1
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Trapote E, Canestrari D, Baglione V. Effects of meteorological conditions on brood care in cooperatively breeding carrion crow and consequences on reproductive success. Front Zool 2023; 20:24. [PMID: 37488542 PMCID: PMC10364382 DOI: 10.1186/s12983-023-00504-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 07/18/2023] [Indexed: 07/26/2023] Open
Abstract
Meteorological stressors (e.g., temperature and rain shortage) constrain brood provisioning in some bird species, but the consequences on reproductive success have been rarely quantified. Here we show, in a cooperatively breeding population of carrion crow Corvus corone in Spain, that individual feeding rates decreased significantly with rising air temperatures both in breeders and helpers, while lack of rain was associated with a significant reduction in the effort of the male helpers as compared to the other social categories. Group coordination, measured as the degree of alternation of nest visits by carers, was also negatively affected by rising temperature. Furthermore, we found that the body condition of the nestlings worsened when temperatures were high during the rearing period. Interestingly, the analysis of a long-term data set on crow reproduction showed that nestling body condition steadily deteriorated over the last 26-years. Although many factors may concur in causing population changes, our data suggest a possible causal link between global warming, brood caring behaviour and the decline of carrion crow population in the Mediterranean climatic region of Spain.
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Affiliation(s)
- Eva Trapote
- Departamento de Biodiversidad y Gestión Ambiental, Universidad de León, Campus de Vegazana s/n, 24071, León, Spain.
| | - Daniela Canestrari
- Departamento de Biodiversidad y Gestión Ambiental, Universidad de León, Campus de Vegazana s/n, 24071, León, Spain
| | - Vittorio Baglione
- Departamento de Biodiversidad y Gestión Ambiental, Universidad de León, Campus de Vegazana s/n, 24071, León, Spain
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2
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He P, Klarevas‐Irby JA, Papageorgiou D, Christensen C, Strauss ED, Farine DR. A guide to sampling design for
GPS
‐based studies of animal societies. Methods Ecol Evol 2022. [DOI: 10.1111/2041-210x.13999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Peng He
- Department of Collective Behaviour Max Planck Institute of Animal Behavior Constance Germany
- Centre for the Advanced Study of Collective Behaviour University of Konstanz Constance Germany
- Department of Biology University of Konstanz Constance Germany
- Department of Evolutionary Biology and Environmental Science University of Zurich Zurich Switzerland
| | - James A. Klarevas‐Irby
- Centre for the Advanced Study of Collective Behaviour University of Konstanz Constance Germany
- Department of Biology University of Konstanz Constance Germany
- Department of Evolutionary Biology and Environmental Science University of Zurich Zurich Switzerland
- Department of Migration Max Planck Institute of Animal Behavior Radolfzell Germany
- Mpala Research Centre Nanyuki Kenya
| | - Danai Papageorgiou
- Department of Collective Behaviour Max Planck Institute of Animal Behavior Constance Germany
- Department of Evolutionary Biology and Environmental Science University of Zurich Zurich Switzerland
| | - Charlotte Christensen
- Department of Collective Behaviour Max Planck Institute of Animal Behavior Constance Germany
- Department of Evolutionary Biology and Environmental Science University of Zurich Zurich Switzerland
- Mpala Research Centre Nanyuki Kenya
| | - Eli D. Strauss
- Department of Collective Behaviour Max Planck Institute of Animal Behavior Constance Germany
- Centre for the Advanced Study of Collective Behaviour University of Konstanz Constance Germany
- Department of Evolutionary Biology and Environmental Science University of Zurich Zurich Switzerland
| | - Damien R. Farine
- Department of Collective Behaviour Max Planck Institute of Animal Behavior Constance Germany
- Department of Evolutionary Biology and Environmental Science University of Zurich Zurich Switzerland
- Division of Ecology and Evolution, Research School of Biology Australian National University Canberra Australia
