Abstract
Predicting ecological consequences of climate change will be improved by understanding how species are affected by contemporary climate variation, particularly if analyses involve more than single ecological variables and focus on large-scale climate phenomena. I used 18 years of data from red-winged blackbirds (Agelaius phoeniceus) studied over a 25-year period in eastern Ontario to explore chronological and climate-related patterns of reproduction. Although blackbirds started nesting earlier in years with warmer springs, associated with low winter values of the North Atlantic Oscillation Index (NAOI), there was no advance in laying dates over the study. Nesting ended progressively later and the breeding season lasted longer over the study, however, associated with higher spring values of NAOI. As the length of the nesting season increased, offspring sex ratios became more female biased, apparently as a result of females adjusting the sex of the eggs they laid, rather than from sex-biased nestling mortality. Clutch size did not vary systematically over the study or with climate. Opposing trends of declining nest success and increasing productivity of successful nests over the study resulted in no chronological change in productivity per female. Higher productivity of successful nests was associated with higher winter NAOI values, possibly because synchrony between nesting and food availability was higher in years with high NAOI values. Other than the association between the start of nesting and spring temperatures, local weather (e.g., temperature, rainfall) patterns that linked NAOI with reproduction were not identified, suggesting that weather patterns may be complex. Because climate affected most aspects of red-winged blackbird reproduction examined, focusing on associations between climate and single variables (e.g., first-egg dates) will have limited value in predicting how future climates will affect populations.
Similar content being viewed by others
References
Andersson MJ, Wallander J, Oring L, Akst E, Reed M, Fleischer RC (2003) Adaptive seasonal trend in brood sex ratio: test in two sister species with contrasting breeding systems. J Evol Biol 16:510–515
Beebee TJC (1995) Amphibian breeding and climate. Nature 374:219–220
Brown JL, Li SH, Bhagabati N (1999) Long-term trend toward earlier breeding in an American bird: a response to global warming? P Natl Acad Sci USA 96:5565–5569
Cordero P, Vinuela J, Aparicio JM, Veiga JP (2001) Seasonal variation in sex ratio and sexual egg dimorphism favouring daughters in first clutches of the spotless starling. J Evol Biol 14:829–834
Crick HQP, Sparks TH (1999) Climate change related to egg-laying trends. Nature 399:423–424
Crick HQP, Dudley C, Glue DE, Thompson DL (1997) U.K. birds are laying eggs earlier. Nature 388:526
Dunn PO, Winkler DW (1999) Climate change has affected breeding date of tree swallows throughout North America. P Roy Soc London B 266:2487–2490
Ewald PW, Rohwer S (1982) Effects of supplemental feeding on timing of breeding, clutch size and polygyny in red-winged blackbirds Agelaius phoeniceus. J Anim Ecol 51:429–450
Fiala KL (1981) Sex ratio constancy in the red-winged blackbird. Evolution 35:898–910
Forchhammer MC, Post E (2004) Using large-scale climate indices in climate change ecology studies. Popul Ecol 46:1–12
Forchhammer MC, Post E, Stenseth NC (1998) Breeding phenology and climate. Nature 391:29–30
Hallett TB, Coulson T, Pilkington JG, Clutton-Brock TH, Pemberton JM, Grenfell BT (2004) Why large-scale climate indices seem to predict ecological processes better than local weather. Nature 430:71–75
Holcomb LD, Twiest G (1970) Growth rates and sex ratios of red-winged blackbird nestlings. Wilson Bull 82: 294–303
Howe HF (1977) Sex-ratio adjustment in the common grackle. Science 198:744–746
Hughes L (2000) Biological consequences of global warming: is the signal already apparent? TREE 15:56–61
Huppop O, Huppop K (2003) North Atlantic Oscillation and timing of spring migration in birds. P Roy Soc London B 270:233–240
Hurrell J (1996) Influence of variations in extratropical wintertime teleconnections on Northern Hemisphere. Geophys Res Lett 23:665–668
Hussell DJT (2003) Climate change, spring temperatures, and timing of breeding of tree swallows (Tachycineta bicolor) in southern Ontario. Auk 120:607–618
Jonzen N, Hedenström A, Hjort C, Lindström A, Lundberg P, Anderson A (2002) Climate patterns and the stochastic dynamics of migratory birds. Oikos 97:329–336
Li SH, Brown JL (1999) Influence of climate on reproductive success in Mexican jays. Auk 116:924–936
