Mark D. Schwartz, University of Wisconsin-Milwaukee, Milwaukee, WI
Phenology is the study of recurring plant and animal life cycle stages, such as leafing and flowering, maturation of agricultural plants, emergence of insects, and migration of birds, especially their timing and relationship with weather and climate. Recently, the value of phenological research for understanding Earth systems interactions and facilitating global change studies has been realized.
As a simple expression of seasonal biology, phenology offers another independent measure (along with climate records and remote sensing observations) of the extent and impact of climate change.
However, phenological data are still not collected and recorded in spatially comprehensive and comparable ways around the world. Thus for now, phenological models can allow simulation of general plant responses, facilitating testing of broad hypotheses in locations and at times when actual phenological data are not available, but with more detail than possible when using remote sensing-derived measures. One set of phenological models that have been successfully applied to assess impacts of climate change on the onset of the spring growing season across temperate regions around the Northern Hemisphere are the Spring Indices (SI). This suite of metrics includes several sub-models and associated measures, all of which can be calculated using daily maximum/minimum surface temperatures and station latitude. SI models process weather data into a form mimicking the spring growth of plants that are not water limited, and are responsive to temperature increases. This paper summarizes earlier SI results from station data that have confirming a nearly universal quicker onset of early spring warmth (SI first leaf date, -1.2
days/decade), late spring warmth (SI first bloom date, -1.0 days/decade), and last spring freeze date (-1.5 days/ decade) across most temperate Northern Hemisphere land regions over the 1955–2002 period. Further, more recent work using longer and denser station data since 1900 across the continental USA has shown: 1) the SI onset of spring growing earlier since the late 1950s, including a dramatic shift in the mid-1980s; 2) regional differences in the Southeast USA; 3) 2012, the earliest year on record; and 4) 2013, among the latest years on record. Finally, preliminary results from on-going work will be presented that uses gridded air temperature data and SI to assess changes in the spring phonological response around the globe in both the past and the future at the century time-scale.
6B.2
Response of Robinia Pseudoacacia First Leaf Date to temperature and Precipitation Change in China in the Past 50 Years
Phenology II: Modeling
DAI junhu, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Chaoyang District, Beijing, China; T. zexing, W. huanjiong and G. quansheng Plant phenology is a significant indicator of climate change. Climate change has affected plant phenology greatly over the past few decades in mid-high latitudes of the Northern Hemisphere.
Previous studies mainly focus on the relationship between plant phenology and temperature, but few of them have evaluated plant response to other climate factors, e.g. precipitation. In order to explain how plant phenology responses to precipitation and compare the magnitude of the impacts of temperature and precipitation on plant phenology, long-term (1963-2012) observations of First Leaf Date (FLD) of Robinia pseudoacacia at 9 stations in China over the past 50 years were analyzed using linear regression and partial least squares (PLS) regression analysis. The results suggest that the years with more precipitation exhibit later Robinia pseudoacacia FLD in most stations except Xi'an and Haerbin, but the correlations are not significant. Compared to temperature, precipitation shows opposite and much lower effects on plant phenology. FLD of Robinia pseudoacacia correlated positively to the spring precipitation in the 2-3 months before the onset dates of FLD. Meanwhile, it is negatively associated with the winter precipitation of the former year. However, the exact dates when such relationship appears varies among different stations, ranging from the former October to February. In addition, precipitation has smaller effect on plant phenology in stations with more precipitation, especially in semi-humid regions.
6B.3
Integrating MODIS satellite information and maize phenological data to detect maize cultivated area Phenology II: Modeling
Jiahua Zhang, Chinese Academy of Sciences, Beijing, Beijing, China; L. Feng and F. Yao Abstract: The accurate and timely information of crop area is vital for crop production and food security. In this study, the Enhanced Vegetation Index (EVI) data from MODerate resolution Imaging Spectroradiometer (MODIS) integrated crop phenological information was used to estimate the maize cultivated area over a large scale in Northeast China. The fine spatial resolution China's Environment Satellite (HJ-1 satellite) images and the support vector machine (SVM) algorithm were employed to discriminate distribution of maize in the reference area. The mean MODIS-EVI time series curve of maize was extracted in the reference area by using multiple periods MODIS-EVI data.
