SEPTEMBER 17, 2019
New research led by the University of East Anglia (UEA) and University of Porto (CIBIO-InBIO) shows how global warming could reduce the mating activity and success of grassland birds.
The study examined the threatened grassland bird Tetrax tetrax, or little bustard, classified as a vulnerable species in Europe, in order to test how rising temperatures could affect future behavior.
The males spend most of their time in April and May trying to attract females in a breeding gathering known as a lek. In leks, to get noticed, males stand upright, puff up their necks, and making a call that sounds like a 'snort." They also use this display to defend their territory from competing breeding males.
The international team of researchers—from the UK, Kenya, Portugal, Spain and Brazil—found that high temperatures reduced this snort-call display behavior. If temperatures become too hot, birds may have to choose between mating and sheltering or resting to save their energy and protect themselves from the heat.
Published in the journal PLOS ONE, the findings show that during the mating season little bustard display behavior is significantly related to temperature, the time of the day—something referred to as circadian rhythms—and what stage of the mating season it is. The average temperature during the day also affects how much birds display and again as temperatures increase, display rates reduce.