scholarly journals Early Breeding Conditions Followed by Reduced Breeding Success Despite Timely Arrival in an Alpine Migratory Songbird

2021 ◽  
Vol 9 ◽  
Author(s):  
Martha Maria Sander ◽  
Dan Chamberlain ◽  
Camille Mermillon ◽  
Riccardo Alba ◽  
Susanne Jähnig ◽  
...  
Keyword(s):  
Resource Availability ◽  
Environmental Conditions ◽  
Migratory Birds ◽  
Light Level ◽  
Negative Effects ◽  
Vegetation Development ◽  
Alpine Population ◽  
Breeding Grounds ◽  
Migratory Songbird ◽  
Early Snowmelt

Timing reproduction to coincide with optimal environmental conditions is key for many organisms living in seasonal habitats. Advance in the onset of spring is a particular challenge to migratory birds that must time their arrival without knowing the conditions on the breeding grounds. This is amplified at high elevations where resource availability, which is linked to snowmelt and vegetation development, shows much annual variation. With the aim of exploring the effects of variability in the onset of local resource availability on reproduction, we compared key life history events in an Alpine population of the Northern Wheatear (Oenanthe oenanthe) between years of contrasting timing of snowmelt. Based on remote sensed images, we identified 2020 as an exceptionally early snowmelt and green-up year compared to the preceding year and the long-term average. Individuals tracked with light-level geolocators arrived well before the snowmelt in 2020 and clutch initiation dates across the population were earlier in 2020 compared to 2019. However, observations from a citizen science database and nest monitoring data showed that the arrival-breeding interval was shorter in 2020, thus the advance in timing lagged behind the environmental conditions. While hatching success was similar in both years, fledging success was significantly reduced in 2020. A trophic mismatch in early 2020 could be a possible explanation for the reduced reproductive success, but alternative explanations cannot be excluded. Our results show that, despite the timely arrival at the breeding grounds and a contraction of the arrival-breeding interval, Wheatears were not able to advance breeding activities in synchrony with environmental conditions in 2020. Earlier reproductive seasons are expected to become more frequent in the future. We show that the negative effects of changing seasons in Alpine migratory birds might be similar to birds breeding at high latitudes, despite their shorter migratory distance.

Nonbreeding season movements of a migratory songbird are related to declines in resource availability

The Auk ◽  
2019 ◽  
Vol 136 (3) ◽  
Author(s):  
Samantha M Knight ◽  
Elizabeth A Gow ◽  
David W Bradley ◽  
Robert G Clark ◽  
Marc Bélisle ◽  
...  
Keyword(s):  
Resource Availability ◽  
Large Scale ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Light Level ◽  
Tree Swallow ◽  
Breeding Sites ◽  
Nonbreeding Season ◽  
Aerial Insectivore ◽  
Migratory Songbird

Abstract There have been an increasing number of observations of itinerancy in migratory songbirds, where individuals move among 2 or more widely separated areas during the “stationary” nonbreeding season. Knowledge of such movements and an understanding of what drives them are important for predicting how migratory populations will respond to environmental change. In this study, we investigated nonbreeding movements of the Tree Swallow (Tachycineta bicolor), an aerial insectivore that breeds across North America and spends the nonbreeding season around the Gulf of Mexico, Florida, Mexico, Central America, and the Caribbean. With year-round tracking data obtained from 133 light-level geolocators deployed at 12 breeding sites ranging from Alaska to Nova Scotia to North Carolina, we show that 44% of individuals made at least one large-scale movement (range: 301–1,744 km) within the nonbreeding range. The frequency of itinerancy decreased with longitude, such that 75% of individuals made a movement in the western portion of the nonbreeding range compared to only 31% in the east. Using the Normalized Difference Vegetation Index (NDVI) as a proxy for resource availability, we found that when individuals did move, they were more likely to move from sites where resources were deteriorating faster (a more negative change in NDVI prior to departure) than their destination sites. There was also evidence that individuals moved to destination sites with higher NDVI and temperature in the autumn, but not in the winter. Our results suggest movements of Tree Swallows during the nonbreeding season are influenced by resource availability, but because not all individuals used multiple nonbreeding sites, the density of individuals at a site and the level of competition may have also been a factor influencing nonbreeding season movements.

scholarly journals A range-wide domino effect and resetting of the annual cycle in a migratory songbird