- Department of Ornithology National Museums of Kenya Nairobi Kenya
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3
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Communal roosting shows dynamics predicted by direct and indirect nepotism in chestnut-crowned babblers. Behav Ecol Sociobiol 2021. [DOI: 10.1007/s00265-020-02958-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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4
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Plaza M, Burke T, Cox T, Flynn‐Carroll A, Girndt A, Halford G, Martin DA, Sanchez‐Fortún M, Sánchez‐Tójar A, Somerville J, Schroeder J. Repeatable social network node‐based metrics across populations and contexts in a passerine. J Evol Biol 2020; 33:1634-1642. [DOI: 10.1111/jeb.13703] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 08/29/2020] [Accepted: 09/05/2020] [Indexed: 01/30/2023]
Affiliation(s)
- Mireia Plaza
- Department of Life Sciences Imperial College London Ascot UK
- Department of Evolutionary Ecology National Museum of Natural Sciences (CSIC) Madrid Spain
| | - Terry Burke
- Department of Animal and Plant Sciences University of Sheffield Sheffield UK
| | - Tara Cox
- Department of Life Sciences Imperial College London Ascot UK
| | | | - Antje Girndt
- Max Planck Institute for Ornithology Seewiesen Germany
- International Max‐Planck Research School (IMPRS) for Organismal Biology University of Konstanz Konstanz Germany
| | | | | | - Moises Sanchez‐Fortún
- Department of Zoology and Anthropology Faculty of Biology University of Barcelona Barcelona Spain
| | - Alfredo Sánchez‐Tójar
- Department of Life Sciences Imperial College London Ascot UK
- International Max‐Planck Research School (IMPRS) for Organismal Biology University of Konstanz Konstanz Germany
- Department of Evolutionary Biology Bielefeld University Bielefeld Germany
| | | | - Julia Schroeder
- Department of Life Sciences Imperial College London Ascot UK
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5
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Ferreira AC, Covas R, Silva LR, Esteves SC, Duarte IF, Fortuna R, Theron F, Doutrelant C, Farine DR. How to make methodological decisions when inferring social networks. Ecol Evol 2020; 10:9132-9143. [PMID: 32953051 PMCID: PMC7487238 DOI: 10.1002/ece3.6568] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 06/17/2020] [Indexed: 11/06/2022] Open
Abstract
Social network analyses allow studying the processes underlying the associations between individuals and the consequences of those associations. Constructing and analyzing social networks can be challenging, especially when designing new studies as researchers are confronted with decisions about how to collect data and construct networks, and the answers are not always straightforward. The current lack of guidance on building a social network for a new study system might lead researchers to try several different methods and risk generating false results arising from multiple hypotheses testing. Here, we suggest an approach for making decisions when starting social network research in a new study system that avoids the pitfall of multiple hypotheses testing. We argue that best edge definition for a network is a decision that can be made using a priori knowledge about the species and that is independent from the hypotheses that the network will ultimately be used to evaluate. We illustrate this approach with a study conducted on a colonial cooperatively breeding bird, the sociable weaver. We first identified two ways of collecting data using different numbers of feeders and three ways to define associations among birds. We then evaluated which combination of data collection and association definition maximized (a) the assortment of individuals into previously known "breeding groups" (birds that contribute toward the same nest and maintain cohesion when foraging) and (b) socially differentiated relationships (more strong and weak relationships than expected by chance). This evaluation of different methods based on a priori knowledge of the study species can be implemented in a diverse array of study systems and makes the case for using existing, biologically meaningful knowledge about a system to help navigate the myriad of methodological decisions about data collection and network inference.