By analysing the temporal shift of crop calendars from northern to southern parts in Northeast China, the lag value was derived from phenological data of twenty-one agro-meteorological stations;
here integrating with the mean MODIS-EVI time series image of maize, a standard MODIS-EVI time series image of maize was obtained in the whole study area. By calculating mean absolute distances (MAD) map between standard MODIS-EVI image and mean MODIS-EVI time series images, and setting appropriate thresholds in three provinces, the maize cultivated area was extracted in Northeast China. The results showed that the overall classification accuracy of maize cultivated area was approximately 79%. At the county level, the MODIS-derived maize cultivated area and statistical data were well correlated (R2 = 0.82, RMSE = 283.98) over whole Northeast China. It demonstrated that MODIS-EVI time series data integrated with crop phenological information can be used to improve the extraction accuracy of crop cultivated area over a large scale.
6B.4
Differential changes in the reproductive cycle of two temperate plants in response to experimental warming
Phenology II: Modeling
Marie R. Keatley, University of Melbourne, Creswick, Vic, Australia; B. J. Nugent and P. K. Ades The evidence of a changing climate influencing plant phenology has grown exponentially over the last 25 years with the majority coming from the examination of flowering records. Given each part of the reproductive cycle influences the preceding and succeeding phases it is not yet clear how changes in one phase may influence another.
Elevated temperature environments allow changes in reproductive phenology to be assessed in greater detail (rather than only using first flowering date), and also allow greater replication to better understand population variability of plastic responses to increased mean temperature.
We examined the differences in the timing of first bud appearance, first flowering, last flowering, seed dispersal, and height of inflorescence in Cynoglossum suaveolens (Sweet Hound's Tongue) and Coronidium scorpioides (Button everlasting) in both an elevated temperature and control (outside) environment (n = 20 plants per treatment). In addition the differences in the seed weight of C. suaveolens and floral disc diameter in C. scorpioides between the two environments were also compared. These are two co-occurring perennial understory species.
The glasshouse mean temperature was on average 5.6°C warmer than the controls. Plants received the same irrigation regime and were watered to field capacity every 1 – 3 days, depending on weather, to standardize any soil moisture interactions with the phenophases.
We found that for both species those subjected to warmer temperatures reached each phenological stage significantly earlier (P < 0.001). For C. suaveolens, the differences in magnitude in the first three phases were similar: bud appearance (54.3 days), first flowering (60.0 days), last flowering (52.9 days). The difference in seed dispersal between the two environments was 38.6 days. In C.
scorpioides the largest difference was in first flowering (56.6 days); followed by bud appearance (50.1 days) and last flowering (38.7 days) and as with C. suaveolens seed dispersal had the least difference (20.9 days).
These differences in turn were reflected in the total durations with glasshouse durations beings significantly longer: 67.5 versus 44.9 days in C. suaveolens and 104.1 versus 75.0 days in C.
scorpioides. For both species the duration from bud appearance to first flowering was significantly longer (P < 0.05) with the flowering and seed development period significantly shorter in the control (P < 0.001). Also for both species the average inflorescence height was significantly taller (P < 0.01)
in the warmer environment: C. suaveolens 205.8 ± 47.5 mm compared to 137.7 ± 43.9 mm; C.
scorpioides 283. 0 ± 65.6 mm compared to 212.0 ± 48.0 mm. The warmer environment also resulted in significantly heavier seed weight in C. suaveolens (5.25 ± 0.46 mg compared to 3.21 ± 1.53 mg) and significantly wider floral disc diameter in C. scorpioides(19.7 ± 2.9 mm compared to 14.9 ± 3.1 mm).