2019 ◽  
Vol 286 (1894) ◽  
pp. 20181916 ◽  
Author(s):  
Elizabeth A. Gow ◽  
Lauren Burke ◽  
David W. Winkler ◽  
Samantha M. Knight ◽  
David W. Bradley ◽  
...  
Keyword(s):  
Annual Cycle ◽  
Migratory Birds ◽  
Light Level ◽  
Timing Of Breeding ◽  
Domino Effect ◽  
Breeding Sites ◽  
Breeding Populations ◽  
Migratory Songbird ◽  
Carry Over ◽  
Timing Of Arrival

Latitudinal differences in timing of breeding are well documented but how such differences carry over to influence timing of events in the annual cycle of migratory birds is not well understood. We examined geographical variation in timing of events throughout the year using light-level geolocator tracking data from 133 migratory tree swallows ( Tachycineta bicolor ) originating from 12 North American breeding populations. A swallow's breeding latitude influenced timing of breeding, which then carried over to affect breeding ground departure. This resulted in subsequent effects on the arrival and departure schedules at autumn stopover locations and timing of arrival at non-breeding locations. This ‘domino effect’ between timing events was no longer apparent by the time individuals departed for spring migration. Our range-wide analysis demonstrates the lasting impact breeding latitude can have on migration schedules but also highlights how such timing relationships can reset when individuals reside at non-breeding sites for extended periods of time.

scholarly journals Reduced Breeding Success Suggests Trophic Mismatch Despite Timely Arrival in an Alpine Songbird

2021 ◽  
Author(s):  
Martha Sander ◽  
Dan Chamberlain ◽  
Camille Mermillon ◽  
Riccardo Alba ◽  
Susanne Jähnig ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Breeding Success ◽  
Migratory Birds ◽  
Light Level ◽  
Trophic Levels ◽  
Science Data ◽  
Long Distance ◽  
Study Region ◽  
Fledging Success ◽  
Trophic Mismatch

Abstract A steady advance in the onset of spring is one of the most prominent footprints of climate warming and requires organisms, including migratory birds, to adapt their annual routines. As lower trophic levels typically adapt faster than higher trophic levels, observations of reduced fitness due to trophic mismatches are becoming more frequent, especially in long-distance migratory birds. We aimed to identify key phenological events, and quantify potential mismatches and their consequences in a migratory songbird population of the Northern wheatear (Oenanthe oenanthe) breeding at high elevations in the European Alps.We used light-level geolocators to track wheatears, and collected information on individual breeding activity and breeding success as well as environmental conditions during the reproductive season. In addition, we used citizen science data and remote sensed images to quantify longer term phenological trends.Snow melt and green-up showed an exceptionally early spring in the study region in 2020, preceded by a relatively average year in 2019. Yet, tracked individuals arrived well before the snowmelt in 2020 and clutch initiation dates across the population were earlier in 2020 compared to 2019. However, this shift lagged behind the advance in environmental conditions. While hatching success was similar in both years, fledging success and overall nest success was significantly reduced in 2020.Our results show that, despite the timely arrival at the breeding grounds, wheatears did not advance breeding activities in synchrony with environmental conditions during the exceptionally early year in 2020. The reduced fledging success suggests a trophic mismatch. However, the underlying mechanisms for hatchling mortality and nest failure remain unknown. Earlier reproductive seasons are expected to become more frequent in the future. We show that the negative effects of changing seasons in Alpine migratory birds might be similar to birds breeding at high latitudes, despite their shorter migratory distance.

scholarly journals Seasonal variation in climate and landcover niches of a migratory bird

2020 ◽  
Author(s):  
Javier Gutierrez Illan ◽  
Guiming Wang ◽  
Fred L Cunningham ◽  
D Tommy King
Keyword(s):  
Habitat Selection ◽  
Environmental Conditions ◽  
Migratory Birds ◽  
Open Water ◽  
Niche Overlap ◽  
Migratory Bird ◽  
Global Changes ◽  
Climatic Niche ◽  
Breeding Grounds ◽  
Spatial Use