McCleery RH, Perrins CM (1998) Temperature and egg-laying trends. Nature 391:30–31
McNicol DK, Robertson RJ, Weatherhead PJ (1982) Seasonal, habitat and sex-specific food habits of red-winged blackbirds: implications for agriculture. Can J Zool 60:3282–3289
Møller AP (2002) North Atlantic Oscillation (NAO) effects of climate on the relative importance of first and second clutches in a migratory passerine bird. J Anim Ecol 71:201–210
Nott MP, Desante DF, Siegel RB, Pyle P (2002) Influences of the El Niño/Southern Oscillation and the North Atlantic Oscillation on avian productivity in forests of the Pacific northwest of North America. Glob Ecol Biogeog 11:333–342
Post E, Langvatn R, Forchhammer MC, Stenseth NC (1999). Environmental variation shapes sexual dimorphism in red deer. P Natl Acad Sci USA 96:4467–4471
Przybylo R, Sheldon BC, Merilä J (2000) Climatic influences on breeding and morphology: evidence for phenotypic plasticity. J Anim Ecol 69:395–403
Sanz JJ (2002) Climate change and breeding parameters of great and blue tits throughout the western Palearctic. Glob Change Biol 8:409–422
Sanz JJ (2003) Large-scale effect of climate change on breeding parameters of pied flycatchers in western Europe. Ecography 26:45–50
Sillett TS, Holmes RT, Sherry TW (2000) Impacts of a global climate cycle on population dynamics of a migratory songbird. Science 288:2040–2042
Stone DA, Weaver AJ, Zwiers FW (2000) Trends in Canadian precipitation intensity. Atmos Ocean 38:321–347
Thomas DW, Blondel J, Perret P, Lambrechts MM, Speakman JR (2001a) Energetic and fitness costs of mismatching resource supply and demand in seasonally breeding birds. Science 291:2598–2600
Thomas DW, Blondel J, Perret P, Lambrechts MM, Speakman JR (2001b) Variation in food supply, time of breeding, and energy expenditure in birds. Science 294:471a
Visbeck MH, Hurrell JW, Polvani L, Cullen M (2001) The North Atlantic Oscillation: past, present, and future. P Natl Acad Sci USA 98:12876–12877
Visser ME, Adriaensen F, van Balen JH, Blondel J, Dhondt AA, van Dongen S, du Feu C, Ivankina EV, Kerimov AB, de Laet J, Matthysen E, McCleery R, Orell M, Thomson DL (2003) Variable response to large-scale climate change in European Parus populations. P Roy Soc London B 270:367–372
Weatherhead PJ (1983) Secondary sex ratio adjustment by red-winged blackbirds. Behav Ecol Sociobiol 12:57–61
Weatherhead PJ (1985) Sex ratios of red-winged blackbirds by egg size and laying sequence. Auk 102:298–304
Weatherhead PJ, Dufour KW (2000) Fledging success as an index of recruitment in red-winged blackbirds. Auk 117:627–633
Weatherhead PJ, Dufour KW (2005) Limits to sexual size dimorphism in red-winged blackbirds: the cost of getting big?. Biol J Linn Soc, in press
Weatherhead PJ, Robertson RJ (1977) Harem size, territory quality and reproductive success in the red-winged blackbird (Agelaius phoeniceus). Can J Zool 55:1261–1267
Weatherhead PJ, Sommerer SJ (2001) Breeding synchrony and nest predation in red-winged blackbirds. Ecology 82:1632–1641
Westneat DF, Clark AB, Rambo KC (1995) Within-brood patterns of paternity and parental behavior in red-winged blackbirds. Behav Ecol Sociobiol 37:349–356
Wettstein JJ, Mearns LO (2002) The influence of the North Atlantic-Arctic Oscillation on mean, variance, and extremes of temperature in the northeastern United States and Canada. J Climate 15:3586–3600
Wimberger PH (1988) Food supplement effects on breeding time and harem size in the red-winged blackbird (Agelaius phoeniceus). Auk 105:799–802
Acknowledgements
I am grateful to the many people who helped to collect these data, particularly Karen Clark, Brent Charland, Drew Hoysak, Kit Muma, Kevin Dufour, Karen Metz, and Stephanie Doucet. Dawn Weber helped with data compilation, logistic support in the field was provided by Queen’s University, and financial support was provided by the Natural Sciences and Engineering Research Council of Canada and the University of Illinois. All the research presented here complies with the laws of Canada, where the research was performed.
Author information
Authors and Affiliations
Corresponding author
Additional information
Communicated by Carol Vleck
Rights and permissions
About this article
Cite this article
Weatherhead, P.J. Effects of climate variation on timing of nesting, reproductive success, and offspring sex ratios of red-winged blackbirds. Oecologia 144, 168–175 (2005). https://doi.org/10.1007/s00442-005-0009-4
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00442-005-0009-4