Warming advanced the timing of each phenophase; however, the advancement was not constant across phenophases resulting in differing durations. The extended flowering and seed development duration in the warmer environment resulted in heavier seed in C. suaveolens whereas larger floral discs developed in C. scorpioides during a shorter development phase.
This demonstrates that reproductive phenophases may have differing advancements in response to increased mean temperature depending on species. Also, advances in first flowering date may be partly compensated through increased flowering and seed maturation durations that can reduce the advancement of seed dispersal date relative to advances in first flowering date. These phenological changes have resulted in changes to the vegetative and reproductive output which could ultimately lead to changes in species abundance, composition and distribution.
6B.5
Phenology and seasonal forecasting in the Pacific: combining traditional knowledge with statistical and dynamical methods to increase community resilience
Phenology II: Modeling
Lynda E. Chambers, Australian Bureau of Meteorology, Melbourne, Victoria, Australia; M. S.
Waiwai, P. Malsale, P. Feke and R. Plotz
Many indigenous people in the Pacific forecast seasonal climate conditions through observation and monitoring of meteorological, astronomical and biological indicators (e.g. phenology). Built over many generations, these knowledge systems are adapted to local conditions to cope with a highly variable and vulnerable environment. Traditional climate knowledge systems continue to influence all aspects of modern Pacific livelihoods from agricultural productivity to disaster response and recovery. In recent years, alternative forecasting methods have been promoted by national meteorological services based on statistical and dynamical modeling of the climate system.
However, in some locations, uptake of these ‘new' methods is low, with locals continuing to use traditional forecasts for many reasons including inadequate access to the new forecasts, insufficient trust in new forecasting methods or historical usefulness of traditional forecasts. Enabling adaptation to changing climatic conditions in the Pacific requires improved understanding of how traditional forecasting methods compare to those based on climate models. Building on global experiences with traditional seasonal forecasting, we develop a methodology for the Pacific region that includes:
1. Documenting traditional indicators used for seasonal climate forecasting;
2. The development of a national monitoring network, based on the traditional indicators identified, including phenology;
3. Comparing the outcomes of traditional forecasts with those based on statistical and dynamical modeling of the climate system;
4. Development of methods for optimally combining traditional and modeling-based forecasts.
This integrated approach to forecasting, illustrated with a case study from Vanuatu, has the potential to improve the accuracy and utility of local forecasts as well as ensuring the communication of climate information is in a locally relevant context.
6B.6
SPACE AND TIME VARIABILITY OF GRAPEVINE PHENOLOGY IN EUROPE Phenology II: Modeling
Gabriele Cola, University of Milan, Milan, Italy; L. Mariani, O. Failla, L. Rustioni, S. G. Parisi, R. Alilla, C. Epifani and G. Dal Monte
Grapevine (Vitis vinifera L.) is cultivated in Europe since five thousand years and during this long period it was exposed to a wide climatic variability with conditions ranging from hot phases (e.g. the Roman optimum) to cold ones (e.g. the Little Ice Age). This work aims to evaluate the effects of European climate variability and change on grapevine cv Chardonnay phenology along the recent period (1981-2012) which was characterized by two homogeneous thermal phases divided by an abrupt shift occurred at the end of the 80s. This goal was pursued applying the operational phenological model of the Iphen project to daily European thermal fields and analyzing the deriving behavior of grapevine phenology (cv Chardonnay) . Since 2006 the Iphen Project (http://cma.entecra.it/iphen/index_EN.html) periodically produces and broadcast Italian maps of phenological analysis and forecasts for grapevine and other relevant natural and cultivated plants such as Olive tree, Cypress, and Locust tree. Maps are the result of the match between phenological modeling and observational data gathered by the volunteer network of the Project. The Iphen phenological model is based on the accumulation of thermal resources - Normal Heat Hours and the whole set of grapevine phenological stages (vegetative and reproductive) is simulated as the overcoming of specific thresholds of cumulated thermal resources. Phenological stages are expressed following the international BBCH scale. The model, calibrated and validated for the Italian area, is here applied the whole European continent on the base of daily temperature fields, obtained by means of geostatistical techniques from free weather station data gathered and broadcasted by NOAA-GSOD (https://data.noaa.gov/dataset/global-surface-summary-of-the-day-gsod). A first validation of the simulation at the continental scale is obtained by comparison with the phenological data collected all over Europe during 2012 by the COST Action FA1003 – Grapenet: East-West Collaboration for Grapevine Diversity Exploration and Mobilization of Adaptive Traits for Breeding.
