That’s quite difficult to say. We are scavengers (we eat everything going but mostly find it easiest to sniff out dead things!) so we could be affected by overfishing. If humans remove too many fish from the shallow waters it could leave us less food to eat and our population is likely to decrease.
We’ve also recently learned that microplastics are found in the stomachs of deep-sea animals so all the pollution that is happen in the surface of the sea is affecting the deep sea too! This could also have a negative impact and reduce our population size.
With climate change, it’s likely we’ll get habitat change and for the crossbills that means forests will break up and get fragmented. That’s not good for keeping populations of birds together and so numbers will no doubt drop.
Climate change might allow TWF species adapted to warmer areas to live in places that are currently too cold – e.g further north and south of the equator and at higher elevations. However, it might also force those species currently living closer to the equator to move. Ultimately, it will depend on the effect climate change has on the various hosts of the parasitoid TWF.