Publications by year
In Press
Inzani E, Kelley L, Boogert N (In Press). Object neophilia in wild herring gulls in urban and rural locations.
Journal of Avian BiologyAbstract:
Object neophilia in wild herring gulls in urban and rural locations
Living with increasing urbanisation and human populations requires resourcefulness and flexibility in wild animals’ behaviour. Animals have to adapt to anthropogenic novelty in habitat structure and resources that may not resemble, or be as beneficial as, natural resources. Herring gulls (Larus argentatus) increasingly reside in towns and cities to breed and forage, yet how gulls are adjusting their behaviour to life in urban areas is not yet fully understood. This study investigated wild herring gulls’ responses to novel and common anthropogenic objects in urban and rural locations. We also examined whether gulls’ age influenced their object response behaviour. We found that, out of the 126 individual gulls presented with objects, 34% approached them. This suggests that the majority of targeted gulls were wary or lacked interest in the experimental set-up. of the 43 gulls that approached the objects, we found that those tested in urban locations approached more slowly than their rural counterparts. Overall, gulls showed no preference for either novel or common anthropogenic objects, and age did not influence likelihood of approach, approach speed or object choice. Individuals paid most attention to the object they approached first, potentially indicative of individual preferences. Our findings indicate that most herring gulls are not as attracted to anthropogenic objects as anecdotal reports have suggested. Covering up obvious food rewards may thus help mitigate human-gull conflict over anthropogenic food sources.
Abstract.
Inzani E, Marshall H, Thompson F, Kalema-Zikusoka G, Cant M, Vitikainen E (In Press). Spontaneous abortion as a response to reproductive conflict in the banded mongoose. Biology Letters
2017
Marshall HH, Vitikainen EIK, Mwanguhya F, Businge R, Kyabulima S, Hares MC, Inzani E, Kalema-Zikusosa G, Mwesige K, Nichols HJ, et al (2017). Lifetime fitness consequences of early-life ecological hardship in a wild mammal population.
Ecology and EvolutionAbstract:
Lifetime fitness consequences of early-life ecological hardship in a wild mammal population
1. Early-life ecological conditions have major effects on survival and reproduction. Numerous studies in wild systems show fitness benefits of good quality early-life ecological conditions (‘silver spoon’ effects).
2. Recently, however, some studies have reported that poor quality early-life ecological conditions are associated with later-life fitness advantages and that the effect of early-life conditions can be sex-specific. Furthermore, few studies have investigated the effect of the variability of early-life ecological conditions on later-life fitness.
3. Here we test how the mean and variability of early-life ecological conditions affect the longevity and reproduction of males and females using 14 years of data on wild banded mongooses (Mungos mungo).
4. Males that experienced highly variable ecological conditions during development lived longer and had greater lifetime fitness, while those that experienced poor early-life conditions lived longer but at a cost of reduced fertility. In females there were no such effects.
5. Our study suggests that exposure to more variable environments in early life can result in lifetime fitness benefits whereas differences in the mean early-life conditions experienced mediates a life history trade-off between survival and reproduction. It also demonstrates how early-life ecological conditions can produce different selection pressures on males and females.
Abstract.
2016
Inzani E, Marshall HH, Sanderson JL, Nichols HJ, Thompson FJ, Kalema-Zikusoka G, Hodge SJ, Cant MA, Vitikainen EIK (2016). Female reproductive competition explains variation in prenatal investment in wild banded mongooses.
Scientific Reports,
6Abstract:
Female reproductive competition explains variation in prenatal investment in wild banded mongooses
Female intrasexual competition is intense in cooperatively breeding species where offspring compete locally for resources and helpers. In mammals, females have been proposed to adjust prenatal investment according to the intensity of competition in the postnatal environment (a form of ‘predictive adaptive response’; PAR). We carried out a test of this hypothesis using ultrasound scanning of wild female banded mongooses in Uganda. In this species multiple females give birth together to a communal litter, and all females breed regularly from one year old. Total prenatal investment (size times the number of fetuses) increased with the number of potential female breeders in the group. This relationship was driven by fetus size rather than number. The response to competition was particularly strong in low weight females and when ecological conditions were poor. Increased prenatal investment did not trade off against maternal survival. In fact we found the opposite relationship: females with greater levels of prenatal investment had elevated postnatal maternal survival. Our results support the hypothesis that mammalian prenatal development is responsive to the intensity of postnatal competition. Understanding whether these responses are adaptive requires information on the long-term consequences of prenatal investment for offspring fitness.
Abstract.
Marshall HH, Sanderson JL, Mwanguhya F, Businge R, Kyabulima S, Hares MC, Inzani E, Kalema-Zikusoka G, Mwesige K, Thompson FJ, et al (2016). Variable ecological conditions promote male
helping by changing banded mongoose group
composition.
Behavioral EcologyAbstract:
Variable ecological conditions promote male
helping by changing banded mongoose group
composition
Ecological conditions are expected to have an important influence on individuals’ investment in cooperative care. However, the nature
of their effects is unclear: both favorable and unfavorable conditions have been found to promote helping behavior. Recent studies
provide a possible explanation for these conflicting results by suggesting that increased ecological variability, rather than changes in
mean conditions, promote cooperative care. However, no study has tested whether increased ecological variability promotes individual-
level helping behavior or the mechanisms involved. We test this hypothesis in a long-term study population of the cooperatively
breeding banded mongoose, Mungos mungo, using 14 years of behavioral and meteorological data to explore how the mean and variability
of ecological conditions influence individual behavior, body condition, and survival. Female body condition was more sensitive
to changes in rainfall leading to poorer female survival and pronounced male-biased group compositions after periods of high rainfall
variability. After such periods, older males invested more in helping behavior, potentially because they had fewer mating opportunities.
These results provide the first empirical evidence for increased individual helping effort in more variable ecological conditions
and suggest this arises because of individual differences in the effect of ecological conditions on body condition and survival, and the
knock-on effect on social group composition. Individual differences in sensitivity to environmental variability, and the impacts this has
on the internal structure and composition of animal groups, can exert a strong influence on the evolution and maintenance of social
behaviors, such as cooperative care.
Abstract.