Eight COST observational sites provided phenological monitoring for Chardonnay in 2012, ranging from Spain to Ukraine, from Cyprus to Czech republic. With reference to observational data, the model showed a Mean Absolute Error of 2.75 days in the simulation of the day of occurrence of the phenological stage of beginning of flowering (BBCH 61). Afterwards, the model was run on the whole 1981-2012 period and maps of the day of occurrence of phenological stage BBCH 61 were produced for each year. The model simulation was limited up to 1000 m of elevation, in order to focus on high quality viticulture. Average data for the two sub-periods 1981-1987 and 1988-2012 and the difference between the two, are presented in figure 1. In order to rightly interpret the results it must be taken into account that the simulation for countries of South Mediterranean and Middle East is negatively affected by the scarcity of meteorological data. The comparison between the phenological behavior of the two sub-periods shows a general advance of recent phenology, more relevant in Koeppen's Cfb climate areas (Oceanic climate, e.g.: France and Germany) and Csa ones (Mediterranean climate, e.g.: Portugal, Spain and Italy). This is explained by the reinforcement of Westerlies after the 1987 climate shift which determined both the strengthening of anticyclonic conditions over the Mediterranean and an higher degree of Oceanicity ove central-western Europe.
The final consequence was the presence of milder temperatures with an advanced phenological
development clearly shown by the variational map of figure 1. Furthermore, it is interesting to highlight the northward shift of the limit of commercial viticulture, represented by the 180-185 doy limit for flowering in the two phenological maps and coherent with results previously presented by the authors. Figure 1 – Mean day of occurrence of beginning of flowering (phenological stage BBCH 61). Maps for period 1988 – 2012and 1981 – 1987 b) are presented. The difference between the two periods, expressed in number of days is also shown. A positive number of days stands for advance of the recent period.
6C.1
Updated trend analysis of heat vulnerability in the United States using a Distributed Lag Nonlinear Model
Thermal Environment and Human Health I
Scott C. Sheridan, Kent State University, Kent, OH; P. G. Dixon
The impacts of heat upon human health have been studied by myriad researchers. Several current themes have been identified: heat events in some areas are becoming more common; the impacts of heat on all-cause mortality seem to have declined over time; and there is a growing debate as to the impacts of mortality displacement (harvesting) on overall mortality totals during heat events. To build upon these themes, we use a recently extended US national database on mortality to assess heat vulnerability across the United States.
For 40 US metropolitan areas, we divide up the full mortality record into 4 sub-periods: 1975-1983, 1984-1992, 1993-2001, and 2002-2010. Using a distributed-lag non-linear model (DLNM), we assess spatio-temporal variability to heat using apparent temperature thresholds for heat-events.
Spatial and temporal variability is observed in the results, with an overall greater vulnerability in the northern and Midwestern cities than in southern cities and most western cities. Trends broadly show a decreased vulnerability over time, although statistically significant increases in mortality still occur with excessive heat events over many locations.
6C.2
Heat stress during the Black Saturday event in Melbourne, Australia Thermal Environment and Human Health I
Stephanie J. Jacobs, Monash University, Clayton, Victoria, Australia; T. Vihma and A. B. Pezza The Black Saturday bushfire event of February 7 2009 devastated the state of Victoria, Australia resulting in 173 deaths. On this day the maximum temperature in Melbourne (state capital of Victoria, population 4 million people) exceeded 46°C, there were wind gusts of over 100 km hr-1 and the relative humidity dropped below 5%. We investigate the severe meteorological conditions of Black Saturday and the risk of heat stress and dehydration for the residents of Melbourne. This is through the analysis of weather station data, air pollution data, the apparent temperature (AT) and the Comfort Formula human energy budget model.