Abstract Background: Resource utilization strategies of avian migrants are a major concern for conservation and management. Consequently, the ability to predict potential shifts in migratory species spatial use and migratory behaviour is a pressing challenge for predictive ecology under global changes. There are two main strategies of resource use adopted by migratory birds: niche tracking for similar environmental conditions and niche switching between different environmental conditions between seasons. Our objective was to examine whether the niche tracking/niche switching hypothesis would better explain seasonal variations in the ecological niche overlap of the American White Pelicans (AWPE, Pelecanus erythrorhynchos). We also tested whether recent changes in the non-breeding ground land-use have altered habitat selection and space use by AWPE. Methods: We used Dirichlet-multinomial models to detect differences in habitat selection between regions and over times with the GPS locations of 36 tracked AWPEs. We estimated climatic and land-cover niche overlap between the breeding and non-breeding grounds to test for niche switches between seasons using ordination methods. Results: Our habitat selection models did not detect shifts in habitat selection by AWPE after 2005. American white pelican strongly selected open water and wetland at the non-breeding and breeding grounds. American white pelicans showed little climatic niche overlap but substantial landscape niche overlap between breeding and non-breeding grounds.Conclusions: Declines in aquacultural acreage did not change AWPE habitat selection in the Northern Gulf of Mexico. Our results did not support the hypothesis that AWPE would be a climatic niche tracker. However, AWPE tracked its foraging habitats, exhibiting strong selection for open water and wetland at both the breeding and non-breeding grounds. Climatic niche switching suggests that AWPE may adapt to future climate changes.

scholarly journals Phenology of two interdependent traits in migratory birds in response to climate change

2015 ◽  
Vol 282 (1807) ◽  
pp. 20150288 ◽  
Author(s):  
Nadiah Pardede Kristensen ◽  
Jacob Johansson ◽  
Jörgen Ripa ◽  
Niclas Jonzén
Keyword(s):  
Climate Change ◽  
Resource Availability ◽  
Migratory Birds ◽  
Egg Laying ◽  
The Other ◽  
Sufficient Evidence ◽  
Hatching Date ◽  
Arrival Date ◽  
Body Of Knowledge ◽  
Asynchronous Hatching

In migratory birds, arrival date and hatching date are two key phenological markers that have responded to global warming. A body of knowledge exists relating these traits to evolutionary pressures. In this study, we formalize this knowledge into general mathematical assumptions, and use them in an ecoevolutionary model. In contrast to previous models, this study novelty accounts for both traits—arrival date and hatching date—and the interdependence between them, revealing when one, the other or both will respond to climate. For all models sharing the assumptions, the following phenological responses will occur. First, if the nestling-prey peak is late enough, hatching is synchronous with, and arrival date evolves independently of, prey phenology. Second, when resource availability constrains the length of the pre-laying period, hatching is adaptively asynchronous with prey phenology. Predictions for both traits compare well with empirical observations. In response to advancing prey phenology, arrival date may advance, remain unchanged, or even become delayed; the latter occurring when egg-laying resources are only available relatively late in the season. The model shows that asynchronous hatching and unresponsive arrival date are not sufficient evidence that phenological adaptation is constrained. The work provides a framework for exploring microevolution of interdependent phenological traits.

Endoparasitism in colonial hosts: patterns and processes

Parasitology ◽  
2007 ◽  
Vol 134 (6) ◽  
pp. 841-852 ◽  
Author(s):  
S. L. L. HILL ◽  
B. OKAMURA
Keyword(s):  
Vertical Transmission ◽  
Environmental Conditions ◽  
Negative Effects ◽  
Temporal Sampling ◽  
Colony Fission ◽  
High Prevalence ◽  
Novel Host ◽  
Patterns And Processes ◽  
Host Parasite ◽  
Lack Of Knowledge

SUMMARYThis study begins to redress our lack of knowledge of the interactions between colonial hosts and their parasites by focusing on a novel host-parasite system. Investigations of freshwater bryozoan populations revealed that infection by myxozoan parasites is widespread. Covert infections were detected in all 5 populations studied and were often at high prevalence while overt infections were observed in only 1. Infections were persistent in populations subject to temporal sampling. Negative effects of infection were identified but virulence was low. Infection did not induce mortality in the environmental conditions studied. However, the production of statoblasts (dormant propagules) was greatly reduced in bryozoans with overt infections in comparison to uninfected bryozoans. Overtly-infected bryozoans also grew more slowly and had low fission rates relative to colonies lacking overt infection. Bryozoans with covert infections were smaller than uninfected bryozoans. High levels of vertical transmission were achieved through colony fission and the infection of statoblasts. Increased fission rates may be a strategy for hosts to escape from parasites but the parasite can also exploit the fragmentation of colonial hosts to gain vertical transmission and dispersal. Our study provides evidence that opportunities and constraints for host-parasite co-evolution can be highly dependent on organismal body plans and that low virulence may be associated with exploitation of colonial hosts by endoparasites.

