Biology subjects

Quinnell, R. J.

Publications and source records attributed to Quinnell, R. J..

3 recordsLinked to original sources

bioRxiv2025

Changes in free-roaming dog population demographics and health associated with a catch-neuter-vaccinate-release program in Jamshedpur, India

Indias large free-roaming dog populations contribute to significant human health, environmental, and social challenges. Population management strategies, such as capture-neuter-vaccinate-return (CNVR), aim to reduce dog numbers, improve their welfare, and reduce human-animal conflict. The Humane Society International, in partnership with the Animal Health Foundation, implemented a CNVR program in Jamshedpur, neutering and vaccinating over 20,000 dogs. This study evaluates the impact of this program on dog health, population structure and size. The study areas encompassed 10 sites within the Jamshedpur Metropolitan Region, including both intervention sites where CNVR was directly applied and sites without direct intervention. Data was collected from May 2014 until December 2018, including bi-annual street surveys, as well as clinical data from the dogs captured and treated. We fit logistic regression, negative binomial, and binomial mixed effects models to assess changes in dog population characteristics, health, and reproductive conditions over time in relation to the CNVR intervention. We found that, over time, the CNVR program significantly reduced the probability of dogs entering the clinic with mange, transmissible venereal tumours, and pregnant. Street surveys showed an increase in sterilised dogs, with higher proportions observed in CNVR-treated sites, although the counts of dogs observed increased overall. The age-structure of free-roaming dogs remained stable over time. In CNVR-treated areas, the probability of observing lactating female dogs decreased, whereas it increased in untreated sites. This work contributes to the growing body of knowledge investigating the impact of dog population management interventions. Continued monitoring and evaluation of CNVR programs are required to identify optimal coverage required to reduce population size effectively.

ecology↗

bioRxiv2021

Assessing the impact of free-roaming dog population management through systems modelling

Free-roaming dogs can present significant challenges to public health, wildlife conservation, and livestock production. Their own welfare may also be a concern, as free-roaming dogs can experience poor health and welfare. Dog population management is widely conducted to mitigate these issues. To ensure efficient use of resources, it is critical that effective, cost-efficient, and high-welfare strategies are identified. The dog population comprises distinct subpopulations characterised by their restriction status and level of ownership, but the assessment of dog population management often fails to consider the impact of the interaction between subpopulations on management success. We present a system dynamics model that incorporates an interactive and dynamic system of dog subpopulations. We identify that methods incorporating both fertility control and responsible ownership interventions (a reduction in abandonment and an increase in shelter adoptions) have the greatest potential to reduce free-roaming dog population sizes over longer periods of time, whilst being cost-effective and improving overall welfare. We suggest that future management should be applied at high levels of coverage and should target all sources of population increase, such as abandonment, births, and free-roaming owned dogs, to ensure effective and cost-efficient reduction in free-roaming dog numbers.

zoology↗

bioRxiv2019

Tritrophic interactions involving a dioecious fig tree, its fig pollinating wasp and fig nematodes

Many species of fig trees (Ficus spp., Moraceae) have nematodes that develop inside their inflorescences (figs). Nematodes are carried into young figs by females of the trees host-specific pollinating fig wasps (Agaonidae) that enter the figs to lay their eggs. The majority of Asian fig trees are functionally dioecious. Pollinators that enter figs on female trees cannot reproduce and offspring of any nematodes they carry will also be trapped inside. The biology of the nematodes is diverse, but poorly understood. We contrasted the development of nematodes carried by the pollinating fig wasp Ceratosolen solmsi marchali into figs on male and female trees of Ficus hispida in Sumatra, Indonesia. Figs were sampled from both male and female trees over a six-month period, with the nematodes extracted to record their development of their populations inside the figs. Populations of three species of nematodes developed routinely inside figs of both sexes: Caenorhabditis sp. (Rhabditidae), Ficophagus cf. centerae and Martininema baculum (both Aphelenchoididae). This is the first record of a Caenorhabditis sp. associated with F. hispida. Mean numbers of nematodes reached around 120-140 in both male and female figs. These peak population sizes coincided with the emergence of the new generation of adult fig wasps in male fig trees. We conclude that figs on female trees can support development and reproduction of some nematode species, but the absence of vectors means that their populations cannot persist beyond the lifetime of a single fig. Just like their fig wasp vectors, the nematodes cannot avoid this routine source of mortality.

ecology↗