In Melbourne, the PM10 concentration was at dangerous levels (over 350 μgm-3) due to bushfire smoke on Black Saturday and the AT showed that heat stress conditions were present, albeit underrepresented due to assumptions in the AT formula. Further investigation into dehydration from energy budget analysis revealed that the meteorological conditions required a sweating rate of 1.1 kg h-1 to prevent heat accumulation to the body. If sweating stopped, hyperthermia could occur in 20 minutes. Sensitivity tests on the human energy budget indicate that the dry air and strong winds on Black Saturday aided latent heat release, but the required sweating rate was virtually unattainable for an average person and would have lead to intense dehydration. In the future, for extremely hot, dry and windy events like Black Saturday, we recommend that the AT is not used as a thermal comfort measure as it underestimates the physical stress people experience.
6C.3
The Application of the European Heat Wave of 2003 to Korean Cities to Analyze Impacts on Heat-Related Mortality
Thermal Environment and Human Health I
J. Scott Greene, University of Oklahoma, Norman, OK; L. Kalkstein, K. Kim, Y. J. Choi and D. G.
Lee
The goal of this research is to transpose the unprecedented 2003 European excessive heat event to six Korean cities and to develop meteorological analogs for each. Since this heat episode is not a model but an actual event, we can use a plausible analog to assess the risk of increasing heat on these cities instead of an analog that is dependent on general circulation (GCM) modeling or the development of arbitrary scenarios. Initially, the meteorological conditions from Paris are characterized statistically and these characteristics are transferred to the Korean cites. Next, the new meteorological dataset for each Korean city is converted into a daily air mass calendar. We can then determine the frequency and character of “offensive” air masses in the Korean cities that are historically associated with elevated heat-related mortality. One unexpected result is the comparative severity of the very hot summer of 1994 in Korea, which actually eclipsed the 2003 analog. The persistence of the offensive air masses is considerably greater for the summer of 1994, as were dewpoint temperatures for a majority of the Korean cities. For all the Korean cities but one, the summer of 1994 is associated with more heat-related deaths than the analog summer, in some cases a sixfold increase over deaths in an average summer. The Korean cities appear less sensitive to heat-related mortality problems during very hot summers than do large eastern and midwestern
U.S. cities, possibly due to a lesser summer climate variation and efficient social services available during extreme heat episodes.
6C.4
Relationships between Temperature and Heat-Related Illness across North Carolina Thermal Environment and Human Health I
Charles E. Konrad II, Southeast Regional Climate Center (SERCC), Chapel Hill, NC; M. M.
Kovach and C. M. Fuhrmann
Heat kills more people than any other weather-related event in the United States, resulting in hundreds of fatalities each year. In North Carolina, heat-related illness (HRI) accounts for over 2,000 yearly emergency department (ED) admissions. In this study, data from the North Carolina Disease Event Tracking and Epidemiologic Collect Tool (NC DETECT) is used to identify empirical relationships between temperature and morbidity across North Carolina across six warm seasons (May-September) from 2007 through 2012. Relationships are explored across different regions (e.g.
coastal plain, piedmont, mountains) and demographics (e.g. gender, age, socioeconomic level, and rural/urban) to determine the differential impact of heat stress on population. Research to date reveals that most of these heat-related admissions occur on days with climatologically normal temperatures; however, admission rates increase substantially on days with abnormally high daily maximum temperatures. The highest admission rates are found in rural areas where labor-intensive crops are grown, and the biggest differences in rates are identified between the counties with the highest and lowest rates of poverty. The empirical relationships identified in this study will be used in a web-based heat vulnerability tool that translates National Weather Service (NWS) temperature forecasts into useful information regarding the probability of public health emergencies (e.g. spikes in heat related morbidity).