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Affiliation(s)
- André C. Ferreira
- Centre d’Ecologie Fonctionnelle et EvolutiveUniv MontpellierCNRSEPHE, IRDUniv Paul‐Valery Montpellier 3MontpellierFrance
- CIBIO‐InBioResearch Centre in Biodiversity and Genetic ResourcesVairãoPortugal
- Department of Collective BehaviorMax Planck Institute of Animal BehaviorKonstanzGermany
| | - Rita Covas
- CIBIO‐InBioResearch Centre in Biodiversity and Genetic ResourcesVairãoPortugal
- FitzPatrick Institute of African OrnithologyDST‐NRF Centre of ExcellenceUniversity of Cape TownRondeboschSouth Africa
| | - Liliana R. Silva
- CIBIO‐InBioResearch Centre in Biodiversity and Genetic ResourcesVairãoPortugal
| | - Sandra C. Esteves
- CIBIO‐InBioResearch Centre in Biodiversity and Genetic ResourcesVairãoPortugal
| | - Inês F. Duarte
- CIBIO‐InBioResearch Centre in Biodiversity and Genetic ResourcesVairãoPortugal
| | - Rita Fortuna
- CIBIO‐InBioResearch Centre in Biodiversity and Genetic ResourcesVairãoPortugal
| | - Franck Theron
- Centre d’Ecologie Fonctionnelle et EvolutiveUniv MontpellierCNRSEPHE, IRDUniv Paul‐Valery Montpellier 3MontpellierFrance
| | - Claire Doutrelant
- Centre d’Ecologie Fonctionnelle et EvolutiveUniv MontpellierCNRSEPHE, IRDUniv Paul‐Valery Montpellier 3MontpellierFrance
- FitzPatrick Institute of African OrnithologyDST‐NRF Centre of ExcellenceUniversity of Cape TownRondeboschSouth Africa
| | - Damien R. Farine
- Department of Collective BehaviorMax Planck Institute of Animal BehaviorKonstanzGermany
- Department of BiologyUniversity of KonstanzKonstanzGermany
- Centre for the Advanced Study of Collective BehaviourUniversity of KonstanzKonstanzGermany
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6
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Nomano FY, Savage JL, Browning LE, Griffith SC, Russell AF. Breeding Phenology and Meteorological Conditions Affect Carer Provisioning Rates and Group-Level Coordination in Cooperative Chestnut-Crowned Babblers. Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00423] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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7
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Testing the Sexual and Social Benefits of Cooperation in Animals. Trends Ecol Evol 2018; 34:112-120. [PMID: 30527795 DOI: 10.1016/j.tree.2018.11.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 11/13/2018] [Accepted: 11/15/2018] [Indexed: 11/23/2022]
Abstract
Theoretical models show that sexual and social selection can stabilise cooperation. However, field tests of these mechanisms have been difficult to conduct and the results are mixed. We discuss the conceptual and practical difficulties associated with testing the role of social and sexual selection on cooperation and argue that there are alternative ways of examining these hypotheses. Specifically, approaches based on the classic theories of sexual selection and signalling, and recent developments in the field of behavioural syndromes, provide mechanisms to insure the reliability of cooperation. In addition, methodological developments (social networks and microtracking) and long-term datasets, allow measuring partner choice in a cooperation context and the resulting fitness benefits for both the cooperators and the individuals that associate with them.
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8
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Sabol AC, Solomon NG, Dantzer B. How to Study Socially Monogamous Behavior in Secretive Animals? Using Social Network Analyses and Automated Tracking Systems to Study the Social Behavior of Prairie Voles. Front Ecol Evol 2018. [DOI: 10.3389/fevo.2018.00178] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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9
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Iserbyt A, Griffioen M, Borremans B, Eens M, Müller W. How to quantify animal activity from radio-frequency identification (RFID) recordings. Ecol Evol 2018; 8:10166-10174. [PMID: 30397456 PMCID: PMC6206221 DOI: 10.1002/ece3.4491] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 07/19/2018] [Accepted: 07/27/2018] [Indexed: 11/26/2022] Open
Abstract
Automated animal monitoring via radio-frequency identification (RFID) technology allows efficient and extensive data sampling of individual activity levels and is therefore commonly used for ecological research. However, processing RFID data is still a largely unresolved problem, which potentially leads to inaccurate estimates for behavioral activity. One of the major challenges during data processing is to isolate independent behavioral actions from a set of superfluous, nonindependent detections. As a case study, individual blue tits (Cyanistes caeruleus) were simultaneously monitored during reproduction with both video recordings and RFID technology. We demonstrated how RFID data can be processed based on the time spent in- and outside a nest box. We then validated the number and timing of nest visits obtained from the processed RFID dataset by calibration against video recordings. The video observations revealed a limited overlap between the time spent in- and outside the nest box, with the least overlap at 23 s for both sexes. We then isolated exact arrival times from redundant RFID registrations by erasing all successive registrations within 23 s after the preceding registration. After aligning the processed RFID data with the corresponding video recordings, we observed a high accuracy in three behavioral estimates of parental care (individual nest visit rates, within-pair alternation and synchronization of nest visits). We provide a clear guideline for future studies that aim to implement RFID technology in their research. We argue that our suggested RFID data processing procedure improves the precision of behavioral estimates, despite some inevitable drawbacks inherent to the technology. Our method is useful, not only for other cavity breeding birds, but for a wide range of (in)vertebrate species that are large enough to be fitted with a tag and that regularly pass near or through a fixed antenna.
