Using Custom Data Expressions Within a Serial Chart to Sum Integer Fields?

[DaveK]

Hello, 

I'm building a Dashboard containing a serial chart which displays multiple bird species and the counts of males, females, young, and unknown. 

I would like to sum the number of bird fields for each row into a new field (totalCount) using a data expression. Can anyone help me put together an expression that will do that? Here's where I ended up with my own expression that doesn't work. 

var portal = Portal('https://www.arcgis.com/');

var fs = FeatureSetByPortalItem(portal, 'HidingthefeatureID',0,

['uplandBird','adultMales','adultFemales','young','unknown'],false);

var totalcount = {

    'fields': [{'name':'sumtotal', 'type':'esriFieldTypeDouble'}],

    'geometryType': '',

    'features':

    [{'attributes':

     {'sumtotal': (fs,'adultMales'+fs,'adultFemales'+fs,'young'+fs,'unknown')

     }}]};

return FeatureSet(Double(totalcount));

Any help is appreciated. 

Thanks.