s Female Preference Hypothesis of Lek Evolution

Movement and Lek Visitation by Female Greater Prairie-Chickens in Relation to Predictions of Bradbury’s Female Preference Hypothesis of Lek Evolution

Radio Transmitters Bias Estimation of Movements and Survival

During 1987 and 1988, we tested the hypotheses that radio transmitter size (14 vs. 18-22 g) and signal strength (1-stage vs. 2-stage) had no effect on estimates of survival, movement, or home range of 54 female greater prairie-chickens (Tympanuchus cupido). Birds (n=33) wearing heavier 2-stage solar transmitters, with twice the reflective surface, had lower (P=0.08) estimated annual survival than birds (n=21) wearing the lighter transmitter. In 2 of 3 seasons, estimates of daily movements, within-day movements, and seasonal ranges were larger (P<0.09) for birds equipped with the more powerful 2-stage transmitters. Differences in estimated movements and home range did not represent true differences because long distance movements were more likely to be detected for birds wearing 2-stage units than for those equipped with 1-stage transmitters

Greater Prairie Chickens Attract Predators to Their Nests

Parental care theory incorporates the idea that ground-nesting parents behave to reduce nest predation. The alternative hypothesis is that parents attract predators to nests. Both hypotheses are supported by ambiguous data. This study shows that nocturnal, mammalian predators preyed upon nests of greater prairie chickens (Tympanuchus cupido) only during incubation when the females were on the nest all night long. No predation was observed during egg-laying when the females were away from their nests. Mortality was significantly greater during incubation than during egg-laying. The implication is that the females attract predators to the nests. An important function of parental care is to reduce the degree of predation on eggs or young. However, Skutch (1949) hypothesized that parental nesting activity attracts predators to nests. This idea has received wide acceptance (Hammond and Foreward, 1956; Klomp, 1970; Willis, 1973), but it is not well supported by evidence (Ricklefs, 1969). Wagner (1957) disagreed with the hypothesis and argued that it is unlikely that snakes, which are major nest predators, watch parent birds to find their nests. Gottfried and Thompson (1978) conducted nest experiments in a predator system dominated by snakes and blue jays (Cyanocitta cristata) and found that parent birds were not attracting these predators to their nests. Some evidence supporting the hypothesis comes from studies of colonial birds (Horn, 1968; Andersson and Wiklund, 1978) but the evidence is not completely clear because the colonies presumably function to reduce predation. Skutch's idea that parent birds attract predators is closely associated with another hypothesis that clutch size is reduced as a result of high predation. 1 Support for field work came from grants from the National Institutes of Health, National Science Foundation, and the Penrose Fund of the American Philosophical Society while the senior author was at Kansas State University. 2 Present address: Division of Science, College of Arts and Science, Widener University, Chester, Pennsylvania 19015. This content downloaded from 207.46.13.133 on Sat, 17 Dec 2016 05:24:46 UTC All use subject to http://about.jstor.org/terms 4 TRANSACTIONS OF THE KANSAS ACADEMY OF SCIENCE Table 1. The arrival and departure times of female Greater Prairie Chickens at the nest during egg laying. Arrival time Departure time Birds Average* Range Average Range 1 1146 1108-122