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Affiliation(s)
- Arne Iserbyt
- Behavioural Ecology and Ecophysiology GroupUniversity of AntwerpWilrijkBelgium
| | - Maaike Griffioen
- Behavioural Ecology and Ecophysiology GroupUniversity of AntwerpWilrijkBelgium
| | - Benny Borremans
- Department of Ecology and Evolutionary BiologyUniversity of California Los AngelesLos AngelesCalifornia
- Interuniversity Institute for Biostatistics and Statistical Bioinformatics (I‐BIOSTAT)Hasselt UniversityDiepenbeekBelgium
| | - Marcel Eens
- Behavioural Ecology and Ecophysiology GroupUniversity of AntwerpWilrijkBelgium
| | - Wendt Müller
- Behavioural Ecology and Ecophysiology GroupUniversity of AntwerpWilrijkBelgium
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10
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Savage JL, Browning LE, Manica A, Russell AF, Johnstone RA. Turn-taking in cooperative offspring care: by-product of individual provisioning behavior or active response rule? Behav Ecol Sociobiol 2017; 71:162. [PMID: 29081573 PMCID: PMC5644705 DOI: 10.1007/s00265-017-2391-4] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Revised: 09/28/2017] [Accepted: 09/29/2017] [Indexed: 11/29/2022]
Abstract
Abstract For individuals collaborating to rear offspring, effective organization of resource delivery is difficult because each carer benefits when the others provide a greater share of the total investment required. When investment is provided in discrete events, one possible solution is to adopt a turn-taking strategy whereby each individual reduces its contribution rate after investing, only increasing its rate again once another carer contributes. To test whether turn-taking occurs in a natural cooperative care system, here we use a continuous time Markov model to deduce the provisioning behavior of the chestnut-crowned babbler (Pomatostomus ruficeps), a cooperatively breeding Australian bird with variable number of carers. Our analysis suggests that turn-taking occurs across a range of group sizes (2–6), with individual birds being more likely to visit following other individuals than to make repeat visits. We show using a randomization test that some of this apparent turn-taking arises as a by-product of the distribution of individual inter-visit intervals (“passive” turn-taking) but that individuals also respond actively to the investment of others over and above this effect (“active” turn-taking). We conclude that turn-taking in babblers is a consequence of both their individual provisioning behavior and deliberate response rules, with the former effect arising through a minimum interval required to forage and travel to and from the nest. Our results reinforce the importance of considering fine-scale investment dynamics when studying parental care and suggest that behavioral rules such as turn-taking may be more common than previously thought. Significance statement Caring for offspring is a crucial stage in the life histories of many animals and often involves conflict as each carer typically benefits when others contribute a greater share of the work required. One way to resolve this conflict is to monitor when other carers contribute and adopt a simple “turn-taking” rule to ensure fairness, but natural parental care has rarely been studied in sufficient detail to identify such rules. Our study investigates whether cooperatively breeding chestnut-crowned babblers “take turns” delivering food to offspring, and (if so) whether this a deliberate strategy or simply a by-product of independent care behavior. We find that babblers indeed take turns and conclude that part of the observed turn-taking is due to deliberate responsiveness, with the rest arising from the species’ breeding ecology. Electronic supplementary material The online version of this article (10.1007/s00265-017-2391-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- James L Savage
- Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ UK.,Behavioural Ecology Group, Department of Animal Sciences, Wageningen University, De Elst 1, 6708 WD Wageningen, The Netherlands.,School of Biological, Earth, and Environmental Sciences, University College Cork, Distillery Fields, North Mall, Cork, T23 TK30 Ireland
| | - Lucy E Browning
- Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ UK.,Fowlers Gap Arid Zone Research Station, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, 2052 NSW Australia
| | - Andrea Manica
- Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ UK
| | - Andrew F Russell
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Tremough Campus, Penryn, TR10 9FE UK
| | - Rufus A Johnstone
- Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ UK
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11
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Galbraith JA, Jones DN, Beggs JR, Parry K, Stanley MC. Urban Bird Feeders Dominated by a Few Species and Individuals. Front Ecol Evol 2017. [DOI: 10.3389/fevo.2017.00081] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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12