6C.5
Summer mortality and synoptic climatology in Khabarovsk Thermal Environment and Human Health I
EA Grigorieva, Russian Academy of Sciences, Birobidzhan, Russia; L. Kalkstein, S. C. Sheridan and J. K. Vanos
The significant impact of weather and climate on human health and well-being has been known for many years. Weather particularly affects public health during the most frequent extreme natural events, resulting in loss of human life during excessive cold and heat events. Heat has a devastating impact on human health: it kills more people in most mid-latitude countries than any other weather phenomenon. Extremely hot periods are associated with increases in weather-related morbidity and mortality in temperate regions, where summer climate variability is at a maximum.
Since all-cause mortality increases during heat waves, an accurate system to warn the public and stakeholders is a necessity. Numerous techniques have been devised in an effort to reduce the impact of extreme heat on the population and to check the effectiveness of warning systems in major cities around the world. As a result of increased awareness related to heat/health system implementation, mortality has decreased over the last few decades (Sheridan et al. 2011). The assumption behind these heat‐health systems is a good understanding of the actual heat‐health relationship at each region where a system is in place. For this reason, the threshold conditions that induce a harmful health response need to be identified.
The research presented here is the third stage the project “A Climate Assessment of the Russian Far East (RFE) for the Purpose of Developing Weather Health Warning Systems”. It involves an evaluation of mortality/weather relationships, which includes a detailed air mass description using the Spatial Synoptic Classification or SSC (Kalkstein et al. 1996; Sheridan 2002). The ‘synoptic' approach takes into account weather situations rather than single elements and links mortality to objectively determined air masses. The initial method of analysis involved the classification of all days into one of seven weather types.
The study area has a midlatitude monsoon climate, characterized by an extreme continental annual temperature regime. The weather data include air temperature, dew point temperature, total cloud cover, sea level pressure, wind speed and wind direction measured four times daily, using months from May to September, 2000-2012, and are organized by 6 hour daily intervals (03, 09, 15 and 21 Local Standard Time). Daily mortality data for the same period were provided by City of Khabarovsk Administration so we could develop the relationship between daily weather and variations in deaths.
Data were subdivided between all cause deaths, gender and the elderly (age 65 and over). For each month, female mortality is 44 %, male mortality 56 % and elderly is near 51 % of all-cause mortality. The first step in mortality evaluation was the creation of daily air mass calendar. Air mass frequencies over months from May to September were examined. The most dominant air mass in summer is moist moderate (27 %) with the same frequency for tropical air masses (moist plus dry).
‘Oppressive' types were identified among the objectively determined air masses as those associated with elevated mortality.
The results show that moist tropical plus and dry tropical air masses are most offensive in Khabarovsk. In particular, for the period from May to September, all cause mortality is 9 % higher than average during days with moist tropical plus air mass (MT+), and 14 % higher during moist tropical double plus (MT++) days. For eldery people mortality is 20 % higher for moist tropical plus, and 30 % higher for moist tropical double plus, yielding 3.4 excess deaths. For summer months mortality may increase more dramatically during oppressive tropical moist days, specifically by 12 (MT+) and 15 % (MT++) for all cause mortality, by 22 (MT+) and 32 % (MT++) for age 65 and over, 14 (MT+) and 16 % (MT++) for women, 9 (MT+) and 14 % (MT++) for men.
For each month from May to September days with moist tropical plus air are the most oppressive.
The month with the greatest anomalous mortality is August. Elderly mortality averaged over 30 % higher during days with moist tropical plus air mass, and even more – 45 % above the mean value at moist tropical double plus days, when daily mortality averages 4.8 deaths above the baseline among people aged 65 and over. Somewhat similar, but less extreme increases in excess mortality are seen during days with dry tropical air, with an increase of 5 % in overall mortality for the period from May to September, and rise of 10 % for summer. During summer season as a whole, dry tropical days yield 17 % excessive deaths for eldery people, 11 % for women and 9 % for men.