scholarly journals ‘Pre-Neolithic’ in Southeast Europe: a Bulgarian perspective

2014 ◽  
Vol 41 ◽  
pp. 95-109 ◽  
Author(s):  
Maria Gurova ◽  
Clive Bonsall
Keyword(s):  
Black Sea ◽  
Resource Availability ◽  
Environmental Conditions ◽  
Distribution Patterns ◽  
Balkan Peninsula ◽  
The Black Sea ◽  
Future Research ◽  
Upper Palaeolithic ◽  
Southeast Europe ◽  
Site Distribution

 This paper discusses why large areas of the central and northern Balkans lack evidence of Mesolithic settlement and what implications this holds for future research into the Neolithization of the region. A marked shift in site distribution patterns between Upper Palaeolithic and Mesolithic is interpreted as a response to changing environmental conditions and resource availability. It is suggested that some important questions of the pattern, processes and timing of the transition to farming across the Balkan Peninsula may only be answered through new archaeological surveys of the Lower Danube valley and exploration of submerged landscapes along the Black Sea, Aegean and Adriatic coasts.

Advances in tracking small migratory birds: a technical review of light-level geolocation

2013 ◽  
Vol 84 (2) ◽  
pp. 121-137 ◽  
Author(s):  
Eli S. Bridge ◽  
Jeffrey F. Kelly ◽  
Andrea Contina ◽  
Richard M. Gabrielson ◽  
Robert B. MacCurdy ◽  
...  
Keyword(s):  
Migratory Birds ◽  
Light Level ◽  
Technical Review

scholarly journals Rainfall-induced changes in food availability modify the spring departure programme of a migratory bird

2011 ◽  
Vol 278 (1723) ◽  
pp. 3437-3443 ◽  
Author(s):  
Colin E. Studds ◽  
Peter P. Marra
Keyword(s):  
Migratory Birds ◽  
Marked Change ◽  
Migratory Bird ◽  
Breeding Period ◽  
Climatic Warming ◽  
Adaptive Responses ◽  
American Redstarts ◽  
Breeding Grounds ◽  
Selection For ◽  
Induced Changes

Climatic warming has intensified selection for earlier reproduction in many organisms, but potential constraints imposed by climate change outside the breeding period have received little attention. Migratory birds provide an ideal model for exploring such constraints because they face warming temperatures on temperate breeding grounds and declining rainfall on many tropical non-breeding areas. Here, we use longitudinal data on spring departure dates of American redstarts ( Setophaga ruticilla ) to show that annual variation in tropical rainfall and food resources are associated with marked change in the timing of spring departure of the same individuals among years. This finding challenges the idea that photoperiod alone regulates the onset of migration, providing evidence that intensifying drought in the tropical winter could hinder adaptive responses to climatic warming in the temperate zone.

scholarly journals Inbred burying beetles suffer fitness costs from making poor decisions

2018 ◽  
Vol 285 (1881) ◽  
pp. 20180419 ◽  
Author(s):  
Jon Richardson ◽  
Pauline Comin ◽  
Per T. Smiseth
Keyword(s):  
Decision Making ◽  
Inbreeding Depression ◽  
Resource Availability ◽  
Environmental Conditions ◽  
Fitness Costs ◽  
Individual Decision ◽  
Burying Beetle ◽  
Individual Decision Making ◽  
Fitness Consequences ◽  
Nicrophorus Vespilloides

There is growing interest in how environmental conditions, such as resource availability, can modify the severity of inbreeding depression. However, little is known about whether inbreeding depression is also associated with differences in individual decision-making. For example, decisions about how many offspring to produce are often based upon the prevailing environmental conditions, such as resource availability, and getting these decisions wrong may have important fitness consequences for both parents and offspring. We tested for effects of inbreeding on individual decision-making in the burying beetle Nicrophorus vespilloides, which uses the size of a carrion resource to make decisions about number of offspring. Both inbred and outbred females adjusted their initial decisions about number of eggs to lay based on carcass size. However, when we forced individuals to update this initial decision by providing them with a different-sized carcass partway through reproduction, inbred females failed to update their decision about how many larvae to cull. Consequently, inbred females reared too many larvae, resulting in negative fitness consequences in the form of smaller offspring and reduced female post-reproductive condition. Our study provides novel insights into the effects of inbreeding by showing that poor decision-making by inbred individuals can negatively affect fitness.

Sign in / Sign up

Export Citation Format

Share Document