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13
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Chappell MA, Buttemer WA, Russell AF. Energetics of communal roosting in chestnut-crowned babblers: implications for group dynamics and breeding phenology. J Exp Biol 2016; 219:3321-3328. [DOI: 10.1242/jeb.144972] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 08/15/2016] [Indexed: 01/22/2023]
Abstract
ABSTRACT
For many endotherms, communal roosting saves energy in cold conditions, but how this might affect social dynamics or breeding phenology is not well understood. Using chestnut-crowned babblers (Pomatostomus ruficeps), we studied the effects of nest use and group size on roosting energy costs. These 50 g cooperatively breeding passerine birds of outback Australia breed from late winter to early summer and roost in huddles of up to 20 in single-chambered nests. We measured babbler metabolism at three ecologically relevant temperatures: 5°C (similar to minimum nighttime temperatures during early breeding), 15°C (similar to nighttime temperatures during late breeding) and 28°C (thermal neutrality). Nest use alone had modest effects: even for solitary babblers at 5°C, it reduced nighttime energy expenditures by <15%. However, group-size effects were substantial, with savings of up to 60% in large groups at low temperatures. Babblers roosting in groups of seven or more at 5°C, and five or more at 15°C, did not need to elevate metabolic rates above basal levels. Furthermore, even at 28°C (thermoneutral for solitary babblers), individuals in groups of four or more had 15% lower basal metabolic rate than single birds, hinting that roosting in small groups is stressful. We suggest that the substantial energy savings of communal roosting at low temperatures help explain why early breeding is initiated in large groups and why breeding females, which roost alone and consequently expend 120% more energy overnight than other group members, suffer relatively higher mortality than communally roosting group mates.
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Affiliation(s)
- Mark A. Chappell
- Department of Biology, University of California, Riverside, Riverside, CA 92521, USA
| | - William A. Buttemer
- School of Biological Sciences, University of Wollongong, Wollongong, New South Wales 2522, Australia
- Centre for Integrative Ecology, Deakin University, Geelong, Victoria 3217, Australia
| | - Andrew F. Russell
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn, Cornwall TR10 9FE, UK
- Fowlers Gap Arid Zone Research Station, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia
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14
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Sorato E, Griffith SC, Russell AF. The price of associating with breeders in the cooperatively breeding chestnut‐crowned babbler: foraging constraints, survival and sociality. J Anim Ecol 2016; 85:1340-51. [DOI: 10.1111/1365-2656.12539] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 04/14/2016] [Indexed: 11/28/2022]
Affiliation(s)
- Enrico Sorato
- Department of Biological Sciences Macquarie University Sydney NSW 2109 Australia
- Department of Physics, Chemistry and Biology (IFM) Linköping University Linköping 58183 Sweden
| | - Simon C. Griffith
- Department of Biological Sciences Macquarie University Sydney NSW 2109 Australia
- Fowlers Gap Arid Zone Research Station School of Biological, Earth and Environmental Sciences University of New South Wales Sydney NSW 2052 Australia
| | - Andy F. Russell
- Fowlers Gap Arid Zone Research Station School of Biological, Earth and Environmental Sciences University of New South Wales Sydney NSW 2052 Australia
- Centre for Ecology and Conservation College of Life and Environmental Sciences University of Exeter, Tremough Campus Penryn TR10 9FE UK
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15
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Liebl A, Nomano F, Browning L, Russell A. Experimental evidence for fully additive care among male carers in the cooperatively breeding chestnut-crowned babbler. Anim Behav 2016. [DOI: 10.1016/j.anbehav.2016.02.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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16
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Liebl AL, Browning LE, Russell AF. Manipulating carer number versus brood size: complementary but not equivalent ways of quantifying carer effects on offspring. Behav Ecol 2016; 27:1247-1254. [PMID: 27418754 PMCID: PMC4943111 DOI: 10.1093/beheco/arw038] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2015] [Revised: 02/01/2016] [Accepted: 02/03/2016] [Indexed: 12/28/2022] Open
Abstract
