18 research outputs found
Threat-sensitive anti-predator defence in precocial wader, the northern lapwing Vanellus vanellus
Birds exhibit various forms of anti-predator behaviours to avoid reproductive failure, with mobbing—observation, approach and usually harassment of a predator—being one of the most commonly observed. Here, we investigate patterns of temporal variation in the mobbing response exhibited by a precocial species, the northern lapwing (Vanellus vanellus). We test whether brood age and self-reliance, or the perceived risk posed by various predators, affect mobbing response of lapwings. We quantified aggressive interactions between lapwings and their natural avian predators and used generalized additive models to test how timing and predator species identity are related to the mobbing response of lapwings. Lapwings diversified mobbing response within the breeding season and depending on predator species. Raven Corvus corax, hooded crow Corvus cornix and harriers evoked the strongest response, while common buzzard Buteo buteo, white stork Ciconia ciconia, black-headed gull Chroicocephalus ridibundus and rook Corvus frugilegus were less frequently attacked. Lapwings increased their mobbing response against raven, common buzzard, white stork and rook throughout the breeding season, while defence against hooded crow, harriers and black-headed gull did not exhibit clear temporal patterns. Mobbing behaviour of lapwings apparently constitutes a flexible anti-predator strategy. The anti-predator response depends on predator species, which may suggest that lapwings distinguish between predator types and match mobbing response to the perceived hazard at different stages of the breeding cycle. We conclude that a single species may exhibit various patterns of temporal variation in anti-predator defence, which may correspond with various hypotheses derived from parental investment theory
Using the phenomenology of memory for recent events to bridge the gap between episodic and semantic memory
From Risk to Opportunity: Climate Change and Flood Policy in Bangladesh
This study identifies current gaps and opportunities of existing flood regulatory frameworks and national climate change strategies of Bangladesh . In so doing, the research develops a framework to reconcile the interest of land, water, and people in order to reduce the vulnerability of extreme flooding and develop strategies for future flood management. The study reveals that the existing flood regulatory framework is only effective for relief and response during times of flooding but has significant gaps and inadequate provisions to increase communities’ adaptive capacity and resilience to deal with future flooding vulnerability under climate change. The flood management system also suffers from a lack of coordination, complex institutional frameworks, and budgetary constraints. The findings of the study also reveal that people’s/communities’ participation is at a very early state in flood-related project formulation and implementation, and they are totally absent at the level of flood management committees. In addition, the study strongly urges introduction of evidence-based flood policy formulation to reconcile the interest of land, water, and people. Working in this way will give people and communities a voice in the decision-making process, ensure the participation of vulnerable people in decision-making around flooding, and take immediate initiatives to fill the existing gaps and weaknesses of flood management system in Bangladesh