Diss. vet.-med. Univ. Bern, 2004.

Parental care in animals can be costly and is shared between both parents in many bird species. Not surprisingly, most studies of how parental care is shared between the sexes are in sexually dimorphic species, and much less in known about sexually monomorphic species where sex cannot be determined in the field. This has prevented a full understanding of parental care behaviors – which are intrinsically linked to fitness – in species such as the Red-headed Woodpecker (Melanerpes erythrocephalus) that is experiencing population declines throughout much of its range. In this study we assessed whether Redheaded Woodpecker brooding time, nestling provisioning rates, and nest cleaning rates vary as a function of parent sex, habitat type (savanna and closed canopy forest), brood size, nestling age, temperature and/or date. We recorded and analyzed 128 hours of high-quality video from 21 broods at Fort A.P. Hill, Virginia where this species is relatively abundant. We captured and color-banded Red-headed Woodpeckers, taking breast feather samples for genetic sexing, and determined brood size and chick age of nests using an extendable pole camera. Using generalized linear mixed models, we found the best predictor of nestling provisioning was an interaction between chick age and date; older chicks were fed more frequently in early summer (before 7 July) compared to late summer. The seasonal reduction in provisioning could be related to a reduction in resource availability, but whether or not provisioning in later nests affects nestling survival warrants further study. We found chick age and parent sex to be the best predictors in brooding models, with females brooding more when chicks are less than 10 days old and males being the only parent to enter the cavity after 10 days. Additionally, males almost exclusively remove fecal sacs from nests, highlighting an observational method to determine sex of breeding adults in the field. Such division of reproductive roles is similar to what is known for dimorphic woodpecker species and likely indicates energetic constraints due to the need for high parental investment from both sexes. Parental care is inextricably linked with habitat quality and home range size. Parents will travel to obtain the resources necessary to provision their young, and larger home ranges during the demanding nestling provisioning stage may indicate increased effort resulting from fewer available resources near the nest. We estimated home range sizes of 25 breeding adult Red-headed Woodpeckers using PinPoint GPS tags and 95% kernel density estimates (KDEs) with plug-in smoothing factors. We modeled the effects of habitat, sex, nest stage, date, and distance to nearest neighbor on home range estimates. Red-headed Woodpecker males have larger home ranges than females, and late summer home ranges are smaller than those measured before 7 July. More study is needed to determine if sex or date is a stronger factor on home range, given our naive sampling which resulted in more females sampled in late summer and observations that did not continue to the end of the breeding season (late August). Since we found date to be an influential factor to both provisioning rate and home range size, it is possible that seasonal resource changes are an important, unstudied factor related to nationwide declines of this species.

The dynamics of pathogen and host relationships relative to disease transmission in wildlife populations are important ecological processes to understand, particularly since spatial dynamics of disease can be driven by movement, behavior, and dispersal of animals. Chronic Wasting Disease (CWD) is an example of this important interface, where little is known regarding origin of the disease or routes of transmission. Surveillance data for CWD in free-ranging mule deer indicates that breeding-age male deer have 2-4 times higher prevalence rates than females or younger age males. In an effort to understand differences that might increase risk for exposure to CWD infective agents, I used GPS data to examine breeding behavior and home range sizes of mule 11 deer. GPS radiocollars were placed on adult (> 2 ½ years) males, females, and young ( < 2 ½ years) males. Data collected during the breeding season was used to infer visitation rates of males to females. Cluster analysis was used to separate data into periods of movement (spatio-temporal clusters) and non-movement. Females formed more spatio-temporal clusters and movement paths than males. However, males spent more time moving, had more long-term periods of movement, moved an estimated 1 km/day more than females, and had more tortuous movement paths. Male home ranges for winter, summer, and breeding seasons were also larger than those of females. Overall, data indicates that males may have an increased risk of exposure to CWD relative to females, because of larger movements and greater space use. These male behavioral differences may result in increased encounter rates with CWD infectious material through greater exposure in the environment to sources such as carcasses from infected animals, their excreta, or contaminated soils. Furthermore, during the breeding season increased male sociality, as suggested by increased movement rates and movement path tortuousity, combined with larger space use may further enhance direct contact with infected individuals and increase exposure to excreta sources such as feces and alimentary secretions due to licking and tending behaviors.

The aim of this thesis was to assess the differences in behavior of the two categories of beef cattle of Limousine breed, reared in the system without market production of milk, specifically heifers and cows with calves. Two seasons were selected (summer and winter) for the observation and the accent was on observing basic categories of behavior, such as feed intake, rest, standing and movement. The place where the research took place was the farm "Černěveský háj" located on the boundary of Strakonice, Prachatice and Budějovice district. Both behavioral studies were conducted for whole twenty-four hours. For night monitoring hunting camera with programmable video recording was used. The recorded data were written to the ethogram using descriptive interval method with length of interval of 10 minutes. During both observations the fundamental rules of ethology were respected. Traced values were evaluated by absolute time, its percentage and frequency and were subsequently completed with appropriate description. The results from this ethological research of heifers and cows with calves during two different seasons show that older cows have more regular and more keep basic categories of behavior during the day and more extend their regular behavior even throughout the year. Older subjects are able to make better use of pasture than heifers and address to it more time of the day (40% resp. 35%). During consummation of preserved feed ration heifers shortened their feed intake compared to cows (39% resp. 31%). By heifers there was also significant movement restriction, but to a lesser extent than in the case of cows. At the same time heifers prolonged period of rest from 33% to 50%. In conclusion, the obtained results show that the area in which the cows are kept is suitable for raising beef cattle without market production of milk. The breeder could only focus more on supplementing of graze with elements supporting natural welfare of beef cattle in year-round grazing.

The Rota bridled white-eye (Zosterops rotensis)(Aves, Passeriformes) has experienced a severe population decline and range restriction over the last four decades. Little is known about this species and factors involved in the decline and range restriction are unclear. This study examined the potential roles of habitat alteration, introduced black drongos (Dicrurus macrocercus), and introduced rats in the decline and gathered more information on the behavior and breeding biology of this species. New life history data were collected and Rota and Saipan bridled white-eyes were found to differ in nest site characteristics and some behaviors. The importance of habitat alteration was assessed by examining Rota bridled white-eye habitat relationships at the microhabitat, within-range, Sabana-wide, and island-wide levels. Rota bridled white-eyes show a preference for high elevation wet forest but what drives their distribution within their current range was unclear. However, the alteration of this forest type by supertyphoon Roy in 1988 was probably the major factor in the decline of Rota BWEs between 1982 and 1996. Black drongo and Rota bridled white-eye relationships were addressed using current and historical survey data. Black drongos were found to prey on Rota bridled white-eyes but they probably only played at most a partial role in the decline of the Rota bridled white-eye. Introduced rats densities were assessed in Rota bridled white-eye areas and on other areas of the island and no evidence for rat numbers limiting Rota bridled white-eyes to their current range was found. / Master of Science

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