Measuring the causal effects of increasing carer number on offspring success is required to understand the evolution of cooperative care systems. Here, we did so using 2 experimental techniques in the chestnut-crowned babbler from outback Australia. Both carer removal and brood size manipulations indicate causal effects of helpers on offspring food acquisition. However, the results were not equivalent, with nestlings receiving more food following brood size manipulations, even after controlling for similar carer to offspring ratios. Experiments designed to quantify the effects of increasing numbers of carers on levels of offspring care are rare in cooperative breeding systems, where offspring are reared by individuals additional to the breeding pair. This paucity might stem from disagreement over the most appropriate manipulations necessary to elucidate these effects. Here, we perform both carer removal and brood enhancement experiments to test the effects of numbers of carers and carer:offspring ratios on provisioning rates in the cooperatively breeding chestnut-crowned babbler (Pomatostomus ruficeps). Removing carers caused linear reductions in overall brood provisioning rates. Further analyses failed to provide evidence that this effect was influenced by territory quality or disruption of group dynamics stemming from the removals. Likewise, adding nestlings to broods caused linear increases in brood provisioning rates, suggesting carers are responsive to increasing offspring demand. However, the 2 experiments did not generate quantitatively equivalent results: Each nestling received more food following brood size manipulation than carer removal, despite comparable carer:offspring ratios in each. Following an at-hatching split-design cross-fostering manipulation to break any links between prehatching maternal effects and posthatching begging patterns, we found that begging intensity increased in larger broods after controlling for metrics of hunger. These findings suggest that manipulation of brood size can, in itself, influence nestling provisioning rates when begging intensity is affected by scramble competition. We highlight that carer number and brood size manipulations are complimentary but not equivalent; adopting both can yield greater overall insight into carer effects in cooperative breeding systems.
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Affiliation(s)
- A L Liebl
- Centre for Ecology & Conservation, College of Life & Environmental Sciences, University of Exeter , Treliever Road, Penryn, Cornwall TR10 9FE , UK and
| | - L E Browning
- UNSW Arid Zone Research Station, School of Biological, Earth & Environmental Sciences, University of New South Wales , Sydney, New South Wales 2052 , Australia
| | - A F Russell
- Centre for Ecology & Conservation, College of Life & Environmental Sciences, University of Exeter , Treliever Road, Penryn, Cornwall TR10 9FE , UK and
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17
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An RFID Based Smart Feeder for Hummingbirds. SENSORS 2015; 15:31751-61. [PMID: 26694402 PMCID: PMC4721805 DOI: 10.3390/s151229886] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 12/08/2015] [Accepted: 12/09/2015] [Indexed: 11/17/2022]
Abstract
We present an interdisciplinary effort to record feeding behaviors and control the diet of a hummingbird species (Phaethornis longirostris, the long-billed hermit or LBH) by developing a Radio Frequency Identification (RFID) based smart feeder. The system contains an RFID reader, a microcontroller, and a servo-controlled hummingbird feeder opener; the system is presented as a tool for studying the cognitive ability of the LBH species. When equipped with glass capsule RFID tags (which are mounted on the hummingbird), the smart feeder can provide specific diets for predetermined sets of hummingbirds at the discretion of biologists. This is done by reading the unique RFID tag on the hummingbirds and comparing the ID number with the pre-programmed ID numbers stored in the smart feeder. The smart feeder records the time and ID of each hummingbird visit. The system data is stored in a readily available SD card and is powered by two 9 V batteries. The detection range of the system is approximately 9–11 cm. Using this system, biologists can assign the wild hummingbirds to different experimental groups and monitor their diets to determine if they develop a preference to any of the available nectars. During field testing, the smart feeder system has demonstrated consistent detection (when compared to detections observed by video-recordings) of RFID tags on hummingbirds and provides pre-designed nectars varying water and sugar concentrations to target individuals. The smart feeder can be applied to other biological and environmental studies in the future.
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18
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Nomano FY, Browning LE, Savage JL, Rollins LA, Griffith SC, Russell AF. Unrelated helpers neither signal contributions nor suffer retribution in chestnut-crowed babblers. Behav Ecol 2015. [DOI: 10.1093/beheco/arv023] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
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