The persistence of oppressive air masses clearly plays a role in excess mortality sensitivity in Khabarovsk, with magnitudes similar to other vulnerable mid-latitude cities like Seoul and New York.
Results demonstrate that the air-mass-based approach is a useful method in assessing impacts of heat stress on mortality, and may be applicable also for predicting health outcomes and increased mortality. Next step is developing of a heat/health watch warning system for Khabarovsk, Russia.
Algorithms will be developed to determine which variables within these air masses explain the greatest variations in mortality (eg, consecutive days of oppressive heat, maximum temperature, time of season).
Acknowledgement. This publication is based partly on work supported by grant RUG1-7062-BB-12 from CRDF Global with funding from the U.S. Department of State (DOS). The opinions, findings, conclusions stated herein are those of the author(s) and do not necessarily reflect those of CRDF Global or the U.S. DOS.
6C.6
Heat Wave Impacts on Motality in Nanjing,China Thermal Environment and Human Health I
Yuxia Ma, Lanzhou University,China, Lanzhou, China; J. Zhang and J. Wang
A variety of research has linked extreme heat to heightened levels of daily mortality. This paper analyses the relationship between mortality and heat wave (duration of high temperature above 35°C is more than 3 days) in Nanjing ,China. Daily mortality in Nanjing was analysed by cause, from January 2004 to December 2009. When the daily maximum temperature is above 35°C, it is defined as a hot day. Extra mortality was calculated by EM=(D-DNo-heat)/DNo-heat, here EM refers to the extra mortality, D is daily death cases, DNo-heat means the average of death cases in no-heat days ( the daily maximum temperature is lower than 35°C) in summer. Our results showed that impact of heat wave on mortality in all causes. Order of causes in Nanjing is Circulatory, Neoplasm, Respiratory, Endocrine, Digestive, Genitourinary, Nervous, Mental, Infectious, Blood and other diseases. Circulatory cause accounts for 37.44%. Second is Neoplasm, occupying 30.02%. The third is Respiratory, taking by 12.99%. Three causes attribute 80.05%. Heat wave impact the order of causes and extra mortality. The highest five extra mortality are Genitourinary, Infectious, Endocrine, Nervous and mental diseases in heat wave, accounting for 100.4%�A97.4%�A62.0%�A56.1% and 48.6%, respectively. There is an attributable of 13.2% of circulatory causes extra mortality.
7A.1
Tonic Immobility and Vigilance Responses of Broiler Chickens to Lighting Regimens during the Hot Dry Season, and the Beneficial Effect of Melatonin
Animal physiology
Victor Olusegun Sinkalu, ABU = Ahmadu Bello University, Zaria-Nigeria, Zaria, Kaduna, Nigeria;
J. O. Ayo, A. B. Adelaiye and J. O. Hambolu
Experiments were conducted with the aim of determining the influence of melatonin administration on vigilance and tonic immobility (TI) responses of Marshall Broiler chickens, reared on different lighting regimens during the hot dry season in the Northern Guinea Savannah zone of Nigeria.
Simple random sampling was used to assign 300 broiler chicks into three groups, comprising 100 chicks each. Group I (12L:12D cycle) was raised under natural photoperiod of 12 h light and 12 h darkness, without melatonin supplementation. Group II (LL) was kept under 24-h continuous lighting, without melatonin administration. Group III (LL + MEL) was raised under 24-h continuous lighting; with melatonin supplementation at 0.5 mg/kg per os, via drinking water. Beginning from day-old, birds in group III were individually administered with melatonin once daily for 56 consecutive days at 17:00 h. Tonic immobility (TI), induced by manual restraint, and vigilance, by self-righting, were graded for three days, 14 days apart in 15 labeled broiler chickens from each of the three groups at 06:00 h, 13:00 h and 18:00 h starting from day 28 up to day 56. The dry-bulb temperature (DBT) and relative humidity (RH) were recorded at the experimental site and